Definitions, Sources and Explanatory Notes

 Category:   Petroleum Prices
 Topic:   Domestic Crude Oil First Purchase Prices by API Gravity

  Definitions

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.
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.
    Domestic Crude oil produced in the U.S. or from its "outer continental shelf" as defined in 43 U.S.C. 1331.
    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.

    For definitions of related energy terms, refer to the EIA Energy Glossary.

      Sources

    Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." ( Forms/Instructions, Background, Survey Methodology and Statistical Details )

      Explanatory Notes

  • Values shown for the current month are preliminary. Values shown for the previous month may be revised to account for late submissions and corrections. Final revisions to monthly and annual values are available upon publication of the June Petroleum Marketing Monthly. Annual averages that precede the release of the June Petroleum Marketing Monthly are calculated from monthly data. Data through 2021 are final.
  • For purposes of this survey, the United States includes the 50 States, the outer continental shelf, and the District of Columbia.