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For gas generated by oil shale pyrolysis, see Oil shale gas.
48 Shale basins in 38 countries, as per the EIA
Derrick and platform of drilling gas wells in Marcellus Shale (Pennsylvania, USA). Shale gas is natural gas formed from being trapped within shale formations. Shale gas has become an increasingly important source of natural gas in the United States since the start of this century, and interest has spread to potential gas shales in the rest of the world. In 2000 shale gas provided only 1% of U.S. natural gas production; by 2010 it was over 20% and the U.S. government's Energy Information Administration predicts that by 2035 46% of the United States' natural gas supply will come from shale gas. Some analysts expect that shale gas will greatly expand worldwide energy supply. Chinais estimated to have the world's largest shale gas reserves. A study by the Baker Institute of Public Policy at Rice University concluded that increased shale gas production in the US and Canada could help prevent Russia and Persian Gulf countries from dictating higher prices for the gas they export to European countries. The Obama administration believes that increased shale gas development will help reduce greenhouse gas emissions. Some studies have alleged that the extraction and use of shale gas may result in the release of more greenhouse gases than conventional natural gas. Other recent studies point to high decline rates of some shale gas wells as an indication that shale gas production may ultimately be much lower than is currently projected. Contents [hide] * 1 History * 2 Geology * 3 Environment * 3.1 Climate * 3.2 Water and air quality * 3.3 Earthquakes * 4 Economics * 5 See also * 6 References * 7 External links| -------------------------------------------------
Shale gas was first extracted as a resource in Fredonia, NY in 1821, in shallow, low-pressure fractures. Horizontal drilling began in the 1930s, and in 1947 a well was first fracked in the U.S. Work on industrial-scale shale gas production did not begin until the 1970s, when declining production potential from conventional gas deposits in the United States spurred the federal government to invest in R&D and demonstration projects that ultimately led to directional and horizontal drilling, microseismic imaging, and massive hydraulic fracturing. Up until the public and private R&D and demonstration projects of the 1970s and 1980s, drilling in shale was not considered to be commercially viable. Early federal government investments in shale gas began with the Eastern Gas Shales Project in 1976 and the annual FERC-approved research budget of the Gas Research Institute, where the federal government began extensive research funding in 1982, disseminating the results to industry. The federal government also provided tax credits and rules benefitting the industry in the 1980 Energy Act.The Department of Energy later partnered with private gas companies to complete the first successful air-drilled multi-fracture horizontal well in shale in 1986. The federal government further incentivized drilling in shale via the Section 29 tax credit for unconventional gas from 1980-2000. Microseismic imaging, a crucial input to both hydraulic fracturing in shale and offshore oil drilling, originated from coalbeds research at Sandia National Laboratories. In 1991 the Department of Energy subsidized Texas gas company Mitchell Energy's first horizontal drill in the Barnett Shale in north Texas. Mitchell Energy utilized all these component technologies and techniques to achieve the first economical shale fracture in 1998 using an innovative process called slick-water fracturing. Since then, natural gas from shale has been the fastest growing contributor to total...