an estimated quantity of all hydrocarbons statistically defined as crude oil or natural gas, which geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Reservoirs are considered proven if economic producibility is supported by either actual production or conclusive formation testing. The area of an oil reservoir considered proven includes those portions delineated by drilling and defined by gas-oil or oil-water contacts, if any, and the immediately adjoining portions not yet drilled, but which can be reasonably judged as economically productive on the basis of available geological and engineering data. In the absence of information on fluid contacts, the lowest known structural occurrence of hydrocarbons controls the lower proven limit of the reservoir.
Crude oil: estimates include oil that can be produced economically through application of improved recovery techniques following successful completion of pilot testing. Estimates do not include:
  • oil that may become available from known reservoirs but is reported separately as "indicated additional reserves";
  • oil, the recovery of which is subject to reasonable doubt because of uncertainty as to geology, reservoir characteristics or economic factors;
  • oil that may occur in untested prospects; and
  • oil that may be recovered from oil shales, coal, gilsonite and other such sources.
Natural gas: estimates are prepared for total recoverable natural gas, non-associated gas and associated-dissolved gas. Estimates do not include gaseous equivalence of natural gas liquids expected to be recovered from reservoir natural gas as it is produced, natural gas being held in underground storage or non-hydrocarbon gases.
a derrick complete with engine-house and other equipment necessary for drilling oil and gas wells. Well (exploratory and development): a hole drilled for the purpose of finding or producing crude oil or natural gas; or providing services related to the production of crude oil and natural gas.Completion: this term refers to the installation of permanent equipment for the production of oil or gas. Oil or gas well: a well completed for the production of oil or gas from one or more zones or reservoirs. Dry hole: a well found to be incapable of producing either oil or gas in sufficient quantities to justify completion as an oil or gas well.
a mixture of hydrocarbons that exists in a liquid phase in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface separating facilities. Production volumes reported as crude oil include:
  • liquids technically defined as crude oil;
  • small amounts of hydrocarbons that exist in the gaseous phase in natural underground reservoirs, but which are liquid at atmospheric pressure after being recovered from oil well (casing head) gas in lease separators;
  • small amounts of non-hydrocarbons produced with the oil.

Natural gas liquids (NGLs):

those reservoir gases liquefied at the surface in lease separators, field facilities or gas processing plants. NGLs consist of field condensates and natural gas plant products such as ethane, pentane, propane, butane and natural gasoline.
Natural gas:
a mixture of hydrocarbon compounds and small quantities of various non-hydrocarbons existing in the gaseous phase or in solution with oil in natural underground reservoirs at reservoir conditions. The natural gas volumes in this Bulletin refer to Standard Conditions of 60o F, 14.73 psia (15.6o C, 760 mm/Hg).
Gross production: the total flow of natural gas from oil and gas reservoirs of associated-dissolved and non-associated gas. Marketed production: corresponds to gross production, minus the volumes of gas flared or re-injected into fields, minus the shrinkage. Re-injection: the total volume of natural gas produced from oil and gas completions, processed through gas-processing plants and field facilities, and used for gas lift, gas injection, and cycling operations. Shrinkage: contraction due to natural gas processing, purification for the extraction of natural gas liquids. Flared: total volume of vented or flared gas.Refinery capacity (operable): the maximum amount of input to crude oil distillation units that can be processed in an average 24-hour period.
Refinery capacity (operable):
the maximum amount of input to crude oil distillation units that can be processed in an average 24-hour period.
Barrels per calendar day (b/cd):
the total number of barrels processed in a refinery within a year, divided by 365 days, thus reflecting all
operational limitations.
Barrels per stream day (b/sd):
the number of barrels of input that a refining facility can process within 24 hours, operating at full capacity under optimal crude and product slate conditions.
Petroleum products:
products obtained from the processing of crude oil, and unfinished oils, NGLs, and other hydrocarbon compounds.
These include aviation gasoline, motor gasoline, naphtha, kerosene, jet fuel, distillate fuel oil, residual fuel oil, liquefied petroleum gas, lubricants, paraffin wax, petroleum coke, asphalt and other products. Gasoline: a mixture of relatively volatile hydrocarbons, with or without small quantities of additives, that have been blended to form a fuel suitable for use in internal combustion engines; includes gasoline used in aviation. .Kerosene: medium hydrocarbon distillates in the 150° to 280° C distillation range, and used as a heating fuel as well as for certain types of internal combustion engine; includes jet fuel, which is a fuel of naphtha, or of kerosene type, suitable for commercial or military purposes in aircraft turbine engines. Distillates: middle distillate type of hydrocarbons. Included are products similar to number one and number two heating oils and diesel fuels. These products are used for space heating, diesel engine fuel and electrical power generation. Residual fuel oil: these are fuels obtained as liquid still bottoms from the distillation of crude used alone or in blends with heavy liquids from other refinery process operations. It is used for the generation of electric power, space heating, vessel bunkering and various industrial purposes.
Output of refined products:

the total amount of petroleum products produced from refinery input in a given period, excluding refinery fuels.

inland delivery, including refinery fuels and losses, as well as products from gas plants; excluding
bunkers. As of this edition, processing gains are not deducted from consumption volumes.

includes products from gas plants and excludes bunkers.

is the arithmetic average of seven selected crudes. These are: Saharan Blend (Algeria); Minas (Indonesia); Bonny Light (Nigeria); Arab Light (Saudi Arabia); Dubai (United Arab Emirates), Tia Juana Light (Venezuela), and Isthmus (Mexico). Mexico is not a Member of OPEC.

announced price reflecting the market development of crude oil and products.

the composite barrel is a consumption weighted average of final consumer prices (including taxes) of the main groups of refined petroleum products.

Agreement of January 20, 1972, between certain OPEC Member Countries and international oil companies introducing adjustments to posted prices to take account of the world currency situation. For its calculations, the Geneva I Agreement used the national currencies of Belgium, France, Germany, Italy, Japan, Netherlands, Sweden, Switzerland and the United Kingdom.