feERG
2020 Nonpoint Oil and Gas Emission
Estimation Tool Version 1.3
Prepared for:
U.S. Environmental Protection Agency
U.S. Environmental Protection Agency
109 T.W. Alexander Drive
Mail Code C339-02
Research Triangle Park, NC 27711
Prepared by:
Eastern Research Group, Inc.
1600 Perimeter Park
Suite 200
Morrisville, NC 27560
August 2, 2022
EPA Contract No. 68HERD19A001
Task Order 17
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TABLE OF CONTENTS
Page
1.0 Introduction 1
1.1 The National Emissions Inventory (NEI) 1
1.2 Nonpoint Oil and Gas Emission Estimation Tool 1
2.0 Background on Development of the Tool 7
2.1 Activity Data 8
2.1.1 Enverus HPDI Data 11
2.1.2 State Oil and Gas Commission Websites 16
2.1.3 National Production Summary 18
2.2 Process Characterization Data 21
2.3 Updates Since 2017 29
3.0 Source Category Emission Estimation Methodologies 30
3.1 Artificial Lifts 31
3.2 Associated Gas Venting and Flaring 33
3.3 Coalbed Methane Dewatering Pump Engines 36
3.4 Condensate Tanks 39
3.5 Crude Oil Tanks 43
3.6 Dehydrators 47
3.7 Drilling Rigs 51
3.8 Fugitive Leaks 56
3.9 Gas-Actuated Pumps 59
3.10 Heaters 63
3.11 Hydraulic Fracturing Pumps 66
3.12 Lateral/Gathering Compressor Engines 69
3.13 Liquids Unloading 71
3.14 Loading 77
3.15 Mud Degassing 81
3.16 Pneumatic Devices 84
3.17 Produced Water Tanks 88
3.18 Well Completions 91
3.19 Wellhead Compressor Engines 95
4.0 Tool Nonpoint Oil and Gas Emissions Summary 99
5.0 NEI Nonpoint Oil and Gas Emissions Summary 102
6.0 Recommended Improvement activities for future Nonpoint Oil and Gas
Emission Inventories 103
Appendix A - Instructions for Using the EPA Nonpoint Oil and Gas Emission
Estimation Tool, Exploration Module (7/27/2022)
Appendix B- Instructions for Using the EPA Nonpoint Oil and Gas Emission Estimation
Tool, Production Module (7/27/2022)
Appendix C - US Oil and Gas Basins (Found in the "National Oil and Gas Tool Report
Appendix C - Data Element Dictionary.xlsx" file)
Appendix D - Data Element Dictionary (Found in the "National Oil and Gas Tool
Report Appendix D - US Oil and Gas Basins.xlsx" file)
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LIST OF TABLES
Page
Table 1-1. SCC Listing 3
Table 2-1. Activity Parameters Needed to Estimate Emissions 8
Table 2-2. Activity Parameter Data Sources by State 9
Table 2-3. Enverus HPDI Data Coverage by State 13
Table 2-4. Oil and Gas Production by State 19
Table 2-5. Oil and Gas Basins Adjacent to CenSARA States 23
Table 2-6. Tool Data Sources by State and Source Type 26
Table 3-1. Emission Sources by Well Type 30
Table 3-2. Liquids Unloading Vent Rates from the U.S. GHG Inventory 75
Table 3-3. Default Liquids Unloading Vent Rates for the Tool 75
Table 3-4. National Default Emissions Factors for Mud Degassing by Mud Base 81
Table 3-5. Whole Gas Bleed Rates for Pneumatic Devices 86
Table 3-6. Pneumatic Device Counts for Oil and Gas Wells 87
Table 4-1. State-wide Tool Emissions Estimates 99
Table 4-2. Source Category Tool Emissions Estimates 100
LIST OF FIGURES
Page
Figure 2-1. Oil and Gas Basins Covered by the CenSARA Study 22
Figure 2-2. Oil and Gas Basins as Defined by the Geologic Provinces Published by the AAPG.23
Figure 3-1. Artificial Lift Engine 31
Figure 3-2. Coalbed Methane Dewatering Pump 37
Figure 3-3. Liquid Storage Tanks 39
Figure 3-4. Permian Basin Tank Battery 44
Figure 3-5. Dehydrator 47
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Nonooint Oil and Gas Emissions Estimation Tool
Figure 3-6. Drilling Rig 52
Figure 3-7. Flanges 56
Figure 3-8. Line Heater 64
Figure 3-9. Hydraulic Fracturing 67
Figure 3-10. Lateral Compressor Engine 69
Figure 3-11. Plunger Lifts 72
Figure 3-12. EIA Supply Region Map 75
Figure 3-13. Truck Loading Operations 78
Figure 3-14. Pneumatic Device 85
Figure 3-15. Produced Water Tanks 88
Figure 3-16. Well Completion 91
Figure 3-17. Wellhead Compressor Engines 96
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Nonooint Oil and Gas Emissions Estimation Tool
1.0 Introduction
1.1 The National Emissions Inventory (NEI)
The U.S. Environ mental Protection Agency's (EPA) Emission Inventory and Analysis
Group (EIAG) produces the National Emission Inventory (NEI) for criteria and hazardous air
pollutants (HAPs) every three years. The NEI is a comprehensive and detailed estimate of air
emissions of both criteria and HAP from all air emissions sources, including both stationary (e.g.
power plants and petroleum refineries) and mobile (e.g. automobiles and aircraft) sources. The
NEI is prepared by the U.S. EPA based primarily upon emission estimates and emission model
inputs provided by State, Local, and Tribal air agencies for sources in their jurisdictions, and
supplemented by data developed by the U.S. EPA. These data are needed for a variety of
reasons, including modeling demonstrations, regulatory analyses, and to produce the National
Air Pollutant Emission Trends report.
Emissions from stationary sources can be divided into two sectors: point sources and
nonpoint sources (nonpoint sources are sometimes referred to as area sources). The NEI point
sources emissions inventory contains emissions estimates for sources that are individually
inventoried and usually located at a fixed, stationary location, although portable sources such as
some asphalt or rock crushing operations are also included. Point sources include large industrial
facilities and electric power plants, but also increasingly include many smaller industrial and
commercial facilities, such as dry cleaners and gas stations, which have traditionally been
included as nonpoint sources.
The NEI nonpoint sources emissions inventory includes emission sources which
individually are too small in magnitude or too numerous to inventory as individual point sources,
and which can often be estimated more accurately as a single aggregate source for a County or
Tribal area. Examples of nonpoint source categories are residential heating and consumer solvent
use.
The 2020 NEI is currently being developed and will utilize the emission estimates
generated by the 2020 Nonpoint Oil and Gas Emission Estimation Tool (the "tool") as described
in Section 1.2. For historical reference, the 2011, 2014, and 2017 NEI and supporting
documentation is available on-line at https://www.epa.gov/air-emissions-inventories/national-
emi ssi on s-inventorv-nei.
1.2 Nonpoint Oil and Gas Emission Estimation Tool
Nonpoint source emissions from the oil and gas exploration and production sector have
gained interest in recent years in the United States as drilling technology has allowed
development of unconventional oil and gas plays in areas where there was previously no activity,
or where activity had subsided after depletion of the conventional reserves. For example, the
areas in and around the Barnett, Haynesville, and Eagle Ford Shales in Texas; the Marcellus
Shale in Ohio, Pennsylvania, and West Virginia; and the Bakken Shale/Williston Basin in North
Dakota and Montana have all experienced a rapid expansion in activity over the last ten years.
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Nonooint Oil and Gas Emissions Estimation Tool
These are referred to as "unconventional" oil and gas plays as the resource must be stimulated
through high-pressure, high-volume hydraulic fracturing to release the oil and gas trapped in the
source formation (such as shale or tight sands). In this tool, these types of wells are assumed to
have been hydraulically fractured when completed, and emissions from the hydraulic fracturing
pump engines are included as a discrete source type (see Section 3.11).
While the major emissions sources associated with oil and gas collection, processing, and
distribution have traditionally been included in the NEI as point sources (e.g. gas processing
plants, pipeline compressor stations, and refineries), the activities occurring "upstream" of these
types of facilities have not been as well characterized in the NEI. In this report, upstream
activities refer to emission units and processes associated with the exploration and drilling of oil
and gas wells, and the equipment used at the wellsite to then extract the product from the well
and deliver it "downstream" to a central collection point or processing facility. The types of unit
processes found at upstream sites include separators, dehydrators, storage tanks, and compressor
engines.
The NEI nonpoint oil and gas emissions inventory is primarily developed using data
supplied to EPA by state air agencies. Where state data is not supplied to EPA, EPA populates
the NEI with the best available data. In the case of nonpoint oil and gas emissions estimates,
EPA has developed the tool described in this report to estimate emissions from this category.
The tool is an Access database that utilizes county-level activity data (e.g. oil production and
well counts), operational characteristics (types and sizes of equipment), and emission factors to
estimate emissions.
The emission estimates generated by the tool are only used in the NEI if state data is not
available. Where state data is available but does not include HAP, EPA estimates HAPs based on
their ratios to VOC or PM in gas composition profiles and adds them to the NEI. The HAP
augmentation procedure is described in detail in the documentation for the 2014 NEI
(https://www.epa.gov/air-emissions-inventories/2014-nationai-emissions-inventorv-nei-data).
This report describes the technical approach used to develop the tool to characterize
emissions from nonpoint oil and gas exploration and production sources for the year 2020. The
tool generates estimates of emissions of oxides of nitrogen (N0X), volatile organic compounds
(VOC), particulate matter (PM), carbon monoxide (CO), ammonia (NH3), sulfur dioxide (SO2),
HAPs, and hydrogen sulfide (H2S) from upstream oil and gas production activities. Specific
source categories included in the tool are:
• Artificial Lift Engines
• Associated Gas Venting
• Coalbed Methane Dewatering Pump Engines
• Condensate Tanks
• Crude Oil Tanks
• Dehydrators
• Drilling Rigs
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Nonooint Oil and Gas Emissions Estimation Tool
• Fugitive Emissions
• Gas-Actuated Pneumatic Pumps
• Heaters
• Hydraulic Fracturing Pumps
• Lateral Compressor Engines
• Liquids Unloading
• Hydrocarbon Liquids Loading
• Mud Degassing
• Pneumatic Devices
• Produced Water Tanks
• Well Completion Venting
• Wellhead Compressor Engines
• Flaring (when used to control emissions from the unit processes listed above)
Many of the source categories covered by the tool are further sub-divided into distinct
source classification codes (SCCs) specific to either a well type (gas or oil), a sub-category of the
broader equipment type (such as fugitive emissions from connectors and fugitive emissions from
valves), or some other distinction. Table 1-1 presents a complete listing of the SCCs covered by
the tool for each of the source categories listed above.
Table 1-1. SCC Listing
Source Category
SCC
SCC Description
Artificial Lift Engines
2310011600
Oil and Gas: Onshore Oil Production/Artificial Lift
Engines
Associated Gas Venting
2310011001
Oil and Gas: Onshore Oil Production/Associated Gas
Venting
CBM Dewatering Pump
Engines
2310023000
Coal Bed Methane NG/Dewatering Pump Engines
Condensate Tanks
2310021010
On-Shore Gas Production /Storage Tanks: Condensate
Condensate Tanks
2310023010
On-Shore CBM Production /Storage Tanks: Condensate
Crude Oil Tanks
2310010200
Oil & Gas Expl & Prod /Crude Petroleum /Oil Well
Tanks - Flashing & Standing/Working/Breathing
Dehydrators
2310021400
On-Shore Gas Production Dehydrators
Dehydrators
2310023400
Coal Bed Methane NG / Dehydrators
Drilling Rigs
2310000220
Oil And Gas Exploration Drill Rigs
Fugitive Emissions
2310011501
On-Shore Oil Production /Fugitives: Connectors
Fugitive Emissions
2310011502
On-Shore Oil Production /Fugitives: Flanges
Fugitive Emissions
2310011503
On-Shore Oil Production /Fugitives: Open Ended Lines
Fugitive Emissions
2310011505
On-Shore Oil Production /Fugitives: Valves
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Nonooint Oil and Gas Emissions Estimation Tool
Table 1-1. SCC Listing
Source Category
SCC
SCC Description
Fugitive Emissions
2310021501
On-Shore Gas Production /Fugitives: Connectors
Fugitive Emissions
2310021502
On-Shore Gas Production /Fugitives: Flanges
Fugitive Emissions
2310021503
On-Shore Gas Production /Fugitives: Open Ended
Lines
Fugitive Emissions
2310021505
On-Shore Gas Production /Fugitives: Valves
Fugitive Emissions
2310021506
On-Shore Gas Production /Fugitives: Other3
Fugitive Emissions
2310023511
On-Shore CBM Production /Fugitives: Connectors
Fugitive Emissions
2310023512
On-Shore CBM Production /Fugitives: Flanges
Fugitive Emissions
2310023513
On-Shore CBM Production /Fugitives: Open Ended
Lines
Fugitive Emissions
2310023515
On-Shore CBM Production /Fugitives: Valves
Fugitive Emissions
2310023516
On-Shore CBM Production /Fugitives: Other3
Gas-Actuated Pumps
2310023310
Coal Bed Methane NG / Pneumatic Pumps
Gas-Actuated Pumps
2310111401
On-Shore Oil Exploration /Oil Well Pneumatic Pumps
Gas-Actuated Pumps
2310121401
On-Shore Gas Exploration: Gas Well Pneumatic Pumps
Heaters
2310010100
On-Shore Oil Production /Heater Treater
Heaters
2310021100
On-Shore Gas Production /Gas Well Heaters
Heaters
2310023100
On-Shore CBM Production /CBM Well Heaters
Hydraulic Fracturing Pumps
2310000660
Oil & Gas Expl & Prod /All Processes /Hydraulic
Fracturing Engines
Hydrocarbon Liquids Loading
2310011201
On-Shore Oil Production /Tank Truck/Railcar Loading:
Crude Oil
Hydrocarbon Liquids Loading
2310021030
On-Shore Gas Production /Tank Truck/Railcar
Loading: Condensate
Hydrocarbon Liquids Loading
2310023030
On-Shore CBM Production /Tank Truck/Railcar
Loading: Condensate
Lateral Compressor Engines
2310021251
On-Shore Gas Production/Lateral Compressors 4 Cycle
Lean Burn
Lateral Compressor Engines
2310021351
On-Shore Gas Production/Lateral Compressors 4 Cycle
Rich Burn
Lateral Compressor Engines
2310023251
On-Shore CBM Production/Lateral Compressors 4
Cycle Lean Burn
Lateral Compressor Engines
2310023351
On-Shore CBM Production/Lateral Compressors 4
Cycle Rich Burn
Liquids Unloading
2310021603
On-Shore Gas Production / Gas Well Venting -
Blowdowns
Liquids Unloading
2310023603
On-Shore CBM Production / CBM Well Venting -
Blowdowns
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Nonooint Oil and Gas Emissions Estimation Tool
Table 1-1. SCC Listing
Source Category
SCC
SCC Description
Mud Degassing
2310023606
On-Shore CBM Exploration /Mud Degassing
Mud Degassing
2310111100
On-Shore Oil Exploration /Mud Degassing
Mud Degassing
2310121100
On-Shore Gas Exploration /Mud Degassing
Pneumatic Devices
2310010300
Oil Production Pneumatic Devices
Pneumatic Devices
2310021300
On-Shore Gas Production Pneumatic Devices
Pneumatic Devices
2310023300
On-Shore CBM Production Pneumatic Devices
Produced Water Tanks
2310000551
Produced Water from CBM Wells
Produced Water Tanks
2310000552
Produced Water from Gas Wells
Produced Water Tanks
2310000553
Produced Water from Oil Wells
Well Completion Venting
2310023600
On-Shore CBM Exploration: CBM Well Completion:
All Processes
Well Completion Venting
2310111700
On-Shore Oil Exploration: Oil Well Completion: All
Processes
Well Completion Venting
2310121700
On-Shore Gas Exploration: Gas Well Completion: All
Processes
Wellhead Compressor Engines
2310021102
On-Shore Gas Production /Natural Gas Fired 2Cycle
Lean Burn Compressor Engines 50 To 499 HP
Wellhead Compressor Engines
2310021202
On-Shore Gas Production /Natural Gas Fired 4Cycle
Lean Burn Compressor Engines 50 To 499 HP
Wellhead Compressor Engines
2310021302
On-Shore Gas Production /Natural Gas Fired 4Cycle
Rich Burn Compressor Engines 50 To 499 HP
Wellhead Compressor Engines
2310023102
On-Shore CBM Production /CBM Fired 2Cycle Lean
Burn Compressor Engines 50 To 499 HP
Wellhead Compressor Engines
2310023202
On-Shore CBM Production /CBM Fired 4Cycle Lean
Burn Compressor Engines 50 To 499 HP
Wellhead Compressor Engines
2310023302
On-Shore CBM Production /CBM Fired 4Cycle Rich
Burn Compressor Engines 50 To 499 HP
a This SCC used for compressor seal leaks.
It should be noted that these source categories do not represent a complete list of all
emission sources or SCCs that may be found at upstream oil and gas exploration and production
sites. However, the most significant nonpoint sources that contribute to emissions have been
included. Sources that were not included due to limited data availability include: salt water
injection engines, well pad construction equipment, workover equipment, and mobile sources.
Associated on-road mobile sources operating in the field, such as service vehicles used during
construction, drilling and production phases, may be included in some states' mobile source
emissions inventories but are not specifically included in the tool.
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Nonooint Oil and Gas Emissions Estimation Tool
ERG developed the tool initially under EPA Contract No. EP-D-11-006, Work
Assignment (WA) 2-05, followed on by subsequent WAs and this Task Order (TO). The
purpose/objectives of the WAs/TO were the following:
1) Develop a nonpoint methodology to estimate county-level emissions of criteria
pollutants and HAP for the upstream oil and gas production sector for 2011, 2014,
2017, and 2020;
2) Implement the methodology to develop county-level emissions inventories for this
sector; and
3) Develop a MS Access-based tool incorporating the methodologies and available
information that may be used by EPA, states, and local agencies to develop state or
region-specific emission inventories for the upstream oil and gas sector based on user
supplied activity and emissions inputs.
The following describes how the information in this report is organized:
Section 2 - background information on development of tool
Section 3 - information on the methodology and emission estimation approach used for
each source category
Section 4 - summary of nonpoint oil and gas emission estimates generated by the tool
Section 5 - summary of nonpoint oil and gas emission estimates in the 2020 NEI
Section 6 - recommended future activities for improving nonpoint oil and gas
emission inventories
Note on greenhouse gas (GHG) emissions
EPA GHG emissions estimates for oil and gas are available at the national level (GHG
Inventory, http://www.epa.gov/climatechange/ghgemissions/usinventorvreport.htmr) and
facility-level (Greenhouse Gas Reporting Program, http://www.epa.gov/ghgreporting/).
While GHG emissions are not the focus of this tool, they are used in the tool in some places
as necessary intermediary steps in the calculation of other pollutants.
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Nonooint Oil and Gas Emissions Estimation Tool
2.0 Background on Development of the Tool
The tool was developed based on work that has been done in this sector over the last
several years by various states, inter-governmental agencies, and EPA. These efforts include
work done by the Texas Commission on Environmental Quality (TCEQ), the Western Regional
Air Partnership (WRAP), and the Central States Air Resource Agencies (CenSARA) to develop
improved nonpoint oil and gas emissions inventories.
In 2010, the seven CenSARA states (Texas, Louisiana, Oklahoma, Arkansas, Kansas,
Missouri and Nebraska) had a combined oil production of approximately 611 million barrels and
a combined gas production of 12.8 trillion cubic feet, representing 48 % of total gas production
and 31% of total oil production in the country, including both conventional and unconventional
resource plays.1 As such, the CenSARA inventory effort covered a wide variety of processes and
well types and was used as the starting point for the tool. In particular, the Excel-based emission
estimation tool that was developed for the CenSARA study was used as the basis for initial
development of the tool described in this report. Subsequent updates to the tool incorporated data
from numerous additional sources, including the TCEQ and WRAP data mentioned above,
related EPA inventory efforts, and data provided to EPA directly from state air agencies.
The basic methodology used to develop the CenSARA inventory was also used to
develop the tool and consisted of the following steps:
• Compile activity data - Oil and gas activity data was obtained to include, but is not
limited to, the number of active wells by well type, gas production and oil production,
spud counts, feet drilled, and water production. The activity data for the tool was
primarily obtained from the Enverus HPDI database, a commercial database that
processes state-level oil and gas commission data into a comprehensive database of
production statistics.2 Data used in this version of the tool is for the calendar year
2020 and is based on HPDI data as of September 2021. As described further in
section 2.1, EPA uses other activity data that is not available in HPDI for certain
states.
• Compile process characterization and emission factor data - To initially populate the
tool, process characterization data and emissions factors from the CenSARA study
were used for the counties in the CenSARA states, and an average of the data for the
CenSARA basins were used for the remainder of the counties in the country. Under
the CenSARA study, these data were developed or collected from a variety of sources
including: 1) oil and gas operator surveys, 2) state minor source permit applications,
and 3) literature review. Emission factors for combustion equipment has primarily
been taken from AP-42. Much of the initial CenSARA process characterization data
used to populate the tool database has since been replaced, as described below in
more detail. For example, EPA GHG Reporting Program data (Subpart W) were used
1 Internet address: http://www.eia. gov/
2 "DI Desktop Database powered by Enverus HPDI." Accessed September 2021. Internet address:
http://www.didesktop.com/
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Nonooint Oil and Gas Emissions Estimation Tool
to develop default values for several categories, including condensate tanks, crude oil
tanks, pneumatic devices, and heaters.3
• Incorporate updated process characterization data - Several state and local air quality
agencies and Regional Planning Organizations (RPOs) provided updates to replace
the default CenSARA and EPA process characterization data. The tool database
contains reference information identifying the source of all inputs into the estimates.
• Develop Access-based tool to house the inventory - A Microsoft Access-based tool
that estimates 2020 nonpoint oil and gas emissions at the county level was then
developed using the compiled activity and process characterization data. The tool has
been programmed to be flexible and allow for user-specified inputs such that users
may update activity and emissions data at the basin and/or county level for future use.
Additional details on the tool and user's instructions are included in Appendices A
(Exploration Module) and B (Production Module).
Finally, the tool has been programmed to facilitate NEI submissions by generating EPA
Emission Inventory System (EIS) staging tables. These tables can be converted into valid XML
files that are in compliance with the EPA-supplied Consolidated Emissions Reporting Schema
(CERS) using an EPA-supplied XML File Generator tool. Therefore, the tool allows users to
both generate the oil and gas emissions and format them for NEI submission.
2.1 Activity Data
Activity data were obtained at the county level for the entire country to include the key
activity parameters that affect emissions. These key activity factors include, but are not limited
to, the number of active wells by well type, gas production and oil production by well type, spud
count, estimated feet (depth) drilled by wellbore type, and water production by well type.
Activity data for the 2020 base year were obtained from the HPDI database, RIGDATA,4 state
oil and gas commission websites, and directly from state and local agencies involved in
development and review of the tool.
Table 2-1 presents the activity data parameters used in the tool to calculate emissions.
Table 2-1. Activity Parameters Needed to Estimate Emissions
Data Parameter
Oil Production (barrels or BBL)
Natural Gas Production (thousand standard cubic feet or MCF)
CBM Production (thousand standard cubic feet or MCF)
3 "Summary of Analysis of 2020 GHGRP Subpart W Data for Use in the 2020 NEI Nonpoint Oil and Gas
Emission Estimation Tool", Memorandum from Mike Pring, Regi Oommen, and Stephen Treimel to Jeff
Vukovich and Jennifer Snyder. December 3, 2021.
4 U.S. Well Starts By Depth Range, January 2020 through December 2020. Used by Permission and Approved for
Publication by Horn Rana at RIGDATA (www.rigdata.com) in e-mail communication to Regi Oommen, Eastern
Research Group, Inc. April 21, 2021.
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-1. Activity Parameters Needed to Estimate Emissions
Data Parameter
Condensate Production (BBL)
Associated Gas Production (MCF)
Oil Well Counts
Natural Gas Well Counts
CBM Well Counts
Oil Well Completions (Conventional and Unconventional)
Natural Gas Well Completions (Conventional and Unconventional)
CBM Well Completions (Conventional and Unconventional)
Produced Water Production at Oil Wells (BBL)
Produced Water Production at Gas/CBM Wells (BBL)
Spud Counts (Vertical, Horizontal, Directional)
Feet Drilled (Vertical, Horizontal, Directional)
Table 2-2 presents the activity parameter data sources for each state for the data types
identified in Table 2-1.
Table 2-2. Activity Parameter Data Sources by State
State
Oil/
Associated
Gas
Production
Natural
Gas/
Condensate
Production
CBM Gas/
Condensate
Production
Produced
Water
Well
Completions
Spud Counts/
Feet Drilled
Alabama
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
AL OGC 2021
Alaska
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Arizona
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Arkansas
2021
ENVERUS/
AROGC 2021
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
AROGC 2021
2021
ENVERUS
2021
ENVERUS
California
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Colorado
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
CO OGC
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-2. Activity Parameter Data Sources by State
State
Oil/
Associated
Gas
Production
Natural
Gas/
Condensate
Production
CBM Gas/
Condensate
Production
Produced
Water
Well
Completions
Spud Counts/
Feet Drilled
Florida
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
FL DEP/
RIGDATA
Idaho
ID OGC 2021
ID OGC 2021
ID OGC 2021
ID OGC 2021
ID OGC 2021
ID OGC 2021
Illinois
IPRB 2022/
2019 ILOGC
CF
2019 EI A CF
2019 EI A CF
CALC_RATIO
IL OGC 2021
IL OGC 2021/
RIGDATA
Indiana
IN OGC 2021
IN OGC 2021
IN OGC 2021
CALC_RATIO
IN OGC 2021
IN OGC 2021
Kansas
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
KS OGC 2021
2021
ENVERUS/
KS OGC 2021
2021
ENVERUS/
KS OGC 2021
Kentucky
2019 KYDEP
CF
2019 KYDEP
CF
2021
ENVERUS
CALC_RATIO
KY DEP 2021
KY DEP 2021
Louisiana
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
CALC_RATIO
2021
ENVERUS
2021
ENVERUS
Maryland
EIA 2021
EIA 2021
EIA 2021
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Michigan
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
MI OGC 2021
2021
ENVERUS
Mississippi
MS OGC 2021
MS OGC
2021
2021
ENVERUS
MS OGC 2021
2021
ENVERUS
MS OGC 2021
Missouri
MO DNR 2021
MO DNR
2021
2021
ENVERUS
MO DNR 2021
2021
ENVERUS
MO OGC 2021
Montana
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Nebraska
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
NE OGC 2021
NE OGC 2021/
RIGDATA
Nevada
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
New Mexico
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
NM OGC 2021
New York
NY OGC 2021
NY OGC
2021
2021
ENVERUS
2021
ENVERUS/
NY OGC 2021
2021
ENVERUS/
NY OGC 2021
2021
ENVERUS/
NY OGC 2021
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-2. Activity Parameter Data Sources by State
State
Oil/
Associated
Gas
Production
Natural
Gas/
Condensate
Production
CBM Gas/
Condensate
Production
Produced
Water
Well
Completions
Spud Counts/
Feet Drilled
North Dakota
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Ohio
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Oklahoma
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
CALC_RATIO
2021
ENVERUS/
OKDEQ 2021
2021
ENVERUS/
OKDEQ 2021
Oregon
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Pennsylvania
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
PA DEP 2021
2021
ENVERUS
2021
ENVERUS
South Dakota
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Tennessee
2021 EIA
2021 EIA
2021EIA
CALC_RATIO
TN OGC 2021
TN OGC 2021
Texas
TCEQ 2021
TCEQ 2021
2021
ENVERUS
2021
ENVERUS/
CALC_RATIO
2021
ENVERUS
2021
ENVERUS
Utah
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
Virginia
2021
ENVERUS
VADEQ 2021
VADEQ 2021
CALC_RATIO
2021
ENVERUS/
VA OGC 2021
2021
ENVERUS/
VA OGC 2021
West Virginia
WVDEP 2021
WVDEP 2021
WVDEP 2021
2021
ENVERUS
WVDEP 2021
WVDEP 2021
Wyoming
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS
2021
ENVERUS/
WY OGC 2021
2021
ENVERUS/
WY OGC 2021
2.1.1 Enverus HPDI Data
The primary data source for obtaining activity data was the Enverus HPDI database. This
subscription-based information service extracts well-level data from state oil and gas
commission websites and prepares it in a standardized format. As part of EPA's Enforcement
Activities, EPA has an annual subscription to the Enverus HPDI database, allowing data
downloads, or "refreshes," to be obtained throughout the year. In accordance with the EPA's
licensing agreement, well-level data is proprietary, but derived products, such as aggregation at
the county-level, are acceptable for public dissemination and use in the tool.
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ERG extracted well identification (HPDIHeader) and production (HPDIProduction)
information for onshore wells and leases. Table 2-3 provides details on the available data by
state, as of the September 2021 refresh. Table 2-3 also includes the update frequency of the data
by state and provides the date of the latest production data included in the September 2021
refresh.
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Table 2-3. Enverus HPDI Data Coverage by State
State
Abbreviation
Production Group
Update
Frequency
Latest Production Data
Alabama
Well
Monthly
May 2021
Alaska
Well
Monthly
June 2021
Arizona
Well
Monthly
May 2021
Arkansas
Well
Monthly
May 2021
California
Well
Monthly
May 2021
Colorado
Well
Monthly
June 2021
Florida
Well
Monthly
June 2021
Kansas
Lease
Monthly
May 2021
Kentucky
Well
Yearly
December 2019
Louisiana
Well/Unit3
Monthly
June 2021
Maryland
Well
Semi-annually
December 2015
Michigan
Lease
Monthly
December 2020
Mississippi
Well
Monthly
January 2021
Missouri
Well
Bi-Monthly
June 2019
Montana
Well
Monthly
May 2021
Nebraska
Well
Monthly
June 2021
Nevada
Well
Bi-Monthly
April 2021
New Mexico
Well
Monthly
June 2021
New York
Well
Yearly
December 2020
North Dakota
Well
Monthly
June 2021
Ohio
Well
Quarterlyb/Y earlyb
March 2021/December 2020
Oklahoma
Well
Monthly
May 2021
Oregon
Well
Yearly
December 2020
Pennsylvania
Well
Monthlyc/Y earlyc
June 2021/December 2020
South Dakota
Well
Yearly
May 2021
Tennessee
Lease
Yearly
December 2016
Texas
Oil Lease/Gas Well
Twice monthly
June 2021
Utah
Well
Monthly
June 2021
Virginia
Well
Yearly
April 2021
West Virginia
Well
Quarterlyb/Y earlyb
March 2021/December 2020
Wyoming
Well
Monthly
June 2021
a Louisiana Department of Natural Resources defines a unit as the "surface area that encompasses part of
or the entirety of a reservoir."
b For Ohio and West Virginia, production data for conventional wells are updated annually, while
production data for unconventional wells are updated quarterly.
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c For Pennsylvania, production data for conventional wells are updated annually, while production data for
unconventional wells are updated quarterly.
ERG imported all of the data from HPDI into an Oracle database for pre-processing. The
Oracle database combines and processes all of the download files into one table of all production
wells for the EPA Enforcement Universe Database. The processing steps are discussed below.
1) Combine Monthly Production and Descriptive Information: For each entity,5 ERG
combined the monthly production with the descriptive information (e.g., API number,
lease name, location, operator, completion date, spud date, latest production date) from
the HPDIHeader table to create the Wells table for the EPA Enforcement Universe
Database.
2) Remove Duplicate Wells: HPDI includes duplicate information for wells in some states
because the data are stored by completion zone rather than at the well or lease level.
Because all of the other descriptive data in HPDI are at the well or lease level, ERG
combined duplicate API numbers (i.e., well bore identifiers6) into a single record to avoid
overcounting wells. ERG excluded the records with missing API numbers (i.e., API_NO
is null) from this "remove duplicate well" step. This could result in some over counting
of wells, but this should be minimal because a limited number of wells/leases did not
have API numbers and there were a small percentage of duplicate wells identified.7
3) Create Updated Active Status Flag (ACTIVE_FLAG): ERG created an updated active
status flag (ACTIVE_FLAG) per month using the latest production date
(LAST_PROD_DATE) after determining that HPDI's status flag (STATUS) was not
always accurate as part of the 2011 version of the Universe Database.8
4) Create Monthly Production Flags: ERG created production flags to identify
miscellaneous well types (e.g., injection, observation, abandoned, pressure maintenance,
N/A) that have monthly oil and gas production in 2020 (PROD_01_20_FLAG through
PROD_12_20). The production flag is "Yes" if the monthly oil or gas production is
greater than zero.
5) Assign Each Well as Oil, Gas, or CBM: Each well was reviewed to determine whether it
should be labeled as an oil, gas, or CBM well. As such, the following hierarchy was used:
a. Enverus HPDI designations of CBM;
b. Wells that had 2020 oil production, but no 2020 natural gas production were assigned
as "oil" wells;
5 HPDI assigns a unique number to each property (i.e., lease, well, unit) in the ENTITY_ID field.
6 API numbers are up to 14 digits long and are broken into four segments. The first two digits correspond to the
state; the next three digits correspond to the county in the state. The next five digits are the unique well identifier
for the county. The next two digits are for the directional side tracks (i.e., horizontal or directional drills that each
have different bottom hole locations), with 00 representing the original well bore. The last two digits are the
event sequence code that distinguish between original completion, reentries, recompletion, and hole deepenings.
Some states do not assign directional side tracks or event sequence codes.
7 Duplicate wells in states with missing API numbers could be identified using the permit number, which should
be unique for each well.
8 ERG found some wells with an "Active" STATUS had not produced in a number of years, while some wells
with an "Inactive" STATUS had production data for 2020.
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c. Wells that had 2020 gas production, but no 2020 oil production were assigned as
"gas" wells; and
d. Wells that had both 2020 oil and gas production were assigned "gas" if the ratio of
gas to oil was greater than 100 MCF per barrel, and were assigned "oil" if the ratio of
gas to oil was less than 100 MCF per barrel.
6) Calculate Well Counts: Counting wells which produced oil, gas, or CBM and summing to
the county-level will likely overestimate the number of wells which actually operated for
an entire year because wells that operated for only one month would be essentially used
as inputs for emission profiles assuming a year of operations for certain source
categories. To account for this, monthly well counts were averaged to develop an annual
average, and these averages were populated in the tool as:
a. NONPOINT_OIL_WELL_COUNT
b. NONPOINT_GAS_WELL_COUNT, and
c. NONPOINT_CBM_WELL COUNT
With the exception of "Oil (and Condensate) Production" and "Feet Drilled," all of the
data parameters shown in Table 2-1 are reported fields in Enverus HPDI. Enverus HPDI reports
total hydrocarbon liquids production for each well, but does not always distinguish between oil
and condensate. As described above, each well was designated as either a gas well or an oil well.
Liquid hydrocarbons produced at gas wells were then considered to be condensate, and liquid
hydrocarbons produced at oil wells were considered to be oil.
Feet drilled and spud counts are needed for the Drilling and Mud Degassing source
categories. While Enverus HPDI reports spud date and well depth for each well, that information
is often lagging or may be incomplete at the time of the data retrieval. Thus, EPA developed an
approach for utilizing the well-specific data from Enverus HPDI and state websites and from
state-level "Well Starts" and "Feet Drilled" published by RIGDATA.4 The approach is as
follows:
1) RIGDATA published total "well starts" and "feet drilled" for 28 states:
Alabama
Florida
Louisiana
Nevada
Oklahoma
Virginia
Alaska
Illinois
Michigan
New Mexico
Pennsylvania
West Virginia
Arkansas
Indiana
Mississippi
New York
Tennessee
Wyoming
California
Kansas
Montana
North Dakota
Texas
Colorado
Kentucky
Nebraska
Ohio
Utah
2) EPA compared the total well starts and feet drilled for the above states to the totals from
the ENVERUS dataset. Where there was no comparison or significant differences
(>30%) between the totals, EPA researched the states OGC websites to download the
exploration data.
a. Four states (Arizona, Maryland, Oregon, and South Dakota) were not on the
RIGDATA list and EPA researched confirmed via their OGC websites that no
drilling occurred in 2020.
b. RIGDATA identified one state, Nevada, as having drilling activity in 2020, but
the data were not available in Enverus or on the Nevada OGC website.
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c. For ten states (Florida, Idaho, Illinois, Indiana, Kentucky, Mississippi, Missouri,
New York, Tennessee, and Virginia), there were no drilling data in the Enverus
dataset. EPA downloaded exploration data from their respective OGC websites.
d. For eight states (Alabama, Colorado, Kansas, Michigan, Nebraska, New Mexico,
Oklahoma, and Wyoming), the Enverus totals appeared low compared to
RIGDATA. As such, EPA supplemented the Enverus data with additional
exploration data from their respective OGC websites, with the exception of
Michigan (no drilling data available on its OGC website).
e. The Enverus totals for four states (California, Ohio, Pennsylvania, and West
Virginia) were greater than the RIGDATA totals, and no additional research was
conducted.
f. Finally, the following seven states (Alaska, Arkansas, Louisiana, Montana, North
Dakota, Texas, and Utah) Enverus and RIGDATA totals were within 30% and
were not supplemented with additional data from their respective OGC websites.
2.1.2 State Oil and Gas Commission Websites
As mentioned above, Enverus HPDI was the primary source for most oil, casinghead gas
(associated gas), natural gas, and condensate activity data for 2020, with the exceptions of the
following states:
• Idaho (liquids and gas)
• Indiana (liquids and gas)
• Mississippi (liquids and gas)
• Missouri (liquids and gas)
• Oregon (liquids and gas)
• Virginia (gas only)
For some states, the Enverus data was supplemented with state data or scaled to match
published totals from the OGC website:
• Arkansas Oil production from Enverus was low compared to the EIA state total. Thus,
the Enverus oil well data were scaled up to align better with EIA.
• Nevada. Gas production from Enverus were low compared to the EIA state total.
Additional production wells were supplemented with the Enverus data to better align
with the EIA state total.
• New York. Oil and gas production from Enverus were low compared to the EIA state
totals. Additional production wells were supplemented with the Enverus data to better
align with the EIA state totals.
For four states, 2020 production data were not available from the Enverus dataset or their
OGC websites. (It's possible that the data may available in the coming months.) As such, prior
year data were carried-forward and scaled to match the EIA production for 2020.
• Illinois. County-level oil production for 2019 were obtained from its oil and gas
association website and were scaled to 2020 production based on the ratio of total
EIA production for years 2020 and 2019. County-level gas production from the 2017
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Oil and Gas Tool were adjusted to 2020 production based on the ratio of total EIA
production for years 2020 and 2017.
• Kentucky. County-level oil and gas production for 2019 were obtained from its OGC
website and were scaled to 2020 production based on the ratio of total EIA production
for years 2020 and 2019.
• Maryland. County-level gas production from the 2017 Oil and Gas Tool were
adjusted to 2020 production based on the ratio of total EIA production for years 2020
and 2017.
• Tennessee. Well-level oil and gas production for 2016 were obtained from a prior
Enverus data pull, and production were scaled to 2020 based on the ratio of total EIA
production for years 2020 and 2016.
Produced water data were primarily available in Enverus for most of the states. When not
reported in Enverus, information was obtained from the state's oil and gas commission website
(e.g., Pennsylvania) or directly from the state (e.g., Kansas). If produced water data were not
available in either Enverus or from the state, then activity estimates were generated for this
source category based on statewide-developed production factors within a state (e.g., Texas) or
from third-party analysis report (e.g., Oklahoma).9
Well completions were primarily available in Enverus for most of the states. When not
reported in Enverus, information was obtained from the state's oil and gas commission website
(e.g., Indiana). If well completions data were not available in either HPDI or the state's oil and
gas commission websites, then no emission estimates were generated for this source category
(e.g., Arizona).
As a result of this analysis, data from the following state oil and gas commission websites
were used to compile the activity data in the tool:
• Alabama Oil and Gas Board: https://www.ogb.state.al.us/ogb/wells
• Arkansas Oil and Gas Conservation Commission:
http ://ao gc. state, ar. us/data/completion, aspx
• Colorado: https://cogcc.state.co.us/data2.html#/downloads
• Florida Department of Environmental Protection: https://floridadep.gov/water/oil-
gas/content/oil-and-gas-permit-database
• Idaho Oil and Gas Conservation Commission: https://ogcc.idaho.gov/monthly-and-
annual-reports/ and https://o gcc.idaho. gov/well-files/
• Illinois State Geological Services:
https://clearinghouse.isgs.illinois.edu/data/geologv/location-points-isgs-wells-and-
borings-database and https://isgs-
oas.isgs.illinois.edu/reports/rwservlet?oil permit activity
9 Veil Environmental. U.S. Produced Water Volumes and Management Practices in 2017. February 2020. Internet
address: http://veilenvironmental.com/publications/pw/pw report 2017 final.pdf
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• Indiana Department of Natural Resources: https://www.in.gov/dnr/oil-and-
gas/publications/monthly-reports/ and https://www.in. gov/dnr/dnroil/5447.htm
• Kansas Geological Services: https://www.kgs.ku.edu/PRS/Ora_Archive/ks_wells.zip
• Kentucky Geological Services: https://kgs.uky.edu/kygeode/services/oilgas/
• Mississippi Oil and Gas Board: https://www.ogb.state.ms.us/wellsearch.php and
https://www.ogb.state.ms.us/proddata.php
• Missouri Department of Natural Resources: https://dnr.mo.gov/land-geologv/businesses-
landowners-permittees/permits/oil-gas
• Nebraska Oil and Gas Conservation Commission:
http://www.nogcc.ne.gov/Publications/NebraskaWellData.zip
• Nevada Division of Minerals:
https://data.nbmg.unr.edu/public/OilGas/Logs/oilgas well index 20200106.xlsx
• New Mexico Oil Conservation Division:
https://wwwapps.emnrd.nm.gov/ocd/ocdpermitting/Data/Wells.aspx
• New York Department of Conservation: https://www.dec.nv. gov/fs/data/wellDOS.zip
and http s://www .dec.nv.gov/energv/36159. html
• Oklahoma Corporation Commission: https://www.dec.nv.gov/energv/36159.html
• Oregon Department of Geology and Mineral Industries:
https://www.oregongeology.org/mlrr/mist/12-2020_MistGasField_Report.xlsx
• Pennsylvania Department of Environmental Protection:
https://www.depgreenport.state.pa.us/ReportExtracts/OG/OilGasWellWasteReport
• Tennessee Department of Environment and Conservation:
https://dataviewers.tdec.tn.gov/pls/enf_reports/f?p=9034:34300:0::NO:::
• Virginia Department of Environmental Quality:
https://energv.vir ginia.gov/dgoinquirv/frmMain.aspx?ctl=9.
https://dmme.Virginia.gov/dgoinquiry/frmMain. aspx?ctl= 1, and
https://energv.vir ginia.gov/dgoinquirv/frmMain.aspx?ctl=2
• Wyoming Oil and Gas Conservation Commission:
http://pipeline.wvo.gov/SpudcompcompMenu.cfm?Skip=%27Y%27&oops=ID70897 and
http://pipeline.wyo. gov/SpudReportsMenu.cfm?Skip=%27Y%27&oops=ID20545
2.1.3 National Production Summary
A summary of the resulting oil and gas 2020 production statistics by state is presented in
Table 2-4. This includes key activity indicators such as natural gas production (associated gas, gas
well, and coalbed methane gas), crude oil production, and condensate production. States not listed
in Table 2-4 (e.g. Connecticut and North Carolina) did not have any oil or gas production in 2020.
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Table 2-4. Oil and Gas Production by State
State
Oil Wells
Gas
Wells
CBM
Wells
Oil (BBL)
Associated
Gas
(MMCF)
Gas Well
Gas
(MMCF)
Condensate
(BBL)
CBM Gas
(MMCF)
CBM
Condensate
(BBL)
Alabama
359
199
4,985
3,909,836
18,203
50,697
15,678
45,114
37,230
Alaska
1,632
225
0
159,536,232
2,854,007
594,034
4,315,721
0
0
Arizona
5
6
0
5,581
1
69
0
0
0
Arkansas
851
8,699
47
4,141,093
4,241
480,905
2,079
841
0
California
41,677
1,715
0
143,756,658
111,243
46,335
116,162
0
0
Colorado
12,275
18,258
4,877
166,381,709
1,093,765
618,610
1,265,105
279,087
90,950
Florida
51
0
0
1,366,217
13,777
0
0
0
0
Idaho
0
2
0
0
0
77
1,400
0
0
Illinois
21,962
652
60
7,513,839
0
1,578
0
265
0
Indiana
4,310
501
110
1,322,888
0
3,410
0
908
0
Kansas
30,253
13,408
3,646
28,227,649
16,400
131,865
23,810
15,953
6,591
Kentucky
10,162
18,664
0
2,281,543
51
93,708
0
0
0
Louisiana
15,213
15,108
4
35,602,684
135,964
3,012,830
632,801
53
4,166
Maryland
0
1
0
0
0
10
0
0
0
Michigan
2,875
7,120
0
4,009,961
5,997
58,088
4,115
0
0
Mississippi
1,378
1,165
0
14,117,103
10,602
17,526
46,844
0
0
Missouri
817
8
0
62,328
0
1
0
0
0
Montana
3,509
4,794
1
18,954,597
80,097
25,716
27,881
2
0
Nebraska
1,313
125
0
1,591,335
22
328
0
0
0
Nevada
46
0
0
207,989
8
0.00
0
0
0
New Mexico
20,759
18,022
5,253
369,715,649
1,388,698
425,349
697,888
201,108
8,656
New York
2,831
6,139
0
216,673
346
11,667
381
0
0
North Dakota
14,646
176
0
432,508,118
994,553
1,186
3,454
0
0
Ohio
15,937
19,423
0
23,204,371
310,989
2,038,650
429,217
0.0
0
Oklahoma
22,938
24,082
2,323
169,919,695
1,407,768
1,225,930
2,233,816
20,098
489,860
Oregon
0
10
0
0
0
320
0
0
0
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Table 2-4. Oil and Gas Production by State
State
Oil Wells
Gas
Wells
CBM
Wells
Oil (BBL)
Associated
Gas
(MMCF)
Gas Well
Gas
(MMCF)
Condensate
(BBL)
CBM Gas
(MMCF)
CBM
Condensate
(BBL)
Pennsylvania
17,415
56,545
300
4,013,618
140,965
7,020,239
1,624,029
4,402
1,534
South Dakota
135
45
0
1,045,161
4,394
338
1,499
0
0
Tennessee
990
772
0
164,212
217
2,553
788
0
0
Texas
181,254
99,632
109
1,497,121,781
3,900,292
6,620,946
273,514,682
4,446
106,572
Utah
4,783
4,404
900
29,846,260
82,700
127,609
377,837
30,482
0
Virginia
12
1,893
6,040
4,736
235
16,139
0
86,409
0
West Virginia
997
45,614
433
18,860,019
0
2,558,465
65,697,681
5,746
0
Wyoming
10,603
10,868
4,399
84,922,888
437,785
950,818
3,882,676
83,468
6,047
Total
441,988
378,275
33,487
3,224,532,422
13,013,321
26,135,996
354,915,543
778,383
751,606
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2.2 Process Characterization Data
As described in the CenSARA10 study, while activities can vary within a basin (e.g. both
oil and gas operations), the geologically influenced characteristics of a specific basin (e.g. depth,
pressure, presence of water, oil quality, gas composition) directly affect activity parameters that
describe oil and gas operations within the basin boundaries, and in turn, influence emissions. A
basin therefore represents a detailed but tractable geographic unit for development of emissions
factors and other process characterization data for oil and gas nonpoint source emissions
estimates.
In the CenSARA study, oil and gas nonpoint source emissions were estimated for each
county within a discrete basin based on equipment characterization, activity data, and emission
factors developed specifically for that basin. This equipment, activity, and emission factor data
were obtained through industry surveys, a review of oil and gas datasets compiled by state and
local agencies, and from existing studies.
Figure 2-1 below illustrates the 19 oil and gas basins included in the geographic scope of
coverage of the CenSARA study.
10 ENVIRON International Company. Oil and Gas Emission Inventory Enhancement Project for CenSARA States.
December 21, 2012. Internet address: www.censara.org/filedepot/folder/10
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Figure 2-1. Oil and Gas Basins Covered by the CenSARA Study
Nationally, the remainder of the country was sub-divided into oil and gas basins (as
defined by the geologic provinces published by the American Association of Petroleum
Geologists (AAPG)) as used under Subpart W of the Greenhouse Gas Reporting Program
(GHGRP).11
Using the AAPG definitions, the country is divided into 114 distinct oil and gas basins.
Figure 2-2 below illustrates the geographic division of the country into oil and gas basins as
defined by the geologic provinces published by the AAPG.
11 U.S. EPA, 2013. Subpart W Basin and County Combinations. Internet address:
http://www.ccdsupport.com/confluence/displav/help/Subpart+W+Basin+and+County+Combinations
22
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 2-2. Oil and Gas Basins as Defined by the Geologic Provinces Published by the
AAPG
The basic methodology employed in development of the CenSARA inventory was used
to develop the national tool described in this report. However, during development and review of
the tool by various stakeholders as part of the initial tool development for the 2011 NEI, it was
determined that county-level resolution was needed to accommodate differing operational
characteristics within a basin. Therefore, the tool currently resolves equipment characterization
and activity data down to the county level.
For the CenSARA states, the input data from the CenSARA study have been used in the
tool. For several oil and gas basins located in states adjacent to the CenSARA states, the AAPG
basin definitions overlap into the CenSARA states. Therefore, CenSARA basin-specific data was
used to initially populate the tool database for these basins. Table 2-5 identifies the basins
adjacent to the CenSARA states where CenSARA basin-specific data was initially input into the
tool.
Table 2-5. Oil and Gas Basins Adjacent to CenSARA States
AAPG Basin
Affected States
CenSARA basin
Anadarko Basin
CO
Anadarko Basin
Las Animas Arch
CO
Cambridge Arch-Central Kansas Uplift
Chadron Arch
SD
Cambridge Arch-Central Kansas Uplift
23
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-5. Oil and Gas Basins Adjacent to CenSARA States
AAPG Basin
Affected States
CenSARA basin
Denver Basin
CO, WY
Denver Basin
Forest City Basin
IA
Forest City Basin
Upper Mississippi Embayment
KY, MS, TN
Illinois Basin
Desha Basin
MS
Louisiana-Mississippi Salt Basins
Illinois Basin
IL, IN, KY
Illinois Basin
Palo Duro Basin
NM
Palo Duro Basin
Permian Basin
NM
Permian Basin
Orogrande Basin
NM
Permian Basin
Mid-Gulf Coast Basin
AL, FL, MS
Western Gulf
Finally, for those basins falling entirely outside of the CenSARA states, national averages
for equipment profiles and activity levels were developed based on the average of the surveyed
basins within the CenSARA states. While this data were used to initially populate the input data
for the tool database, many different state agencies, RPOs, and EPA supplied data that have been
used in the current version of the tool.
For example, for certain source categories such as well completions and mud degassing,
gas composition data developed by EPA for regulatory development purposes was used for the
non-CenSARA basins.12 Gas composition profiles developed under this effort were used as
default profiles for:
• Associated Gas Venting (Oil Wells)
• Fugitives (Gas Wells)
• Gas-Actuated Pumps (Gas Wells)
• Liquids Unloading (Gas Wells)
• Mud Degassing (Oil and Gas Wells)
• Pneumatic Devices (Gas Wells)
• Well Completions (Oil and Gas Wells)
Appendix C contains a comprehensive list of each county in the United States and the
associated AAPG oil and gas basin name, and under the CenSARA inventory (if applicable).
Appendix C also identifies what data was initially used to populate the tool database for each
county. This was either data from a specific CenSARA basin for the CenSARA states
(CENSARA_2012), data from a specific CenSARA basin for certain basins/counties adjacent to
the CenSARA states as listed in Table 2-5 (CENSARA_EXTENSION), or nationally-averaged
data from all CenSARA basins (CENSARA_AVG). While Appendix C identifies the initial
reference for the data used to populate the tool database, numerous updates have been made to
the tool since it was initially developed to incorporate EPA, state, and local data. The tool
12 U.S. EPA, 2011. "Composition of Natural Gas for use in the Oil and Natural Gas Sector Rulemaking",
Memorandum from Heather P. Brown to Bruce Moore. July 28, 2011.
24
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Nonooint Oil and Gas Emissions Estimation Tool
database contains specific references at the county level for each data element used in the
emission estimation algorithms.
Table 2-6 provides a broad overview of the types of data currently found in the tool. The
table indicates "S" for state supplied data, "D" for default CenSARA data, "E" for EPA data,
"B" for Bureau of Ocean Energy Management (BOEM) data, or "R" for RPO data (e.g.
CenSARA or WRAP). In many instances, a mix of these data types are used to estimate
emissions for a single source category. In these cases, each type of data found in the tool is
identified.
25
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-6. Tool Data Sources by State and Source Type
State
Artificial Lifts
Associated Gas
Condensate Tanks
Crude Oil Tanks
Dehydrators
Drilling Rigs
Fugitive Leaks
Gas-actuated Pumps
Heaters
Hydraulic Fracturing
Pumps
Lateral/Gathering
Compressor Engines
Liquids Unloading
Loading
Mud Degassing
Pneumatic Devices
Produced Water
Tanks
Well Completions
Wellhead Compressor
Engines
AL
D,S
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,S
R
R,S
R
R
R
R
R
R
R
R
R
R
AK
D
B,D,
D,E,
D,E,
D,E,
D
B,D,
D,E
D
D
D,E
D,E
D,E
B,D,
D
B,D,
D,E
D
E
S
S
S
E
E
E
AZ
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
AR
R
E,R
E,R
E,R
E,R
R
R
E,R
R
R
R
E,R
R
E,R
R
E,R
R
R
CA
D,S
D,E
D,E
D,E
D,S
D
D,E,
S
D,S
D
D,S
D,E,
S
D,E
D,E
D,E,
S
D
D,E
D,E,
S
D,S
CO
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
R
R
R
R
R
R
R
R
R
R
R
R
FL
D,S
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,S
R
R,S
R
R
R
R
R
R
R
R
R
R
ID
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
IL
D,R,
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R,
S
R
R
R
R
R,S
R
R
R
R
R
R
R
S
IN
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
R
R
R
R
R
R
R
R
R
R
R
R
KS
R
E,R
E,R
E,R
E,R
R
R,S
E,R
R
R
R,S
E,R
R
E,R,
S
R
E,R,
S
R
R
KY
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
D,R
D,E,
D,E,
D,E,
D,E,
D,R
D,E,
D,E,
D,R
R
R
R
R
R
R
R
R
R
R
R
R
26
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-6. Tool Data Sources by State and Source Type
State
Artificial Lifts
Associated Gas
Condensate Tanks
Crude Oil Tanks
Dehydrators
Drilling Rigs
Fugitive Leaks
Gas-actuated Pumps
Heaters
Hydraulic Fracturing
Pumps
Lateral/Gathering
Compressor Engines
Liquids Unloading
Loading
Mud Degassing
Pneumatic Devices
Produced Water
Tanks
Well Completions
Wellhead Compressor
Engines
LA
R,S
E,R
E,R,
S
E,R
E,R
R
R
E,R
R
R
R
E,R
R
E,R
R
E,R
R
R,S
MD
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
MI
D
D,E
D,E
D,E
D,E,
S
D
D,E
D,E,
S
D
D,S
D,E
D,E
D,E
D,E
D
D,E
D,E,
S
D
MS
D,R,
S
D,E,
R
D,E,
R,S
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R,
S
MO
R
E,R
E,R
E,R
E,R
R
R
E,R
R
R
R
E,R
R
E,R
R
E,R
R
R
MT
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,E,
R
D,E
D,E,
R
D,R
D,E,
R
D,E,
R
D,E,
R
NE
R
E,R
E,R
E,R
E,R
R
E,R
E,R
R
R
E,R
E,R
R
E,R
R
E,R
R
R
NV
D,S
D,E
D,E
D,E
D,E,
S
D
D,E,
S
D,E,
S
D
D,S
D,E,
S
D,E
D,E
D,E,
S
D
D,E
D,E,
S
D,S
NM
D,E,
R,S
D,E,
R
D,E,
R,S
D,E,
R,S
D,E,
R,S
D,E,
R,S
D,E,
R,S
D,E,
R
D,E,
R,S
D,R
D,E,
R,S
D,E,
R
D,E,
R,S
D,E,
R,S
D,R
D,E,
R,S
D,E,
R,S
D,E,
R,S
NY
D,S
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D,S
D,E,
S
D,E
D,E
D,E,
S
D
D,E
D,E,
S
D,S
ND
R
E,R,
S
E,R
E,R
E,R
E,R
E,R
E,R
E,R
R
R
E,R
D,E
E,R
R
R
R
R
OH
D,S
D,E
D,E
D,E
D,E,
S
D
D,E,
S
D,E
D
D,S
D,E,
S
D,E
D,E
D,E,
S
D
D,E
D,E,
S
D,S
27
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Nonooint Oil and Gas Emissions Estimation Tool
Table 2-6. Tool Data Sources by State and Source Type
State
Artificial Lifts
Associated Gas
Condensate Tanks
Crude Oil Tanks
Dehydrators
Drilling Rigs
Fugitive Leaks
Gas-actuated Pumps
Heaters
Hydraulic Fracturing
Pumps
Lateral/Gathering
Compressor Engines
Liquids Unloading
Loading
Mud Degassing
Pneumatic Devices
Produced Water
Tanks
Well Completions
Wellhead Compressor
Engines
OK
R,S
E,R
E,R,
S
E,R
E,R
R
R
E,R
R
R
R
E,R
R
E,R
R
E,R
R
R,S
OR
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
PA
D
D,E
D,E
D,E
D,E
D
D,E,
S
D,E
D
D
D,E
D,E
D,E
D,E,
S
D
D,E
D,E
D
SD
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R
TN
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R
TX
S
E,R
E,R,
S
E,R,
S
E,R,
S
R
E,R
E,R
R,S
R,S
E,R
E,R
R,S
E,R,
S
R
E,R,
S
R,S
S
UT
D,R
D,E
D,E,
R
D,E,
R,S
D,E,
R,S
D,R,
S
D,E,
R,S
D,E,
R
D
D,R
D,E,
R,S
D,E,
R
D,E
D,E,
R
D
D,E,
R,S
D,E,
R,S
D,R
VA
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
D
D,E
D,E
D,E
D,E
D
D,E
D,E
D
WV
D
D,E,
S
D,E
D,E
D,E
D
D,E,
S
D,E
D
D
D,E,
S
D,E,
S
D,E
D,E
D,E
D,E,
S
D,E
D
WY
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R
D,E,
R
D,R
D,R
D,E,
R
D,E,
R
D,E,
R
D,E,
R
D,R
D,E,
R,S
D,E,
R
D,R
a D = Default data from CenSARA Study, E = EPA, R = RPO (CenSARA or WRAP), S = state, B = BOEM
28
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Nonooint Oil and Gas Emissions Estimation Tool
2.3 Updates Since 2017
The final version of the 2020 Nonpoint Oil and Gas Emission Estimation Tool was
completed in July of 2022. The primary updates made since finalization of the 2020 version of
the tool include:
• Updated Activity Data. Oil and gas exploration and production activity data was
updated to reflect 2020 as described in Section 2.1 using data from the Enverus
database, RIGDATA, and various state oil and gas commission websites.
• Basin Factor Updates. Basin factors were update using several data sources:
o GHGRP data was analyzed to develop updated basin factors for several source
categories including storage tanks, dehydrators, fugitive equipment leaks,
heaters, pneumatic devices, associated gas venting/flaring, and wellhead
compressor engines.
o Western Regional Air Partnership (WRAP) data was used to develop updated
basin factors for several source categories for Montana, New Mexico, North
Dakota, and South Dakota.
o Data provided by the California Air Resources Board (CARB) was used to
develop updated basin factors for several source categories.
o US Energy Information Administration (EIA) data was used to update the
volumes of gas vented/flared in the associated gas venting and flaring category.
• Emission Factor Updates. Emission factors were updated for several source
categories:
o Drilling and hydraulic fracturing engine emission factors were updated using the
MOVES model for 2020.
o The flaring CO emission factor was updated based on updates to AP-42.
o A SO2 emission factor from AP-42 was added for heater treaters.
• Temperature Updates. Updated annual average temperature data by county using
EPA's 2020 Weather Research Factorization (WRF) model data.
• Methodoloev Updates. The methodology used to estimate VOC emissions from
associated gas venting and flaring was revised to include only process-based
emissions (accounting for VOC sent to the flare). The tool no longer uses the AP-42
flaring VOC emission factor in the calculation.
29
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Nonooint Oil and Gas Emissions Estimation Tool
3.0 Source Category Emission Estimation Methodologies
Emissions for individual oil and gas nonpoint source categories were developed using a
bottom-up approach that begins with developing mass emission rates for each pollutant based on
an activity surrogate (e.g. tons per well, tons per barrel of oil, tons per feet drilled). These by-
surrogate emission rates were then scaled to county-level emissions by multiplying the emission
rates by the scaling surrogate or activity from a particular county (e.g. gas well counts, horizontal
feet drilled, crude oil production, etc.).
Emissions calculations are performed within the Microsoft Access database. Data field
names and definitions for calculation inputs are shown in Appendix D (Data Element Dictionary)
in the same format and nomenclature as they appear in the database tool. Appendix D also
provides the national "default" value for each variable (and reference) used in the calculations
when state-supplied data is unavailable. Refer to the instructions included in Appendices A and
B for details on how the database is organized.
The following sections describe emissions calculations for each source category; it is
noted that some of these methodologies may apply to multiple SCCs and thus, are calculated
separately in the tool. Example calculations are provided for each source category. The examples
are provided for illustrative purposes only and may not match the totals calculated by the tool
due to rounding or updates to any of the activity or emission factor inputs.
Table 3.1 below identifies the source categories associated with each type of well (oil or
gas), and the primary activity parameter used as the basis to scale emissions up to the county
level.
Table 3-1. Emission Sources by Well Type
Category
Activity Basis
Oil
CBM
Gas
Artificial Lifts
Oil Well Count
Yes
No
No
Associated Gas
Oil Production
Yes
No
No
Coalbed Methane
l)ewaterin« Pump Engines
CBM Well Counts
No
Yes
No
Condensate Tanks
Condensate Production
No
Yes
Yes
Crude Oil Tanks
Oil Production
Yes
No
No
Dehydrators
Gas, Associated Gas, and CBM
Production; Gas and CBM Well Counts
No
Yes
Yes
Drill Rigs
Estimated Feet Drilled
Yes
Yes
Yes
Fugitive Leaks
Oil, Gas, and CBM Well Count
Yes
Yes
Yes
Gas-Actuated Pumps
Oil, Gas, and CBM Well Count
Yes
Yes
Yes
Heaters
Oil, Gas, and CBM Well Count
Yes
Yes
Yes
Hydraulic Fracturing Pumps
Horizontal Spud Count
Yes
Yes
Yes
Lateral/Gathering
Compressor Engines
Gas and CBM Well Count
No
Yes
Yes
Liquids Unloading
Gas and CBM Well Count
No
Yes
Yes
Loading
Oil and Condensate Production
Yes
Yes
Yes
30
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Nonpoint Oil and Gas Emissions Estimation Tool
Table 3-1. Emission Sources by Well Type
Category
Activity Basis
Oil
CBM
Gas
Mud Degassing
Spud Counts
Yes
Yes
Yes
Pneumatic Devices
Oil, Gas, and CBM Well Count
Yes
Yes
Yes
Produced Water Tanks
Produced Water Production
Yes
Yes
Yes
Well Completions
Completion Count
Yes
Yes
Yes
Wellhead Compressors
Gas and CBM Well Count
No
Yes
Yes
3.1 Artificial Lifts
Artificial lifts refer specifically to engines located at oil wells that provide lift to the
liquids in a well up to the wellhead. Generally, artificial lift engines are small natural gas-fired
engines. In the past decade, there has been an increased use of electrified artificial lift engines
powered by the grid; for this kind, emissions are assumed to be zero. Figure 3-1 shows a pump
jack with an artificial lift engine (inset).1
Figure 3-1. Artificial Lift Engine
1 Personal Communication between Ms. Julie McDill, MAR AM A. Ms. Megan Murphy, WVDEP, and Mr. Mike
Pring, Eastern Research Group, Inc. January 24, 2014.
31
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Nonooint Oil and Gas Emissions Estimation Tool
The basic methodology for estimating emissions from a single non-electrified artificial
lift engine is shown below:
Rnafnnn F - ^ X HPX LF Xtannual
Equation 1) Eengine 907185
where:
Eengine are emissions from an artificial lift engine [ton/year/engine]
EFi is the emissions factor of pollutant i [g/hp-hr]
HP is the horsepower of the engine [hp]
LF is the load factor of the engine
tannmi is the annual number of hours the engine is used [hr/yr]
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
Artificial lift engine emissions have been scaled up to the county level on the basis of oil
well counts. The methodology for scaling up artificial lift engine emissions is shown below:
Equation 2) Eengine T0TAL = n x Eengine x /pumpjack x (1 — FE) x W0IL T0TAL
where:
Eengine,total is the total emissions from artificial lift engines in a county [ton/yr]
n is the total number of artificial lift engines per well [engine/well]
Eengine is the total emissions from an artificial lift engine (as shown in Equation 1)
[ton/yr/engine]
fpumpjack is the fraction of oil wells with artificial lift engines
FE is the fraction of artificial lift engines that are electric
Woil, total is the total number of oil wells in a county [wells]
Example Calculation for Artificial Lift:
Using the equations provided above, NOx emissions from artificial lift engines in Calhoun
County, Arkansas were calculated as follows:
F _ EF x HP x LF x tannual
engine 907,185
where:
E engine = emissions from an artificial lift engine [ton/yr/engine]
EF = 8.24 [g/hp-hr]
HP = 77.5 [hp]
LF = 0.85 (load factor for the engine)
tannmi = 8,000 [hr/yr]
907,185 [g/ton]
32
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Nonooint Oil and Gas Emissions Estimation Tool
Therefore:
_ 8.24x77.5x0.85x8,000
engine- 907,185
E engine — 4.79 [ton/yr/engine]
Total NOx emissions from all artificial lift engines in Calhoun County can be evaluated as
follows:
EengineJOTAL ~ n X ^engine X fpumpjack X (1 ^OIL ,TOTAL
where:
Eengine,total is the total emissions from artificial lift engines in a county [ton/yr]
n = 1 [engine/well]
Eengine = 4.79 [ton/yr/engine]
fpumpjack = 0.95 (fraction of oil wells with artificial lift engines)
FE = 0.965 (fraction of artificial lift engines that are electrified)
WOIL,TOTAL =18 [wells]
Therefore:
EenginejoTAL = lx4.79x0.95x(l-0.965)xl8
E engine, TOTAL — 2.86 [ton/yr]
3.2 Associated Gas Venting and Flaring
This section refers to the practice of venting associated gas from oil wells which
sometimes takes place when the well is not connected to a gas sales pipeline or when the amount
of gas produced by the well is so limited that is not profitable for capture. In some areas of the
country, this gas may be flared.
The calculation methodology for estimating county-wide emissions from associated gas
venting is shown below in Equation 3:
Equation 3) E
assoc,gas,i
Px(QaSSoc,gaS,i)>
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Nonooint Oil and Gas Emissions Estimation Tool
Qassoc,gas,i is the venting rate of associated gas per unit of oil production [MCF/bbl]
Pou is the annual county-wide oil production [bbl/yr]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
fi is the mass fraction of pollutant i in the associated gas
Fflare is the fraction of associated gas controlled with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
3.5xl0~5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Flaring emissions from associated gas controls
Emissions from flaring controls applied to associated gas are included in this source
category. The methodology for estimating emissions from flaring of associated gas is described
below:
Eflare,assoc,gas is the county-wide flaring emissions of pollutant i from vented associated gas
[ton/yr]
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
Qassoc,gas is the volume of associated gas vented per barrel of oil produced [MCF/bbl]
F is the fraction of associated gas vent controlled with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
HV is the local heating value of the gas [BTU/SCF]
Pou is the annual county-wide oil production [bbl/yr]
2,000 is the unit conversion factor lbs/ton
The methodology for estimating SO2 emissions from flaring of associated head gas is
Equation 4) E
flare,assoc,gas
' EFt x Qassoc gas x F x (Ccapmrei )x (Cefficiency )x HV ^ ^ \ / Qo
where:
shown below:
Equation 5)
E
assocgas, flare ,S02
where:
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Nonooint Oil and Gas Emissions Estimation Tool
Eassocgas,.fiare,so2 's the county-wide SO2 emissions from flaring of associated gas [ton/yr]
P is atmospheric pressure [1 atm]
Qassoc,gas is vented volume of associated gas per barrel of oil [MCF/bbl]
Pou is the annual county-wide oil production [bbl/yr]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the associated gas [g/mol]
T is the atmospheric temperature [298 K]
fHS is the mass fraction of H2S in the associated gas
Ffiare is the fraction of associated gas vents controlled by flare
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
3.5xl0~5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
County-wide emissions from associated gas venting and associated gas flaring are
estimated directly from Equations 3-5. The sum of venting and flaring emissions by pollutant
yield the total county-wide emissions from associated head gas that is not captured for sale.
Example Calculation for Associated Gas Venting:
Using the equations provided above, VOC emissions for associated gas venting in
Columbia County, Arkansas were calculated as follows:
assoc.gas
Px(QaSSoc,gas)xPou
W
MW,
xTx3.5xlO
-5
gas
X-
/
907,185
¦x
(l-
F xC xC
flare captured efficiency J
where:
Eassoc,gas is the county-wide emissions of VOC from associated gas venting [ton/bbl]
P = 1 [atm]
Qassoc,gas — 0.00365 [MCF/bbl]
Pou = 1,231,945 [bbl/yr]
R = 0.082 [L-atm/mol-K]
MWgas = 24.25 [g/mol]
T= 298 [K]
/= 0.262 (the mass fraction of VOC in the associated gas)
Ffiare = 0 (the fraction of associated gas vent controlled with flares)
Ccaptured =1.0 (capture efficiency expressed as fraction)
Ceffwiency = 0.98 (control efficiency expressed as fraction)
3.5xl0"5 [MCF/L]
907,185 [g/ton]
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Nonooint Oil and Gas Emissions Estimation Tool
Therefore:
Px(0.00365)x 1,231,945 1 0.262 . n 1 n n
= (0*82/ Jx298x3.5x.0-' X^X(l-°Xl0>
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-2. Coalbed Methane Dewatering Pump
The basic methodology for estimating emissions from a single non-electrified CBM
dewatering pump engine is shown below:
Pn .. n F _ EFt xHPxLFxtanmial
Equation 1) Eengine 907185
where:
Eengine are emissions from a CBM dewatering pump engine [ton/year/engine]
EFj is the emissions factor of pollutant I [g/bp-hr]
HP is the horsepower of the engine [hp]
LF is the load factor of the engine
tannuai is the annual number of hours the engine is used [hr/yr]
907,185 is the unit conversion factor g/ton
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Nonooint Oil and Gas Emissions Estimation Tool
Extrapolation to countv-level emissions
CBM dewatering pump engine emissions have been scaled up to the county level on the
basis of CBM well counts. The methodology for scaling up CBM dewatering pump engine
emissions is shown below:
Equation 2) e . TnTiT = nxE . xf x(l-FE)xW
^ / engine,TOTAL engine J pump V / i
engine,TOTAL engine J pump - ' CBM ,TOTAL
where:
Eengine,total is the total emissions from CBM dewatering pump engines in a county [ton/yr]
n is the total number of CBM dewatering pump engines per well, generally equal to 1 (n=l)
[engine/well]
Eengine is the total emissions from a CBM dewatering pump engine (as shown in Equation 1)
[ton/yr/engine]
fpump is the fraction of CBM wells with dewatering pump engines
FE is the fraction of CBM dewatering pump engines that are electric
Wcbm,total is the total number of CBM wells in a county [wells]
Example Calculation for CBM dewatering pump engines:
Using the equations provided above, NOx emissions from CBM dewatering pump engines
in Calhoun County, Arkansas may be calculated as follows:
F _ EF x HP x LF x tannual
engine 907,185
where:
E engine = emissions from a CBM dewatering pump engine [ton/yr/engine]
EF = 8.24 [g/hp-hr]
HP = 77.5 [hp]
LF = 0.85 (load factor for the engine)
tannmi = 8,000 [hr/yr]
907,185 [g/ton]
Therefore:
_ 8.24x77.5x0.85x8,000
engine- 907,185
E engine — 4.79 [ton/yr/engine]
Total NOx emissions from all CBM dewatering pump engines in Calhoun County can be
evaluated as follows:
Eengine,TOTAL U X Eengine X f pump X ^' ^0 X ^CBM ,TOTAL
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Nonpoint Oil and Gas Emissions Estimation Tool
where:
Eengine,total i§ the total emissions from CBM dewatering pump engines in a county [ton/yr]
n = 1 [engine/well]
Eengine — 4,79 [ton/yr/engine]
fpump = 0.95 (fraction of CBM wells with CBM dewatering pump engines)
FE = 0.965 (fraction of CBM dewatering pump engines that are electrified)
WCBM,TOTAL =18 [wells]
Therefore:
EenpnejoTAL = 1 x4.79x0.95x (1 - 0.965) xl 8
E engine, TOTAL — 2.86 [ton/yr]
[Note - the example above is for illustrative purposes only, there are currently no default factors
available to estimate emissions from CBM dewatering pump engines.]
3.4 Condensate Tanks
Condensate storage tanks are considered a significant source of VOC emissions. Liquid
storage tank losses are generated by flashing and by working and breathing processes, although
generally the emissions are dominated by flashing losses. This analysis uses a combined-losses
emissions factor and assumes that the gas compositions from both processes are identical. Figure
3-3 shows liquid storage tanks in the Barnett Shale,
Figure 3-3. Liquid Storage Tanks
The methodology for estimating condensate tank combined losses is shown below:
Equation 6)
j-, EPcondensate,tanks,VOC w |\, n n w n s, n 1
^condensate,tanks,VOC 2 000 VRU ' flare captured efficiencyJ
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Econdensate,tanks, VOC IS the VOC emissions per liquid unit throughput from condensate tanks
[tons/bbl]
EFcondensate,tanks,voc is the VOC emissions factor for combined losses from condensate tanks
[lb-VOC/bbl]
Fvru is the fraction of condensate production controlled by vapor recovery units
Ffiare is the fraction of condensate production controlled by flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
2,000 is the unit conversion factor lb/ton
The methodology for estimating condensate tank combined losses from other pollutants i
in the gas is shown below:
^ ^ ^ _ t? w weight fraction^
equation I) ^condensate,tanks,i ^condensate,tanks,VOC * weigfit fractionyoc
where:
Econdensate,tanks,i is the emissions of pollutant i per liquid unit throughput from condensate tanks
[tons/bbl]
Econdensate,tanks, VOC is the VOC emissions per liquid unit throughput from condensate tanks
[tons-VOC/bbl]
(weight fraction/weight fractionvoc) is the mass-based weight fraction of pollutant i divided
by the weight fraction of VOC in the gas
Flaring emissions from condensate tank controls
This source category includes any flaring emissions associated with controls applied to
condensate tanks. The methodology for estimating emissions from flaring of condensate tank
flash gas is described below:
Equation 8)
P x O xF x (c )x (c )x ^'X "1 A 000
l - /N ^condensate,tanks flare V captured J V efficiency ) | QQQ I /
F = P X
flare, tank, i condensate
\
where:
Efiare,tank,i is the county-^wide flaring emissions of pollutant i from condensate tank controls
[ton/yr]
Pcondensate is the annual county-wide condensate production [bbl/yr]
Qcondensate,tank is the uncontrolled volume of tank losses vented per unit of condensate
throughput [MCF/bbl]
Ffiare is the fraction of condensate tanks with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
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Nonooint Oil and Gas Emissions Estimation Tool
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
HV is the local heating value of the gas [BTU/SCF]
2,000 is the unit conversion factor lb/ton
1,000 is the unit conversion factor MCF/MMCF
The methodology for estimating SO2 emissions from flaring of oil and condensate flash
gas is shown below:
Equation 9)
f
Pxio xF x(c )x(c )xP )
condensate,tank flare V captured.) V efficiency) condensate)
T7
flare, tank, S02
^capturedJ V efficiency)
xTx 3.5xl0"5
r 2/
xJh2s x/907,185
where:
Eflare,.tank,so2 is the county-wide SO2 flaring emissions from condensate tanks controls [ton/yr]
P is atmospheric pressure [1 atm]
Qcondensaiejank is the uncontrolled volume of tank losses vented per unit of condensate
throughput [MCF/bbl]
Ffiare is the fraction of condensate tanks with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
Pcondensate is the annual county-wide condensate production [bbl/yr]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the flash gas [g/mol]
T is the atmospheric temperature [298 K]
f/l s is the mass fraction of H2S in the flash gas
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
To estimate county-wide total controlled and uncontrolled condensate tank emissions,
which includes venting and flaring, for each pollutant i, Equation 10 below is used:
EqUatlOn 10) Fi con(jensa^e ^anks,TOTAL ^condensate ,tanks ,i ^ ^condensate ^ ^tank ^ fiare ,tanks ,i
where:
Econdensate,tanks,TOTAL is the county-wide total emissions for pollutant i from condensate tanks
[tons/yr]
Econdensate,tanks,i is the combined losses of pollutant i per liquid unit throughput from
condensate tanks [tons/bbl]
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Nonooint Oil and Gas Emissions Estimation Tool
Pcondensate is the annual county-wide condensate production [bbl/yr]
Ftank is the fraction of condensate directed to tanks [%]
Efiare,tanks,i is the county-wide flaring emissions of pollutant i from condensate tank controls
[ton/yr]
Example Calculation for Condensate Tanks:
Using the equations provided above, VOCand SO2 emissions from condensate tank
venting and flaring in Columbia County, Arkansas were calculated as follows:
Venting Emissions:
EFcondensate,tanks,VOC w ^ w n w n 1
^condensate,tanks,VOC 2~000 L VRU Efiare * ^captured * ^efficiencyJ
where:
Econdensate,tanks, VOC is the VOC emissions per liquid unit throughput from condensate tanks
[tons/bbl]
EFcondensate, tanks, VOC = 3.60 [lb-VOC/bbl]
Fvru = 0 (fraction of condensate tanks controlled by a VRU)
Fflare = 0.315 (fraction of condensate tanks with flares)
Ccaptured =1.0 (capture efficiency expressed as fraction)
Cejflciency = 0.98 (control efficiency expressed as fraction)
2,000 is the unit conversion factor lb/ton
Therefore:
3.60 r
Econdensate,tanks,VOC ~ 2~000 ^ _ ^ _ 0.315 X 1 X 0.98]
Econdensate,tanks,VOC = 0.001244 [tOns/bbl]
Flaring Emissions:
VOC emissions from flaring of condensate tank vapors may then be calculated as
follows:
p = p y o x F x (c )x (c )x ^ xFlV j
flare,tank condensate condensate,tanks flare V captured J V efficiency J j QQQ jJ '
where:
Eflare.tank is the county-wide flaring emissions of VOC from condensate tank controls [ton/yr]
Pcondensate = 275,892 [bbl/yr]
Qcondensate,tank = 0.037 [MCF/bbl]
Fflare = 0.315 (fraction of condensate tanks with flares)
Ccaptured =1.0 (capture efficiency expressed as fraction)
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Nonooint Oil and Gas Emissions Estimation Tool
Ceffidency = 0.98 (control efficiency expressed as fraction)
EF = 0.66 [lb/MMBtu]
HV = 2,597 [BTU/SCF]
2,000 [lb/ton]
1,000 (conversion factor)
Therefore:
( , ^ , 0.66 x 2,597\ .
Efiare.tank = 275,892 x (0.037 x 0.315 x (1.0) x (0.98) x — J/2,000
Eflare,tank = 2.71 [tOn/yr]
Total VOC emissions from all condensate tanks in Columbia County can be evaluated as
follows:
Z7 Z7 y D y F I Z7
condensate,tanks,TOTAL condensate, tanks ,VOC condensate tank flare,tanks
where:
Econdensate,tanks, TOTAL is the county-wide total emissions of VOC from condensate tanks [ton/yr]
Econdensate,tanks,VOC — 0.0012 [tons/bbl]
Pcondensate = 275,892 [bbl/yr]
Ftank = 1 (fraction directed to tanks)
Eflare, tanks = 2.71 [tOn/yr]
Therefore:
Econdensate,tanks,TOTAL = 0.001244 X 275,892 X 1 + 2.71
Econdensate,tanks,TOTAL — 345.9 [ton/yr]
3.5 Crude Oil Tanks
Crude oil tanks are used to store liquid product at a well pad or central tank battery prior
to transfer downstream to a refinery. Figure 3-4 shows a central tank battery (circled) in the
Permian Basin adjacent to numerous well pads with pump jacks.2
Crude oil tank emissions are generated by working and breathing processes. The
methodology for estimating oil tank venting emissions is shown in Equations 11-12. This
methodology is based on a combined working and breathing losses VOC emissions factor on a
per unit throughput basis (mass emissions per barrel of oil).
2 Google Earth, 2014. "Permian Basin Tank Battery." 32°28' 16.26" N and 102°49'26.40" W. November 14, 2011.
March 25, 2014.
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-4. Permian Basin Tank Battery
Equation 11)
p P v tanks,VOC „ v Tl P p y C Y C
''oil,tanks,VOC 1 oil ^ ^ QQQ tank L VRU ' flare " °captured " °efficiency
where:
Eon,tanks,voc Is the county-wide annual VOC venting losses from oil tanks [tons-VOC/yr]
Pon is the annual county-wide oil production [bbl/yr]
EFon,tanks,voc is the VOC emissions factor for total losses from oil tanks [Ib-VOC/bbl]
Ftank is the fraction of oil directed to tanks [%]
Fvru is the fraction of oil production controlled by vapor recovery units
F'fiare is the fraction of oil production controlled by flares
Ccaptured is the capture efficiency of the flare
Cefficiency is the control efficiency of the flare
2,000 is the unit conversion factor lb/ton
The methodology for estimating crude oil tank losses from other pollutants i in the emissions is
shown below:
weight fraction;
Equation 12) EmmnkSii - Eoil)tanksyoc x weigM fractionyoc
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Eon,tanks,i is the county-wide annual losses of pollutant i from oil tanks [tons/yr]
Eon,tanks,voc is the county-wide annual VOC venting losses from oil tanks [tons-VOC/yr]
(weight fraction/weight fractionVoc) is the mass-based weight fraction of pollutant i divided
by the weight fraction of VOC in the gas
Flaring emissions from oil tank controls
This source category includes any flaring emissions associated with controls applied to
crude oil tanks. The methodology for estimating emissions from flaring of oil tank gas losses is
described below:
f
Equation 13) E~e k • — Poil x Qoil k flash xFflare x(c captured )x{c effici )x j /2,000
v
1,000
where:
Efiare,tank,i is the county-wide emissions from crude oil tank flaring [ton/yr]
Poii is the annual county-wide oil production [bbl/yr]
Qoii,tanks,flash is the volume of gas flared per unit of oil throughput [MCF/bbl]
Fflare is the fraction of oil tanks with flares
Ccaptured is the capture efficiency of the flare
Cejfldency is the control efficiency of the flare
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
HV is the local heating value of the gas [BTU/SCF]
1,000 is the unit conversion factor MCF/MMCF
2,000 is the unit conversion factor lb/ton
The methodology for estimating SO2 emissions from flaring of oil tank losses is shown
below:
Equation 14)
J flare,tank, S02
^ ^ ^Qoil.tanks, flash ^ ^flare ^ 'captured ^'efficiency ^oil )
MW,
xTx3.5xl0
-5
¦f 2/
xJh2s X/907 i85
8&s
where:
Eflare,.tank,so2 is the county-wide SO2 emissions from flaring controls in oil tanks [ton/yr]
P is atmospheric pressure [1 atm]
Qoii,tank,flash is the volume of gas vented per unit of oil throughput [MCF/bbl]
Fflare is the fraction of crude oil tanks with flares
Ccaptured is the capture efficiency of the flare
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Nonooint Oil and Gas Emissions Estimation Tool
Ceffidency is the control efficiency of the flare
Pou is the annual county-wide oil production [bbl/yr]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
f/l s is the mass fraction of H2S in the gas
3.5xl0~5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
Equations 11-14 provide county-wide estimates directly using by-county oil production
as a surrogate. The total county-wide emissions from crude oil tanks are the sum of flaring and
crude tank working and breathing emissions (by-pollutant).
Example Calculation for Crude Oil Tanks:
Using the equations provided above, VOC emissions for crude oil tanks in Columbia
County, Arkansas were calculated as follows:
p p v 0tanksyoc y r vTi p p v r v r I
'-'oil,tanks,VOC ' oil * ^ QQQ rtank * L rVRU rflare * l.captured. * ^efficiencyJ
where:
Eon,tanks,voc is the county-wide annual VOC venting losses from oil tanks [tons-VOC/yr]
Poil = 1,231,945 [bbl/yr]
EFoil, tanks, VOC = 0.287 [lb-VOC/bbl]
Ftank — 1 (fraction directed to tanks)
Fvru = 0 (fraction controlled by VRU)
Fflare = 0 (fraction flared)
Ccaptured =1.0 (capture efficiency expressed as fraction)
Ceffidency = 0.98 (control efficiency expressed as fraction)
2,000 [lb/ton]
Therefore:
Eoil,tanks,voc = 1,231,945 x Hjjl x [1 - 0 - 0 x 1.0 x 0.98)]
E oil,tanks,voc = 177 [tons-VOC/yr]
Flaring emissions are calculated similarly to the example given above for condensate
tanks. In this case, since the fraction of crude oil tank vapors sent to flares is zero, there are no
flare emissions.
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Nonpoint Oil and Gas Emissions Estimation Tool
3.6 Dehydrators
This source category refers to wellhead dehydrator units. Dehydrator units are used to
remove excess water from produced natural gas prior to delivery to the pipeline or to a gas
processing plant. Two main sources of emissions are found in a dehydrator device: hydrocarbon
emissions (including VOC and HAPs) are generated in the dehydrator still vent, and combustion
emissions are generated in the dehydrator reboiler. In addition, if dehydrator still vents are
controlled by flare, combustion emissions from flaring controls contribute to the total dehydrator
emissions. Figure 3-5 shows a glycol dehydrator in the Barnett shale.
Figure 3-5. Dehydrator
The basic methodology for estimating county-wide emissions from dehydrator still vents
is shown in Equation 15:
EF r 1
Equation 15) Estmvenlyoc = Pg$ax | qqqX2 ()00 ~~' ;'n /X^;
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Estuivent,voc is the county-wide VOC emissions from dehydrator still vents [ton/yr]
Pgas is the annual county-wide gas production [MCF/yr]
EFstuivent is the VOC emission factor for dehydrator still vent per unit of gas throughput [lb-
VOC/MMCF]
Fflare is the fraction of dehydrator vents with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
2,000 is the unit conversion factor lb/ton
1,000 is the unit conversion factor MCF/MMCF
The methodology for estimating dehydrator still vent emissions from other pollutants i is
shown below:
1 t? t? w weight fraction^
bquation 16) bstillventii - bstillventyoc x weight fractionvQC
where:
Estuivent.i is the county-wide emissions of pollutant i from dehydrator still vents [ton/yr]
Estuivent,voc is the county-wide VOC emissions from dehydrator still vents [ton/yr]
(weight fraction/weight fractionVoc) is the mass-based weight fraction of pollutant i divided
by the weight fraction of VOC in the vented gas
The basic methodology for estimating emissions for the dehydrator reboiler is equivalent
to that of a standard field heater:
Equation 17) Ereboil„, t = N x X Waas
where:
Ereboiier.i is the county-wide emissions from pollutant i from dehydrator reboilers [ton/yr]
N is the number of dehydrators per well [1/well]
EFi is the emission factor for pollutant i for natural gas-fired small boilers [lb/MMCF]
Qreboiier is the heater size [MMBtu/hr]
tannmi is the annual hours of operation [hr]
he is a heater cycling fraction of operating hours that the heater is firing
HV is the local natural gas heating value [Btui0Cai/SCF]
Wgas is the county-wide number of active gas wells in a particular year [well/yr]
2,000 is the unit conversion factor lb/ton
Flaring emissions from dehydrator venting controls
The methodology for estimating county-wide emissions from flaring of dehydrator still
vent gas is described below:
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Nonooint Oil and Gas Emissions Estimation Tool
Equation 18)
flare, dehy,i
^gas ^ Qdehydrator,vent ^1 flare /N captured //N efficiency
(c W(c )
V captured / V efficiency J
x
EFtxHV\
106 /
'2,000
where:
Efiare.dehy.i is the county-wide emissions of pollutant i from dehydrator vent gas flaring [ton/yr]
Pgas is the annual county-wide gas production [MCF/yr]
Qdehydrator, vent is the volume of gas flared per unit of gas throughput in dehydrator [MCF
vented/MMCF natural gas]
Fflare is the fraction of dehydrators with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
HV is the local heating value of the gas [BTU/SCF]
2,000 is the unit conversion factor lb/ton
106 is the unit conversion factor SCF/MMCF
The methodology for estimating SO2 emissions from flaring of dehydrator vent gas is
shown below:
Equation 19)
f
F = Px
flare, dehydrator, S02
PmsxQ,
gas ^ dehydrator,vent fla
^ ^flare ^ 'captured efficiency )
MW,
xTx3.5xl0
-5
8&s
xJ'h.s X J
907,185
where:
Eflare,dehydrator,so2 is the county-wide SO2 flaring emissions from flaring of dehydrator vent gas
[ton/yr]
P is atmospheric pressure [1 atm]
Pgas is the annual county-wide gas production [MCF/yr]
Qdehydrator, vent is the volume of gas flared per unit of gas throughput [MCF vented/MMCF
natural gas]
Ffiare is the fraction of dehydrators with flares
Ccaptured is the capture efficiency of the flare
Ceffwiency is the control efficiency of the flare
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the dehydrator venting gas [g/mol]
T is the atmospheric temperature [298 K]
f/l s is the mass fraction of H2S in the dehydrator venting gas
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
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Nonooint Oil and Gas Emissions Estimation Tool
Extrapolation to countv-level emissions
Equations 15-19 provide direct county-level estimates of pollutant emissions from
dehydrator still vents, reboilers, and flaring controls. Emissions of the same pollutant each of
these three sub-categories should be added together to arrive at total county-level dehydrator
emissions (still vent + reboiler + flaring).
Example Calculation for Dehvdrators:
Using the equations provided above, VOC emissions from the still vents and reboilers of
dehydrators in Cleburne County, Arkansas were calculated as follows:
Still Vent emissions:
FF r l
p =P X stillvent y 1 Z7
stillveniVOC gas ^ QOOX 2 000 flare captured efficiencyJ
where:
Estuivent,voc is the county-wide VOC emissions from dehydrator still vents [ton/yr]
Pgas = 139,458,888 [MCF/yr]
EFsaiivent = 0.528 [lb-VOC/MMCF]
Ffiare = 0 (fraction of dehydrator vents with flares)
Ccaptured =1.0 (capture efficiency expressed as fraction)
Ceffidency = 0.98 (control efficiency expressed as fraction)
2,000 [lb/ton]
1,000 [MCF/MMCF]
Therefore:
0 528
E,a.„.voc = 139,458,888 x 1000 x 2000 x[l- 0x1.0x0.98)]
Estillvent,VOC — 36.8 [ton/yr]
Flaring emissions are calculated similarly to the example given above for condensate
tanks. In this case, since the fraction of still vent vapors sent to flares is zero, there are no flare
emissions.
Reboiler emissions:
j-, „ w EFVoc ^ Qreboiler ^ ^annual ^ w T/IA
^reboiler, voc jv X ~HV~X. 2. 000 gas
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Ereboiier, voc is the county-wide emissions of VOC from dehydrator reboilers [ton/yr]
N = 1 [per well]
EFvoc = 5.5 [lb/MMCF]
Qreboiier = 0.9875 [MMBtu/hr]
tannual = 8,672. 5 [hr/yr]
he = 1 (cycling fraction of operating hours that the heater is firing)
HV= 1,035 [Btuiocai/SCF]
Wgas = 490 [wells]
2,000 [lb/ton]
Therefore:
5.5 x 0.9875 x 8,672.5 x 1 ^
Ereboiier,VOC ~ 1 X 1,035 X 2,000 X 490
Ereboiier,VOC — 11.15 [ton/yr]
Total VOC emissions from dehydrators in Cleburne County can be evaluated as follows:
Edehy,VOC — Estillvent,VOC + Ereboiier,VOC
Edehy, voc = 36.8 [ton/yr] + 11.15 [ton/yr]
Edehy,voc = 48.0 [ton/yr]
3.7 Drilling Rigs
Drilling rig emissions come from three primary engine types: Draw works, Mud pumps
and Generators. Each of these three engine types is used for differing periods of time throughout
the drilling process and are likely to have different load factor and sizes. Each of the three
engines is also likely to be of differing model years and hence Tier levels. Some drilling rigs
operate with a set of large generator engines which provides electric power to the other prime
movers of the rig - draw works and mud pumps; these type of rigs are referred to here as diesel-
electric rigs. Figure 3-6 shows a drilling rig in the Barnett shale.
In order to account for variations in engine characteristics and their effect in final
emissions, average emissions for each type of engine k (k=drawworks, mud pumps or
generators) is estimated separately. In addition, operation parameters such as time and load
factor may vary for vertical, directional, and horizontal wellbores; hence emissions are estimated
separately for both drilling methods using equations 20 and 21. Directional wells are included
with vertical wells for purposes of the calculation.
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-6. Drilling Rig
Emissions for a single engine of type k are estimated according to Equation 20:
t-i ,• r\r\\ r-» EF jX-H P jsX.LF fcX. f-eveTLt^^-
Equation 20) Eengine Ki = 907;185
where:
Eengine k,i are emissions of pollutant i from an engine type k [ton/spud]
EFj is the emissions factor of pollutant i [g/hp-hr]
HPk is the horsepower for an engine k in the county [hp]
LFk is the load factor of the engine k
tevem is the number of hours engine k is used [hr/spud]
n is the number of type-k engines in the typical drill rig
907,185 is the mass unit conversion [g/ton]
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Nonooint Oil and Gas Emissions Estimation Tool
The emission factor for pollutant i, EFi, is an emissions factor derived from EPA's
NONROAD2008 model and based on the representative population of drilling engine of various
tier levels in NONROAD. The emissions factor for drill-rig equipment varies by horsepower
range, and there are three possible horsepower bins applicable to the typical range of equipment
sizes for drill rig engines. Hence, three sets of possible engine emissions factors (by HP) are
used.
Emissions from a single drill rig (EdriUrigT0TALi) are estimated in Equation 21 as the
sum of individual emissions from each drill rig engine as calculated with Equation 20 in
[tons/spud]:
Equation 21) EdrillrigTOTAL,i 2 Eengine k,i
Two distinct drill-rig configurations may be found in various basins:
• Diesel-mechanical (D) drill rigs: in which all k engines are diesel-fueled
• Diesel-electric (DE) powered drill rigs: in which only the generator is powered by
diesel and the draw works and mud pumps are electric (and thus do not have direct
emissions associated with them)
Thus equations 20 and 21 will vary by these two configurations, and a set of input values
for each the four combinations of vertical/horizontal wellbores and diesel/diesel-electric rigs
must be applied.
Emissions from drill rigs correlate to the depth of the wellbore, which will vary between
horizontal and vertical wellbores; thus emissions can be estimated on a "per foot drilled' basis
using the equation below.
Equation 22) [Edrilling,i\vertical/horizontal =
EdrillrigTOTAL,iDx(.1~FDE)+EdrillrigTOTAL,iDExFDE
'spud
vertical
horizontal
where
Edrilling,i's the total emissions for a horizontal or vertical spud per unit of feet drilled
[tons/ft]
EdriiirigTotAL,i is the emissions from a single diesel-powered drill rig (from Equation 21)
for a vertical or a horizontal spud [tons/spud]
Fde is the fraction of drill rigs that are diesel-electric
EdruirigTOTAL,iDE is the emissions from a single diesel-electric drill rig (from Equation 21)
for a vertical or a horizontal spud [tons/spud]
Dspud is the depth of a vertical or horizontal spud [ft/spud]
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Nonooint Oil and Gas Emissions Estimation Tool
Extrapolation to countv-level emissions
Emissions per feet drilled are scaled to county-level drilling emissions according to
Equation 23.
Equation 23)
Edrill,county-wide,i \Edrilling,i\vert:^caj ^ Dvertical \Edrilling ^^orizontaj ^ Dhorizontal
where:
Edrui,county-wide,i is the total emissions of pollutant i from county-wide drilling activity [tons/yr]
Edrilling,i is the total emissions from drilling a single well [tons/ft]
Dverticai is the total depth drilled in the county for vertical wells in a particular year [ft/yr]
Dhorizontai is the total depth drilled in the county for horizontal wells in a particular year [ft/yr]
Example Calculation for Drill Rigs:
Drill rigs are classified as mechanical, or diesel electric. Mechanical rigs typically operate
three types of engines during drilling: draw works engines (draw), mud pump engines (mud), and
generator engines (gen). Diesel electric rigs are powered by a battery of diesel-electric generator
engines. Wells are classified as vertical (a vertical wellbore), directional (a wellbore that is
angled or deviates from vertical), and horizontal (after an initial vertical direction, the well is
drilled horizontally). No vertical wells were drilled in Cleburne County, and there are no diesel
electric rigs. Using the equations provided above, NOx emissions from drilling in Cleburne
County, Arkansas were calculated as follows:
Emissions from a draw works engine during horizontal drilling:
EF x HP x LF x tevent x n
Edraw works nnn -rot
where:
Edraw works = are emissions of NOx from a draw works engine [ton/spud]
EF =4.258 [g/hp-hr]
HP = 557.5 [hp]
LF = 0.4 (load factor for the engine)
tevent = 200 [hr/spud]
n = 2 (number of draw work engines in the typical drill rig)
907,185 [g/ton]
Therefore:
4.258x 557.5x 0.4x 200x2
^draw works 907 185
Edraw works = 0.42 [ton /spud]
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Nonooint Oil and Gas Emissions Estimation Tool
Using similar methodology, emissions for mud pump and generator engines during
horizontal drilling were calculated to yield:
Edraw works = 0.42 [ton /spud]
Emudpump = 0.90 [ton /spud]
Egenerator = 1.19 [ton /spud]
Total NOx emissions from all drill rig engines per spud can be evaluated as follows:
EdrillrigTOTAL 2 Eengine
EdrillrigTOTAL =2.51 [ton/spud]
Total NOx emissions on a per foot basis are then calculated using:
[ dr'-ttin9\verticai/jlorizontai
EdrillrigTOTAL n X (1 ^De) + EdriUrigT0TAL X FDE
Dspud
vertical
horizontal
where
^drilling ls the total emissions for a horizontal or vertical spud per unit of feet drilled [tons/ft]
EdrillrigTOTAL,D = 2-51 [ton/spud]
Fde = 0 (fraction of drill rigs that are diesel-electric)
EdrillrigTOTAL,DE = 0 [ton /spud]
Dspud = 9,318.1 [ft/spud]
Therefore:
„ _ 2.51x(l—0) + (0 0)
^drilling horizontal 9~318~L
Edrilling horizontal ~ 0.0002693 [ton /ft]
Finally, county-wide emissions may be calculated as follows:
Edrill,county-wide \Edrilling\vert.^caj ^ Dvertical \Edrilling\horizontaj ^ Dhorizontal
where:
Edrui,county-wide is the total emissions of NOx from county-wide drilling activity [ton/yr]
Edrilling,vertical = 0 [tons/ft]
Dvertical = 0 [ft/yr]
Edrilling,horizontal = 0.00002693 [tons/ft]
Dhorizontai = 596,026.5 [ft/yr]
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Nonpoint Oil and Gas Emissions Estimation Tool
Therefore:
Edrill,county-wide = 0.00002693 X 596,026.5
Edrill,county-wide — 160.55 [tOIl /yr]
3.8 Fugitive Leaks
This source category refers to leaking emissions of produced gas that escape through well
site and pipeline components such as connectors, flanges, open-ended lines, valves, and
compressor wet seals. It must be noted that this source category refers only to fugitive emissions
components located at the wellhead and that large transmission pipeline fugitives and other
midstream fugitives sources are not part of this analysis. Figure 3-7 shows numerous flanges
(circled) and a series of separators at a multi-well pad in the Marcellus shale. 1
Figure 3-7. Flanges
Fugitive emissions for an individual typical well are estimated according to Equation 24:
Equation24) -'I EF,> *. 185
i
where:
Efugmvej is the fugitive emissions for a single typical well for pollutant j [ton/yr/well]
EFi is the emission factor of TOC for a single component i [kg/hr/component]
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Nonooint Oil and Gas Emissions Estimation Tool
Ni is the total number of components of type i
tannmi is the annual number of hours the well is in operation [8760 hr/yr]
Yj is the mass ratio of pollutant j to TOC in the vented gas
907.185 is the unit conversion factor kg/ton
In addition, fugitive leaks from wellhead compressor seals can be estimated from the
following equations:
Equation 25) Et
compressor, fug ,CH 4
Px{Vvented)xt
MW x^x3-5xl0
^ gas J
^ (.fwellhead ^-^lateral
907,185*1,000 gas
where:
Ecompressorjug, ch4 is the county-wide CH4 fugitive emissions from compressor seals [ton/yr]
P is atmospheric pressure [1 atm]
Vvented is the volume of leaked methane per compressor [SCF/compressor/hour]
t is the annual hours of operation for wellhead compressors [hrs/yr]
R is the universal gas constant [0.082 L-atm/mol-K]
MW gas is the molecular weight of the pollutant [g/mol]
T is the atmospheric temperature [298 K]
fwellhead is the fraction of wells with wellhead compressors
Niaterai is the number of gas wells served by a lateral compressor engine
Wgas is the county-wide number of gas wells
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
1,000 is the unit conversion factor SCF/MCF
To estimate emissions of other pollutants (VOC, H2S) the following equation may be
used:
MWi w M,
Equation 26) compressor, fug,i compressor, fug,rm X , „T7- X
MW M
1Y1 CH4 1Y1CHA
where:
E compressor,fug,i is the county-wide compressor fugitive emissions for pollutant i [ton/yr]
EF compressor,fug,ch4 is the compressor fugitive emissions for CH4 [ton CFU/yr]
MWi is the molecular weight of pollutant i [lb/lb-mol]
MWcm is the molecular weight of CH4 [lb/lb-mol]
Mch4 is the mole percent of CH4 in the local gas [%]
Mi is the mole percent of pollutant in the local gas [%]
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Nonooint Oil and Gas Emissions Estimation Tool
Extrapolation to countv-level emissions
County-wide fugitive emissions from well-site piping components are estimated
according to Equation 27:
Equation 27) E^ugitiveT0TAL = E^^- xNwell
where:
Efugitive,total is the total fugitive emissions from well-site piping components in the county
[ton/yr]
Efugitivej is the fugitive emissions for a single well of pollutant j [ton/yr/well] (from Equation
24)
Nweii is the total number of active wells in the county [wells]
Total county-wide fugitive emissions are the sum of compressor seal emissions and
component fugitive emissions-
Example Calculation for Fugitive Leaks:
Fugitive emissions at gas well and oil well sites occur from connectors, flanges, open-
ended lines, compressor seals, and valves. Using the equations provided above, VOC emissions
for fugitive leaks from valves at gas wells in Cleburne County, Arkansas were calculated as
follows:
Eu„„, =(ZEFxNx* W 907,185
i
where:
Efugitive is the VOC emissions for a single gas well from valves [ton/yr/well]
EF = 0.0045 [kg TOC/hr/valve]
N = 12 [valves/well]
tannuai = 8,760 [hr/yr]
Y = 0.036 [VOC to TOC ratio]
907.185 [kg/ton]
Therefore:
Efugnive = (0.0045X 12x 8,760x 0.036) /907.185
E fugitive = 0.0188 [ton/well]
Total VOC emissions from fugitive leaks from valves at gas wells in Cleburne County
were calculated as follows:
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Nonooint Oil and Gas Emissions Estimation Tool
^fugitive,TOTAL ^fugitive^" ^well
where:
Efugitive,total is the total fugitive emissions from valves in Cleburne County [ton/yr]
EfUgmve = 0.0188 [ton/yr/well]
NWeii = 490 [wells]
Therefore:
^ fugitive,TOTAL = 0-0188x490
Efugitive,total = 9.21 [ton/yr]
3.9 Gas-Actuated Pumps
Gas-actuated pumps refer to small gas-driven plunger pumps used at oil and gas
production sites, to provide a constant supply of chemicals or lubricants to specific flow lines or
equipment. These are regularly used in sites where electric power is unavailable. As part of their
operation, gas-driven pumps vent part of the driving gas to the atmosphere, making them a VOC
and CH4 emissions source. Two types of gas-actuated pumps were considered: Kimray pumps
and chemical injection pumps (CIP). For oil wells only CIPs are assumed to be used. Annual
vented gas rates per well from Kimray pumps are estimated following Equation 28:
EF P
Equation 28) Ekimmy CHA = x Qkimray x ^
1,000 x
MW ix^x3-5xl0
-5
gas ,
y
where:
Ekimray,ch4 is the per-well CH4 emissions from Kimray pumps [tons- CH4/well-yr]
EFch4 is the CH4 emissions factor for a Kimray pump per unit throughput [SCF-
CH4/MMCF]
Qkimray is the gas pumped per well annually with Kimray pumps [MMCF/well-yr]
P is the atmospheric pressure [1 atm]
R is the universal gas constant [0.082 L-atm/mol-K]
MW gas is the molecular weight of CH4 [g/mol]
T is the atmospheric temperature [298 K]
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
1,000 is the unit conversion factor SCF/MCF
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Nonooint Oil and Gas Emissions Estimation Tool
Emissions from CIPs are estimated based on Equation 29:
Equation 29) Er„ ,,, = / V,,,. ~ /
907,185 " 24 ,,000xff«/Mw Ixrx3.5xl0-'
where:
Ecip,ch4 is the per-well CH4 emissions from CIP pumps [tons- CH4/well-yr]
EFch4 is the CH4 emissions factor for a CIP pump [SCF- CH4/pump/day]
Ncip is the number of CIPs per well [pump/well]
tcip is the regular operation time for chemical injection pumps [hrs/yr]
P is the atmospheric pressure [1 atm]
R is the universal gas constant [0.082 L-atm/mol-K]
MWcm is the molecular weight of CH4 [g/mol]
T is the atmospheric temperature [298 K]
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
1,000 is the unit conversion factor SCF/MCF
To estimate emissions from other pollutants (VOC, CO2, H2S, HAPs) from Kimray and
CIP pumps, the following equation may be used:
MW M,
Equation 30) EpumpJ = EpumpcH4 x , jttt x
MWcha, MCHi
where:
Epump.i is the emissions for pollutant i per well from CIPs or Kimray Pumps [ton/well-yr]
Epump,ch4 is the CH4 emissions from CIPs or Kimray Pumps [ton CH4/well-yr] (from
Equations 28 or 29)
MWi is the molecular weight of pollutant i [lb/lb-mol]
MWcm is the molecular weight of CH4 [lb/lb-mol]
Mch4 is the mole percent of CH4 in the local gas vented from the pump [%]
Mi is the mole percent of pollutant in the local gas vented from the pump [%]
Extrapolation to countv-level emissions
To estimate county-wide annual emissions from gas-actuated pumps for each pollutant,
the scaling surrogate used is well counts, according to Equation 31:
Equation 31)
EGAP, i = [(ECiP, i +Ekimrayii) X Wgas]gaswells + [EciP, i x Woil\oilwells
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Egap, i is the annual county-wide emissions for pollutant i from gas-actuated pumps [ton/yr]
Ecip, i is the emissions from chemical injection pumps per well type (gas or oil) [ton/yr-well]
Ekimray, i is the emissions from kimray pumps per well [ton/yr-well]
Wgas is the number of active gas wells in a particular county [wells]
Won is the number of active oil wells in a particular county [wells]
Example Calculation for Gas-Actuated Pumps:
Using the equations provided above, VOC emissions for gas-actuated pumps in Cleburne
County, Arkansas were calculated as follows:
Kimrav Pumps
FF P
F _ CH 4 y Q y £
kimray ,CH 4 r\f\*i 1 oc kimray f / \
*»'185 ,,OOOx[[«,MlvJxrx3.5xlO-
where:
Eumray,cm is the per-well CH4 emissions from Kimray pumps at gas wells [tons-CH4/well-yr]
EFcm = 1,041 [SCF- CH4/MMCF]
Qkimmy = 42.9 [MMCF/well-yr]
P = 1 [atm]
R = 0.082 [L-atm/mol-K]
MWcm = 16.04 [g/mol]
T= 298 [K]
907,185 [g/ton]
1,000 [SCF/MCF]
3.5xl0"5 [MCF/L]
f = l_ x42 9x
kimray,CH4 - - A
Therefore:
1,041
x^fz.y x //n \\
907,185 1,000 x ((0-082/ )X298x3.5xl0"5)
16.04
E kimray, CH4 — 0.923 [tons CFU/well/yr]
VOC emissions are then calculated using:
MW M
f = f IV! vrV0C lrlvoc
kimray kimray,CHi \/1X\I A/1
lVL CHA lVL CH4
where:
Eumray is the emissions of VOC per well from Kimray Pumps [ton/well-yr]
EFkimray, ch4 = 0.923 [ton CH4/well-yr]
MWvoc = 52.1 [lb/lb-mol]
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Nonooint Oil and Gas Emissions Estimation Tool
MWcm = 16.04 [lb/lb-mol]
Mch4 = 0.94 [percent CH4, expressed as a fraction]
Mvoc = 0.01 [percent VOC, expressed as a fraction]
Therefore:
E - 0 923x^-x^-
kimmy • , Q.94
E kimray — 0.032 [ton/well-yr]
Chemical Injection Pumps
EFr„, trip P
17 CH 4 yy AT w _CIP_\S
CIP ,CH 4 ~ 10^ ivc/p A A
* i,ooox[(«/WmJxrx3.5xio-=
where:
ch4 is the per-well CH4 emissions from CIP pumps at gas wells [tons- CH4/well-yr]
EFch4 = 260 [SCF- CH4/pump/day]
Ncip = 0.142 [pump/well]
tap = 8,760 [hrs/yr]
P = 1 [atm]
R = 0.082 [L-atm/mol-K]
MWCH4 = 16.04 [g/mol]
T= 298 [K]
907,185 [g/ton]
1,000 [SCF/MCF]
3.5xl0"5 [MCF/L]
Therefore:
260 „1/lo 8,760 P
CIP CH4 = X0.142X X // no, , \ -A
907,185 24 l,000x (l0-08^ 04)x 298x 3.5 x 10"5)
E cip, ch4 = 0.279 [tons CH4/well/yr]
Using the same methodology as above for Kimray pumps, VOC emissions from CIP
pumps are estimated as:
Ecip= 0.011 [ton/well/yr]
Total VOC emissions from all gas-actuated pumps in Cleburne County can be evaluated
as follows:
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Nonooint Oil and Gas Emissions Estimation Tool
Egap [(^C7P Ekimray^) ^ gas wells ^ ^oilloil wells
where:
Egap is the annual county-wide VOC emissions from gas-actuated pumps [ton/yr]
Ecip = 0.011 [ton/yr-well]
Eumray = 0.032 [ton/yr-well]
Wgas = 490 [wells]
Won = 0 [wells]
Therefore:
Egap = [(0.011 + 0.032) X 490]fl,aswejjs + [0.011 X 0]ouweiis
E gap = 21.1 [ton/yr]
3.10 Heaters
This category refers to natural gas-fired external combustors used in oil and gas
production facilities to provide heat input to separators (separator heaters or heater treaters), to
prevent the formation of hydrates during pressure reductions (line heaters), or to provide heat to
tanks (tank heaters). This category does not refer to reboilers used in dehydrators as those
emissions are captured in the dehydrator source category. Figure 3-8 shows a line heater at a
natural gas well in the Marcellus shale.1
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-8. Line Heater
The basic methodology for estimating emissions for all pollutants except SO2 for a single
heater is shown in Equation 32. Local fuel gas properties will vary between gas wells and oil
wells; hence emissions are estimated separately for this category. Due to limited field data for
this category, all other parameters unrelated to local gas composition were assumed to be the
same for gas and oil wells.
T7T7 v/1 \/ f s/ Up
Fnilrltion 32^ F heater theater annual
^ ~ (HV x 2,000)
where:
Ei,eater is the emissions from a given heater [ton/yr]
EFheater is the emission factor for a heater for a given pollutant [lb/million SCF]
Qheater is the heater MMBTU/hr rating [MMBTUrated/hr]
Imm# is the annual hours of operation [hr/yr]
he is a heater cycling fraction to account for the fraction of operating hours that the heater is
firing (if not available, hc=. 1)
HV is the local natural gas heating value [BTUi0Cai/SCF]
2,000 is the unit conversion factor lb/ton
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Nonooint Oil and Gas Emissions Estimation Tool
The methodology for estimating SO2 emissions from heaters requires first estimating the
mass of gas combusted in the heater, and then uses the mass fraction of H2S in the gas and the
assumption that all H2S is converted to SO2. This methodology is described in Equation 33.
2x f„ ,
Equation 33) Eheater^ =
Qheater ^ ^annual ^
W)
where:
Eheater,so2 is the SO2 emissions from a given heater [ton-S02/yr]
fHS is the mass fraction of H2S in the gas
Qheater is the heater MMBTU/hr rating [MMBTUrated/hr]
tannmi is the annual hours of operation [hr/yr]
he is a heater cycling fraction to account for the fraction of operating hours that the heater is
firing
HV is the local natural gas heating value [MMBTUi0Cai/scf]
P is atmospheric pressure [1 atm]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
3.5xl0"3 is the unit conversion factor SCF/L
907,185 is the unit conversion factor g/ton
1,000 is the unit conversion factor SCF/MCF
Extrapolation to countv-level emissions
County-wide heater emissions are estimated by determining the typical number of heaters
per well and scaling up by well count. This is shown in Equation 34:
Equation 34) EheaterJ0TAL = Eheater x Nheater x W3
TOTAL
where:
Eheater,total is the total heater emissions in a county for a specific pollutant [ton/yr]
Eheater is the total emissions from a single heater for a specific pollutant [ton/yr]
Nheater is the typical number of heaters per well throughout in the county
Wtotal is the total number of wells in the county
Example Calculation for Heaters - Gas:
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Nonooint Oil and Gas Emissions Estimation Tool
Using the equations provided above, NOx emissions from heaters at gas wells in Cleburne
County, Arkansas were calculated as follows:
P _ EFheater X Qheater X ^ annual X
heater (HV x 2,000)
where:
E heater = emissions from a single heater [ton /yr]
EF heater — 100 [lb NOx/MMCF]
Q heater — 0.61 [MMBtu/hr]
t annual= 8,760 [hr/yr]
he =1 (heater cycling fraction of operating hours that the heater is firing)
HV = 1,035 [MMBtu/MMCF]
2,000 [lb/ton]
Therefore:
_ 100x0.61x8,760x1
heater~ (1,035x2,000)
E heater — 0.258 [ton/heater/yr]
Total NOx emissions from all heaters in Cleburne County can be evaluated as follows:
Eheater,TOTAL ~ ^heater * ^heater TOTAL
where:
E heater, total = total emissions from heaters [ton/yr]
E heater — 0.258 [ton/heater/yr]
N heater — 0.5 [heaters/well]
Wtotal = 490 [wells]
Therefore:
Eheater,TOTAL = 0.258 X 0.5 X 490
E heater, TOTAL — 63.21 [ton/yr]
3.11 Hydraulic F racturing Pumps
This category refers to equipment used in hydraulic fracturing practices during well
completions and recompletions, generally related to unconventional oil and gas production such
as shale gas and tight sands oil/gas. Engines used during hydraulic fracturing are generally large
diesel-fueled pumps that can be a significant NOx emissions source. Figure 3-9 shows hydraulic
fracturing of three wells in the Marcellus shale.1 The hydraulic fracturing pump engines are lined
up on the red tractor trailer rigs.
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-9, Hydraulic Fracturing
Average emissions factors for hydraulic fracturing engines were derived from EPA's
NONROAD2008 model based on the oil equipment source category bin in NONROAD. The
basic methodology for estimating exhaust emissions from engines used at a hydraulic fracturing
event is shown below:
p f W F mxHPxLFxN^xt^
Equation 35) E= »x
907,185
where:
Effacing, event is the exhaust emissions for pollutant i from a single tracing event [ton/event]
7? is the number of engines used per fracing event
EFi is the emissions factor of pollutant i [g/hp-hr]
HP is the horsepower of the engine [hp]
LF is the load factor of the engine
Nmges is the number of stages per fracing event [stage/event]
tstage is the duration of the fracturing stage [hr/stage]
907,185 is the unit conversion factor g/ton
Extrapolation to county-level emissions
Fracing pump emissions can be scaled up to the county level on the basis of horizontal
spuds. It is assumed that hydraulic fracturing is performed in all horizontal spuds and thus the
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Nonooint Oil and Gas Emissions Estimation Tool
methodology for scaling up fracturing pump engine emissions is based on this surrogate as
shown below:
Equation 36) Ef TnTsr = N , xE
T- ^ frac, pumps,TOTAL events
frac ,pumps ,TOTAL events fracing ,event
where:
Efrac,pump,total is the total emissions from fracing pump engines in the county [ton/yr]
Nevents is the number of unconventional well completions in a particular year [spuds/yr]
Efradng,event is the total exhaust emissions from engines in a single fracing event [ton/event]
Example Calculation for Hydraulic Fracturing Pumps:
Using the equations provided above, NOx emissions from hydraulic fracturing pumps in
Cleburne County, Arkansas were calculated as follows:
EFi X HPx LF X N s X t
h — tiX - —
fracing,eventi 907185
where:
E fracing,event,i = emissions from a single fracturing event [ton/event]
n = 8.5 [engines/event]
EF= 5.831 [g/hp-hr]
HP = 2,033 [hp]
LF = 0.688 (load factor for the engine)
N stages — 10.5 [stages/event]
t stage — 2.25 [hr/stage]
907,185 [g/ton]
Therefore:
5.831x2,033x0.688x10.5x2.25
fracing ~ ¦ x 907,185
E fracing = 1.81 [ton/event]
Total NOx emissions from all hydraulic fracturing pumps in Cleburne County can be
evaluated as follows:
^ fracing,TOTAL ^ fracing ^ ^ events
where:
E fracing, total = total emissions from hydraulic fracturing pumps in a county [ton/yr]
E fracing = 1.81 [ton/event]
N events — 133 [spuds/yr]
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Nonpoint Oil and Gas Emissions Estimation Tool
Therefore:
E freeing,TOTAL = 1.81X133
E freeing, TOTAL = 241 [t01l/yr]
3.12 Lateral/Gathering Compressor Engines
Lateral compressor engines are used to gather gas from multiple individual wells,
generally serving groups of approximately 10 to 100 wells. These engines are generally medium
size and larger than wellhead compressor engines, but often not large enough to trigger Title V
or other major source permitting requirements. Lateral compressor engines were categorized into
two main categories and thus emissions are estimated for each type of engine and consequently
extrapolated to county-wide emissions. These categories of compressors are:
• Rich burn compressors
• Lean burn compressors
Figure 3-10 shows a large, lateral compressor engine operating in the Barnett shale.
Figure 3-10. Lateral Compressor Engine
The basic methodology for estimating emissions from lateral compressor engines is
shown in Equation 37:
FF x HPxTFxt
Equation 37) ^ ^ x (I - xCF,)
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Eengine.type are emissions from a particular type (rich vs. lean) of compressor engine
[ton/yr/engine]
EFi is the emissions factor of pollutant i [g/hp-hr] (note that this value may be differ
between rich-burn vs. lean-burn engines)
HP is the horsepower of the engine [hp]
LF is the load factor of the engine
tannmi is the annual number of hours the engine is used [hr/yr]
Fcontrolled is the fraction of lateral compressors of a particular type that are controlled
CFi is the control factor for controlled engines for pollutant i
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
County-level emissions are represented by a mix of the two types of lateral compressors.
Single engine emissions are scaled to county level using the fraction (F) of these engine types to
total engines, the fraction of wells served by lateral compressor engines, and the total gas well
count in a county, according to equation below:
Equation 38) EengineT0TAL = [FHchEengineHch + FleanEenginelean)xWgas x—
lateral
where:
Eengine, total is the total emissions from lateral compressor engines in a county [ton/yr]
Frich is the fraction of rich-burn lateral compressors in the county amongst all lateral
compressors
Eengine,rich is the total emissions from a single rich burn compressor engine per Equation (37)
[ton/yr]
Flean is the fraction of lean-burn lateral compressors in the county amongst all lateral
compressors
Eengine,lean is the total emissions from a single lean burn compressor engine per Equation (37)
[ton/yr]
Wgas is the total gas well count in a county
Niaterai is the number of gas wells served by a lateral compressor engine
Example Calculation for Rich-Burn Lateral Compressor:
Using the equations provided above, NOx emissions from rich-burn lateral compressor
engines in Cleburne County, Arkansas were calculated as follows:
F _ EF x HP x LF x tannual „
engine,rich 907 185 controlled '
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Nonooint Oil and Gas Emissions Estimation Tool
where:
E engine, rich = emissions from a rich-burn lateral compressor engine [ton/yr/engine]
EF = 8.24 [g/hp-hr]
HP = 97.0 [hp]
LF = 0.74 (load factor for the engine)
tannmi = 8,760 [hr/yr]
Fcontrolled = 0.44 (fraction controlled)
CF= 0.90 (control factor)
907,185 [g/ton]
Therefore:
8.24x97.0x0.74x8,760 „ „
engine, rich = ^85 X (1 - 0.44 X 0.90)
E engine, rich = 3.45 [ton/yr/engine]
Total NOx emissions from all rich-burn lateral compressor engines in Cleburne County
can be evaluated as follows:
^'engine, rich, TOTAL rich ^ ^engine, rich ) ^ gas ^ at
lateral
where:
E engine, rich, total = total emissions from rich-burn lateral compressor engines in a county
[ton/yr]
F rich = 0.490 (fraction of rich burn engines)
E engine, rich = 3.45 [ton/yr/engine]
w gas = 490 [wells]
N lateral = 32.05 (number of gas wells served by a lateral compressor engine)
Therefore:
Eengine, rich,TOTAL = (0.490 X 3.45) X 490 X
E engine, rich, TOTAL — 25.8 [ton/yr]
3.13 Liquids Unloading
This source category refers to emissions from venting gas from gas wells to prevent
liquid build-up in the well that could limit production. This practice is also commonly referred as
"well blowdowns". Vented gas from liquids unloading is a VOC emissions source. Some wells
use plunger lifts for liquids unloading, which can also result in vented emissions. Liquids
unloading emissions may be controlled by a combustion device such as a flare, or may also be
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Nonooint Oil and Gas Emissions Estimation Tool
controlled by a variety of devices and practices that reduce venting from the liquids unloading.
Figure 3-11 shows 2 wells equipped with plunger lifts.3
Figure 3-11. Plunger Lifts
Emissions from liquids unloading are based on the average venting volume per liquids
unloading and the gas composition of the vented gas. The calculation methodology for
estimating emissions from a single liquids unloading event is shown below in Equation 39:
Equation 39)
p
liquidsunbading, i
( \
f
¦a-5
^MW x 3.5x10
' gwj j
X-
f
907,185
where:
Enquids unloading,i is the emissions of pollutant i from a single liquids unloading event [ton/event]
P is atmospheric pressure [ 1 atm]
Vvented % the volume of vented gas per liquids unloading [MCF/event]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
fi is the mass fraction of pollutant i in the vented gas
3 Artificial Lift R&D Council, 2014. Internet address: http://www.alrdc.org/production/
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Nonooint Oil and Gas Emissions Estimation Tool
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Emissions from flare controls for liquids unloading vents
In areas where flaring is used to control liquids unloading vents, the methodology for
estimating flaring emissions is described below:
Equation 40)
f EFi XVvented xFx(ccapmrei)x(cefficiency)xHV
E
flare, liquidsunlo ading
captured / efficiency / . . 11/ .. yy
1 000 ^aS blowdown
where:
Eflare,liquids unloading is the county-wide flaring emissions of pollutant i for liquids unloading
[ton/yr]
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
Vvented is the volume of vented gas per liquids unloading [MCF/event]
F is the fraction of well liquids unloading that are flared
Ccaptured is the capture efficiency of the flare
Cefficiency is the control efficiency of the flare
HV is the local heating value of the gas [BTU/SCF]
Wgas is the county-wide number of active gas wells for a particular year [wells]
Nbiowdown the number of annual blowdowns per well in the county [event/yr-well]
1,000 is the unit conversion factor MCF/MMCF
2,000 is the unit conversion factor lb/ton
The methodology for estimating SO2 emissions from flaring of liquids unloading gas is
shown below:
Equation 41)
f \
P >< Rented X ™oa, X NUowdown)x F X (Cmp(urJx (Cefflcimcy )
^ flare,UquidsunIoading,S02
MWr
xTx3.5xlO
-5
gas J
X.Us X Z
907,185
where:
Eflare,uquidSunbading,so2 & the county-wide S02 flaring emissions from flaring of liquids
unloading vent gas [ton/yr]
P is atmospheric pressure [1 atm]
Vvented is the volume of vented gas per liquids unloading [MCF/event]
Wgas is the county-wide number of gas wells [wells]
Nbiowdown the number of annual blowdowns per well in the county [event/yr-well]
F is the fraction of liquids unloading with flares
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Nonpoint Oil and Gas Emissions Estimation Tool
Ccaptm-ed is the capture efficiency of the flare
Ceffidency is the control efficiency of the flare
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the liquids unloading gas [g/mol]
T is the atmospheric temperature [298 K]
/„ v is the mass fraction of H2S in the liquids unloading venting gas
3.5x10"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
The U.S. Inventory of Greenhouse Gas Emissions and Sinks (U.S. GHG Inventory) was
updated in 2014 to reflect newly available data on emissions from liquids unloading.4
Specifically, EPA analyzed a report issued in September of 2012 by the American Petroleum
Institute (API) and America's Natural Gas Alliance (ANGA) entitled "Characterizing Pivotal
Sources of Methane Emissions from Natural Gas Production". Using data presented in the
report, EPA developed updated vent rates (Vvan.i in Equation 40) for liquids unloading
activities based on U.S. EIA Supply Regions. Figure 3-12 below shows the six EIA Supply
Regions used in the U.S. GHG Inventory.
4 U.S. EPA, 2013. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. Internet address:
http://www.epa.gov/climatechange/ghgemissions/usinventorvreport.html
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Figure 3-12. EIA Supply Region Map
Table 3-2 below shows the vent rates (Vvented in Equation 40) by EIA Supply Region for
each venting scenario used in the U.S. GHG Inventory.
Table 3-2. Liquids Unloading Vent Rates from the U.S. GHG Inventory
EIA Supply
Region
Wells venting
with plunger
lift (%)
Wells venting
without plunger
lift (%)
Vent Rate for
Wells with
Plunger Lift
(scf/yr/well)a
Vent Rate for Wells
without Plunger Lift
(scf/yr/well)a
North East
4.3
11.26
314,626
166,174
Midcontinent
2.33
4.14
1,379,958
230,199
Rocky Mountain
12.88
1.52
154,300
2,579,444
South West
3.32
19.47
3,547
96,748
West Coast
7.59
6.80
345,343
304,048
Gulf Coast
2.32
7.08
70,021
300,592
a Whole gas vent rates.
In order to utilize this information within the structure and methodology used in the tool,
a weighted vent rate was developed for all wells in a county. Calculation of a weighted vent rate
was accomplished using the data in Table 3-2. For example, the updated default liquids
unloading vent rate for the North East EIA Supply Region is calculated as follows (using the
2011 value of 153,773 wells in the North East as shown in Table 3-3):
Euq«ids_«nioading= 32,421 (scf/yr/well)
Table 3-3 shows the resultant default vent rates used in the tool (data from the West
Coast Region has been used for the State of Alaska). As these are annual vent rates, where this
information is used in the tool, the frequency of liquids unloading venting has been set equal to
one event per year. Additionally, as these rates reflect some level of control (through the use of
plunger lifts), where this information is used in the tool, a value of "NA" is used for the control
method, and no additional reduction from use of controls has been applied.
Table 3-3. Default Liquids Unloading Vent Rates for the Tool
EIA Supply Region
Gas Well
Count
Default Vent Rate for all
Wells (scf/yr/well)
North East
153,773
32,421
Midcontinent
87,193
41,659
Rocky Mountain
58,285
59,047
South West
41,919
18,956
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Nonooint Oil and Gas Emissions Estimation Tool
Table 3-3. Default Liquids Unloading Vent Rates for the Tool
EIA Supply Region
Gas Well
Count
Default Vent Rate for all
Wells (scf/yr/well)
West Coast
1,516
46,884
Gulf Coast
71,629
22,913
Extrapolation to countv-level emissions
The total county-level emissions from all liquids unloading are evaluated following
Equation 42:
Equation 42) ^liquidsuniiiding,TOTAL ^'liquidsimiiidingi ^^blowdowns^^^gas ^ ^controldevice^ ^-"efficiency!
where:
Eliquids unloading, total are the total county-wide emissions of pollutant i from liquids unloading
[tons/yr]
Eiiquids unloading,i are the liquids unloading emissions from a single liquids unloading event
[tons/event]
Nbbwdowns is the number of annual blowdowns per well in the county [event/yr-well]
Wgas is the total number of active gas wells in the county for a particular year [well]
Fcontrol,device is the fraction of liquids unloading in the county that were controlled
Cefficiency is the control efficiency of the control technology used (plunger lifts for example)
Example Calculation for Liquids Unloading:
Using the equations provided above, VOC emissions from liquids unloading in Cleburne
County, Arkansas were calculated as follows:
f \
Jliquidsunloading
P Rented)
MW
xTx3.5xlO
,-5
X-
/
907,185
where:
E Hquidsunioading = emissions from a single liquids unloading event [ton/event]
P = 1 [atm]
V vented — 5.9375 [MSCF/event]
R = 0.082 [L-atm/mol-K]
MW gas = 17.3066 [g gas/mole gas]
T= 298 [K]
/= 0.03429 [VOC fraction]
3.5xl0"5 [MCF/L]
907,185 [g/ton]
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Nonooint Oil and Gas Emissions Estimation Tool
Therefore:
E
liquidsunloading
(0.082/ J
lx (5.9375)
A
17.3066''x298x3-5x10 5 J
0.03429
X 907,185
E liquidsunloading — 0.004541 [ton/event]
In this example, liquids unloading emissions are controlled through the use of a Plunger
lift, ESP, or Beam Pump.
Therefore, total VOC emissions from liquids unloading venting in Cleburne County were
calculated as follows:
^liquidsurdding,TOTAL ^'liquidsun&ading^' ^blowdowrf^^gas ^^controldevice^^ejficiency)
where:
Eiiquidsunbading,total are the total county-wide emissions of VOC from blowdowns [ton/yr]
Eiiquidsunioading = 0.004541 [ton/event]
Nbiowdown = 64 [event/yr-well]
Wgas = 490 [wells]
Fcontrol,device = 0.3769 (fraction controlled)
Ceffidency = 0.7063 (control efficiency expressed as fraction)
Therefore:
£%,M,,lM„i!roHI. = 0.004541x64x490x(l-0.3769x 0.7062)
E liquidsunloading,TOTAL — 104.5 [ton/yr]
Note that if liquids unloading emissions were controlled through the use of flares, flaring
emissions would be calculated using equations 40 and 41.
3.14 Loading
This category refers to loading losses that occur when transferring hydrocarbon liquids,
crude oil or condensate, from storage tanks to cargo trucks. Figure 3-13 shows truck loading
operations at a tank battery in Mississippi.
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-13. Truck Loading Operations
The emissions from loading operations will vary by the gas speciation of the working
losses; hence emissions were calculated separately for each hydrocarbon liquid. Equations 43-46
may be used for both categories (SCCs). The loading loss rate is estimated following Equation
43:
Equation 43)
L = 12.46 x
f S xV xMWga! ^
T
where:
L is the loading loss rate [lb/LOOOgal]
S is the saturation factor taken from AP-42 default values based on operating mode (here
assumed as submerged loading: dedicated normal service)
V is the true vapor pressure of the liquid loaded [psia]
MWgas is the molecular weight of the vapor [Ib/lb-mole]
T is the temperature of the bulk liquid [°R]
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Nonooint Oil and Gas Emissions Estimation Tool
VOC track loading emissions are then estimated by Equation 44 which is dependent on
the VOC fraction in the gas. When available, county-specific working/breathing gas
compositions from condensate/crude oil storage tanks were used in Equations 44-46; however
when county-level data was limited or unavailable, produced gas analyses were used to speciate
emissions from each pollutant.
L 42
Equation 44) Eloading, voc j~ooo ^ ^voc ^ 2 ooo
where:
Eloading, voc are the VOC tank loading emissions [ton-VOC/bbl]
L is the loading loss rate [lb/l,000gal]
Yvoc is the weight fraction of VOC in the vapor in the liquid loaded
42 is a unit conversion [gal/bbl]
2,000 is a unit conversion [lbs/ton]
Emissions of other pollutants are calculated based on Equation 45:
r ,fN „ w weight fraction;
Equation 45) EloadingX - Eloadingyoc x we^ht fractionvoc
where:
E loading,i is the total loading emissions of pollutant "i" per barrel of liquid [ton/bbl]
(weight fraction/weight fractionvoc) is the mass-based weight fraction of pollutant i
divided by the weight fraction of VOC in the gas
Extrapolation to countv-level emissions
Annual emissions per pollutant i from condensate loading were scaled to county-level by
annual condensate production per Equation 46:
Equation 46) Etank loadout, i ^loading, i ^ Pcondensate ^ Ftrucked
where:
Etank loadout, i is the annual county-level emissions for pollutant i from condensate tank load-out
[ton/yr]
Ehading, i is the emissions for pollutant i from loading per barrel [ton/bbl]
P condensate is the total annual of barrels condensate produced county-wide [bbl/yr]
Ftrucked is the fraction of condensate production that is delivered by truck
Annual emissions per pollutant i from oil loading were scaled to county-level by annual
oil production per Equation 47:
Equation 47) ^tanfc loadout,oil, i ^loading, i ^ Poil ^ Ptrucked
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Nonooint Oil and Gas Emissions Estimation Tool
where:
Etank badout, i is the annual county-level emissions for pollutant i from crude oil tank load-out
[ton/yr]
Ebading, i is the emissions for pollutant i from loading per barrel [ton/bbl]
P on is the total annual county-wide oil production [bbl/yr]
Ftrucked is the fraction of oil production that is delivered by truck
Example Calculation for Loading:
Using the equations provided above, VOC emissions for condensate loading in Columbia
County, Arkansas were calculated as follows:
L = 12.46 x
( SxVxMW„„A
gas
T j
where:
L is the loading loss rate [lb/l,000gal]
S = 0.6 (based on submerged loading: dedicated normal service)
V = 5.12 [psia]
MWgas = 54.2 [lb/lb-mole]
r=540 [°R]
Therefore:
, f0.6x5.12x54.2^)
L = 12.46X
I 540 J
L= 3.84 [lb/l,000gal]
Total VOC emissions from all condensate loading in Columbia County can be evaluated
as follows:
L 42
^loading,VOC ^ Ynnr X
1,000 voc 2,000
where:
Eloading, voc we the VOC tank loading emissions [ton-VOC/bbl]
L = 3.84 [lb/l,000gal]
Yvoc = 0.933
42 [gal/bbl]
2,000 [lb/ton]
Therefore:
3.84 42
Eloading ~ ^ 0.933 X
1,000 ' 2,000
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Nonooint Oil and Gas Emissions Estimation Tool
Eioading = 0.0000752 [ton-VOC/bbl]
Annual emissions of VOC from condensate loading are then scaled to the county-level
using:
Etank loadout Eload.ing,VOC ^ Pcondensate ^ ^"trMcfced
where:
Etank loadout is the annual county-level emissions of VOC from condensate tank load-out
[ton/yr]
Ehading,voc = 0.0000752 [ton-VOC/bbl]
P condensate = 275,892 [bbl/yr]
Ftrucked = 1
Therefore:
Etank loadout = 0.0000752 x 275,892 x 1
Etank loadout= 20.76[ton/yr]
3.15 Mud Degassing
Drilling mud degassing refers to the practice of extracting the entrained gas from the
drilling mud once it is outside of the wellbore. During this process VOCs and CH4 (and other
pollutants in the gas) are vented to the atmosphere. National default emissions factors for mud
degassing are available from The Climate Registry Reporting Protocol as shown in Table 3-4:
Table 3-4. National Default Emissions Factors for Mud Degassing by Mud Base
Emission Source
Emission Factor Units5
Emission Factor Units6
Mud degassing - water-
based mud
881.84 lbs THC / drilling
day
0.2605 tonnes CH4/ drilling
day
Mud degassing - oil-based
mud
198.41 lbs THC / drilling
day
0.0586 tonnes CH4/ drilling
day
Mud degassing - synthetic
mud
198.41 lbs THC / drilling
day
0.0586 tonnes CH4/ drilling
day
5 Wilson, Darcy, Richard Billings, Regi Oommen, and Roger Chang, Eastern Research Group, Inc. Year 2005
Gulfwide Emission Inventory Study, U.S. Department of the Interior, Minerals Management Services, Gulf of
Mexico OCS Region, New Orleans, December 2007, Section 5.2.10.
6 Based on gas content of 65.13 weight percent CH4, derived from sample data provided in the original source of
the emission factors. Original sample data is as follows, in terms of mole%: 83.85% CH4, 5.41% C2H6, 6.12%
C3H8, 3.21% C4H10, and 1.40% C5H12 (Wilson et al„ 2007)
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Nonooint Oil and Gas Emissions Estimation Tool
Water-based mud emissions factors were assumed as a default conservative value, but
this parameter may be updated in the tool. To account for the use of different mud bases within a
region, the CH4 emissions factor may be estimated as a weighted average based on a usage
fraction of each mud type within a county.
Applying the local-gas CH4 mass fraction to the mud degassing emission factors provides
the site-representative emissions as shown in Equation 48. Because the mud entrained gas is the
gas coming out directly from the wellbore during drilling, produced gas compositions by well
type are used to characterize these emissions. Equations 48-49 are applicable to both oil and gas
wells mud degassing emissions, however gas compositions and surrogate values (spuds) will
vary for each well type.
Equation 48) e =m XEF xl 102x M°m
n y mudgas„CH4 1V drill * J^1 mud,CH4 * 1 *1
U.ojoD
where:
E mudgas,cH4 is the mud degassing emissions for CH4 per spud [ton/spud]
Ndnii is the number of drilling days per spud [drilling days/spud]
EFmud,cH4 is the emissions factor for CH4 [tonne CFU/drilling days]
0.8385 is the mole percent of CH4 from the vented gas used to derive the emissions factor
(EF)
Mem is the mole percent of CH4 in the local gas vented during mud degassing [percent,
expressed as a fraction] (if county-specific CH4 emissions factor is used, M=0.8385)
1.102 is the conversion of tonnes to short tons
To estimate emissions from other pollutants in the vented gas Equation 49 may be used:
Equation 49) - - MW< M
— x x
MW M
lviyvCH 4 1V1CH 4
where:
E mud gas,i is the mud degassing emissions for pollutant i per spud [ton/spud]
EFmudgas, cm is the vented emissions for CH4 [ton CFU/spud]
MWi is the molecular weight of pollutant i [lb/lb-mol]
MWcrn is the molecular weight of CH4 [lb/lb-mol]
Mem is the mole percent of CH4 in the local gas vented during mud degassing [percent,
expressed as a fraction]
Mi is the mole percent of pollutant in the local gas vented during mud degassing [percent,
expressed as a fraction]
Extrapolation to countv-level emissions
To estimate county-wide annual emissions, mud degassing emissions by spud are scaled
with the county-wide count of drilling events (spuds), according to Equation 50:
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Nonooint Oil and Gas Emissions Estimation Tool
Equation 50) Emudgas,TOTAL i Emudgas, i ^ SSpUds
where:
Emudgas,total,i is the annual county-wide emissions for pollutant i from mud degassing [ton/yr]
Emudgas, i is the emissions from mud degassing from a drilling event [ton/spud]
Sspuds is the number of wells drilled in a county for a particular year [spud/yr]
Example Calculation for Mud Degassing:
Using the equations provided above, VOC emissions for mud degassing in Cleburne
County, Arkansas were calculated as follows:
M
F =N x FF x1 1f)2x CH4
mudgas,CH4 iy drill L^1 mudgas,CH4 ^ n
where:
Emudgas, CH4 is the mud degassing emissions for CH4 per spud [ton/spud]
Ndriu = 20.22 [drilling days/spud]
EFmudgas, ch4 = 0.2605 [tonnes CFU/drilling days]
Mem = 0.94 [percent, expressed as a fraction]
0.8385 = [mole fraction CH4 used to derive emission factor]
1.102 [ton/tonnes]
Therefore:
Em,,^rHA= 20.22x0.2605x1.102 x- °M
TnudgQ.s ,CH 4 Q 8385
E mudgas, CH4 — 6.51 [tons CH4/well/yr]
VOC emissions are then calculated using:
p —p MWV0C Mvoc
mudgas,VOC mudgas ,CH 4 liJjiy n*
Ivl W ch 4 ch 4
where:
Emudgas,voc is the emissions of VOC per completion [ton/completion]
Emudgas,CH4 =6.51 [ton CH4/well-yr]
MWvoc = 52.1 [lb/lb-mol]
MWcrn = 16.04 [lb/lb-mol]
Mch4 = 0.94 [percent CH4, expressed as a fraction]
Mvoc = 0.01 [percent VOC, expressed as a fraction]
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Nonooint Oil and Gas Emissions Estimation Tool
Therefore:
52.1 0.01
mudgasyOC • X X q
E mudgas,VOC — 0.225 [ton/well-yr]
Total VOC emissions from all mud degassing in Cleburne County can be evaluated as
follows:
Emudgas,TOTAL Emudgas,VOC X Sspuds
where:
Emudgas,total is the annual county-wide VOC emissions from mud degassing [ton/yr]
Emudgas,voc = 0.225 [ton/spud]
Sspuds = 133 [spud/yr]
Therefore:
Emudgas,TOTAL 0.225 X 133
Emudgas,total = 29.93 [ton/yr]
3.16 Pneumatic Devices
Pneumatic devices are located at the well site and use high-pressure produced gas to
produce mechanical motion. These devices are typically under operation throughout the year and
they may or may not vent the working fluid during operation, making them a potentially
significant source of VOC emissions. Figure 3-14 shows a pneumatic device at a well in the
Marcellus shale.1
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Nonpoint Oil and Gas Emissions Estimation Tool
Figure 3-14. Pneumatic Device
The counts of pneumatic devices vary between oil and gas wells, thus emissions are
estimated separately for both well types. Emissions from pneumatic devices vary by the bleed
rate of the device. Here it is assumed that four configurations can be found in a typical well: high
bleed, low bleed, intermittent and no bleed. Emissions for the first three types of device i must be
estimated. The methodology for estimating the emissions from pneumatic devices for a particular
type of well are shown in Equation 51:
Equation 51) £
f,
pneumatic, j
907,1851 ,
IKxA'.x,
annual
x-
^MW lx^><3-5xl0
W "msj J
1,000 x
where:
Epneumaticj is the total emissions of pollutant j from all pneumatic devices for a particular type
of well (oil vs. gas) [ton/yr/well]
fj is the mass fraction of pollutant j in the vented gas (produced gas)
V, is the volumetric bleed rate from device i [SCF/hr/device]
Ni is the number of devices i found in a type of well (oil vs. gas) [devices/well]
tamimi is the number of hours per year that devices were operating [8760 hr/yr]
P is the atmospheric pressure [1 atm]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
3.5x10"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
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Nonooint Oil and Gas Emissions Estimation Tool
1,000 is the unit conversion factor SCF/MCF
Extrapolation to countv-level emissions
County-wide pneumatic device emissions for each well type are estimated according to
Equation 52:
Equation 52) E'pnemlatjqTOTAL,j ^'pneumatiqj ^^gasoroil
where:
Epneumatk,total,j is the total pneumatic device emissions of pollutant j in the county [ton/yr]
Epneumaticj is the pneumatic device emissions of pollutant j for a type of well (gas vs. oil)
[ton/yr/well]
Wgas or oil IS the total number of active gas (or oil) wells in the county [wells]
Total emissions from pneumatic devices will be the combination of county-wide
emissions from each well type:
Equation 53) E' a]]pneullla[jcsj pneumatic.TOTAL, j j,,/(,vuv,//v pneumatic.TOTAL, j Jo//UY,//v
Subpart W of the GHGRP prescribes bleed rates for low bleed, high bleed, and
intermittent bleed devices that are to be used by reporters to estimate emissions. These rates,
shown in Table 3-5 below, have been incorporated into the tool as default bleed rates for
pneumatic devices used at oil and gas wells.
Table 3-5. Whole Gas Bleed Rates for Pneumatic Devices
Onshore petroleum and natural gas production
Bleed Rate (scf/hour/component)
Low Bleed Pneumatic Devices
1.39
High Bleed Pneumatic Devices
37.3
Intermittent Bleed Pneumatic Devices
13.5
The U.S. GHG Inventory utilizes per-well pneumatic device counts that are used in the
tool. For gas wells, the total device counts in the U.S. GHG Inventory were used to derive
default device counts by device type using the distribution between low, intermittent, and high
bleed devices found in the CenSARA inventory and survey effort. The updated default device
counts are shown in Table 3-6 below for each EIA Supply Region. (Note that for oil wells, the
total device counts by device type will be updated in future inventories as EPA has identified a
calculation error for the oil well device counts shown in Table 3-6.)
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Nonooint Oil and Gas Emissions Estimation Tool
Table 3-6. Pneumatic Device Counts for Oil and Gas Wells
EIA Supply Region
Oil Well Device Counts
Gas Well Device Counts
Low
Bleed
High
Bleed
Intermittent
Bleed
Low
Bleed
High Bleed
Intermittent
Bleed
North East
0.495
0.267
0
0.144
0.222
0.120
Midcontinent
0.495
0.267
0
0.460
0.709
0.382
Rocky Mountain
0.495
0.267
0
0.434
0.669
0.360
South West
0.495
0.267
0
0.394
0.607
0.327
West Coast
0.495
0.267
0
0.297
0.458
0.247
Gulf Coast
0.495
0.267
0
0.206
0.318
0.171
Example Calculation for Pneumatic Devices:
Using the equations provided above, VOC emissions from low-bleed pneumatic devices
located at gas wells in Cleburne County, Arkansas were calculated as follows:
£ —f-
pneumatic,VOC,well
907,185
XN Xtannua,
V ' J
X-
ff \ \
l,000x
^ MW x^x3-5xl0
vv W J
where:
Epneumatic, voc,well is the total emissions of VOC from low-bleed pneumatic devices
[ton/yr/well]
/= 0.0342 [VOC fraction]
V = 3.151 [SCF/hr/de vice]
N = 0.99 [devices/well]
tannual = 8,V60 [hr/yr]
P = 1 [atm]
R = 0.082 [L-atm/mol-K]
MWgas = 17.31 [g/mol]
T= 298 [K]
3.5xl0"5 [MCF/L]
907,185 [g/ton]
1,000 [SCF/MCF]
Therefore:
151 x 0-99X8'760)XL000x((0,082i73i)x298x3.5xl0-5)
Epneumatic, VOC,well — 0.021 [tOIl/yr/wcll]
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Nonpoint Oil and Gas Emissions Estimation Tool
VOC emissions from low-bleed pneumatic devices located at gas wells in Cleburne
County can be evaluated as follows:
F =F xW
pneumatiQVOC,TOTAL pneumatiQVOC,well gas
where:
Fpmumam.vocjoTM. is the total pneumatic device emissions of VOC from low-bleed pneumatic
devices located at gas wells in Cleburne county [ton/yr]
Epneumatic, voc,well = 0,021 [ton/yr/well]
Wgv, = 490 [wells]
Therefore:
W.vw= 0.021x490
Epneumatic,VOC = 10.3 [tOll/Vl |
3.17 Produced Water Tanks
Water tank emissions are generated by working and breathing processes from tanks used
to store produced water. Figure 3-15 shows produced water tanks in the Barnett Shale.
Figure 3-15. Produced Water Tanks
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Nonooint Oil and Gas Emissions Estimation Tool
Because information on oil and gas field handling of produced water is limited, emissions
from this source were assumed uncontrolled. The methodology for estimating water tank
emissions is shown below separately for gas wells and oil wells as water production and gas
compositions for each well-type will differ:
Gas well water tanks
FF
t- c a\ Z7 watertanks,CH4 w ^ w r
equation &water,gaswells,CH4 ~ ^ QQQ water,,gas X ^tank
where:
Ewater,,gasweih,cH4 is the county-wide annual CH4 emissions from water tanks located at gas
wells [tons/yr]
EFWater,tanks,ch4 is the emissions factor for CH4 from working/breathing losses from water
tanks in gas well sites [lb/bbl]
Pwater,gas is the county-wide annual water production [bbl/yr] from gas wells
Ftank is the fraction of produced water directed to tanks [%]
2,000 is the unit conversion factor lbs/ton
Oil well water tanks
^ m ^ {EFWater ,LPwells,CH4 XE + EFwater RPweUs CH4 x(l~F)) ^ n
Equation 55) Ewater oilwells CH4 = xFtank x Pwater o
where:
Ewater,oil wells,CH4 IS the county-wide annual CH4 emissions from water tanks located at oil wells
[tons/yr]
EFwater,LPWeiis,cH4 is the emissions factor for CH4 from working/breathing losses from water
tanks at low pressure oil wells (i.e. wells with artificial lifts) [lb/bbl]
EF water,RPweiis, ch4 is the emissions factor for CH4 from working/breathing losses from water
tanks at regular pressure oil well sites [lb/bbl]
F is the fraction of water production from oil wells with artificial lifts
Ftank is the fraction of produced water directed to tanks [%]
Pwater,oil IS the annual county-wide water production [bbl/yr] from oil wells
2,000 is the unit conversion factor lbs/ton
To estimate emissions of other pollutants in the losses from water tanks, the following
equation may be used:
MW: M;
Equation 56) E ^ = EF ^ x———x
CH4 MW M
1V1 CH4 1V1CH4
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Nonooint Oil and Gas Emissions Estimation Tool
where:
E water,wells,i IS the water tank county-wide venting losses of pollutant i from water tanks at
particular well type (oil or gas) [ton/yr]
EFwater,weiis,ch4 is the water tank emissions for CH4 for a particular well type [ton CH4/yr]
MWi is the molecular weight of pollutant i [lb/lb-mol]
MWcrn is the molecular weight of CH4 [lb/lb-mol]
Mch4 is the mole percent of CH4 in the water tanks gas (local produced gas) [%]
Mi is the mole percent of pollutant in the water tanks gas (local produced gas) [%]
Extrapolation to countv-level emissions
County-wide emissions from produced water tanks are estimated directly from equations
55 through 57. The sum of oil wells and gas wells water tank emissions yield total county-wide
emissions from water tanks.
Example Calculation for Produced Water Tanks:
Using the equations provided above, VOC emissions for produced water tanks in
Columbia County, Arkansas were calculated as follows:
Venting emissions (CH4) from gas wells:
FF
p _ water,tank „ p
water,gaswell ^ 000 water,gas tank
where:
Ewater,gasweii is the county-wide annual CH4 emissions from water tanks located at gas wells
[ton/yr]
EFwater,tank = 0.11 [lb CH4/bbl]
Pwater,gas = 1,234,207 [bbl/yr]
Ftank = 1 [%]
2,000 [lb/ton]
Therefore:
0.11
2,000
Ewater,,gaswell ~ Xl,234,207 Xl
E water, gasweii — 67.9 [tons CH4/yr]
VOC emissions are then calculated using:
MW M
f = f lY1 vrVOC y 1Y1VOC
water,gaswell ,VOC water, gaswell
MW M
CH 4 CH 4
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Nonpoint Oil and Gas Emissions Estimation Tool
where:
E water,gasweii,voc is the emissions of VOC from produced water at gas wells [ton/yr]
EFwater.gaswell = 6/.9 [tons CH4/V1 ]
MWvoc = 59.5 [lb/lb-mol]
MWch4 = 16.04 [lb/lb-mol]
Mem = 0.89 [percent CII4, expressed as a fraction]
Mvoc = 0.04 [percent VOC, expressed as a fraction]
Therefore:
_ 59.5 w 0.04
water,giisitiettyop 16 04 ^ 0 89
Ewater,gamell,VOC — 11.32 [tOll/yi]
3.18 Well Completions
This category refers to emissions from well completions events, which includes initial
completions and recompletions. Data provided in the HPDI database includes a count of annual
well completions (combines initial and recompletions), thus county-wide emissions will be a
combination of the two. However, well completions characteristics will vary by well type; hence
emissions are estimated separately for gas well completions and oil well completions.
Additionally, emissions are estimated separately for unconventional and conventional
completions.
Figure 3-16 shows temporary storage tanks used to collect flowback fluids at an
unconventional well completion in the Barnett Shale. Emissions are generated as gas entrained in
the flowback fluid is emitted through open vents at the top of the tanks.
Figure 3-16. Well Completion
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Nonooint Oil and Gas Emissions Estimation Tool
The calculation methodology for estimating emissions from a single, uncontrolled
completion event is shown below in Equation 57. Emissions from well completions controlled by
flaring or use of green completions are the calculated using equations 58 - 60 as described below.
f \
Equation 57)
v completion ,i
Pxio )
completion /
MW„
xTx3.5xlO
-5
X-
ft
907,185
where:
Ecompletion,i is the uncontrolled emissions of pollutant i from a single completion event
[ton/event]
P is atmospheric pressure [1 atm]
Qcompietwn is the uncontrolled volume of gas generated per completion [MCF/event]
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the gas [g/mol]
T is the atmospheric temperature [298 K]
fi is the mass fraction of pollutant i in the completion venting gas
3.5xl0"5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Flaring emissions from well completion controls
The methodology for estimating flaring emissions from completion venting processes is
described below:
Equation 58) E
( EFt X Qcompietion X
flare,completion
F X {Ccaptured )X efficiency )X
'captured
1,000
A
-xWC
county
/2,000
where:
Eflare,completion is the county-wide flaring emissions of pollutant i for well completions [ton/yr]
EFi is the flaring emissions factor for pollutant i [lb/MMBtu]
Qcompietwn is the uncontrolled volume of gas generated per completion [MCF/event]
F is the fraction of well completions with flares
Ccaptured is the capture efficiency of the flare
Cejjiciencx is the control efficiency of the flare
HV is the local heating value of the gas [BTU/SCF]
WCcounty is the county-wide number of well completion events for a particular year
[events/yr]
2,000 is the unit conversion factor lbs/ton
1,000 is the unit conversion factor MCF/MMCF
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Nonooint Oil and Gas Emissions Estimation Tool
The methodology for estimating SO2 emissions from flaring of completion vent gas is
shown below:
Equation 59)
J flare,completion, S 02
Px(q
xWC
completion county >
)xFx {c red )x {ceffici )
MW,
xTx3.5xlO
-5
gas
p 7/
xJh2sx/9 07185
where:
Eflare,completion,so2 is t'"16 county-wide SO2 flaring emissions from flaring of completion vent gas
[ton/yr]
P is atmospheric pressure [1 atm]
Qcompietwn is the uncontrolled volume of gas generated per completion [MCF/event]
WCcounty is the county-wide number of well completion events for a particular year
[events/yr]
F is the fraction of well completions with flares
Ccaptured is the capture efficiency of the flare
Ceffidency is the control efficiency of the flare
R is the universal gas constant [0.082 L-atm/mol-K]
MWgas is the molecular weight of the completion venting gas [g/mol]
T is the atmospheric temperature [298 K]
fHS is the mass fraction of H2S in the completion venting gas
3.5xl0~5 is the unit conversion factor MCF/L
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
Controlled, county-wide emissions are obtained by scaling-up well completions by well
type using the number of completion events by well type by year and accounting for any controls
used. This is done by applying Equation 60:
Equation 60)
F =F xWC (l -F x(c )x(r )-F )+F
completioiiTOTAL completion} countyx flare V captured) V efficiency) green) flare,completio^i
where:
Ecompletion,total are the total emissions county-wide of pollutant i from well completions
[tons/yr]
Ecompletion,i are the completion emissions from a single completion event [tons/event]
WCcounty is the county-wide total completions events in a particular year [events/yr]
Fflare is the fraction of completions in the county controlled by flare
Ccaptured is the capture efficiency of the flare
Cejjiciencx is the control efficiency of the flare
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Nonooint Oil and Gas Emissions Estimation Tool
Fgreen is the fraction of completions in the county that were controlled by green completion
techniques
Efbre,completion,i is the county-wide flaring emissions from flaring of completion vent gas
[ton/yr]
Example Calculation for Well Completions:
Using the equations provided above, VOC emissions from venting of controlled
(accounting for both flaring and green completions) oil well completions in Columbia County,
Arkansas were calculated as follows:
vcompletion
f \
Pxio )
y^completion /
/MW x^x3-5xl0
vv/ J y
X-
/
907,185
where:
Ecompietwn is the uncontrolled emissions of VOC from a single completion event [ton/event]
P = 1 [atm]
Qcompietion — 226 [MCF/event]
R = 0.082 [L-atm/mol-K]
MWgaS = 24.25 [g/mol]
T= 298 [K]
/= 0.26 [VOC fraction]
3.5xl0"5 [MCF/L]
907,185 [g/ton]
Therefore:
J completion
(0.082/ \
V /OA ?V
lx(226)
-v-5
2425,x 298x3.5x10
x-
0.26
907,185
E completion =1.84 [ton/event]
Well completion flaring emissions are calculated similarly to the example given above
for condensate tanks. In this case, E flare, completion,voc = 0.552 [ton/yr]
Total VOC emissions from well completion venting and flaring in Columbia County were
calculated as follows:
F = F
completioifTOTAL completion
^ '^^county^ ^flare ^ captured) ^ efficiency) ^green) ^
v flare,completion
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Nonpoint Oil and Gas Emissions Estimation Tool
where:
Ecompietion,total are the total emissions county-wide of VOC from well completions [tons/yr]
Ecompietion =1.84 [tons/event]
WCcounty = 62 [events/yr]
Fflare = 0.833 (fraction flared)
Ccaptured = 0.898 (capture efficiency expressed as fraction)
Cejjiciency = 0.98 (control efficiency expressed as fraction)
Fgreen = 0.167 (fraction green completions)
Eflare,completion = 0.552 [tOll/yi]
Therefore:
EOT1^-™nl=l-84x62(l-0.833x(0.898)x(0.98)-0.167)+0.552
E completion, TOTAL — 11,95 j f 011 /\ 1 |
3.19 Wellhead Compressor Engines
Wellhead compressor engines are generally small natural gas-fired engines located at the
well site and used to boost produced gas pressure from downhole pressure to the required
pressure for delivery to a transmissions pipeline. Compressor engines may also be used to assist
in removal of accumulated liquids in the wellbore (artificial lift), or as vapor recovery units to
collect vapors from various equipment on the wellpad for routing to a control device or sales
line. The fractional usage of these engines will depend on the basin characteristics; hence for
those basins that largely require wellhead compression, this may be a significant nonpoint source
of NOx emissions. Figure 3-17 shows two wellhead compressor engines in the Barnett shale.
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Nonooint Oil and Gas Emissions Estimation Tool
Figure 3-17. Wellhead Compressor Engines
Compressor engines found at a wellhead were categorized into two main categories in
this analysis and thus emissions are estimated for each type of engine and consequently
extrapolated to county-wide emissions. These categories of compressors are:
• Rich burn compressors
• Lean burn compressors
The basic methodology for estimating emissions from wellhead compressor engines is
shown in Equation 61:
^ x HP x LF x t al „
Equation 61) Emgine Jype = x (1 - Fcontrolled x ( /¦ ,)
y\J / ,1oj
where:
Eengine,type are emissions from a particular type (rich vs. lean) of compressor engine
[ton/yr/engine]
EFi is the emissions factor of pollutant i [g/hp-hr] (note that this may be different for NOx
emissions from rich-burn vs. lean-burn engines)
HP is the horsepower of the engine [hp]
LF is the load factor of the engine
tannmi is the annual number of hours the engine is used [hr/yr]
Fcomroiied is the fraction of compressors of a particular type (rich vs. lean) that are controlled
CFi is the control factor for controlled engines for pollutant i
907,185 is the unit conversion factor g/ton
Extrapolation to countv-level emissions
County-level emissions are made up of the combination of emissions from each type of
wellhead compressor, rich burn and lean burn. Emissions are scaled to county level using the
usage fraction (F) of each engine type against all other compressor engines, the fraction of wells
with wellhead compressor engines, and the total gas well count in a county, according to
equation below:
Equation 62) £'engine^TOTAL ^J^rich^engin%rich -^leatfiengine}ean)^^^gas ^ fwellhead
where:
Eengine,total is the total emissions from wellhead compressor engines in a county [ton/yr]
Frich is the fraction of rich-burn wellhead compressors in the county amongst all wellhead
compressors
Eengine,rich is the total emissions from a single rich burn compressor engine per Equation (61)
[ton/yr]
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Nonooint Oil and Gas Emissions Estimation Tool
Fiecm is the fraction of lean-burn wellhead compressors in the county amongst all wellhead
compressors
Eengine.iean is the total emissions from a single lean burn compressor engine per Equation (61)
[ton/yr]
Wgas is the total gas well count in a county
jwellhead is the fraction of all gas wells in the county with wellhead compressor engines
Example Calculation for Rich-Burn Wellhead Compressor:
Using the equations provided above, NOx emissions from rich-burn wellhead compressor
engines in Cleburne County, Arkansas were calculated as follows:
F = annual y(1 F XCF )
rich i oc cotitvollcd. '
EF x HP xLFxt„
907,185
where:
E engine, rich = emissions from a rich-burn wellhead compressor engine [ton/yr/engine]
EF = 8.24 [g/hp-hr]
HP = 105.5 [hp]
LF = 0.77 (load factor for the engine)
tannmi = 8,370 [hr/yr]
Fcontrolled = 0.44 (fraction of engines controlled)
CI =0.90 (control factor)
907,185 [g/ton]
Therefore:
8.24x105.5x0.77x8,370 „ „ . . n
Eengine,rich = x(l -0.44x0.90)
E engine, rich = 3.73 [ton/yr/engine]
Total NOx emissions from all rich-burn wellhead compressor engines in Cleburne County
can be evaluated as follows:
^engine, rich,TOTAL X^rich ^ ^engine, rich J^^^gas ^ fwellhead
where:
E engine, rich, total = total emissions from rich-burn compressor engines in a county [ton/yr]
F rich = 0.490 (fraction of rich burn engines)
E engine, rich = 3.73 [ton/yr/engine]
Wgas = 490 [wells]
/ wellhead = 0.0845 (fraction of gas wells with compressor engines)
Therefore:
E™g™,ti
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Nonooint Oil and Gas Emissions Estimation Tool
E engine, rich, TOTAL, =75.7 [tOHs/NOx/yi]
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Nonooint Oil and Gas Emissions Estimation Tool
4.0 Tool Nonpoint Oil and Gas Emissions Summary
Table 4-1 presents a summary of nonpoint oil and gas emissions generated by the tool by
state for 2020.
Table 4-1. State-wide Tool Emissions Estimates
Total HAP
State
NOx (TPY)
VOCs (TPY)
CO (TPY)
(TPY)
Alabama
4,010
9,725
5,729
405
Alaska
2,413
9,402
4,580
775
Arizona
8
20
12
1
Arkansas
4,203
7,804
3,950
376
California
753
145,898
1,729
10,359
Colorado
24,960
60,554
33,031
6,037
Florida
24
496
65
24
Idaho
2
6
3
<1
Illinois
13,394
53,286
20,365
390
Indiana
2,619
11,893
3,697
88
Kansas
22,168
55,787
32,873
1,367
Kentucky
12,086
35,879
17,792
801
Louisiana
19,205
57,837
27,002
6,711
Maryland
<1
1
1
<1
Michigan
9,017
11,122
12,777
544
Mississippi
1,748
6,380
2,759
260
Missouri
370
812
568
8
Montana
2,055
28,798
3,436
1,615
Nebraska
293
1,794
457
22
Nevada
3
122
8
3
New Mexico
62,997
231,810
91,980
18,716
New York
734
5,640
1,040
111
North Dakota
39,061
233,539
43,690
16,241
Ohio
1,729
17,689
2,365
565
Oklahoma
32,818
163,634
35,977
5,731
Oregon
10
17
14
1
Pennsylvania
34,380
122,091
48,764
25,134
South Dakota
181
1,207
151
57
Tennessee
774
2,184
1,155
41
Texas
191,922
1,236,194
288,369
44,193
Utah
7,001
46,255
10,797
1,603
Virginia
3,498
8,684
4,994
498
West Virginia
20,340
152,749
31,844
11,366
Wyoming
16,427
81,188
25,068
3,932
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Nonooint Oil and Gas Emissions Estimation Tool
Table 4-1. State-wide Tool Emissions Estimates
State
NOx (TPY)
VOCs (TPY)
CO (TPY)
Total HAP
(TPY)
Total
531,202
2,800,498
757,044
157,975
While there is some variability in emissions due to regional and basin-specific factors
such as the VOC weight percent in natural gas, in general, the relative magnitude of state-wide
emissions is dependent on the level of oil and gas activity in each state. As shown in Table 4-1,
the highest emissions occur in those states with the highest oil and gas production.
Table 4-2 presents a summary of national emissions for 2020 for each source category as
calculated by the tool.
Table 4-2. Source Category Tool Emissions Estimates
NOx
VOCs
CO
Total HAP
Source Category
(TPY)
(TPY)
(TPY)
(TPY)
Artificial Lifts
128,310
14,494
187,479
14,479
Associated Gas
19,735
295,047
87,400
33,577
CBM Dewatering Pump Engines
<1
<1
<1
<1
Condensate Tanks
3,206
431,258
14,198
8,045
Crude Oil Tanks
3,417
732,926
15,133
18,952
Dehydrators
531
102,380
1,232
65,600
Drill Rigs
39,660
1,655
6,061
855
Fugitives
<1
240,627
<1
1,244
Gas-Actuated Pumps
<1
156,446
<1
1,178
Heaters
29,660
2,803
42,809
976
Hydraulic Fracturing
20,558
823
2,777
442
Lateral/Gathering Compressor Engines
118,887
3,518
168,408
2,769
Liquids Unloading
104
95,319
462
450
Loading Emissions
<1
36,221
<1
867
Mud Degassing
<1
24,012
<1
90
Pneumatic Devices
<1
527,562
<1
3,048
Produced Water
<1
87,411
<1
268
Well Completions
410
42,266
1,816
742
Wellhead Compressor Engines
166,723
5,730
229,270
4,394
Total
531,202
2,800,498
757,044
157,975
As Table 4-2 illustrates, NOx emissions are largely dominated by wellhead and lateral
compressor emissions. This is particularly true for states with a large number of active gas wells.
Other significant sources of NOx include artificial lift engines, drill rigs, and well-site heaters.
Pneumatic devices, crude oil storage tanks, and condensate tanks are the most significant sources
100
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Nonooint Oil and Gas Emissions Estimation Tool
of VOC emissions in many states. Other key sources of VOC emission include associated gas,
dehydrators, and fugitives (equipment leaks).
101
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Nonooint Oil and Gas Emissions Estimation Tool
5.0 NEI Nonpoint Oil and Gas Emissions Summary
To develop emissions estimates for the nonpoint oil and gas sector in the 2020 NEI, some
states relied on the tool described in detail in this report. While there is much overlap between
the NEI and the tool, it is worth emphasizing again that the tool is not the oil and gas sector NEI.
For many states, the nonpoint oil and gas sector data submitted for inclusion in the NEI are
exactly the same (or very close to the same) as the data generated by the tool. This is true for
states like Oklahoma that participated in the CenSARA study and which provided corrections
and additional input during the development of the tool and which used the tool to generate the
data that were submitted to the NEI. This is also the case for states like North Dakota that
accepted the NEI emissions data for this sector that were generated by EPA using the tool. In
other cases, (e.g., Texas), states have collected data from oil and gas operators directly and have
supplemented that data with data from the tool as needed. And still other states (e.g.,
Pennsylvania) have used the tool in an iterative fashion, generating separate sets of emissions
using specific emission factors, activity values, and input parameters selected to reflect a variety
of source categories (e.g., coal-bed methane wells, conventional gas wells, unconventional wells)
and summed the results (on a county-by-county basis) to yield a more accurate representation of
emissions from this sector in their states. In short, the tool has been used to inform the NEI, but
the parameters incorporated into the tool (and the emissions generated by the tool) may or may
not be the same as the data incorporated into the NEI.
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Nonooint Oil and Gas Emissions Estimation Tool
6.0 Recommended Improvement activities for future Nonpoint Oil
and Gas Emission Inventories
The nonpoint oil and gas emissions estimation tool developed under this effort provides
EPA with default emission estimates for each oil and gas producing county in the country. As
mentioned above, these estimates have been used by EPA to gapfill the NEI when state-supplied
data is unavailable. Currently, emission estimates in the tool are based on process
characterization data and emission factors developed by CenSARA, EPA, the WRAP, and
numerous state and local air quality agencies. As available, the data included in the tool is
resolved spatially down to the county level to provide a greater geographic specificity. For some
areas of the country, region specific information was not available and the tool has been
populated for these areas using default data from the CenSARA inventory or from EPA. It is
expected that these areas have their own unique characteristics that are not reflected in the data
currently used in the tool.
Many states, intergovernmental agencies, and other groups have developed their own oil
and gas nonpoint emission inventories using localized data such as air permitting records and
drilling permits and authorizations and have submitted these inventories to EPA for inclusion in
the NEI. Additionally, EPA anticipates that substantial amounts of new information on the oil
and gas sector will become available in the coming years from a variety of ongoing studies being
conducted by government, academic, and industry researchers and organizations. For example,
the required reporting of GHG emissions and other data by the oil and gas sector under Subpart
W of GHGRP continues to expand, and the recent changes to the New Source Performance
Standards (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAP)
applicable to this industry have required much more detailed monitoring and recordkeeping than
this industry was subject to even three or four years ago. As such, EPA continues to review
information and data from these sources as they become available for potential incorporation into
the tool.
Given the above, the following recommended improvements are presented for
consideration for future development and refinement of the tool:
• Continued coordination between EPA. states, and intergovernmental aeencies to
exchange and share information from their oil and eas nonvoint source inventory
vroerams. Many states have compiled nonpoint emission estimates and
methodologies for oil and gas sources. For example, TCEQ's oil and gas inventory
served as the starting point for development of the CenSARA inventory, which was
then developed further into the tool; Pennsylvania has developed a specific emissions
inventory for unconventional exploration and production; and Wyoming inventories
individual oil and gas well pads. A free and open exchange of data, including
mechanisms to make such data sharing easy for all users, would be beneficial to all
parties. This is especially important for states that have relied on their own data with
or without supplementing that data with data from the tool. In addition, it would be
helpful to compare inventories compiled by states to what is generated by the tool,
especially in cases where the state estimates and the tool estimates differ
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Nonooint Oil and Gas Emissions Estimation Tool
dramatically. This comparison would help facilitate much-needed quality control
analysis. This is especially important where emission methodologies differ as, for
example, where states rely on individual company submissions for each individual
wellhead site and the tool relies on county-level activity factors and process
characterization data. The National Oil & Gas Emissions Committee has created an
information repository to facilitate such information transfer
(http ://vibe. cira. colo state. edu/OGEC/).
• Conduct data collection surveys in areas not under the CenSARA domain. In
addition to reaching out to interested states and intergovernmental agencies that are
currently collecting data or estimating emissions from nonpoint oil and gas sources,
additional surveys should be conducted to obtain basin-specific process
characterization data for areas of the country that are not currently well characterized
in the tool.
• Add processes, control devices, and source cateeories. Additional processes such as
saltwater injection, vapor recovery unit engines, turbines, flares (as a separate source
type), construction and workover equipment, and other source categories could be
added to the tool as suggested by stakeholders.
• Update emission estimation methodoloeies to account for electric-vowered
equipment. Many wellhead sites, especially those in urban areas with access to
electrical power, are being hooked up to the grid to power equipment currently
powered by field gas. Including options in the tool to identify the fraction of units
powered by electricity would help refine the emission estimates for affected
categories.
• Allow for various levels of eranularitx. The ability to perform more granular
estimates at the sub-basin, field, or formation level or for well type (e.g. conventional
and unconventional) or age could be beneficial for states that have those data
available. A less granular approach may be best where detailed sub-basin data are
lacking.
• Improve the tool reports capability. The tool could be modified to facilitate
generation of additional reports requested by stakeholders, which would aid in data
analysis and quality assurance operations.
• Consider addine a module to evaluate midstream oil and eas emissions. A number
of states collect point-source emissions data from midstream oil and gas companies
and submit that data to the NEI. For states that do not collect point-source midstream
data, it would be helpful to include nonpoint emissions module for this sector. In
addition, the demarcation between the midstream and upstream sectors could be made
more clear to determine exactly what the tool currently covers, and what it does not.
Alternatively, an entirely separate midstream tool could be developed.
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Nonooint Oil and Gas Emissions Estimation Tool
Appendix A - Instructions for Using the EPA Nonpoint Oil and Gas Emissions
Estimation Tool, Exploration Module (7/27/2022)
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Nonooint Oil and Gas Emissions Estimation Tool
Instructions for Using the 2020 EPA Nonpoint Oil and Gas Emissions Estimation Tool,
Exploration Module (7/27/2022)
1.0 Introduction
Under Work Assignment with U.S. EPA, Eastern Research Group, Inc. (ERG) was tasked to develop a tool that
state, local, and tribal (SLT) agencies could use to develop a nonpoint source emission inventory for upstream oil
and natural gas activities. To this end, ERG prepared the EPA Nonpoint Oil and Gas Emissions Estimation Tool
for the 2011 base year to assist agencies in compiling, allocating, and adjusting upstream oil and natural gas
activity data, and developing county-level nonpoint source emission estimates.
In support of the 2014 NEI, U.S. EPA directed ERG to redesign the Tool to enhance the User experience. Such
enhancements included, but were not limited to: 1) the development of a "Dashboard View" to guide the User; 2)
the creation of data entry forms; 3) the creation of a MS Excel-based data import/export utility; 4) ability to view
EPA default data; and 5) more flexibility in how data are presented. As part of this work and to increase the
efficiency, the Tool was split into two separate modules (i.e., two separate databases): exploration activities and
production activities. These instructions address use of the exploration module.
For the 2017 NEI, U.S. EPA directed ERG to build upon the re-engineered Production and Exploration Tools to
reflect 2017 activity, as well as include additional PM species, update county FIPS code changes, and include
new source categories and pollutants, when available.
For the 2020 NEI, EPA included basin-level speciation and non-speciation factor updates. The tool generated
estimates for 57 source classification codes (SCCs) and 70 pollutants. Where state or local data were not
submitted to the NEI, EPA uses the estimates generated for inclusion in the 2020 NEI.
2.0 MS-Access Databases
The Nonpoint Oil and Gas Emissions Estimation Tools were programmed in MS-Access. This platform offered
several advantages, particularly in accessibility (software is available to most users), familiarity (MS-Access is
used by most SLT agencies in preparation of Emission Inventory System (EIS) data files), and portability (the tool
modules can be e-mailed as zipped files that are less than 25 MB each in size).
Included with the tool are the "area_bridgetool" blank staging tables which are to be used for preparation of EIS
data files.
3.0 Tool Data Flow
The basic concept of the tool is to calculate the source category emissions using the activity data, emission
factors, and basin factors. A conceptual flow is:
Inputs-Activity
Emission Factors
Source Category Emissions
¦?
Basin Factors
EIS Base Table
Compiled Emissions
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Nonpoint Oil and Gas Emissions Estimation Tool
4.0 Steps for Using the Oil and Natural Gas Tool for Exploration Sources to Generate Emissions
In this section, steps will be outlined to generate emissions from the Exploration sources.
Note: If the User will be editing an existing version of the database and wishes to reset the tool and regenerate
the emissions, the following steps are recommended:
a. Click on the "Reset All Selections/Go to Step 1" button at the top of the Dashboard; and
b. Compact and Repair the database.
4.1 Preparation
Prior to running the tool, the User must properly link the data tables in the Nonpoint Emissions Staging Tables
within the tool. To do this, follow the instructions below:
1) Place both the "OIL GAS TOOL 2020 NEI EXPLORATION V1. 3.accdb" and the
"area_bridgetool.accdb" database tables in the same directory. It is recommended that the User creates
an "EPA_OIL_GAS_2020" directory on their hard drive.
2) Open the "OIL_GAS_TOOL_2020__NE!_EXPLORATION_V1_3.accdb" database. You will need to
"Enable Content" if the message pops up.
SECURITY WARNING Some active content has been disabled. Click for more details.
© «
Enable Content
Custom
RESET
GO TO DASHBOARD
„t! GO TO HOME
I "lil EPA Oil and Gas - Exploration Activities X|
EPA Oil and Gas Tool, 2020 NEI Versib
Module
Click on the
"Enable
Content" button
Activities
Welcome to the U.S. Environmental Protection Agency (EPA) Oil and Gas Tool - Exploration Activities Module. This Module
allows the User to generate county-level emission estimates of criteria and hazardous air pollutants (CAPs and HAPs) for oil
and gas source categories related to exploration activities. When finished, data can be exported to Emission Inventory
System (EIS) Staging tables.
To begin, first link to the EIS Staging tables in the area_bridgetool.accdb database. When finished, please click the "BEGIN"
button below to make your geographic and source category selections.
LINK TO EIS
STAGING TABLES
BEGIN (go to
DASHBOARD VIEW)
CLICK FOR A LIST OF
UPDATES TO THIS
VERSION OF THE
TOOL
3) Click on the "LINK TO EIS STAGING TABLES" button, and a pop-up box will appear. Follow the
instructions to link in the EIS Staging tables in the "area_bridgetool.accdb" database (see figure below). If
successfully linked, 10 tables will be linked.
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Nonpoint Oil and Gas Emissions Estimation Tool
m Link EIS Tables
Link EIS Tables
EIS Import Tables
Status Table Name
-fl
ControlApproach
ControlMeasure
ControlPollutant
Click on the "Select Source
Database" button, and locate
the "area_bridgetool_v2.accdb"
database
When finished. Click here.
4) Once you have identified the location of the "area_bridgetooLv2.accdb" database to link, click on the
"Link Tables" button. If successful, 10 tables will be linked. When finished click on the "When finished,
Click here." button.
H Link EIS Tables
Link EIS Tables
EIS Import Tables
Status Table Name
ControlApproach
S
ControlMeasu££_
~" Conbro
Successful:
Once you have identified the
"area_bridgetool_v2.accdb"
database, click on the "Link
Tables" button
Unsuccessful:
C:\WORK\OIL_GAS\2020\INVENTORY\INVENTORYWIS_
VORX Varea_bridgetool.,
Select Source Database Link Tables
•
When finished. Click here.
5) Click the "BEGIN (go to DASHBOARD VIEW)" button to go to the Dashboard View.
6) In the Dashboard View, there are 10 tabs labeled Steps 1 through 10. The User will need to follow all ten
steps in order to generate the emission estimates.
4,2 Steps to Generate Emissions
1) Step 1 - Select the Geographic Level. In Step 1, the User selects the geographic-level of the emissions
inventory based on interest. On this page, the User will see some of the Geographic Area Type maps
which include: EIA Supply Region; EPA Regional Offices; NEMS Regions; Ozone Attainment Status;
Regional Planning Organization; or Subpart W Basin. Most Users will select the "STATE" view. When
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Nonpoint Oil and Gas Emissions Estimation Tool
finished, click the "When finished, click here to complete this step." button, A message box will appear
instructing the User to proceed to Step 2.
2D Geographic and Source Selections
Oil and Gas Tool: Explora
Step o - View/Edit Basin Factors [ _j|i |i i 'iill111 il'iiiT
Step 1 - Select Geographic Level step 2 - Select Sp
Step 1 -
Select a
geographic
level.
ies - Dashboard View
tep 8 - Po«it Source Activity Adjustments ) Step 9 - Point Source Emission Adjustments | Step 10 - Final Emissions | Master References
| Step 3 - Select Source Categor y Level j Step 4 - Select Specific Source Category ' Step 5 - View/Edit County-Level Activity Data
Please select the geographic level at which you are generating emission estimates.
EIA Supply Region
AREA_TYPE
PICK_ONE •
EIA SUPPLY REGION
K8
EPA REGION
~
NATIONWIDE
~
NEMS REGION
OZONE ATTAINMENT STATUS
E
REGIONAL PLANNING ORGANIZATION
~
STATE
m
SUBPART W BASIN
q
1 H
When
finished, click
here to
complete this
step.
I Record: H < 4 of 8
No Filter Search
1
After making
the selection,
click this
button.
2) Step 2 - Select Specific Geographic Location. Click the "Step 2 - Select Specific Geographic Location"
tab to continue. In Step 2, the User selects the specific geographic location of interest. The User may
select more than specific location. When finished, click the "When finished, click here to complete this
step." button. A message box will appear instructing the User to proceed to Step 3.
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Nonpoint Oil and Gas Emissions Estimation Tool
3) Step 3 - Select the Source Category Level. Click the "Step 3 - Select Source Category Level" tab to
continue. In Step 3, the User can either pick to generate emission estimates for all oil and gas exploration
source categories or individually select source categories. When finished, click the "When finished, click
here to complete this step." button. A message box will appear instructing the User to proceed to Step 4.
ff] Geographic and Source Selections
Oil and Gas Tool: Exploration Activities - Dashboard View
Back to Home Page
I
Reset All Selections/Go to Step 1
I
Step 6 - View/Edit Basin Factors
Step 1 - Select Geographic Level
Step 7 - View/Edit Emission Factors Step 3 - Point Source Activity Adjustments Step
1 Step 2 - Select Specific Geographic Location | Step 3 - Select Source Category Level
Please select the source category level at which you are generating emission estimates.
SOURCE_CATEGORY
PICK_ONE
0
•
LL OIL AND GAS EXPLORATION SOURCE CATEGORIES
~
SELECT OIL AND GAS EXPLORATION SOURCE CATEGORIES
H
*
1 IB 1
Step 3 - Select the
Source Category level.
Master References
County-Level Activity Data
When
finished, click
here to
complete
this step. =
After making the
selection(s), click
this button.
4) Step 4 - Select Specific Source Category. Click the "Step 4 - Select Specific Source Category" tab to
continue. In Step 4, the User can select the specific Source Categories to generate emission estimates. If
in Step 3, the User selected "ALL OIL AND GAS EXPLORATION SOURCE CATEGORIES", then all
source categories will be checked. At this point, the User may choose to deselect certain source
categories. When finished, click the "When finished, press here" button. A message box will appear
instructing the User to proceed to Steps 5, 6, and 7 to review/edit the activity data, basin factors, and
emission factors; or to proceed directly to Step 8 for Point Source Activity Adjustments.
|=U Geographic and Source Selections
Oil and Gas Tool: Exploration Activities - Dashboard View
Back to Home Page ^ResetAl^elertions/Goto^e^^j EXITTOOL
Step 6 - View^dit Basin Factors
Step 1 - Select Geographic Level
Step 7 - View/Edit Emission Factors _J_ Step 8 - Point Source Activity Adjustments | Step 9 - Point source mission Agistments
J Step 2 - Select Specific Geographic Location [ Step 3 - Select Source Category Level Step 4 - Select Specific Source Category
Step 4 - All Source
Categories are selected.
t source bmtssion Agistments step iu - unai Emissions ¦ wist
Please select the specific source categor(ies) for which you are generating emission estimates.
.tep iu - unai Emissions Mister References
Step 5 - View/Edit County-Level Activity Data
SOURCE_CATEGORY
see
SCC_DESCRIPTION
PICK_AT_LEAST_ONE -
2310000220
Oil And Gas Exploration Drill Rigs
D
HYDRAULIC FRACTURING
2310000660
Oil & Gas Expl & Prod /All Processes /Hydraulic Fracturing Engines
n
When
finished, press
here
MUD DEGASSING
2310023606
On-Shore CBM Exploration /Mud Degassing
m
MUD DEGASSING
2310111100
On-Shore Oil Exploration /Mud Degassing
ia
MUD DEGASSING
2310121100
On-Shore Gas Exploration /Mud Degassing
m
/
WELL COMPLETIONS
2310023600
On-Shore CBM Exploration: CBM Well Completion: All Processes
m
WELL COMPLETIONS
2310111700
On-Shore Oil Exploration: Oil Well Completion: All Processes
n
WELL COMPLETIONS
2310121700
On-Shore Gas Exploration: Gas Well Completion: All Processes
After making the
*
selection(s), click
this button.
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Nonooint Oil and Gas Emissions Estimation Tool
If in Step 3, the User selected "SELECT OIL AND GAS EXPLORATION SOURCE CATEGORIES", then
no source categories will be checked. At this point, the User will select one or more source categories.
When finished, click the "When finished, press here" button. A message box will appear instructing the
User to proceed to Steps 5, 6, and 7 to review/edit the activity data, basin factors, and emission factors;
or to proceed directly to Step 8 for Point Source Activity Adjustments.
"^fl Geographic and Source Selections
Oil and Gas Tool: Exploration Activities - Dashboard View
Back to Home Page f fl~Reset All Selections/G^^tep 1 [ |[ EXITTOQ^^"
Step 4 - No Source
Categories are selected.
Step 6 • View/Edit Basin Factors ( Step 7 • View/Edit Emission Factors j Step 8 - Point Source Activity Adjustments ] Step 9
Step 1 - Select Geographic Level | Step 2 - Select Specific Geographic Location | Step 3 - Select Source Category Level | Step 4 - Select Specific Source Catego
Please select the specific source categor(ies) for which you are generating emission estimates.
^ Mast
Master References
Step 5 - View/Edit County-level Activity Data
SOURCE_CATEGORY
DRILL RIGS
HYDRAULIC FRACTURING
MUD DEGASSING
MUD DEGASSING
MUD DEGASSING
WELL COMPLETIONS
WELL COMPLETIONS
WELL COMPLETIONS
SCC - SCC_DESCRIPTION
2310000220 Oil And Gas Exploration Drill Rigs
2310000660 Oil & Gas Expl & Prod /All Processes /Hydraulic Fracturing Engines
2310023606 On-Shore CBM Exploration /Mud Degassing
2310111100 On-Shore Oil Exploration /Mud Degassing
2310121100 On-Shore Gas Exploration /Mud Degassing
2310023600 On-Shore CBM Exploration: CBM Well Completion: All Processes
2310111700 On-Shore Oil Exploration: Oil Well Completion: All Processes
2310121700 On-Shore Gas Exploration: Gas Well Completion: All Processes
PICK_AT_LEAST_ONE -
~
n
0
E
~
0
e
G
When
finished, press
here
After making the
selection(s), click
this button.
5) Step 5 - View/Edit Countv-Level Activity Data. Click the "Step 5 - View/Edit County-Level Activity Data"
tab to continue. In Step 5, the User can view and edit the activity data that EPA has compiled for the
geographic area and source categories selected.
Geographic ana Source Selection!
Oil and Gas Tool: Exploration Activities - Dashboard View
^^^ac^^om^age=^^^e5envl^elections/Got^tein^^^^EXr^OO^^™
Step 6 - View/Edit Baan Factors Step 7 - ViewyEdit Emission Factors Step 8-Point Source Activity Adjustments Step 9 - Point Source Emission Adjustments Step 10-Final Emissions Master References
Step 1 - Setect Geographic Level Step 2 - Select Specific Geographic Location Step 3 - Select Source Category Level Step 4 • Select Specific Source Category Step 5 - View^dt Cointy-LeveJ Acttvrty Data
Please setect the source category you would Ike to view/edit.
To continue with this step, the User will need to pick an activity dataset to view/edit. If the "Drilling and
Mud Degassing Activity" button is chosen, the User will then be asked to choose a well type.
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Nonpoint Oil and Gas Emissions Estimation Tool
Pal Geographic and Source Selectionsj =1] County Level Activity Data Sets
COUNTY-LEVEL DRILLING AND MUD DEGASSING ACTIVITY DATA ENTRY FORM
Click on the county-level well type data set you wish to view/edit.
Oil Wells
Gas Wells
CBM Wells
When finished,
click here
Once the well type is selected, an Activity Data form will appear that the User can view or edit. To get to
the next county, at the bottom of the screen is the record number. Use the triangle arrows to move
through the counties.
phic and Source Selections X |:" County Level Activity Data Sets X^^^Activrt^Dat^^l^Well^^X
COUNTY-LEVEL DRILLING AND MUD DEGASSING ACTIVITY DATA ENTRY FORM - OIL WELLS
State Abbreviation |ar
State and County FIPs Code 05027
County Name Columbia
Basin Name Louisiana-Mississippi Salt Basins
Year 2020
County-Level Oil Well Spud Counts, Vertical Drilled Wells
County-Level Oil Well Spud Counts, Horizontal Drilled Wells
County-Level Oil Well Spud Counts, Directional Drilled Wells
County-Level Oil Well Spud Counts, Unknown Drilled Wells
County-Level Oil Well Depth Drilled, Vertical Drilled Wells
County-Level Oil Well Depth Drilled. Horizontal Drilled Wells
County-Level Oi
County-Level Oi
If new values are
entered, please enter a
reference.
When finished,
dick here
The User may also edit activity data in MS-Excel by using the "Import/Export Data..." button.
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Nonpoint Oil and Gas Emissions Estimation Tool
f5 Geographic and Source Selections X j]js] County Level Activity Data Sets X I Activity Data - Oil Wells XI
COUNTY-LEVEL DRILLING AND MUD DEGASSING ACTIVITY DATA ENTRY FORM OIL WELLS
State Abbreviation |AR
State and County FIPs Code 05027
County Name Columbia
Basin Name Louisiana-Mississippi Salt Basins
Year 2020
Filter for this Basin only Remove Basin Filter
Values here can be edited
Current Value
Current Value Reference
2017 Value
2017 Reference
Applicable Source Categories
County-Level Oil Well Spud Counts, Vertical Drilled Wells
0
ENVERUS.2021
3
HPDI_2018
Mud Degassing
County-Level Oil Well Spud Counts, Horizontal Drilled Wells
0
ENVERUS.2021
0
HPDI.2018
Mud Degassing
County-Level Oil Well Spud Counts, Directional Drilled Wells
0
ENVERUS.2021
0
HPDI.2018
Mud Degassing
County-Level Oil Well Spud Counts, Unknown Drilled Wells
2
ENVERUS.2021
0
HPDI.2018
Mud Degassing
County-Level Oil Well Depth Drilled, Vertical Drilled Wells
0.00
AVG.WELL_DEPTH.AR
16,628.57
HPDI.2018.RIGDATA
Drilling Rigs
County-Level Oil Well Depth Drilled, Horizontal Drilled Wells
0.00
AVG_WELL.DEPTH.AR
0.00
HPDI.2018.RIGDATA
Drilling Rigs
County-Level Oil Well Depth Drilled, Directional Drilled Wells
0.00
AVG.WELL_DEPTH.AR
0.00
HPDI.2018.RIGDATA
Drilling Rigs
County-Level Oil Well Depth Drilled, Unknown Drilled Wells
12^08.00
AVG_WELL.DEPTH.AR
0.00
HPDI.2018.RIGDATA
Drilling Rigs
When finished,
click here
If the user elects to edit activity data iri MS-Excel, after clicking the button, the data is then exported into
MS-Excel as shown below.
Import/Export Data
Import/Export Data
Data Activity Oil Well
Export Import ©Help
Export the data to an Excel file
Step 1 - Export activity
data to Excel.
(It is recommended that
you save this file for later
upload.)
([ Export to Exce^^J)**,,,*,,'"^
A MS-Excel workbook will open when finished exporting. It is required that the User save this file to the
hard drive for later upload. In the Excel file, the User can only edit the yellow shaded cells. When
completed, simply save the file.
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Nonpoint Oil and Gas Emissions Estimation Tool
STATE_At
AR
STATE.COUNTY
05001
COUNTY_NAME
Arkansas
BASIN
Louisiana-Mississippi Salt Basins
YEA
202
DAT A_CATEGORY
County-Level Oil Well Spud Counts, Unknown Drilled Wells
PREVIOUS. tfj
0
PREVIOUS_REFE
HPDL2018
CURRENT VA
0 /
CURRENT REFERENC
ENVERUS_£S£1
AR
05001
Arkansas
Louisiana-Mississippi Salt Basins
202
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0 /
ENVERUS_202V
AR
05003
Ashley
Louisiana-Mississippi Salt Basins
202
County-Level Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0 /
ENVERUS.2021 \
AR
05003
Ashley
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018.RIGDAT/
0 /
ENVERUS.2021 \
AR
05005
Baxter
Ozark Uplift
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0/
ENVERUS.2021 \
AR
05005
Baxter
Ozark Uplift
202
County-Leva
1PDL2018
ENVERUS.2021 \
AR
05007
Benton
Ozark Uplift
202
County-Lev<
Step 2 - The User can edit
the yellow-shaded cells.
HPDL2018
ENVERUS.2021 \
AR
05007
Benton
Ozark Uplift
202
County-Levf
•0
ENVERUS 2021 \
AR
05009
Boone
Ozark Uplift
202
Couniy-Lev«
HPDL2018
0
ENVERUS.2021 \
AR
05003
Boone
Ozark Uplift
,:u.
County-Lev*
HPDL2018 I
0
ENVERUS 2021 \
AR
05011
Bradley
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021 I
AR
05011
Bradley
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021
AR
05013
Calhoun
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021
AR
05013
Calhoun
202C
Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021
AR
05015
Carroll
Ozark Uplift
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021
AR
05015
Carroll
Ozark Uplift
202
County-Leve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021
AR
05017
Chicot
Louisiana-Mississippi Salt Basins
202
County-Leve
Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021 I
AR
05017
Chicot
Louisiana-Mississippi Salt Basins
202
County-L
VE
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS_2021 /
AR
05019
Ctaik
Louisiana-Mississippi Salt Basins
202
County-L«
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018 \
0
ENVERUS.2021 /
AR
05013
Clark
Louisiana-Mississippi Salt Basins
202
County-L(
ve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021 /
AR
05021
Clay
Illinois Basin
202
County-Leve
Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0
ENVERUS.2021 /
AR
05021
Clay
Illinois Basin
202
County-Leve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
ENVERUS.2021 /
AR
05023
Cleburne
Arkoma Basin
202
County-Level Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
\
ENVERUS.2021 /
AR
05023
Cleburne
Arkoma Basin
2U2
Oil Well Depth Drilled, Unknown Drilled Wells
0
HP0L2018.RIGDAT*
°\
ENVERUS.2021 /
AR
05025
Cleveland
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
o\
ENVERUS.2021 /
AR
05025
Cleveland
Louisiana-Mississippi Salt Basins
202
County-Leve
Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDL2018
0 \
ENVERUS.2021 /
AR
05027
Columbia
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
2 \
ENVERUS_20§/
AR
05027
Columbia
Louisiana-Mississippi Salt Basins
202
County-Leve
I Oil Well Depth Drilled, Unknown Drilled Wells
0
HPDI_2018_RIGDAT
12208 \
AVG_WELL^fiEPTH_AR
AR
05029
Conway
Arkoma Basin
202
County-Leve
I Oil Well Spud Counts, Unknown Drilled Wells
0
HPDL2018
0 \
ENVEBUSC2021
If data edits were made, then the User will need to go back to the Tool and click on the "Import/Export
Data..." button to initiate importing the edited data file. After clicking, the Import/Export form will appear.
The User will need to:
• Step 1 - Click on the "Import" tab,
• Step 2 - Click the "Select File" button
• Step 3 - Map to the location of the edited data, and click "OK"
• Step 4 - Click on the "Import from Excel" button
Import/Export Data
Import/Export Data
Data Activity Oil Well
x Close Form
Step 1 - Click on
. I Hi .it . I
Export ^tmportj0Help
Step 2 - Click on the
"Select File" button
import the Selected Excel File
|c:\WORK\OIL_GAS\RE_ENGINEEmNG\lTERATION_009 2i|l4_NEI
C ^Import From ExcgC} (^Select FileJ)
Step 4 - Click on the
"Import from Excel" button
Step 3 - Map to the
location of the edited data
The edited data is now imported into the Tool.
6) Step 6 - View/Edit Basin Factors. Click the "Step 6 - View/Edit Basin Factors" tab to continue. In Step 6,
the User can view and edit the basin factor data that EPA has compiled for the geographic area and
source categories selected.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Drill Rigs Horizontal
Drill Rigs Vertical
Oil ancHjas Exploration Sources -Uasin Factors
Please click op^tfwSource category below to view/&tHtthe
basin factors.
Hydraulic Fracturing
Mud Degassing
Well Completions
Please click on the source category below to view/edit the gas
on data.
Mud Degassing Gas
Composition Data
Well Completions
Gas Compostion Data /
Step 6 - Pick a source
category basin factor or
gas composition dataset
to view or edit.
i=il Geographic and Source Selections
Oil and Gas Tool: Exploratic
Back to Home Page j^^eseHui Selectio
Step 1 - Select Geographic Level j Step 2 - Select Specifi*
Step 6 - View/Edit Basin Factors [ step 7 - View/Edit Emis!
Please select the source category you would like t<
When finished,
continue to Step 7.
Step 4 - Select Specific Source Category | Step 5 - View/Edit County-Level Activity Data
ep 9 - Point Source Emission Adjustments | Step 10 - Final Emissions ] Master References
When finished, please continue to Step 7 to View/Edit Emission Factors
In the Basin Factors form, the User can view/edit the data. If the User updates values for one county in
basin, then all other counties in the basin and state can be updated by clicking on the "Click to apply
these values to all other counties in the same basin for the state." button. Additionally, the User can
export and import data to MS-Excel similar to the procedure outlined in Step 5.
i^t] Geographic and Source Selections X 3! Basin Factors -
HORIZONTAL DRILLING RIGS BASIN FACTORS FORM
State Abbreviation AR
State and County FIPs Code 05027
County Name Columbia
Basin Name jLouisiana-Mississippi Salt Basins
Seleci>a4fles
:o create a
3 custom filter
zs
The User can filter for
specific locations.
The User can export
and import the data
into MS-Excel.
When finished,
click here
Current Value
Current Value Reference
EPA Default Value
EPA Default Value Reference
2017 Value
2017 Value Reference
Horizontal-Drill Rig Spud Depth (ft/spud)
8800.0 >
—' CEN53»558
CENSARA.STUDY.2012JWERAGE
/1122
CENSARA.STUDYJD12
Horizontal-Draw Rig Load Factor
f 0.67
CENSARA.SnjDY.2012 \
j 0.58
CENSARA.STUDY.2012.AVERAGE
j 0.67
CENSARA.STUDY.20V
Number of Horizontal-Draw Rig Engines (count/rig)
j2
CENSARA.STUDY.2012 \
/ 2
CENSARA_STUDY_2012_AVER<
»GE
/
' CFMSARii ST"nV I(l1 1
Values from the 2017
Horizontal-Draw Spud Duration (hrs/spud)
/ 53&2
CENSARA.STUOY.2012 \
EPA default values
cannot be edited.
GE
Horizontal-Drill Rig Mud Pumps Horsepower (HP)
0
CENSARA.STUDY.2012
5E
Tool. Values here
Horizontal-Drill Rig Mud Pumps Load Factor
0
CENSARA.STUDY.2012
iE
n
cannot be edited.
Horizontal-
Horizontal-
If new values are entered,
please enter a reference.
CENSARA.STUDY.2012
2
CENSARA.STUOY.2012.AVEw
0
CENSARA.STUDY.2012
CENSARA.STUDY.2012_AVER>
;e
0
CENSARA.STUDY.2012
Diesel-Hori
0
CENSARA.STUDY.2012
772
CENSARA.STUDY.2012.AVER/
i
CENSARA.STUDY.2012
Diesel-Hori
zontal Drill Kigs Load Factor
\ 0
CENSARA.STUDY.2012 /
06
CENSARA.STUDY_2012.AVIR
GE
I 0
CENSARA.STUDY.2012
Diesel-Horizontal Drill Rigs Number of Engines (count/rig)
\ 0
CENSARA.STUDY.2012 /
T 2
CENSARA.STUDY.2012.AVEGI
\Gi
\ 0
CENSARA.STUDY.2012/
Diesel-Horizontal Drill Rigs Spud Duration (hrs/spud)
\ °
CENSARA.STUDY.2012 /
\ 200
CENSARA.STUDY.2012.AVJTRAGE
\ 0
CENSARA.STUDY.20l/
Diesel-Electric-Horizontal Drill Rigs Horsepower (HP)
\ 0
CENSARA_STUDY_2012/
ysoo
CENSARA.STUD Y_20! 2AVERAGE
\ 0
CENSARA_STUDY_2p12
Diesel-Electric Horizontal Drill Rigs Load Factor
CENSARA_STUDY_2J>ft
CENSARA_STUDY_201£AVERAGE
\ 0
CENSARA.STUD^2012
Diesel-Electric-Horizontal Drill Number of Engines (count/rig)
0 \
CENSARA_STUO/2012
3\
C ENSARA.STUDVVD12.AVERAGE
CENSARA SjdDY.2012
Diesel-Electric-Horizontal Drill Spud Duration (hrs/spud)
0 N
^ CENSAgA^fuDY.2012
0 \
CENSARASJm6y.20I2.AVERAGE
0 X,
CENJAK^STUDY.2012
Similarly, the User can view/edit the gas composition data for select categories.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
7) Step 7 - View/Edit Emission Factors. Click the "Step 7 - View/Edit Emission Factors" tab to continue, in
Step 7, the User can view or edit the emission factors that are used to generate the emission estimates
for the source categories selected.
u Geographic and Source Selections
Oil and Gas Tool: Exploration Activities - Dashboard View
|| Reset All Selections/Go to Step 1^|| EXITTO
Back to Home Page
Step 1 - Select Geographic Level ! Step 2 - Select Specific Geographic Location Step 3 - Select Sourc
Step 6 - View/Edit Basin Factors Step 7 - View/Edit Emission Factors step 8 - Point Source Activity
Please select the emission factor source category you would like to view/edit.
Step 7 - Pick emission
factors for a source
category to view or edit.
Oil and Gas (Exploration Sources - Emission Factors
Please click on a Source Category below to view/edit
emission [factors.
Step 5 - View/Edit County-Level Activity Data
;p 10 - Final Emissions | Master References
When finished, please continue to Step 8 for Point Source Activity Adjustments
When finished,
continue to Step 8.
Once a Source Category has been selected, the User can view or edit the emission factors. Remember to
update the reference field (EMISSION_FACTOR_SOURCE) for any updated emission factors.
Geographic and Source Selection
I 3 FORM_HYDRAUllC_FRACTURING,Ef X
HYDRAULIC FRACTURING EMISSION FACTORS FORM
ST - BASIN
ATTAINMEN -
SOURCE_CATEGORY -
SCC
SCC_SHOI - POLLUTANT -
POLLUTANT_DESCR - POLLUTAN - EMISS!ON_FA< - E - EMISSK - »
AR ArkomarUasin
AR ArkfJma Basin
"ATTAINMENT
ATTAINMENT
^YDRAUUC FRACTURING
HYDRAUUC FRACTURING
2310000660
2310000660
Oil & Gas Ex Ethylbenzene
Oil & Gas Ex Styrene
Ethyl Benzene 100414
Styrene 100425
9.14K125r04 G HP-HR
f \> G HP-HR
AR /yxoma Basin
ATTAfWMENT HYORAUUC FRACTURING
2310000660
Oil & Gas Ex 1,3-Butadiene 1,3-Butadiene 106990
T958528E-04G HP-HR
AR Arkoma Basin
ATTAINMENT HYORAUUC FRACTURING
2310000660
Oil & Gas Ex Acrolein
Acrolein 107028
B.873381E-03K HP-HR
AR /Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Toluene
Toluene 108883
/7.290602E-03 6 HP-HR
AR / Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Hexane
Hexane 110543
/ 1.266875E-04 Q HP-HR
When
AW Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Polycyclic Orgc Anthracene 120127
/ 2.029268E-05 G\ HP-HR
finished, dick
AR Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Propionaldehy Propionaldehyde 123386
/ 5.410304E-03 G1 HP-HR
here
«R Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Polycyclic Orgs Pyrene 129000
/ 3.171553E-05 G \ HP-HR
IR Arkoma Basin
ATTAINMEN! HYDRAULIC FRACTURING
2310000660
Oil & Gas Ex Xylenes (Mixe< Xylenes (Mixed Isomt 1330207
1 2.696867E-03 G
HP-HR
iVR Arkoma Basin
ATTAINMENT! HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Chromium Cor Chromium (VI) 18540299
6.738941E-09 G
HP-HR
AR Arkoma Basin
ATTAINMENT
HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Polycyclic Orgc Benzo[g,h,i,]Perylene 191242
1.795181E-06 G
HP-HR
HP-HR
AR Arkoma Basin
ATTAINMENT
HY
Emission Factors are
presented at the state,
l&GasEx Polycyclic Org; lndeno[l,2,3-c,d]Pyre 193395
7.030915E-07 G
AR Arkoma Basin
ATTAINMENT
HY
18tGasEx Polycyclic Orgc Benzo[b]Fluoranthem 205992
1.12306E-06 G
HP-HR
AR Arkoma Basin
ATTAINMENT
HY
1 & Gas Ex Polycyclic Orgc Fluoranthene 206440
3.25717E-05 G
HP-HR
AR Arkoma Basin
ATTAINMENT
HY
basin, and attainment
status level.
l&GasEx Polycyclic Org£ 8enzo[k]Fluoranthen< 207089
8.518818E-07 G
HP-HR
AR Arkoma Basin
ATTAINMENT
1 & Gas Ex Polycyclic Orgc Acenaphthylene 208968
2.298891E-04 G
-IP-HR
When
nished,
AR Arkoma Basin
ATTAINMENT
HY
1 & Gas Ex Polycyclic Orgc Chrysene 218019
2.913389E-06 G
HP-HR
f
AR Arkoma Basin
ATTAINMENT
HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Formaldehyde Formaldehyde 50000
5.897982E-02 G
HP-HR
AR Arkoma Basin
ATTAINMENT
HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Polycyclic Orgc Benzo[a]Pyrene 50328
^ 7.133008E-07 G
HP-HR
click here
&R Arkoma Basin
ATTAINMENT
HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Polycyclic Orgs Dibenzo(a.h]Anthrace 53703 J
1.195512E-07 G
HP-HR
4R Arkoma Basin
ATTAINMENT
HYDRAUUC FRACTURING
2310000660
Oil & Gas E
These emission factors
• /
1.635179E-03 G
HP-HR
Lr Arkoma Basin
ATTAINMENT/ HYDRAUUC FRACTURING
2310000660
Oil & Gas E
/
2.30254E-06 G
HP-HR
AR Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas E
can be edited. If changes
/
1 6.861636E-05 G / HP-HR
AR Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas E
are made, please update
the reference.
1 1.006927E-02 G I HP-HR
Aft Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas E
121
\ 5.391868E-06 G / HP-HR
AR\ Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas E
165
\ 2.996139E-06 GJ HP-HR
AR \ Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Mercury Comp Mercury 7439976
\ 1.854732E-08 3 HP-HR
AR Vrkoma Basin
AR Aricoma Basin
ATTAINMENT HYDRAUUC FRACTURING
ATTAINMENT HYDRAUUC FRACTURING
2310000660
2310000660
Oil & Gas Ex Nickel Compoi Nickel 7440020
Oil & Gas Ex Antimony Corr Antimony 7440360
\s.238648E-06 1 HP-HR
V.621601E-06to HP-HR
AR ArRnrna Basin
ATTAINMENT HYDRAULIC FRACTURING
2310000660
Oil & Gas Ex Arsenic Compc Arsenic 7440382
1395385E-O0 G HP-HR
AR Arkom^Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Cadmium Com Cadmium 7440439
5\35112E-(K G HP-HR
AR Arkoma Basin
ATTAINMENT HYDRAUUC FRACTURING
2310000660
Oil & Gas Ex Cobalt Compoi Cobalt 7440484
1.41^15^06 G HP-HR
-------
Nonpoint Oil and Gas Emissions Estimation Tool
8) Step 8 - Point Source Activity Adjustments. Click the "Step 8 - Point Source Activity Adjustments" tab to
continue. After the activity data, basin factors, and emission factors have been reviewed and/or updated,
the User may enter point source activity adjustments to account for emissions that are to be reported to
the point sources emissions inventory. If the User does not have any point source activity adjustments,
then they will need to click the "When finished, click here to complete this step." button. A message box
will appear instructing the User to proceed to Step 9.
Ill Geographk : -«-'Gc to S:*o 1 EXIT TOOL
Step l-Select Geographic level Step 2 - Select Specific Geograpbc Location step 3 • Select Source Category Level Step 4-Select Specific Source Category Step 5 - ViewyEtSt County-Levei Activity Data
Step 6 - Vtew/Edt Basin Factors Step 7 - View^dt Emtsson Factors Step 8 - Point Source Activity Adjustments step 9 - Point Source Emission Adjustments Step 10 - Final Emissions Master References
Please select the source category you would Ike to view/edit to make point source activity adjustments.
Currently, ALL point source activity adjustments (e.g. county-level point source spud counts, county-level
point source feet drilled, county-level well completions, etc.) are defaulted to zero (i.e., no point source
activity adjustments).
Geographic and Source Selections X I (3] TORM.WELL.COMPLEnON_PS_ACTIVITY X|
WELL COMPLETIONS/HYDRAULIC FRACTURING POINT SOURCE ACTIVITY ADJUSTMENT FORM
State abbreviation: AR
State and County FIPs Code: 05027
County name: Columbia
Year 2020|
Point Source Well Completions from Oil Wells
Point Source Well Completions from Gas Wells
Point Source Well Completions from CBM Wells
Point Sources
Conventional
Wells Value
Point Sources
Unconventional
Wells Value*
0
0
0
0
0 0
When
finished, dick
here
* Hydraulic Fracturing point source subtractions are accounted for in "Point Sources Unconventional Wells Value"
-------
Nonpoint Oil and Gas Emissions Estimation Tool
It is encouraged that point source activity adjustments have priority over point source emission
adjustments. Additionally, Users should pay careful attention to ensure that the point source
activity data is entered in the same units as the nonpoint activity data. Users should refer to the
"Nonpoint Source SCCs and Point Source SCCs Crosswalk" button to identify point source SCCs. After
any point source activity adjustments have been made, proceed to Step 9.
9) Step 9 - Point Source Emission Adjustments. Click the "Step 9 - Point Source Emission Adjustments" tab
to continue. In Step 9, the User can make point source emission adjustments directly in the emission
tables. Select a Source Category to open. If a User has no point source emissions adjustments, they may
click on the "When finished, click here to complete this step" button.
"51 Geogr*phK and Source Vrt«tKWi»
Oil and Gas Tool: Exploration Activities - Dashboard View
j^^acktoHom^ag^^^^netAHSe!ectlons/GotoSte|u^^^^^xi^OO^^™
Step I - Select Geographic le.d ' Step 2 - Select Speofic Gcoorapht locabort | Step 3-Select Sotfce Category Lend | Step* - Select Speofic Soutt«C»tegcor j Step S-Wew/Edit County¦LevttAdwayOta
Step 6 • Vew£6tBMn Factors [ Step 7 - view£
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Users can
enter point
source
emissions
adjustments
i'M.'i c V : r IORM wi.it (iiMPiimwiMBSBHS
When
WtLL COMPLETIONS POINI SOURCL EMISSIONS ADJUSI MtN
Hydrogen Sulfide
Metn»ne
Carbon Monoxide
finished,
click here
to finalize
the
emissions.
After point source emission adjustments are made (if applicable), then the User should proceed to Step
10.
10) Step 10 - Final Emissions. Click the "Step 10 - Final Emissions" tab to continue. In Step 10, the User can
review the final emissions, update county-level activity data, emission factors, and basin factors that the
User updated, retain point source activity and/or point source emission adjustments, or generate the
Emission Inventory System (EIS) data tables.
fU Geographic and Source Selection*
ixploration Activities - Dashboard View
set All Selections/GotoStepT^^-DO^OO^-
Oil and Gas Exploration Sources - Summary Emissions
If you updated activity data, and would like to replace the original
values, please click on the appropriate source categories.
Update Wei
Completions and
Hydraulic Fracturing
Activity Data.
If you updated basin factors, and would like to igplaie Hie til iginal
values, please click on the appropriate source categories.
UpdatgJ>i!—*
" Update
Hydraulic
Fracturing
Basin Factors.
Update Mud
Update Wei
Oegassrg
Completions
¦^Factors.
Basin Factors
Basin Factors
If you updated emission factors, and would like to replace the
original values, please click on the appropriate source categories.
Update
Update Dri Hydraulic
Rig Emission Fractumg
Factors. Emission
Factors.
Update Mud
""uBBatsHAieJl
Degassing
Completions
Emission
Emission )"
Factors
Factojv-"^
If you updated lusln factors gas composition data and would liKe
to replace the original values, please click on the appropridl
rce categories.
Update Mud
~lJpB3te-Wiel
Degassing
Completions
Basin Gas
Basn Gas
Composition
Composition
Data
Data
If you made point source activity adjustments, and would like to re-use them, please click on the appropriate source categories.
Save Ord Rigs
point source
activity
adjustments
ii nwip noint snurrp pmissinn ariitistiiipnlv 4IUI wiiulil lih* to rr use llii-m iiIh^P Hii K nn tup annronriatp inurrp ratponripv
Save Hydraulic
Save Mud
Save Wei
Fractumg
Degassing
Completions
point source
pont source
port source
activity
activity
activity
adjustments
adjustments
adjustments
If the User
updated
activity data or
emission
factors, then
they can be re-
used by
clicking here.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Additional notes:
1) In the EIS Staging Tables, the ControlApproach. ControlMeasure, ControlPollutant, Emissions,
EmissionsProcess, Location, and ReportingPeriod are populated.
2) EPA's EIS area_bridgetool (included in the .zip file) can be used to generate the .xml file needed for EIS
upload.
3) If the User wishes to reset the tool, and regenerate the emissions, the following steps are recommended:
a. Click on the "Reset All Selections/Go to Step 1" button at the top of the Dashboard.
b. Compact and Repair the database.
3D Geographic and Source Selections
Oi[and GasJTool: Exploration Activities- Dashboard View
Back to Home Page^^ (^eset All Selections/Go to Step^^
Step 1 - SelecUCeographic Level
Step 6 - View/Eat Basin Factors
Step 2 - Select Specific
Step 7 - View/Edit E
graphic Location
p Factors | Step 3 - Point Source
To return to the
Home page, click
here.
Oil and G
mary Emi:
Emissions
Click here t
generate th
)urce Category
and Pollutant
Emissions
To reset the Tool,
please click here.
Adjustments | Step 9 - Point Source Emission Adjustments
Please select Yhe type of summary emissions you wouVl like to view, or to generate the EIS s^ging tables.
Exploration Sources - S
Source Category
and Pollutant
Emissions by State
Drill Rig
Emissions
Table
Hydraulc
Mud
Wei
Fracturing
Degassing
Completions
Emissions
Emissions
Emissions
Table
Table
Table
Click here to
generate the
calculated
emission
records.
Emission Inventory System (EIS) Staging Tables
Click here to
create EIS
Staging Tables
Click hereto
clear EIS Staging
Tables
If you updated activity data, and would like to replace the original
values, please click on the appropriate source categories.
If you updated emission factors, and would like to replace the
original values, please click on the appropriate source categories.
4) References cited for the original data in the Tool are found in the "Master References" tab.
Step 1 • Select Geographic level
Step 6 ¦ Baan Factors
References are compfed rto a srtgle table. The
Step 2 - Select Soeofc Pooracfrc Location
FIELD_REFERENCE
ALOGC_202l|
AP1_2009b
A VG_WE IL_0£ PTH _A R
AVG_W£lL_0£PTH_CA
AVG_WEU_0€PTH_CO
AVG_WRL_D€PTH_KS
AVG_WEll_D£PTH_LA
A VG_WELL_D€ PTH _M I
AVG_WELL_D£PTH_ND
AVG_WELl_D€PTH_OH
AVG_WELL_D€PTH_OK
AVG_WEU_0€PTH_PA
AVG_WEU_DEPTH_TX
AVG WELL D€PTH_WY
References cited in the Tool
for the original data are here.
Steo 3 - Select Sc^ce Category Level
Step 4 ¦ Select Speoftc Souce Category
Step 9 ¦ Pent Soiree Emsson AcQutSnerts
Step S • Mew£dt Ccwvtylevel Actvtfy Data
Step K) • F*»al Emssons Master References
Vet references entered by the User.
Alabama Oil and Gas Commiss
API Compendium (8/2009), Table
Calculated avg feet per well for®
Calculated avg feet per well for 4
Calculated avg feet per well for a
FIELD_REFER£NCE_D€SCRlPTlON
i. Exploration data downloaded November 2021
|?4-ll
rfcansas wells and applied to missing wells
Lhfornia wells and applied to missing wells
ftlorado wells and applied to missing wells
Calculated avg feet per well for Kansas wells and applied to missing wells
Calculated avg feet per well for Louisiana wells and applied to missing wells
Calculated avg feet per well for Michigan wells and applied to missing wells
Calculated avg feet per well for North Dakota wells and applied to missing wells
Calculated avg feet per well for Ohio wells and applied to missing wells
Calculated avg feet per well for Oklahoma wells and applied to missing wells
Calculated avg feet per well for Pennsylvania wells and applied to missing wells
Calculated avg feet per well for Texas wells and applied to missing wells
Calculated avg feet per well for Wyoming wells and applied to missing wells
-------
Nonooint Oil and Gas Emissions Estimation Tool
Appendix B - Instructions for Using the EPA Nonpoint Oil and Gas Emissions
Estimation Tool, Production Module (7/27/2022)
-------
Nonooint Oil and Gas Emissions Estimation Tool
Instructions for Using the 2020 EPA Nonpoint Oil and Gas Emissions Estimation Tool,
Production Module (7/27/2022)
5.0 Introduction
Under Work Assignment with U.S. EPA, Eastern Research Group, Inc. (ERG) was tasked to develop a tool that
state, local, and tribal (SLT) agencies could use to develop a nonpoint source emission inventory for upstream oil
and natural gas activities. To this end, ERG prepared the EPA Nonpoint Oil and Gas Emissions Estimation Tool
for the 2011 base year to assist agencies in compiling, allocating, and adjusting upstream oil and natural gas
activity data, and developing county-level nonpoint source emission estimates.
In support of the 2014 NEI, U.S. EPA directed ERG to redesign the Tool to enhance the User experience. Such
enhancements included, but were not limited to: 1) the development of a "Dashboard View" to guide the User; 2)
the creation of data entry forms; 3) the creation of a MS Excel-based data import/export utility; 4) ability to view
EPA default data; and 5) more flexibility in how data are presented. As part of this work and to increase the
efficiency, the Tool was split into two separate modules (i.e., two separate databases): exploration activities and
production activities. These instructions address use of the exploration module.
For the 2017 NEI, U.S. EPA directed ERG to build upon the re-engineered Production and Exploration Tools to
reflect 2017 activity, as well as include additional PM species, update county FIPS code changes, and include
new source categories and pollutants, when available.
For the 2020 NEI, EPA included basin-level speciation and non-speciation factor updates. The tool generated
estimates for 57 source classification codes (SCCs) and 70 pollutants. Where state or local data were not
submitted to the NEI, EPA uses the estimates generated for inclusion in the 2020 NEI.
6.0 MS-Access Databases
The Nonpoint Oil and Gas Emissions Estimation Tools were programmed in MS-Access. This platform offered
several advantages, particularly in accessibility (software is available to most users), familiarity (MS-Access is
used by most SLT agencies in preparation of Emission Inventory System (EIS) data files), and portability (the tool
modules can be e-mailed as zipped files that are less than 25 MB each in size).
Included with the tool are the "area_bridgetool" blank staging tables which are to be used for preparation of EIS
data files.
7.0 Tool Data Flow
The basic concept of the tool is to calculate the source category emissions using the activity data, emission
factors, and basin factors. A conceptual flow is:
EIS Base Table
Compiled Emissions
8.0
Steps for Using the Oil and Natural Gas Tool for Production Sources to Generate Emissions
-------
Nonpoint Oil and Gas Emissions Estimation Tool
In this section, steps will be outlined to generate emissions from the Production sources.
Note: If the User will be editing an existing version of the database and wishes to reset the tool and regenerate
the emissions, the following steps are recommended:
c. Click on the "Reset All Selections/Go to Step 1" button at the top of the Dashboard; and
d. Compact and Repair the database
Preparation
Prior to running the tool, the User must properly link the data tables in the Nonpoint Emissions Staging Tables
within the tool. To do this, follow the instructions below:
7) Place both the "OIL GAS TOOL 2020 NEI PRODUCTION V1 3.accdb" and the
"area_bridgetool.accdb" database tables in the same directory. It is recommended that the User creates
an "EPA_OIL_GAS" directory on their hard drive.
8) Open the "OIL_GAS_TOOL_2020_NEI_PRODUCTION_V1_3.acedb" database. You will need to "Enable
Macros" if the message pops up.
CT/ SECURITY WARNING Some active content has been disabled. Click for mo re details.
© «
Enable Content
Custom
RESET
GO TO DASHBOARD
¦EH go to home
~^i] EPA Oil and Gas • Production Activities X|
EPA Oil and Gas Tool, 2020 NEI \
Click on the
'Enable Content"
button
:tion Activities
Module
Welcome to the U.S. Environmental Protection Agency (EPA) Oil and Gas Tool - Production Activities Module. This Module
allows the User to generate county-level emission estimates of criteria and hazardous air pollutants (CAPs and HAPs) for oil
and gas source categories related to production activities. When finished, data can be exported to Emission Inventory
System (EIS) Staging tables.
To begin, first link to the EIS Staging tables in the area_bridgetool.accdb database. When finished, please click the "BEGIN" button
below to make your geographic and source category selections.
LINK TO EIS
STAGING TABLES
BEGIN (go to
DASHBOARD VIEW)
CLICK FOR A LIST OF
UPDATES TO THIS
VERSION OF THE
TOOL
9) Click on the "LINK TO EIS STAGING TABLES" button, and a pop-up box will appear. Follow the
instructions to link in the EIS Staging tables in the "area_bridgetool.accdb" database (see figure below). If
successfully linked, 10 tables will be linked.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
m Link EIS Tables
Link EIS Tables
EIS Import Tables
Status Table Name
-fl
ControlApproach
ControlMeasure
ControlPollutant
Click on the "Select Source
Database" button, and locate
the "area_bridgetool_v2.accdb"
database
When finished. Click here.
10) Once you have identified the location of the "area_bridgetool.accdb" database to link, click on the "Link
Tables" button. If successful, 10 tables will be linked. When finished click on the "When finished, Click
here." button.
H Link EIS Tables
Link EIS Tables
EIS Import Tables
Status Table Name
ControlApproach
S
ControlMeasu££_
~" Conbro
Successful:
Once you have identified the
"area_bridgetool_v2.accdb"
database, click on the "Link
Tables" button
Unsuccessful:
C:\WORK\OIL_GAS\2020\INVENTORY\INVENTORYWIS_
VORX Varea_bridgetool.,
Select Source Database Link Tables
•
When finished. Click here.
11) Click the "BEGIN (go to DASHBOARD VIEW)" button to go to the Dashboard View.
12) In the Dashboard View, there are 10 tabs labeled Steps 1 through 10. The User will need to follow all ten
steps in order to generate the emission estimates.
8.1 Steps to Generate Emissions
11) Step 1 - Select the Geographic Level. In Step 1, the User selects the geographic-level of the emissions
inventory based on interest. On this page, the User will see some of the Geographic Area Type maps
which include: EIA Supply Region; EPA Regional Offices; NEMS Regions; Ozone Attainment Status;
Regional Planning Organization; or Subpart W Basin. Most Users will select the "STATE" view. When
-------
Nonpoint Oil and Gas Emissions Estimation Tool
finished, click the "When finished, click here to complete this step." button, A message box will appear
instructing the User to proceed to Step 2.
^si Geographic and Source Selections
Oil and Gas Tool: Production Acf^
Step 6 - ViewfeltBaan Factors I
Step 1 • Select Geographic Level
^^board View
Step 1 -
Select a
geographic
level.
Step 8 - Pont Source Activity Adjustments
Step 9 - Pant Source Emission Adjustments
Step 10 - Final Emissions
Master References
Step 3 - Select Sotra Category Level
Please select the geographic level at which you are generating emission estmates.
AREA TYPE
PICK ONE -
EIA SUPPLY REGION
D
EPA REGION
~
NATIONWIDE
B
^EMS REGION
OZONE ATTAINMENT STATUS
~
REGIONAL PLANNING ORGANIZATION
H
STATE
m
SUBPART W BASIN
E
*
B
Record. i< < 4 of S ~ M ~ No Filter
Search
When
finished, cick
here to
complete this
step.
After making
the selection,
click this
button.
Step 4 - Select Specific Source Category
El A Supply Region
Step 5 - Vew/Eckt County-Level Activity Data
12) Step 2 - Select Specific Geographic Location. Click the "Step 2 - Select Specific Geographic Location"
tab to continue. In Step 2, the User selects the specific geographic location of interest. The User may
select more than specific location. When finished, click the "When finished, click here to complete this
step." button. A message box will appear instructing the User to proceed to Step 3.
id Source S^ectkHH
Oil and Gas Tool: Production Activities - Dashboard View
Page [^esetAHSei^ttons/GotoStepl
Back to Home P,
Please select the speafic geographic location at which you are generating emission estmates.
Step 2 - Select the
specific geographic
location(s)
AREA_TYPE
- AREA_DESCRIPTION
STATE_NAME -
PICK AT LEAST ONE -
MOMENT hj
SWTS
AK
Alaska
wmom
STATE
Al
Alabama
~
When
STATE
AR
Arkansas
~
finished, ctdc
STATE
AZ
Arizona
~
complete this
STATE
CA
California
~
step.
STATE
CO
Colorado
~
STATE
CT
Connecticut
~
STATE
DC
District Of Columbia
~
STATE
DE
Delaware
~
STATE
FL
Florida
~
STATE
GA
Georgia
~
STATE
HI
Hawaii
~
After making the
STATE
IA
lowa
~
¦ ¦
STATE
ID
Idaho
~
selectiori(s), click
STATE
IL
Illinois
~
this button.
STATE
IN
Indiana
~
STATE
KS
Kansas
~
STATE
KY
Kentucky
~
STATE
LA
Louisiana
~
STATE
MA
Massachusetts
~
STATE
MD
Maryland
~
STATE
ME
Maine
~
STATE
Ml
Michigan
~
STATE
MN
Minnesota
~
STATE
MO
Missouri
~
STATE
MS
Mississippi
~
STATE
MT
Montana
~
STATE
NC
North Carolina
~
STATE
NO
North Dakota
~
13) Step 3 - Select the Source Category Level. Click the "Step 3 - Select Source Category Level" tab to
continue. In Step 3, the User can either pick to generate emission estimates for all oil and gas production
source categories or individually select source categories. When finished, click the "When finished, click
here to complete this step." button. A message box will appear instructing the User to proceed to Step 4.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
"31 Geographic and Source Selections
Oil and Gas Tool: Production Activities - Dashboard View
Back to Home Page JReset All^elections/G^^te^^^^^^^xr^roQ^=
Step 6 ¦ Vtew/Edjt Basin Factors
Step 1 - Select Geography Level
Step 7 • ViewjEdit Emcaon Factors | Step 8 - Point Source Activity Adjustments t Ste
Step 2 - Setect Speafic Geographic Location 3 : k Csre :: y Levd_
Please select the source category level at which you are generating emission estimates.
Step 3 - Select the
Source Category
level.
s ] Master References
County-Level Activity Data
SOURCE_CATEGORY - i PICK_ONE
ALL UPSTREAM PRODUCTION OIL AND GAS SOURCE CATEGORIES
j SELECT UPSTREAM PRODUCTION OIL AND GAS SOURCE CATEGORIES
* ~
When
finished, click
here to
complete
this step.
After making
the
selection(s),
click this
button.
14) Step 4 - Select Specific Source Category. Click the "Step 4 - Select Specific Source Category" tab to
continue. In Step 4, the User can select the specific Source Categories to generate emission estimates. If
in Step 3, the User selected "ALL OIL AND GAS PRODUCTION SOURCE CATEGORIES", then all
source categories will be checked. At this point, the User may choose to deselect certain source
categories. When finished, click the "When finished, press here" button. A message box will appear
instructing the User to proceed to Steps 5, 6, and 7 to review/edit the activity data, basin factors, and
emission factors: or to proceed directly to Step 8 for Point Source Activity Adjustments.
I Jtj Geographic am) Source Selections I
- Dashboard View
Oil and Gas Tool: Production Activities
Step 4-All
1
Back to Home Page Reset All Selections/Go to Step 1 [|
EXIT TOOL
Source Categories
are selected.
SOURCE_CATEGORY
see
SCC_DES0
- pickjvt;
*AST_ONE -
JL
ARTIFICIAL LIFTS^^SflBiiH^fl
2310000330
Oil & Gas Expl & Prod /All Processes /Artificial Lift
0
ASSOCIATED GAS
2310011000
On Shore Crude Oil Production All Processes
0
When
finished, press
here
CBM DEWATERING PUMPS
2310023000
Coal Bed Methane NG / Dewatering Pump Engines
0
CONDENSATE TANKS
2310021010
On-Shore Gas Production /Storage Tanks: Condensate
0
t
CONDENSATE TANKS
2310023010
On-Shore CBM Production /Storage Tanks: Condensate
0
CRUDE OIL TANKS
2310010200
Oil & Gas Expl & Prod /Crude Petroleum /Oil Well Tanks - Flashing & St;
0
DEHYDRATORS
2310021400
On-Shore Gas Production Dehydrators
0
DEHYDRATORS
2310023400
Coal Bed Methane NG / Dehydrators
0
FUGITIVES
2310011501
On-Shore Oil Production /Fugitives: Connectors
0
FUGITIVES
2310011502
On-Shore Oil Production /Fugitives: Flanges
0
FUGITIVES
2310011503
On-Shore Oil Production /Fugitives: Open Ended Lines
1
FUGITIVES
2310011505
On-Shore Oil Production /Fugitives: Valves
After making the
FUGITIVES
2310021501
On-Shore Gas Production /Fugitives: Connectors
selection(s), click
this button
FUGITIVES
2310021502
On-Shore Gas Production /Fugitives: Flanges
FUGITIVES
2310021503
On-Shore Gas Production /Fugitives: Open Ended Lines
FUGITIVES
2310021505
On-Shore Gas Production /Fugitives: Valves
0
FUGITIVES
2310021506
On-Shore Gas Production /Fugitives: Other
0
FUGITIVES
2310023511
On-Shore CBM Production /Fugitives: Connectors
0
If in Step 3, the User selected "SELECT OIL AND GAS PRODUCTION SOURCE CATEGORIES", then
no source categories will be checked. At this point, the User will select one or more source categories.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
When finished, click the "When finished, press here" button, A message box will appear instructing the
User to proceed to Steps 5, 6, and 7 to review/edit the activity data, basin factors, and emission factors;
or to proceed directly to Step 8 for Point Source Activity Adjustments.
Oil and Gas Tool: Production Activities
- Dashboard View
Step 4- No Source
Back to Home Page | ResetAIISelections/GotoStepl 1
EXIT TOOL
¦
Categories are selected.
—
Step 6 - View^dit Basin Factors
Step 7 - View/Edit Emission Factors Step 8 - Point Source Activity Adjustments
Step 9 - Point Source Emission A
djustments
Step 10 - Final Errxssl
Step 1 - Select Geographic Level
Step 2 - Select Specific Geographic Location Step 3 - Select Source Category Level
Step 4 - Select Sp<
afic Source Category
Ste
P 5
Please select the specific source categories) for which you are generating emission estimates for.
SOURCE_CATEGORY
see
SCC_DESCRIPTION
- PICK_AT_LEAST_ONE -
[v
(ARTIFICIAL LIFTS^BflHE^^fi
2310000330
Oil & Gas Expl & Prod /All Processes /Artificial Lift
~
ASSOCIATED GAS
2310011000
On Shore Crude Oil Production All Processes
~
When
finished, press
here
CBM DEWATERING PUMPS
2310023000
Coal Bed Methane NG / Dewatering Pump Engines
~
CONDENSATE TANKS
2310021010
On-Shore Gas Production /Storage Tanks: Condensate
~
CONDENSATE TANKS
2310023010
On-Shore CBM Production /Storage Tanks: Condensate
~
T
CRUDE OILTANKS
2310010200
Oil & Gas Expl & Prod /Crude Petroleum /Oil Well Tanks -
Flashing & Sfe ~
i
DEHYDRATORS
2310021400
On-Shore Gas Production Dehydrators
~
After making the
selection(s), click
DEHYDRATORS
2310023400
Coal Bed Methane NG / Dehydrators
~
FUGITIVES
2310011501
On-Shore Oil Production /Fugitives: Connectors
o
FUGITIVES
2310011502
On-Shore Oil Production /Fugitives: Flanges
~
this button.
FUGITIVES
2310011503
On-Shore Oil Production /Fugitives: Open Ended Lines
~
FUGITIVES
2310011505
On-Shore Oil Production /Fugitives: Valves
~
FUGITIVES
2310021501
On-Shore Gas Production /Fugitives: Connectors
~
FUGITIVES
2310021502
On-Shore Gas Production /Fugitives: Flanges
~
FUGITIVES
2310021503
On-Shore Gas Production /Fugitives: Open Ended Lines
~
FUGITIVES
2310021505
On-Shore Gas Production /Fugitives: Valves
~
FUGITIVES
2310021506
On-Shore Gas Production /Fugitives: Other
~
FUGITIVES
2310023511
On-Shore CBM Production /Fugitives: Connectors
~
FUGITIVES
2310023512
On-Shore CBM Production /Fugitives: Flanges
~
FUGITIVES
2310023513
On-Shore CBM Production /Fugitives: Open Ended Lines
~
PI
15) Step 5 - View/Edit Countv-Level Activity Data. Click the "Step 5 - View/Edit County-Level Activity Data"
tab to continue. In Step 5, the User can view and edit the activity data that EPA has compiled for the
geographic area and source categories selected.
==Back^^o^T Page J^^eseWU^elections/G^^te^^^^^^^Xt^OO^
~=j] Geographic and Source Selections
Oil and Gas Tool: Production Activities - Dashboard View
Step 6 - View/Edit Basin Factors
Step 1 - Select Geographic Level
Step 7 - View/Ecit Emission Factors Step 8 - Point Source Activity Adjustments
Step 2 - Select Specific Geographic Location Step 3 - Select Source Category Level
m. jl u|l. ¦¦ y hull n.i li ninn.^nHil f p. .nty _ lot.ol activity data
Step 9 - Point Source Emission Adjustments
Step 4 - Select Specific Source Category
Step 10 - Final Emissions
Step 5 - View/E
Click here to
review the
Natural Gas
Production Data.
Click here to
review the
Coalbed Methane
Production Data.
thed. please continue to Step 6 to Vij
Pick a type of production
dataset
Once the county-level data set is selected, an Activity Data form will appear that the User can view or
edit. To get to the next county, at the bottom of the screen is the record number. Use the triangle
arrows to move through the counties.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Import/ Export
Curfent Value
91,723,520.00
,392,200.00
If new values are
entered, please enter a
reference.
County-Level Natural Gas Production (MSCF)
County-Level Condensate Production from natural gas wells (BBL)
County-Level Natural Gas Well Counts
Fraction of natural gas wells in the county needing compression
Current Value Refel
ENVERUS.2021
ENVERUS.2021
ENVERUS.2021
EPA_2021b
Values from the 2017
Tool. Values here
cannot be edited.
SI Geographic and Source Selections X | ~ Activity Data: Natural Gas X
Natural Gas Production Activity Data
When finished, click
hfrs
When finished,
click here
State Abbreviation
State and County FIPs Code
County Name
Basin Name
Year
|AR
'imi
The User can filter
for specific
Cleburne
2020
The User may also edit activity data in MS-Excel by using the "Import/Export Data..." button.
m Geographic and Source Selections X JI] Activity Data: Natural Gas
Natural Gas Production Activity Data
m
State Abbreviation
State and County FIPs Code 05023
County Name Cleburne
Basin Name Arkoma Basin
Year 2017
Filter for this Basin only
Remove Basin Filter
Values here can be edited
Import/Export
Data...
Current Value
Current Value Reference
2014 Value
2014 Value Reference
County-Level Natural Gas Production (MSCF)
141,392,200.00
HPDI.2018
226,113,000.00
HPDI.2016
When finished.
County-Level Condensate Production from natural gas wells (BBL)
0.00
HPDI.2018
0.00
HPDI.2016
click here
County-Level Natural Gas Well Counts
1,073
HPDI.2018
889 HPDI_2016
Fraction of natural gas wells in the county needing compression
0.140
EPA.2019
0.085
CENSARA_STUDY_2012
If the user elects to edit activity data in MS-Excel, after clicking the button, the data is then exported into
MS-Excel as shown below.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
pa] Import/Export Data
Import/Export Data
Activity: Natural Gas
X Close Form
Export Import
Export the data to an Excel file
Step 1 - Export activity
data to Excel.
(It is recommended that
you save this file for later
upload.)
CjVj® Export to Excel
h.
A MS-Excel workbook will open when finished exporting. It is required that the User save this file to the
hard drive for later upload. In the Excel file, the User can only edit the yellow shaded cells. When
completed, simply save the file.
STATE ABBR
STATE COUNTY HPS IcOUNTY NAME j BASIN
YEAR
DATA CATEGORY
PREVIOUS VALUE
PREVIOUS REFERENCE
CURRENT VATljE
CURRENT REFEREN(
AK
02013
Aleutians East
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
/
ENVEmJS 2021
AK
02013
Aleutians East
Not Assigned - SURVEY AVERAGE
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPOI 2018
0 /
ENVERUS^2021
AK
02013
Aleutians East
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
/
ENVERUS 2021
AK
02013
Aleutians East
Not Assigned - SURVEY AVERAGE
2020
Fraction of natural gas wells in the county needing compression
7.562142E-02
EPA 2019
7.124^34E-02
EPA 2021b \
AK
02016
Aleutians West
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
0 /
ENVERUS 2031
AK
02016
Aleutians West
Not Assigned - SURVEY AVERAGE
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
/
ENVERUS 2021
02016 lAleutians West
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
/
ENVERUS 202l\
AK
02016 Aleutians West
Not Assigned - SURVEY AVERAGE
2020
Fraction of natural gas wells in the county needing compression
7.562142E-02
EPA 2019
7.I24434E-02
EPA 2021b \
AK
02020 [Anchorage
AK cook inlet Basin
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
of
ENVERUS 2021
AK
02020 Anchorage
AKCook Inlet Basin
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
of
ENVERUS 2021
AK
02020 Anchorage
AKCook Inlet Basin
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
d
ENVERUS 2021
AK
02020 |Anchorage
AK Cook Inlet Basin
2020
Fraction of natural gas wells in the county needing compression
0.2028985
EPA 2019
.212963
EPA 2021b
AK
02050 Bethel
Yukon-Koyukuk Province
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
ENVERUS 2021
A*
02050 Bethel
Yukon-Koyukuk Province
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 201S
ENVERUS 2021
M
02050 jBethel
Yukon-Koyukuk Province
2020
Fraction of natural gas wells In the ci
Step 2-The U
edit the yellow-
ser can
shaded
EPA 2019
7.124434E-02
EPA 2021b
02060 Bristol Bay
Bristol Bay Basin
2020
County-Level Condensate Productio
HPDI 2018
ENVERUS 2021
AK
AK
02060 Bristol Bay
02068 |Denaii
Bristol Bay Basin
2020
Fraction of natural gas wells in the c
unty needing compression
7.562142E-02
EPA 2019
'.124434E-02
EPA 2021b
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
ENVERUS 2021
AK
02068 Denaii
Not Assigned - SURVEY AVERAGE
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
ENVERUS 2021
AK
02068 toenail
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
ENVERUS 2021
AK
02068 |oenalf 1 Not Assigned -SURVEY AVERAGE
2020
Fraction of natural gas wells in the county needing compression
7.562142E-02
EPA 2019
7 124434E-02
EPA 2021b
AK
02070 |Dillingham |Yukon-Koyukuk Province
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
°\
ENVERUS 2021 i
AK
02070 |Dillingham lYukon-Koyukuk Province
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
\
ENVERUS 2021/
AK
02070 Dillingham Yukon-Koyukuk Province
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
\
ENVERUS 202U
—
02070 iDillinRham
Yukon-Koyukuk Province
2020
Fraction of natural gas wells in the county needing compression
7.562142E-02
EPA 2019
7.12B434E-02
EPA 2021b /
02090 Fairbanks North Star
interior Lowlands Basin
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
0 \
ENVERUS 20jfl
02090 (Fairbanks North Star
Interior lowlands Basin
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
0 \
ENVERUS 2TO1
AK
02090 Fairbanks North Star
interior Lowlands Basin
2020
County-Level Natural Gas Well Counts
0
HPDI 2018
0 \
ENVERUS _J021
AK
02090 Fairbanks North Star
Interior Lowlands Basin
2020
Fraction of natural gas wells in the county needing compression
7.562142E-02
EPA 2019
7.124434^-02
EPA 202}b
AK
02100 tHaines
Not Assigned - SURVEY AVERAGE
2020
County-Level Natural Gas Production (MSCF)
0
HPDI 2018
0 \
ENVEiy^S 2021
AK
02100 iHaines
Not Assigned - SURVEY AVERAGE
2020
County-Level Condensate Production from natural gas wells (BBL)
0
HPDI 2018
0 ^
EJ^yfRUS 2021
If data edits were made, then the User will need to go back to the Tool and click on the import/Export
Data..." button to initiate importing the edited data file. After clicking, the Import/Export form will appear.
The User will need to:
• Step 1 - Click on the "Import" tab
• Step 2 - Click the "Select File" button
• Step 3 - Map to the location of the edited data, and click "OK"
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Step 4 - Click on the "Import from Excel" button
H] Import/Export Data
Import/Export Data
Activity: Natural Gas
Step 1 - Click on
the "Import" tab.
Step 2 — Click on the
"Select File" button
Step 4 - Click on the
"Import from Excel" button
Import the Selected Excel File
jC:\WORK\OIL_GAS\RE_ENGINEE^ING\lTERATI O N_009_2(^4_NEI
Cj^jhmport From ExceL^
\
[ (cy Select File J)
Step 3 - Map to the
location of the edited data
The edited data is now imported into the Tool.
16) Step 6 - View/Edit Basin Factors. Click the "Step 6 - View/Edit Basin Factors" tab to continue. In Step 6,
the User can view and edit the basin factor data that EPA has compiled for the geographic area and
source categories selected.
Oil and Gas Tool: Production Activities - Dj
ashboard V
Step 6 - Pick a Source Category
Basin Factor or Gas Composition
dataset to view/edit
i
Back to Home Page | Reset All Selections/Go to Step 1 | EXITTOOL
Oil and Gas Production Sources
Please click on the source categoryjjelov
^^jMrstffTactors.
^vrew/edit the
Tlease^kJuiiithesource category below to view/edit the
gas^oTTrjfewtion factors.
ArtifklaflJfts
Dehydrators
Liquids Unloading
Associated Gas
Gas-Actuate^H^mps
Associated Gas
Fugitives
Loading Operations
Condensate Tank
Liquids Unloading
CBM Dewatering
Pumps
Gas-Actuated Pumps
Pneumatic Devices
Crude Oil Tank
Loading Operations
^Condensate Tank
Heaters
Produced Water
Dehydrators
Pneumatic Devices
Crudel^ii^ank
Lateral/Gathering
Compressors
Wellhead
Compressors
Fugitives
Produc^sHrt/ater
In the Basin Factors form, the User can view/edit the data. If the User updates values for one county in a
basin, then all other counties in the basin and state can be updated by clicking on the "Click to apply
these values to all other counties in the same basin for the state." button.
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Nonpoint Oil and Gas Emissions Estimation Tool
Current Vs
CurrentVaT
EPA Defaul
CENSARA_STUDY_2012_
CENSARA.STXJDY.2012.
CENSARA.STUDY.2012.
0.8103769
! 34611 EPA TOTi
EPA default values
cannot be edited.
Values from the
2017 Tool. Values
here cannot be
EPA_2021b
CENSARA_STUDY_2012_EXTENSIONl
AVERAGE
N06C.Sep.2019
editeckoGc.
NOGC.Sep.2019
NOGC.Sep.2019
CENSARA_STUDY_20j
ENSION
CENSARA_STUDYJW?>VERAGE
CENSARA.STUDY
ENSION
When finished, click
"il Geographic and Source Selections X jS Basin Factors: Crude Oil Tanks
Crude Oil Tanks Basin Factors Form
The User can filter
for specific locations.
If new values are
entered, please enter a
reference.
Crude OH Fraction directed to Tanks
Fraction of Oil Tanks with Flares
Fraction of Oil Tanks with a VRU
Average VOCs loss (lb VOCs/SBL Crude Oil)
Flaring Capture Efficiency (%)
Flaring Control Efficiency (%)
Gas Venting Rate (MCF gas/BBl Crude Oil)
State Abbreviation
State and County FIPs Code
County Name
Basin Name
01001
Autauga
^lid-Gulf Coast Basin
Import/Ex port
Data...
lect values
create a
filter
Similarly, the User can view/edit the gas composition data for select categories.
17) Step 7 - View/Edit Emission Factors. Click the "Step 7 - View/Edit Emission Factors" tab to continue. In
Step 7, the User can view or edit the emission factors that are used to generate the emission estimates
for the source categories selected.
Oil and Gas Tool: Production Activities - Dashboard View
Lateral/Gathering Compressors
Artificial Lifts
Crude Oil Tanks
Associated Gas
Dehydrators
Liquids Unloading
Wellhead Compressors
CBM Dewatering Pump Engines
Fugitives
lensate Tanks
Heaters
Back to Home Page [ Reset All Selections/Go to Step 1 | exit tool
Step 7 - Pick a Source
Category Emission Factor
dataset to view/edit
Oil and Gas Production Sources - Emission Factors
btep i - beiect ^eograpnic Levei btep z - ^eiect ^peanc ueograpnic Location btep j - beiect soi
Step 6 - View/Edit Basin Factors Step 7 - View/Edit Emission Factors step 8 - Point Source Activity Adji.
Please select the emission factor source category you would like to view/edit.
Please click on a Source Category below to view/edit
" emission factors. ~
Note: there are no emission factors to review for Gas-Actuated Pumps, Loading
Operations, Pneumatic Devices, and Produced Water
Once a Source Category has been selected, the User can view or edit the emission factors. Remember to
update the reference field (EMISSION_FACTOR_SOURCE) for any updated emission factors.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
•• - ; ; v ¦
Illinois Basin
Ifftnois Basin
/Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
Illinois Basin
\lllinois Basin
ois Basin
ois Basin
WELLHEAD COMPRESSORS EMISSION FACTORS FORM
ATTAINMEN * SOURCE_CATEGORY -
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Currently, ALL point source activity adjustments (e.g. county-ievei point source well counts, county-level
point source barrels of oil produced, etc.) are defaulted to zero (i.e., no point source activity adjustments).
HEATERS POINT SOURCE ACTIVITY ADJUSTMENT FORM
State abbreviation:
AR
State and County FIPs Code:
05023
Enter the point
sources activity data
Cleburne
2020
Point Source Well Counts
When finished,
click here
Gas Wells
~~cBirw«U5
0
When
finished, click
here
7
it is encouraged that point source activity adjustments have priority over point source emission
adjustments. Additionally, Users should pay careful attention to ensure that the point source
activity data is entered in the same units as the nonpoint activity data. Users should refer to the
"Nonpoint Source SCCs and Point Source SCCs Crosswalk" button to identify point source SCCs. After
any point source activity adjustments have been made, proceed to Step 9.
19) Step 9 - Point Source Emission Adjustments. Click the "Step 9 - Point Source Emission Adjustments" tab
to continue. In Step 9, the User can make point source emission adjustments directly in the emission
tables. Select a Source Category to open. If a User has no point source emissions adjustments, they may
click on the "When finished, click here to complete this step" button.
Select a Source Category to
make point source
emissions adjustments
ections/G^oStep^^'^^^X^TOOr"
Production Sources - Point Source Emission Adjus
Please click on a Source Category below to view/edit calculated
emission records for point sources adjustments.
When
finished,
click here
to proceed
to Step 10.
Tufts
Associated Gas
CBM Dewatering Pump Engines
Condensate Tanks
nks
Select a Source
Category to apply
saved point source
emissions
adjustments
Clear all point source
emissions holding tables
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Point source emission estimates are to be entered in the "POINT_EMISSIONS_TPY" field. It is
important to note that if point source activity adjustments were made in Step 8, then point source
emission adjustments should NOT be made in these tables for overlapping SCCs. Also, point
source emission adjustments need to be entered as tons per year (TRY).
WELLHEAD COMPRESSORS POINT SOURCE EMISSIONS ADJUSTMENT FORM
When finished,
When
fiiished, dick
click here to
here
STATE •
STATE* -
COUNTY_NA - SCC
SOURCE_CATEGORY
POLLUTAI
finalize
_TPY - POINT_EMISSIONS_TPY
0S023 IftR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
75003
Ethyl Ch
825E-04
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
75014
Vinyl Ch
emissions.
205E-03
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
75070
Acetalde
1.3091
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
75092
Methylene Chloride
3.131818E-03
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
75343
Ethylidene Dichloride
3.695546E-03
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
78875
Propylene Dichloride
4.212296S-03
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
79005
1,1,2-Trich loroetha ne
4.979591E-03
0
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
79345
1,1,2,2-Tetrachloroethane
6.263637E-03
\:
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
91203
Naphthalene
1.165036E-02
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
92524
Biphenyl
3.319727E-02
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
CH4
Methane
253.4544
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
CO
Carbon Monoxide
76.93658
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
C02
Carbon Dioxide
22303.99
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR El
4.246591E-0;
.
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR El
Users can enter ooint
171.740;
'
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR El
1.563307E-0;
*
:
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR El
suui uc emissions
2.0250:
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR El
adjustments.
1.563307E-0;
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR Fl
2.02502
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
PM-CON
PM Condensible
2.009387
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
S02
Sulfur Dioxide
0.1192249
05023
AR
Cleburne
2310021202
WELLHEAD COMPRESSOR ENGINES
VOC
Volatile Organic Compounds
18.46957
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
100414
Ethyl Benzene
1.946151E-03
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
100425
Styrene
9.338181E-04
f0
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
106934
Ethylene Dibromide
1.671456E-03
0
05023
AR
Clebume
2310021302
WELLHEAD COMPRESSOR ENGINES
106990
1,3-Butadiene
5.202699E-02
0
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
107028
Acrolein
0.2063816
0
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
108883
Toluene
4.378839E-02
0
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
108907
Chlorobenzene
1.01229E-03
0
05023
AR
Cleburne
2310021302
WELLHEAD COMPRESSOR ENGINES
1330207
Xylenes (Mixed Isomers)
0.0153024
0
After point source emission adjustments are made (if applicable), then the User should proceed to Step
10.
20) Step 10 - Final Emissions. Click the "Step 10 - Final Emissions" tab to continue. In Step 10, the User can
review the final emissions; update county-level activity data, emission factors, and/or basin factors they
provided in Steps 5 through 7; or generate the Emission Inventory System (EIS) data tables.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Emissions Tables by Source
CBM
Dewatermg
Pump Engine
Emissions Table
Condensate
Tanks
Emissions Table
Lateral
Gathering
Compressors
Emesions Tab!
Gas-Actuated
Pumps
Emesions Table
Dehydrators
Emesions Table
Fugitives
Emissions Table
Heaters
Emissions Table
Loading
Operations
missions Table
Pneumatic
Devices
Emissions Table
Produced
Water
Emissions Tab]:
Compressors
Emissions Table
Update
Produced
Water .
Oil and Gas Production Sources - Summary Emissions
Emission tables
by Source
Category.
EIS Staging
tables can be
developed.
If the User
updated activity
or emission
factors, then
they can be re-
used by clicking
here.
If you updated emission factors, and would like to re-use them, please click on the appropriate source categories.
Update Update Crude Update Update Update
Condensate 01 Tanks Dehydrators Fugitives Heaters
Tanks Emission Emission Emission Emission Emission
Factors Factors Factors Factors Factors
Final emissions are
elections/Go to Step 1
presented here.
ArtrfkalUfts
Associated Gas
^m^S»ns Table
Emissions Table
If you updated-aetwitydata, ana wouidfflnrte-repjace the origin
I0es7please click on the appropriate source catej
;iry Enmsi
enerate the
Pollutant
Emissions
Click hereto
generate the
Source Category
and Pollutant
Emissions
Click here to
generate the
calculated
Update Oil
Wei Counts/
Production
"\Data
Update Gas
Wei Counts/
Production
Data
Update CBM
Wei Counts/
Production
Data
Click herMp
generate the\
Source Category N
and Pollutant
Emissions by State
Summary screen (continued)
Oil and Gas Production Sources - Summary Emissions
If you updated basin factors, and would like to re-use them, please click on the appropriate source categories.
Update
Condensate
Tanks Basm
Factors
Update
Update Lateral/
Heaters Basin Gathering
Factors Compressors
Basn Factors
Update Update
Dehydrators Fugcves Basn
Basr Factors Factors
If the User updated Basin Factors or gas composition data,
then they can be saved and re-used by clicking here.
Update Gas-
Actuated
Pumps Bas*i
Factors
Update
Loadrg
Operations
Basin Factors
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Summary screen (continued)
Oil and Gas Production Sources - Summary Emissions
If you made point source activity adjustments, and would like to re-use them, please click on the appropriate source categories.
Additional notes:
1) In the EIS Staging Tables, the ControlApproach, ControlMeasure, ControlPollutant, Emissions,
EmissionsProcess, Location, and ReportingPeriod are populated.
2) EPA's EIS area_bridgetool (included in the .zip file) can be used to generate the .xrnl file needed for EIS
upload.
3) If the User wishes to reset the tool, and regenerate the emissions, the following steps are recommended:
a. Click on the "Reset All Selections/Go to Step 1" button at the top of the Dashboard.
b. Compact and Repair the database.
-------
Nonpoint Oil and Gas Emissions Estimation Tool
Oij and-Gas Jool: Production Activities - Dashboard View
Step 1 -JSeiect Geographic Level
actors
To return to
the Home
page, click
here.
f summary emissions yo
To exit the
Tool, click
here.
Specific Geographic location
Step 3 - Select Source Category Level
Step 8 - Point Source Activity Adjustments
Step 4 - Select Specific Source Category
Step 9 - Point Soiree Emtssjon Adjustments
Step 5 - Viewytdrt Co
- Final Emissions
nerate the EIS Staging tables.
Oil and Gas Production Sources - Summary Emissions
Click here to
generate the
Pollutant
Emissions
Summary Emissions
Click here to Click here to
generate the generate the
Source Category Source Category
and Pollutant and Pollutant
Emissions Emissions by State
Click here to
generate the
calculated
emission
records.
Final Emissions Tables by Source Category
Artificial Lfts
Emissions Table
Dehydrators
Emissions Table
Liquids
Unloading
Emissions Table
Associated Gas
Emissions Table
Fugitives
Emssions Table
Condensate
Dewatemg Tanks
Pumo Engine r . i ' t.i.l
Emsswns Table Emssw s Table
Gas-Actuated
Pumps
Emissions Table
Heaters
Emssions Table
Loadng Pneumatic Produced
Operations Devices Water
Emssions Table Emssions Table Emissions Table
Crude 01
Tanks
Emssions Table
Lateral
Gathering
Compressors
Emssions Table
Wefiead
Compressors
Emissions Table
4) References cited for the original data in the Tool are found in the "Master References" tab.
~jj] Geographic and Source Selections X |
Oil and Gas Tool: Production Activities - Dashboard View
Back to Home Page
Reset All Selections/Go to Step 1
Step 1 - Select Geographic Level
Step 6 - View/Edit Basin Factors
References are compied Into a single table.
References cited in the Tool
for the original data are here.
led Source Category Level
ity Adjustments
Step 4 - Select Specific Source Category
Step 9 - Point Source Emission Adjustments
Step 5 - View/Edit County-Level Activity Data
Step 10 - Final Emissions Master References
ot reflect references entered by the User.
FIELD_REFEB£ttf^"^
'1 1 FltLD_RtFERENCE_DESCRIPTION
'J*/- PIllinois production data front 2019 carried forward and adjusted by the 2020 to 2019 EIA state totals
2019_INOGC_ADJ_2020
Indiana production data fro™2019 carried forward and adjusted by the 2020 to 2019 EIA state totals
2019_KY_EIA_2020
Kentucky production data from 2019 carried forward and adjusted by the 2020 to 2019 EIA state totals
ADEC_2016
Alaska Department of Environmental Conservation. Personal communication to Mr. Mike Pring/ERG from
ADEC_2019
Personal communication from Molly Birnbaum, ADEC to Jennifer Snyder, EPA. September 19, 2019.
API_2009a
API Compendium (8/2009), Table 4-5
API_2009b
API Compendium (8/2009), Table 4-11
AZDEQ_2019
Arizona Department of Environmental Quality. 2017 Production Reports received on 2/27/2019 via FTP
BOEM_2014
Bureau of Ocean Energy Management, Speciation data for North Slope, AK.
CA LC_P W_TX_P ROD
Produced water factor calculated from 2020 Texas wells reporting produced water, and applied to missing wells.
CALC_VEIL_RATIO
Produced water production factors calculated from the Veil Report
CALC_WTR_LA_PROD
Produced water factor calculated from 2018 Louisiana wells reporting produced water, and applied to missing wells.
CARB_2021
Basin factor updates for select source categories
CENRAP_2008
ENVIRON. Recommendations for Improvements to the CENRAP STATES' OIL AND GAS EMISSIONS INVENTORIES. November 2008
-------
Nonooint Oil and Gas Emissions Estimation Tool
Appendix C - US Oil and Gas Basins (found in the "National Oil and Gas Tool
Report Appendix C - Data Element Dictionary.xlsx" file)
-------
Nonooint Oil and Gas Emissions Estimation Tool
Appendix D - Data Element Dictionary (found in the "National Oil and Gas Tool
Report Appendix D - US Oil and Gas Basins.xlsx" file)
------- |