United States
Environmental Protection
Agency
Environmental Research
Laboratory
Gulf Breeze FL 32561
Research and Development
EPA-600/S3-84-048 Apr. 1984
&EPA Project Summary
Drill Mud Assessment Chemical
Analysis Reference Volume
The reference volume documents
chemical characterization data for 11
industry-supplied drill fluid mixtures and
one commercial drill-fluid additive. Used
drilling fluids from the Gulf of Mexico
were supplied to the U.S. Environmental
Protection Agency (EPA), Environmen-
tal Research Laboratory at Gulf Breeze,
Florida, by the Petroleum Equipment
Suppliers. The Gulf Breeze laboratory
then provided Science Applications,
Inc., with samples as part of a multi-
disciplinary effort to assess and cata-
logue the acute aquatic toxicity and
chemical composition of the drilling
fluids. Each drilling fluid was analyzed
chemically for heavy metal and hydro-
carbon content. Theanalysisforeach of
the 11 drilling fluids is presented in four
parts: (1) drilling fluid elemental con-
centrations, (2) whole drilling fluid
organic concentrations, (3) particulate
phase organic concentrations, and (4)
dissolved phase organic concentrations.
This Project Summary was developed
by EPA's Environmental Research
Laboratory. Gulf Breeze. FL. to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
EPA is required to issue permits for the
discharge of drilling fluids into waters of
the Outer Continental Shelf under the
National Pollutant Discharge Elimination
System (NPDES). Knowledge of the con-
centrations of aromatics, aliphatics, <
metals, and other constituents of drilling :
fluid is necessary m order to predict the ';
impact of thefluidson the marineenviron- •
ment :
Drilling fluids in general are mineral- :
based, typically enriched in barium (in the :
form of barite BaSCU), chromium or zinc, :.
to name a few elements, and are fortified
with a variety of other (usually synthetic
materials) to obtain desired consistencies
for drill-line lubrication and well-hole
pressure control. The mineral base is
usually a mixture of barite and various
clays, and other additives are predom-
inantly organic-based but can contain
relatively high concentrations of heavy
metals Presumably, drilling fluids dis-
charged offshorewill not contain harmful
concentrations of additives such as
petroleum-derived compounds and other
suspected toxicants.
Methods
Each drilling fluid sample was chemi-
cally analyzed for heavy metal and hydro-
carbon content in three distinct phases.
(1) the bulk or whole mud, (2) a suspended
particulate phase derived from the bulk
mud sample, and (3) a dissolved phase
After freeze drying and powdering,
aliquots of bulk muds were removed for
barium analysis by instrumental neutron
activation and for analysis for iron, alumi-
num, chromium, lead, zinc, cadmium,
copper, strontium, and calcium by atomic
absorption analysis. Analysis of the sus-
pended particulate material was similar,
but barium was also analyzed by atomic
adsorption spectrophotometry This was
also true for the dissolved phase.
The aromatic and aliphatic content of
the three phases was determined by
extraction and subsequent fractionation
by column chromatography The hexane
eluant would include aliphatic hydrocar-
bons and PCBs, if these were present in
the samples tested. The hexane:benzene
eluant would contain aromatic hydrocar-
bons varying from toluene to polynuclear
aromatics, if these were present in the
samples tested. The third fraction, the
methylene chloride:methanol eluant,
would contain polar acids and more polar
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: pesticides, if these were present in the
j: samples tested. However, no PCBs, di-
:;oxms or pesticides were reported to be
:: pcesent in the samples tested.
Data Presentation
Metal concentrations were expressed
as percent or /ug/g dry weight for bulk or
whole mud and the paniculate phase and
mg/g wet weight for the dissolved phase
All gas chromatographic data were re-
corded and reduced to digital format by
computerized data reduction programs
All concent rat ions of resolved component
peaks have been reported on a microgram
or nanogram per liter of bulk drilling fluid
basis Water content measurements were
made so that conversion of concentration
data to dry weight could also be made
In the reference volume, analytical
procedures are documented, as well as
measurements in the form of concentra-
tions and chemical identifications It is
readily apparent from the organic analysis
that a number of samples contain sub-
stantial amounts of petroleum-derived
hydrocarbons It was not possible to
identify the sources of hydrocarbons in
these fluids, although the analytical evi-
dence is against crude oil contamination
from the bore-hole. Instead, in the cases
of noticeable hydrocarbon presence,
these components appear to have been
refined petroleum fractions
This Project Summary was prepared by staff of Science Applications, Inc., La Jo/la,
CA 92038
Thomas W. Duke is the EPA Project Officer (see below).
The complete report, entitled "Drill Mud Assessment Chemical Analysis
Reference Volume," (Order No. PB 84-170 000, Cost. $22.00. subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone- 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Research Laboratory
U.S. Environmental Protection Agency
Gulf Breeze, FL 32561
,1 U S GOVERNMENT PRINTING OFFICE, 1984 759-015 7700
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use S300
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