Fossil Fuels


petroleum, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth; it is also called crude oil. It consists principally of a mixture of hydrocarbons, with traces of various nitrogenous and sulfurous compounds.

Origin and Natural Occurrence

During the past 600 million years incompletely decayed plant and animal remains have become buried under thick layers of rock. It is believed that petroleum consists of the remains of these organisms but it is the small microscopic plankton organism remains that are largely responsible for the relatively high organic carbon content of fine-grained sediments like the Chattanooga shale which are the principle source rocks for petroleum. Among the leading producers of petroleum are Saudi Arabia, Russia, the United States (chiefly Texas, North Dakota, Alaska, and California), China, Iran, Canada, the United Arab Emirates, Mexico, Brazil, Kuwait, Iraq, Nigeria, Venezuela, and Norway. The largest proven reserves are in the Middle East, but the United States and Russia also have large reserves.

Exploration and Drilling of Wells

Because of the subterranean origin of petroleum it must be extracted by means of wells. Until an exploratory well, or wildcat, has been dug, there is no sure way of knowing whether or not petroleum lies under a particular site. In order to reduce the number of exploratory wells drilled, scientific methods are used to pick the most promising sites. Sensitive instruments, such as the gravimeter, the magnetometer, and the seismograph, may be used to find subsurface rock formations that can hold crude oil. Drilling is a fairly complex and often risky process. Some wells must be dug several miles deep before petroleum deposits are reached. Many are now drilled offshore from platforms standing in the ocean bed. Usually the petroleum from a new well will come to the surface under its own pressure. Later the crude oil must be pumped out or forced to the surface by injecting water, air, natural gas, steam, carbon dioxide, or another substance into the deposits. Enhanced recovery techniques have increased the percentage of oil that can be extracted from a field.

Composition and Refining of Petroleum

The physical properties and exact chemical composition of crude oil varies from one locality to another. The different hydrocarbon components of petroleum are dissolved natural gas, gasoline, benzine, naphtha, kerosene, diesel fuel and light heating oils, heavy heating oils, and finally tars of various weights (see tar and pitch). The crude oil is usually sent from a well to a refinery in pipelines (see under pipe) or tanker ships.

The hydrocarbon components are separated from each other by various refining processes. In a process called fractional distillation petroleum is heated and sent into a tower. The vapors of the different components condense on collectors at different heights in the tower. The separated fractions are then drawn from the collectors and further processed into various petroleum products. One of the many products of crude oil is a light substance with little color that is rich in gasoline. Another is a black tarry substance that is rich in asphalt.

As the lighter fractions, especially gasoline, are in the greatest demand, so-called cracking processes have been developed in which heat, pressure, and certain catalysts are used to break up the large molecules of heavy hydrocarbons into small molecules of light hydrocarbons. Some of the heavier fractions find eventual use as lubricating oils, paraffins, and highly refined medicinal substances such as petrolatum.

See also petrochemicals.

History and Development of Petroleum

Petroleum has been known throughout historical time. It was used in mortar, for coating walls and boat hulls, and as a fire weapon in defensive warfare. Native Americans used it in magic and medicine and in making paints. Pioneers bought it from the Native Americans for medicinal use and called it Seneca oil and Genesee oil. In Europe it was scooped from streams or holes in the ground, and in the early 19th cent. small quantities were made from shale. In 1815 several streets in Prague were lighted with petroleum lamps.

The modern petroleum industry began in 1859, when the American oil pioneer E. L. Drake drilled a producing well on Oil Creek in Pennsylvania at a place that later became Titusville. Many wells were drilled in the region. Kerosene was the chief finished product, and kerosene lamps soon replaced whale oil lamps and candles in general use. Little use other than as lamp fuel was made of petroleum until the development of the gasoline engine and its application to automobiles, trucks, tractors, and airplanes. Today the world is heavily dependent on petroleum for motive power, lubrication, fuel, dyes, drugs, and many synthetics. The widespread use of petroleum has created serious environmental problems. The great quantities that are burned as fuels generate most of the air pollution in industrialized countries, and oil spilled from tankers and offshore wells has polluted oceans and coastlines.

See also energy, sources of; oil industry.


See K. K. Landes, Petroleum Geology of the United States (1970); S. Schackne and N. D. Drake, Oil for the World (2d ed. 1960); L. Mosley, Power Play: Oil in the Middle East (1973).

The Columbia Encyclopedia, 6th ed. Copyright© 2018, The Columbia University Press.

Fossil Fuels: Selected full-text books and articles

Temporarily FREE! Energy: What Everyone Needs to Know By Jose Goldemberg Oxford University Press, 2012
Librarian's tip: Chap. 4 "Fossil Fuels"
No Stopping Fossil Fuels By Kumar, Supriya USA TODAY, Vol. 143, No. 2830, July 2014
Oil Is King, but Coal, Natural Gas Gaining USA TODAY, Vol. 142, No. 2819, August 2013
Energy: Perspectives, Problems, and Prospects By Michael B. McElroy Oxford University Press, 2010
Librarian's tip: Chap. 5 "Coal: Origin, History, and Problem," Chap. 6 "Oil: Properties, Origin, History, Problems, and Prospects," Chap. 7 "Natural Gas: Origin, History, and Prospects"
A Cubic Mile of Oil: Realities and Options for Averting the Looming Global Energy Crisis By Hewitt D. Crane; Edwin M. Kinderman; Ripudaman Malhotra Oxford University Press, 2010
Librarian's tip: Especially Chap. 5 "Our Energy Inheritance: Fossil Fuels"
The Fossil Fuels War By Foster, John Bellamy Monthly Review, Vol. 65, No. 4, September 2013
Children Are Likely to Suffer Most from Our Fossil Fuel Addiction By Perera, Frederica P Environmental Health Perspectives, Vol. 116, No. 8, August 2008
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
Cleaning Up Coal: From Climate Culprit to Solution By Morse, Richard K Foreign Affairs, Vol. 91, No. 4, July/August 2012
Untapped Resource: Natural Gas: Safer Cleaner Energy That Pays for Itself By Frodl, Michael G.; Manoyan, John M National Defense, Vol. 93, No. 666, May 2009
Unconventional Fossil-Based Fuels: Economic and Environmental Trade-Offs By Michael Toman; Aimee E. Curtright; David S. Ortiz; Joel Darmstadter; Brian Shannon Rand, 2008
Birth Defects and Mothers' Proximity to Natural Gas Development: Is There a Connection? By Konkel, Lindsey Environmental Health Perspectives, Vol. 122, No. 4, April 2014
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
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