American Oil and Gas Reporter - January 2017 - 129

says almost doubled that state's production
compared with 2014. The state with the
largest estimated decline in natural gas
production in 2015 was Louisiana, which
dropped 150 Bcf, or 8.0 percent.
Drilling down, EIA reports proved reserves of nonassociated natural gas decreased by 60.9 Tcf in 2015, a 19 percent
decline from 2014. Estimated production
of nonassociated gas increased 1 percent,
from 22.8 Tcf in 2014 to 23.1 Tcf in
2015. The largest increase in nonassociated
gas production, according to EIA, was in
Pennsylvania (Marcellus Shale), where
nonassociated gas production increased
from 4.2 Tcf in 2014 to 4.8 Tcf in 2015.
Proved reserves of casinghead gas decreased from 69.1 Tcf to 65.5 Tcf in
2015, EIA goes one, a decrease of 5 percent. Estimated production of casinghead
gas increased 17 percent, going from 5.3
Tcf in 2014 to 6.2 Tcf in 2015. EIA
reports the largest increase in casinghead
gas production was in Texas RRC Districts
1, 2, and 8, coinciding with the gains in
oil production from the Eagle Ford Shale
and Permian Basin.
Proved reserves of U.S. coalbed
methane decreased from 15.7 Tcf in 2014
to 12.5 Tcf in 2015, EIA says, a 20 percent
drop. Estimated production of coalbed
methane decreased 10 percent, going from
1.40 Tcf in 2014 to 1.27 Tcf in 2015.
Among individual states, EIA reports,
New Mexico experienced the largest decrease (900 Bcf) in coalbed methane reserves, followed by Wyoming and Colorado (declining by 800 Bcf and 700
Bcf, respectively). No states reported an
increase in coalbed methane proved reserves in 2015.
Proved reserves of U.S. shale gas decreased from 199.7 Tcf in 2014 to 175.6
Tcf in 2015, according to EIA. The share
of natural gas from shale compared with
total U.S. proved gas reserves increased
from 51 percent in 2014 to 54 percent in
2015. Estimated production of shale gas
increased 13 percent, going from 13.4
Tcf in 2014 to 15.2 Tcf in 2015.
EIA reports Pennsylvania had the highest
level of proved shale gas reserves at 53.5
Tcf, followed by Texas at 42.6 Tcf, and
West Virginia at 19.2 Tcf. Oklahoma had
the fourth largest proved shale gas reserves
at 18.6 Tcf, and EIA says Ohio became
the fifth-largest as its Utica/Pt. Pleasant
Shale proved reserves rose to 12.4 Tcf.
Seven shale plays-the Marcellus, Eagle Ford, Woodford, Barnett, Haynesville/Bossier, Utica/Pt. Pleasant, and
Fayetteville-contained 91 percent of
U.S. shale gas proved reserves at yearend of 2015, according to EIA. The
Marcellus Shale remained the play with
the largest shale gas reserves, even though

its total declined the most (11.8 Tcf, or
14 percent). The second-largest shale
gas play was the Eagle Ford, where
proved reserves declined 17 percent in
2015.
Proved reserves in the Barnett Shale-
the oldest and fourth largest shale gas
play in the United States-decreased by
7.3 Tcf.
EIA notes that the estimated dry natural

gas content-the volume of gas that remains
after gas liquids and nonhydrocarbon impurities are removed-of total U.S. natural
gas proved reserves decreased from 368.7
Tcf in 2014 to 307.7 Tcf, a 16 percent
drop. The estimated volume of natural
gas plant liquids contained in total proved
reserves decreased from 15.0 billion
barrels in 2014 to 12.7 billion barrels in
2015, a 15 percent decline.
r

Rising World Methane Emissions
Are Not Caused By Gas Industry
The natural gas industry is not responsible for a rise in worldwide methane
emissions observed since 2007, according
to a pair of scientific studies.
The U.S. National Oceanic and Atmospheric Administration published results
of a study in the journal Nature, while
Researchers at Royal Holloway, University
of London, published a report in Global
Biogeochemical Cycles, the journal of the
American Geophysical Union. Both studies
put the rise in global methane emissions-
which NOAA estimates at 28 million tons
a year between 2007 and 2013-at the feet
of biological sources.
"We believe methane produced by microbial sources-cows, agriculture, landfills,
wetlands and freshwaters-are responsible
for the increase, but we cannot yet pinpoint
which are the primary drivers," says Stefan
Schwietzke, the NOAA study's lead author
and a scientist with the Cooperative Institute
for Research in Environmental Sciences
at the University of Colorado Boulder,
which worked with NOAA.
The University of London reached a
similar conclusion, according to a published report that quotes professor Euan
Nisbet saying, "While agricultural emissions are likely increasing . . . and probably
have been an important component in
the increase, we find that tropical wetlands
are likely the dominant contributor to
(emission) growth."
NOAA says its study employed "a database roughly 100 times larger than previous
(databases)." Because methane emissions
have distinct isotopic signatures, NOAA
says researchers were able to distinguish
whether a sample came from fossil fuel
development, natural geologic sources, microbial activity, or biomass burning.
Greater Efficiency
The NOAA study did conclude that
fossil fuel emissions were 20-60 percent
greater than previous studies had estimated,
and were responsible for 132 million-165

million tons of the 623 tons of methane
being emitted annually by all sources.
"We recognize the findings may seem
counterintuitive: Methane emissions from
fossil fuel development have been underestimated dramatically, but they are
not directly responsible for the increase
in total methane emissions observed since
2007," Schwietzke comments.
He says that while natural gas production
has increased, NOAA found that the rate
of methane leakage has decreased from 8
percent to 2 percent over the past 30 years.
"The absolute amount of emissions has
remained constant," Schwietzke reports.
Another published report notes NOAA's
2 percent figure is corroborated by a
Carnegie Mellon University study published
earlier this year in Environmental Science
and Technology. According to that report,
Carnegie Mellon measured methane leaks
from both conventional and unconventional
wells in Pennsylvania's Marcellus Shale.
Kathleen Sgamma, vice president of
government and public affairs for the
Western Energy Alliance, hails the results
as evidence that federal rules to limit the
oil and gas industry's methane emissions
are misguided.
She says, "The NOAA study and several
others show that increased global methane
emissions are not from oil and natural gas
production, but from natural sources such
as wetlands and natural seeps. It is time
for the administration to stop punitive regulations on the only industry that captures
methane in substantial quantities and puts
it to beneficial use. We wish the administration would recognize good science and
stop the climate change orthodoxy that
actually punishes a real solution."
Sgamma says the upstream industry has
reduced its methane emissions by 21 percent
since 1990 at the same time natural gas
production has risen 47 percent. She cites
a report by the Environmental Defense
Fund and the University of Texas that puts
well site emissions at 0.38-0.42 percent. r
JANUARY 2017 129

American Oil and Gas Reporter - January 2017

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