Petroleum

Petroleum (from Greek petra – rock and oleum – oil), crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish liquid. A widely believed myth is that the oil itself is flammable, however it is actually the gas that evaporates from the oil that is flammable. Petroleum exists in the upper strata of some areas of the Earth's crust. Another name is naphtha, from Persian naft or nafátá (to flow). It consists of a complex mixture of various hydrocarbons, largely of the alkane series, but may vary much in appearance, composition, and purity. It is an important "primary energy" source (IEA Key World Energy Statistics). Petroleum is also the raw material for many chemical products, including solvents, fertilizers, pesticides, and plastics.

Classification

The oil industry classifies "crude" by the location of its origin (e.g., "West Texas Intermediate, WTI" or "Brent") and often by its relative weight (API gravity) or viscosity ("light", "intermediate" or "heavy"); refiners may also refer to it as "sweet", which means it contains relatively little sulfur, or as "sour", which means it contains substantial amounts of sulfur and requires more refining in order to meet current product specifications.

Related Topics:
Oil industry - API gravity - Viscosity - Sulfur

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The world reference barrels are:

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• Brent Blend, comprising 15 oils from fields in the Brent and Ninian systems in the East Shetland Basin of the North Sea. The oil is landed at Sullom Voe terminal in the Shetlands. Oil production from Europe, Africa and Middle Eastern oil flowing West tends to be priced off the price of this oil, which forms a benchmark. See also Brent crude.
• West Texas Intermediate (WTI) for North American oil.
• Dubai used as benchmark for the Asia-Pacific region for Middle East Oil
• Tapis (from Malaysia, used as a reference for light Far East oil)
• Minas (from Indonesia, used as a reference for heavy Far East oil)
• The OPEC Basket consisting of
• Arab Light Saudi Arabia
• Bonny Light Nigeria
• Fateh Dubai
• Isthmus Mexico (non-OPEC)
• Minas Indonesia
• Saharan Blend Algeria
• Tia Juana Light Venezuela

OPEC attempts to keep the price of the Opec Basket between upper and lower limits, by increasing and decreasing production. This makes the measure important for market analysts. The OPEC Basket, including a mix of light and heavy crudes, is heavier than both Brent and WTI.

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See also http://tonto.eia.doe.gov/ask/crude_types1.html

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