Oil shale

Oil shale, a fine-grained sedimentary rock, contains significant amounts of kerogen (a solid mixture of organic chemical compounds), from which technology can extract liquid hydrocarbons. Authorities have described the name oil shale as a promotional misnomer, since the rock is not necessarily a shale and its kerogen is not crude oil; it requires more processing than crude oil, which affects its economic viability as a crude oil substitute. Deposits of oil shale are located around the world, including major deposits in the United States of America. Global deposits are estimated as equivalent to 2.8 trillion to 3.3 trillion barrels of recoverable oil.