Key Terms |
Definition |
API Gravity |
An arbitrary scale expressing the gravity or density of liquid petroleum products.
The measuring scale is calibrated in terms of degrees API; it is calculated as follows:
Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5
The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API
and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below.
Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity.
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Crude Oil |
A mixture of hydrocarbons that exists in liquid phase in natural underground
reservoirs and remains liquid at atmospheric pressure after passing through
surface separating facilities. Depending upon the characteristics of the crude
stream, it may also include:
Small amounts of hydrocarbons that exist in gaseous phase in natural
underground reservoirs but are liquid at atmospheric pressure after being
recovered from oil well (casinghead) gas in lease separators and are subsequently
commingled with the crude stream without being separately measured. Lease
condensate recovered as a liquid from natural gas wells in lease or field
separation facilities and later mixed into the crude stream is also included;
Small amounts of nonhydrocarbons produced with the oil, such as sulfur and
various metals;
Drip gases, and liquid hydrocarbons produced from tar sands, oil sands,
gilsonite, and oil shale.
Liquids produced at natural gas processing plants are excluded. Crude oil is refined to produce
a wide array of petroleum products, including heating oils; gasoline, diesel and jet fuels;
lubricants; asphalt; ethane, propane, and butane; and many other products used for their
energy or chemical content.
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Domestic |
Crude oil produced in the U.S. or from its "outer continental shelf" as defined in
43 U.S.C. 1331.
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First Purchase (of Crude Oil) |
An equity (not custody) transaction involving an arms-length transfer of ownership of crude oil
associated with the physical removal of the crude oil from a property (lease) for the first time.
A first purchase normally occurs at the time and place
of ownership transfer where the crude oil volume sold is measured and recorded on a run
ticket or other similar physical evidence of purchase. The reported cost is the actual amount
paid by the purchaser, allowing for any adjustments (deductions or premiums) passed on to the
producer or royalty owner.
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