Crude oil
Crude oil consists of a mixture of petroleum liquids and gases (together with associated impurities) pumped out of the ground through oil wells.
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2 Extraction 3 Pricing 4 Origins 5 See also 6 External links |
Classification
The oil industry classifies "crude" by the location of its origin (e.g., "western Texas" or "Brent") and often by its relative weight or viscosity ("light", "intermediate" or "heavy"); drillers may also refer to it as "sweet", which means it contains relatively little sulfur (in the form of the gas H2S) and requires less refining, or as "sour", which means it contains substantial acid gases and requires more refining. The presence of H2S also adds considerably to the extraction costs of crude, as one cannot simply emit this highly toxic gas into the atmosphere. Usually refiners either process it into elemental sulphur and then dispose of it, or reinject it into a depleted gas reservoir.
Extraction
Various techniques aid in recovering oil from depleted or low pressure reservoirs, including Beam Pumps, Electrical Submersible Pumps (ESPs), and Gas Lift. Other techniques include Water Injection and Gas Re-injection, which help to maintain reservoir pressure, usually at the cost of altering the ratio of these products in the produced oil.Pricing
The price of oil fluctuates quite widely in response to crises or recessions in major economies, because any economic downturn reduces the demand for oil. On the supply side the OPEC cartel uses its influence to stabilise or raise oil prices. In the early spring of 1999 the average price of around US$14 per barrel (less than US $0.15 per liter), made crude oil the second-cheapest liquid in the world. In March 2003 Brent crude stood at US $33 per barrel. The New York Mercantile Exchange (NYMEX) trades almost all crude oil and provides the basis of the world's oil pricing.Origins
Most geologistss view crude oil, like coal and natural gas, as the product of compression of ancient vegetation over geological timescales. A few scientists, notably Thomas Gold, have suggested other, abiogenic, theories for the origins of crude oil. See also
External links
History and Analysis of Crude Oil Prices