The gas surge
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Fracking has ignited an energy revolution, with still-uncertain consequences for climate and the environment
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Nearly 70 years ago, a small group of engineers
and geologists gathered at a dusty gas drilling
site in southwestern Kansas to try an experi-
ment. They pumped nearly 4000 liters of gelled
gasoline and sand some 700 meters down a bore-
hole into a thick bed of limestone, in hopes that
the pressurized gunk would fracture the rock
and release more natural gas. The “hydraulic fracturing”
test failed. But success ultimately followed: Today, frack-
ing, as it is known, is revolutionizing the energy industry,
enabling firms to extract natural gas from a source once
considered unpromising—vast deposits of shale, which is
too dense for gas to flow freely (Science, 25 June 2010,
p. 1624). By penetrating the shale with boreholes that
bend horizontally, and then pumping in millions of liters
of fluids and sand under high pressure, drillers can force
open minute cracks that release valuable streams of gas.
Extensive shale gas deposits—or “plays” as they are
S P E C I A L S E C T I O N
A fracking well in Pennsylvania taps shale gas
deposits some 2 kilometers down.
By David Malakoff
27 JUNE 2014 • VOL 344 ISSUE 6191 1465SCIENCE sciencemag.org
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1466 27 JUNE 2014 • VOL 344 ISSUE 6191 sciencemag.org SCIENCE
known in the industry—are found around
the world (see map, p. 1467). So far, however,
the shale gas boom is largely confined to the
United States, where over the past decade
companies have drilled thousands of frack-
ing wells into once obscure geological for-
mations, including the Marcellus Shale in
Pennsylvania, the Barnett in Texas, and the
Haynesville in Louisiana. (In other shale
plays, such as the Bakken in North Dakota,
fracking is primarily used to produce oil.)
The resulting surge in natural gas is re-
making U.S. energy markets—and causing
economic ripple effects globally. Shale gas
has made the United States the world’s lead-
ing natural gas producer and now accounts
for about 40% of U.S. production, up from
less than 2% in 2001. The share is projected
to grow to 53% by 2040, and natural gas
prices have tumbled as abundance grows
(see graphs, p. 1467). That’s helped acceler-
ate a shift away from coal to natural gas for
generating electricity and prompted energy-
intensive manufacturing firms to shift pro-
duction from overseas factories to the United
States, creating hundreds of thousands of
jobs. The United States is also boosting natu-
ral gas exports to other nations—reversing its
traditional role as an energy importer.
The shale gas shake-up has been accom-
panied by plenty of controversy—and new
research—as the stories in this special sec-
tion illustrate. Scientists are debating frack-
Geophysicists at Chesapeake Energy use 3D
visualizations to plan fracking wells, which
stretch horizontally into shale deposits. P
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SPECIAL SECTION GAS REVOLUTIONSPECIAL SECTION
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27 JUNE 2014 • VOL 344 ISSUE 6191 1467SCIENCE sciencemag.org
ing’s impact on water quality (see p. 1468)
and whether the shale gas boom will help
or hurt efforts to curb climate change (see
p. 1472). They are also exploring potential
links to human-caused earthquakes (Science,
23 March 2012, p. 1436), air pollution, and
habitat fragmentation.
Basic researchers are also sizing up this
new resource. They are searching for life
deep in shale deposits (p. 1470) and poten-
tially transformative ways to convert the
methane in natural gas into liquid fuels and
other chemicals (p. 1474). Some are exam-
ining the origins of shale gas, trying to de-
termine whether it is primarily the product
of methane-producing microbes or thermal
breakdown of organic matter (see p. 1500).
And analysts continue to debate just how
much shale gas is really out there—and how
quickly the current boom could turn bust.
For the moment, any downturn seems
distant. Canada, which already gets 15% of
its natural gas from shale, is ramping up
production. China, Europe, and Russia are
eyeing their essentially untapped shale de-
posits. Public opposition to fracking is grow-
ing in some nations, however, and drilling
technologies that have performed well in
the United States may not work well over-
seas, where the shale can have very different
properties. One thing is clear: The shale gas
revolution is still in its infancy, with plenty
of growing pains ahead. ■
Basins with resource estimate
Basins without resource estimate
Source: U.S. Energy Information Administration
Source: U.S. Energy Information Administration, Annual Energy Outlook 2012
2
4
6
8
10
1990 2000 2010 2020 2030 2040
12
20
12 d
oll
ars
pe
r m
illi
on
Btu Past Projected
Lower recovery rates from wells
Higher recovery rates from wells
Referencescenario
The world has vast deposits of gas-rich shale …Six nations—the United States, China, Argentina, Algeria, Canada, and Mexico—hold
an estimated 80% of documented shale gas deposits.
but so far shale gas has had the biggest impact in the United States …As other U.S. sources of natural gas decline, shale gas production is projected to
expand and provide 53% of the total by 2040.
where abundant supplies have helped reduce natural gas prices.Future natural gas prices will depend, in part, on the future productivity of wells.
Source: U.S. Energy Information Administration, Natural Gas Annual 2012
1990 2000 2010 2020 2030 2040
Past Projected
Shale gas
All other sources
0
5
10
15
20
25
30
35
40
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The gas surgeDavid Malakoff
DOI: 10.1126/science.344.6191.1464 (6191), 1464-1467.344Science
ARTICLE TOOLS http://science.sciencemag.org/content/344/6191/1464
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