also known as shale rock, is a sedimentary rock
that contains an organic material called kerogen, which can be converted to crude oil
. Contrary to the name, oil shale does not contain any oil
, but is made up of solid materials and has a fine-grain texture. Oil shale is found in huge volumes, but is difficult to develop.
Oil shale contains organic matter that can be used for oil and combustible gas after it is decomposed and distilled. Deposits of oil shale can contain little to no economic value or can span thousands of square miles and reach thicknesses of 700 meters or greater. Oil shale is located in fresh water and salt lakes, marine basins, tidal shelves, coastal swamps and more. Compared to coal, oil shale has more mineral matter, higher hydrogen and lower oxygen content. Extracting oil from oil shale is also more complicated than extracting regular oil. After being mined and heated to a high temperature, oil shale creates a liquid that is separated and collected.
The Green River Formation, which spans Colorado, Utah and Wyoming, has the largest oil shale deposits on the globe, ranging from 1.2 to 1.8 trillion barrels, although not all the resources are recoverable. An estimated 800 billion barrels of recoverable oil from oil shale exists in the United States, which is three times as much as Saudi Arabia's known oil reserves. According to the U.S. Energy Information Administration (EIA), about 9.35 trillion cubic feet of dry natural gas was produced directly from shale deposits in 2013, which was roughly 39 percent of total U.S. dry natural gas production in 2013.
- ↑ “U.S. Geological Survey”, “Energy Resource Program, Oil Shale,” accessed January 29, 2014
- ↑ “U.S. Energy Information Administration”, “Glossary, S” accessed January 29, 2014
- ↑ “U.S. Energy Information Administration”, “Energy in Brief,” accessed January 28, 2014
- ↑ Stephen A. Sonnenberg, "Core Analysis and Unconventional Reservoirs," accessed April 22, 2014
- ↑ Oil Shale and Tar Sands Programmatic Environmental Impact Statement, "About Oil Shale," accessed March 30, 2015
- ↑ U.S. Energy Information Administration, "How much shale gas is produced in the United States?," November 21, 2014