Introduction to special issue

The gas surge

See allHide authors and affiliations

Science  27 Jun 2014:
Vol. 344, Issue 6191, pp. 1464-1467
DOI: 10.1126/science.344.6191.1464

702—PERCENT INCREASE IN U.S. SHALE GAS PRODUCTION SINCE 2007

40—PERCENT SHALE GAS SHARE OF TOTAL U.S. PRODUCTION

47—PERCENT INCREASE IN U.S. ELECTRICITY GENERATED USING NATURAL GAS SINCE 2005

15,000,000—LITERS OF WATER AND CHEMICALS PUMPED INTO A TYPICAL FRACKING WELL

Nearly 70 years ago, a small group of engineers and geologists gathered at a dusty gas drilling site in southwestern Kansas to try an experiment. They pumped nearly 4000 liters of gelled gasoline and sand some 700 meters down a borehole 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, fracking, 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 known in the industry—are found around the world (see map). So far, however, the shale gas boom is largely confined to the United States, where over the past decade companies have drilled thousands of fracking wells into once obscure geological formations, 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.)

Geophysicists at Chesapeake Energy use 3D visualizations to plan fracking wells, which stretch horizontally into shale deposits.

PHOTO: MARK THIESSEN

The resulting surge in natural gas is remaking U.S. energy markets—and causing economic ripple effects globally. Shale gas has made the United States the world's leading 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). That's helped accelerate a shift away from coal to natural gas for generating electricity and prompted energy-intensive manufacturing firms to shift production from overseas factories to the United States, creating hundreds of thousands of jobs. The United States is also boosting natural gas exports to other nations—reversing its traditional role as an energy importer.

The shale gas shake-up has been accompanied by plenty of controversy—and new research—as the stories in this special section illustrate. Scientists are debating fracking'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 potentially transformative ways to convert the methane in natural gas into liquid fuels and other chemicals (p. 1474). Some are examining the origins of shale gas, trying to determine 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 deposits. Public opposition to fracking is growing in some nations, however, and drilling technologies that have performed well in the United States may not work well overseas, 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.

Further reading

R. D. Vidic, S. L. Brantley, J. M. Vandenbossche, D. Yoxtheimer, J. D. Abad, Impact of shale gas development on regional water quality. Science 340, 1235009 (2013).

W. L. Ellsworth. Injection-induced earthquakes. Science 341, 1225942 (2013).

R. J. Conrado, R. Gonzalez, Envisioning the bioconversion of methane to liquid fuels. Science 343, 621–623 (2014).

A. R. Brandt et al., Methane leaks from North American natural gas systems. Science 343, 733–735 (2014).

B. G. Hashiguchi et al., Main-group compounds selectively oxidize mixtures of methane, ethane, and propane to alcohol esters. Science 343, 1232–1237 (2014).

X. Guo et al., Direct, nonoxidative conversion of methane to ethylene, aromatics, and hydrogen. Science 344, 616–619 (2014).

D. A. Stolper et al., Formation temperatures of thermogenic and biogenic methane. Science 344, 1500–1503 (2014).

Navigate This Article