EPA's Hydraulic Fracturing Research in Brief
Drinking
Water Well
Hydraulic Fracturing
Water Cycle
The EPA's study includes research
on hydraulic fracturing of shale
formations to extract natural gas and
oil. The scope of the research is defined
by the hydraulic fracturing water
cycle—five areas where the process
has the potential to impact drinking
water resources. It begins with water
acquisition and ends with treatment
and/or disposal of wastewater.
Number of Projects by Research Activity
The EPA is using a variety of research
activities to answer five primary and
16 secondary research questions, as
outlined in the Agency's Plan to
Study the Potential Impacts of
Hydraulic Fracturing on Drinking
Water Resources, www.epa.
gov/hfstudy. EPA researchers are
conducting 21 individual research
projects that fall under five types of
activities: analysis of existing data,
scenario evaluations, laboratory
studies, toxicity assessments and case
studies. Research progress for each
type of research activity is summarized
in the 2012 Progress Report.
Analysis of existing data
Scenario evaluations
Laboratory studies
Toxicity assessment
Retrospective case studies
Prospective case studies
EPA/601/F-12/006
November 2012
United States
Environmental Protection
Agency
Study of the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources
2012 Progress Report
Well Injection
Gas Well Water Well
Drinking Water
| Resources
Gas and Water
Resources
I Mostly Gas
Resources
U.S. Environmental Protection Agency
Office of Research and Development
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Well Injection
What is well injection?
Process of pumping hydraulic fracturing fluid down the well at high
pressures to create cracks in rock formations that allow oil or gas to flow
from small pores to the production well
Why is the EPA looking at well injection as part of this study?
• Hydraulic fracturing fluids or naturally occurring substances may travel
from fractures to drinking water resources
• Possible pathways may include faulty well construction, intersection of
induced fractures with natural fractures or man-made structures (e.g.,
abandoned wells, shallow operations and fluid releases)
What are the possible impacts of the injection and fracturing
process on drinking water resources?
Study Questions
How effective are current well
construction practices at containing
gases and fluids before, during and after
hydraulic fracturing?
Can subsurface migration of fluids or
gases to drinking water resources occur,
and what local geologic or man-made
features might allow this?
Research Projects
Literature Review
Service Company Analysis
Well File Review
Subsurface Migration
Modeling
Retrospective Case Studies
Literature Review
Service Company Analysis
Well File Review
Subsurface Migration
Modeling
Retrospective Case Studies
Research Projects
Analysis of existing data
• Scenario evaluations
Laboratory studies
Toxicity assessment
• Retrospective case studies
Prospective case studies
Literature Review
Review and summarize literature on possible subsurface migration due to:
• Faulty well construction
• Nearby natural or man-made conduits
Service Company Analysis
Review and summarize standard operating procedures provided by nine hydraulic fracturing service
companies—owners and operators of production wells—for information on:
• Practices related to establishing the mechanical integrity of wells being hydraulically fractured
• Procedures used during injection of the fracturing fluid
Well File Review
Veil files are a record of activities that occurred at production wells that have been provided by the
nine hydraulic fracturing operators. This effort will review well construction data found in 333 randomly
selected well files to assess the effectiveness of current well construction practices at isolating the
wellbore from surrounding ground water
Subsurface Migration Modeling
Numerical modeling of five subsurface fluid migration scenarios that explore the potential for gases
fluids to move from the fractured zone to drinking water aquifers
and
Retrospective Case Studies
Consider potential impacts from shallow operations, fluid releases and poor well constructk
www.epa.gov/hfstudy
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