Petroleum

Petroleum (also known as crude oil or simply oil) is a naturally occurring, yellowish-black liquid found in geological formations beneath the Earth's surface. It is commonly refined into various types of fuels.

Composition

Petroleum is composed of hydrocarbons of various molecular weights and other organic compounds. The composition varies widely depending on where and how the petroleum was formed. In fact, chemical analysis of petroleum can help identify its source of origin.

Formation

Petroleum is formed by hydrocarbons (a hydrocarbon is a compound made up of carbon and hydrogen) with the addition of certain other substances, primarily sulphur. Petroleum in an unrefined state has been utilized by humans for over 5000 years. Oil in general has been used since early human history to keep fires ablaze, and also for warfare.

Extraction

Petroleum is extracted from the ground using oil drilling. This latter stage comes after the studies of structural geology (at the reservoir scale), sedimentary basin analysis, reservoir characterization (mainly in terms of the porosity and permeability of geologic reservoir structures).

Refining

After extraction, crude oil is processed in oil refineries to create fuel oil, gasoline, liquefied petroleum gas, and other non-fuel products such as pesticides, fertilizers, pharmaceuticals and plastics. The oil refining process includes the removal of impurities, conversion of heavy hydrocarbons to lighter ones, and separation of useful components.

Environmental impact

The use of petroleum has a significant impact on the environment due to the production of carbon dioxide and other greenhouse gases. Oil spills can also have devastating effects on the environment, damaging ecosystems and killing wildlife.

See also

• Oil refinery
• Fossil fuel
• Peak oil
• Oil spill
• Hydrocarbon

References

Petroleum Resources
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