Oil Shale is fine grained rock which contains significant amounts of Kerogen. New drilling technology can extract liquid
hydrocarbons. Oil shale requires more processing then crude oil, which is more expensive. Most exploitation of oil shale involves
mining followed by shipping elsewhere, after which one can burn it directly to generate electricity, or undertake further
processing. The most-often used methods of surface mining are open pit mining and strip mining. These procedures remove most
of the overlying material to expose the oil shale deposits, and are practical when the deposits are close to the surface.
The world's largest Oil Shale reserve is located in Colorado, Wyoming, and Utah in the Green River Basin Oil Shale Formation.
Shale Gas, natural gas located in shale rock, is located
far beneath the earth's surface. Because shale has insufficient permeability to allow significant fluid flow to a well
bore, most shale is not a source of natural gas. Shale gas is one of a number of “unconventional” sources
of natural gas; other unconventional sources of natural gas include coalbed methane, tight sandstones, and methane hydrates.
Shale has low matrix permeability, so gas production in commercial quantities requires fractures
to provide permeability. Shale gas has been produced for years from shales with natural fractures; the shale gas boom in recent
years has been due to modern technology in creating extensive artificial fractures around well bores. Horizontal drilling
is often used with shale gas wells.
