American Oil and Gas Reporter - April 2017 - 137

Water Well Methane Is Natural, UT Says
AUSTIN, TX.-High levels of methane
found in water wells in two counties near
Fort Worth probably are attributable to
shallow natural gas deposits, and are not
because of hydraulic fracturing activities
in the underlying Barnett Shale, a University of Texas study shows.
Published in the journal Groundwater,
UT says, the study used chemical and
geographic evidence to tie the elevated
methane levels found in certain water
wells to methane in natural shallow deposits. J.P. Nicot, a research scientist at
the Bureau of Economic Geology, a unit
of the UT Jackson School of Geosciences,
led the research.
"Over geologic time, methane has accumulated into these shallower reservoirs.
These freshwater wells are very close to
these shallower reservoirs, and may be the
source of the methane," Nicot suggests.
To examine the source and extent of
methane in water wells, UT says, researchers collected 509 well water samples
across 12 counties in the western Barnett
Shale play and analyzed them for methane,
major ions and carbon isotopes. Most
collected samples were from the regional
Trinity Aquifer, and showed low levels
of dissolved methane.
The university points out 85 percent
of the samples showed methane levels in
the groundwater of less than 0.1 milligrams

of methane per liter of water. UT adds a
cluster of 11 wells in Parker and Hood
counties had methane levels greater than
10.0 mg/l.
The study area includes wells in the
Silverado neighborhood outside Fort
Worth in Parker County. UT says the
neighborhood is in the epicenter of the
high-methane wells, although the six mile
by eight mile area also includes wells
with low methane levels. Researchers began at the center of the cluster and worked
outward until no methane was detected
in water samples, the university describes.
According to UT, researchers used
carbon isotope analysis to determine a
thermogenic origin for the detected
methane, which they say rules out biogenic
sources, but the study did not pinpoint
whether the gas came from the deeper
Barnett Shale or shallower Strawn Group
Formation. Additional analysis linked the
methane to the shallow natural gas deposits
of the Strawn, UT says, when a 2015
study found nitrogen isotopes associated
with the Strawn.
"Combining alkane, noble gas and nitrogen compositions and isotope ratios
allowed us to distinguish natural gas
sourced from the deep Barnett Shale from
the shallow Strawn Group," says Toti Larson, a researcher at the Jackson School's
Department of Geological Sciences.

BUDGET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FROM PAGE 119
"You cannot automatically assume
that a Republican administration is going
to be universally supportive, or that Democrats are going to oppose," he urged.
"This is a nonpartisan issue. We have
very strong and surprising support from
Democrats-even liberal ones-where one
would least expect it. The lesson is to go
into every state with eyes wide open and
not take anything for granted."
According to Fore, property rights ac-

Coming In May
Special reports spotlight the results of a project Devon Energy implemented in the STACK play to
leverage next-generation technologies such as fiber optic distributed
sensing and electromagnetic imaging
to enhance completion designs and
fracture geometries.

tivists occasionally team with environmental
extremists to use eminent domain as a
wedge issue. "We have to do a better job
of communicating how rarely these projects
actually use eminent domain," he advised.
"Even when we have the authority, it actually is exercised to the full extent in
only 2 percent of cases across the country.
Folks say that private, for-profit companies
are coming to steal land, but no, about 98
percent are happy we are there and enjoy
the compensation. When people call their
elected officials and say they want the
money associated with a project, that it
affects their bottom lines, too, that can
have a powerful effect."
However, Fore added, for the minority
whose only response to a pipeline right
of way is "never," eminent domain is a
necessary tool. "For that 2 percent, it is
not about money and we cannot get
around them," he described. "You cannot
do anything to compensate them, but
they are very much the exception to the
rule."
❒

Correlations
In addition to chemical evidence, UT
says, analysis found a strong correlation
between water well proximity to the Strawn
Group and high methane levels, with no
correlations found between those wells
and the nearest hydraulically fractured
wells. According to the university, the
study also notes Parker and Hood counties
contain relatively few fractured wells compared with other counties in the Barnett
Shale, such as Denton County, that have
water wells with low methane levels.
Although the findings suggest that
methane from the Strawn Group is the
most likely source for the methane in
water wells in Parker and Hood Counties,
UT says researchers cannot entirely rule
out the possibility that some of the methane
may have come from leaks caused by
hydraulic fracturing. It says researchers
suggest that leaks from deep reservoirs
may help explain certain cases from other
studies in which methane in water wells
increases over time, as well as cases
where methane is present in water wells
where it used to be absent.
The study was funded by the Research
Partnership to Secure Energy for America.
❒

Anadarko Petroleum Buys
McMoRan's Gulf Assets
HOUSTON-Anadarko Petroleum
Corp. has completed its acquisition of
Freeport-McMoRan Oil & Gas's deepwater Gulf of Mexico assets.
According to Anadarko, the acquisition
will double its ownership in the Lucius
development to 49 percent, and double
its Gulf production to more than 160,000
net barrels of oil equivalent a day. The
deal adds three operated deepwater facilities, bringing the company's total operated facilities to 10.
"As a result of closing this transaction,
Anadarko now operates the largest number
of floating production facilities in the
deepwater Gulf of Mexico, which provides
a competitive advantage to leverage this
infrastructure into attractive new investment
opportunities. This region continues to
play a key role in our portfolio by contributing to our higher-margin oil growth
profile, while generating substantial future
free cash flow to accelerate the growth of
our world-class U.S. onshore assets in
the Delaware and Denver-Julesburg basins,"
says Al Walker, Anadarko chairman, president and chief executive officer.
❒
APRIL 2017 137

American Oil and Gas Reporter - April 2017

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