Shale gas

Shale gas is natural gas extracted from rock shale. Shale gas is one of a number of "unconventional" sources of natural gas; other unconventional sources of natural gas include coalbed methane, tight gas, and gas hydrates.

Shale has low matrix permeability, so oil and gas companies create fractures for permeability. Shale gas has been extracted for years from shales with natural fractures; the shale gas boom in recent years has been due in part to technology in hydraulic fracturing (fracking) to create extensive artificial fractures around well bores.

Gas in rocks with a permeability of <0.1md have been classified as unconventional, although more recently the National Petroleum Council (NPC) has defined unconventional gas as "natural gas that cannot be produced at economic flow rates nor in economic volumes unless the well is stimulated by a large hydraulic fracture treatment, a horizontal wellbore, or by using multilateral wellbores or some other technique to expose more of the reservoir to the wellbore."

U.S. Reserves
For more see Shale gas and oil reserves Shale gas appears to have high initial production rates but then steeper decline rates than conventional gas wells, and there is a high degree of variability within shale plays; how this is accounted for can affect total reserve estimates.

According to the U.S. Energy Information Administration (EIA), U.S. shale gas production has increased fourteen-fold from 2002 to 2012; as of 2012, shale gas accounts for 22% of U.S. gas production and 32% of total remaining recoverable gas resources in the United States. By 2030, EIA projects that shale gas will represent 14% of total global gas supplies, and has launched the "Global Shale Gas Initiative" (GSGI) to help facilitate this projection.

Some argue that high shale resource assessments in the US have been driven in part by the relaxation of how gas reserves are estimated for financial reporting purposes, enabling companies to overstate reserves, and issue debt and stock against those overstatments.

Related SourceWatch articles

 * Coalbed methane
 * Coal plant conversion projects
 * Energy in Depth
 * Fracking
 * Marcellus Shale
 * Natural gas
 * Natural gas transmission leakage rates
 * West Virginia and coal

State-by-state fracking profiles
Click on the map below for state-by-state information on fracking:

External Resources
''Wikipedia also has an article on natural gas. This article may use content from the Wikipedia article under the terms of the GFDL.''