OIL & NATURAL GAS TERMINOLOGY
There are many terms that are synonymous with the oil and gas industry.
ABANDON: To discontinue attempts to produce oil or gas from a well or lease and to plug the reservoir in accordance with regulatory requirements and recover equipment. ACIDIZE: Increase the flow of oil from a well by introducing acid into a limestone formation to open passages through which oil can flow into the well bore. ACQUISITION WELL: A well drilled in exchange for a mineral interest in a property. It is also referred to as an obligation well. ACRE-FOOT: A reservoir analysis measure of volume. One acre foot represents the volume which would cover one acre to a depth of one foot. ADVANCED ROYALTY: An advance payment made by the owner of an operating interest to the royalty owner for a specific number of units of minerals regardless of whether oil or gas was extracted within the year. The payment is recoverable out of future production. AFE: Authorization for expenditures. It is a form used during the planning process for a well about to be drilled. It can also be used for other projects. The form includes an estimate of costs to be incurred in the intangible drilling costs (IDC) category and in the tangible equipment category. Costs are shown in total with accompanying breakdowns. The form represents a budget for the project against which actual expenditures are compared. AIR DRILLING: The use of compressed air as a substitute for drilling mud in rotary drilling. AIR/GAS LIFT: Method of raising oil from the formation by injecting air or gas directly into the fluid in the casing. ALLOWABLE: The regulated amount of oil or gas that a well or lease can produce during a given time period. ANTICLINES: Underground mountain-shaped strata covered with caprock or an impervious layer. API: Abbreviation for American Petroleum Institute, established in 1920. API GRAVITY: Liquid petroleum product measure of gravity of the product. Derived from a formula using specific gravity. APPORTIONMENT ACCOUNTS: Accounts used to accumulate expenses during a period, with the accounts being credited for amounts charged to activities on some predetermined basis. ASSOCIATED GAS: Natural gas, occurring in the form of a gas cap, overlying an oil zone. BAFFLES: A device which changes the direction of flow of fluids. BARREL (BBL): A standard measure of volume for crude oil and liquid petroleum products. One barrel equals 42 U.S. gallons. BATTERY: Group of lease storage tanks. BEAM: The horizontal portion of an "I" beam pumping unit. BEAM WELL: A well from which oil is lifted by using a pumping unit and sucker rods and pump. BLOWOUT: Strong flow of oil or gas, uncontrolled, from a reservoir to the surface and into the atmosphere. BOILERHOUSE: A slang term. "Fake" a report without having performed any work. BONUS: The consideration received by the lessor or sublessor on execution of the oil or gas lease. BOTTOM HOLE CONTRIBUTIONS: Money or property given to an operator for their use in drilling a well on property in which the payor has no property interest. The contribution is payable when the well reaches a predetermined depth, regardless of whether the well is productive or nonproductive. Usually, the payor receives geological data from the well. BOTTOM HOLE PRESSURE: The pressure at the bottom of a well in the producing formation. BRITISH THERMAL UNIT (BTU): A measure of the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit. BS OR BS&W: An abbreviation for basic sediment, or basic sediment and water. BS&W is produced along with oil. CARRIED INTEREST: A sharing arrangement in which one party agrees to pay the cost incurred on behalf of another which is the carried party. After production begins, the carried party receives no income until the carrying party has recouped all of their costs incurred on behalf of the carried party. CARRIED PARTY: The party for whom funds are advanced in a carried interest arrangement. CARRYING PARTY: The party advancing funds in a carrying interest arrangement. CARVED-OUT INTEREST: An interest that occurs when the owner of a working interest assigns it to another as an overriding royalty, net profits interest, or production payment. CARVED-OUT OIL OR GAS PAYMENT: A payment in oil or gas assigned by the owner of a working interest or fee interest. The payment is expressed in dollars, in barrels, in MCF, or as a period of time, to be paid out of a fractional part of the fee interest or working interest. The payment will run for a period shorter than the life of the interest from which it was carved. CASINGHEAD GAS: Gas produced along with crude oil from oil wells. CASING PRESSURE: Gas pressure in a well that is built up between the casing and tubing or casing and drill pipe. CATHEAD: A spool shaped device attached to a winch around which rope is wound for hoisting and pulling. CATLINE: A hoisting or pulling line powered by a cathead; lifts equipment around the rig. CAT WALK: The narrow walkway on a drilling rig or on top of a tank battery. CELLAR: An excavation under the rig floor to provide space for working equipment during drilling. CENTRIFUGE: Machine in which samples of oil are placed and whirled at high speed to break out sediment. CHECKERBOARD ACREAGE: Mineral interests situated in a checkerboard pattern. Generally, this is done to spread the risk or to make sure the producer will have some ownership if production is found. CHRISTMAS TREE: A term applied to the valves and fittings assembled at the top of a well to control the flow of oil. CLEAN OUT COSTS: Costs incurred to clean out a well to maintain its productive capacity or to restore it to original capacity. For example, the cost of removing sand and tubing or opening the pores in the producing formations. CLEARING ACCOUNTS: Accounts used to accumulate expenses during a period, with the balance allocated to other accounts on some predetermined basis at the end of the period. (See also APPORTIONMENT ACCOUNTS.) COMPLETION: Refers to the work performed and the installation of permanent equipment for the production of oil or gas from a recently drilled well. CONDENSATE: A light hydrocarbon liquid which is in a gaseous state in the reservoir but which becomes liquid at the surface. CONNATE WATER: Water originally in the producing formation. CONTINUING INTEREST: Any interest in mineral property that lasts for the entire period of the lease contract with which it is associated. CONVEYANCE: The assignment or transfer of mineral rights to another person. COST CEILING: The limit placed on the "carrying value" of mineral assets in the cost center. COST CENTER: The geological, geographical, or legal unit with which costs and revenues are identified and accumulated. Examples are the lease, the field country, etc. CROSS SECTION MAPPING: Maps of cross-section of underground formation.