Abbreviation for American Petroleum Institute, established in 1920.

A standard industry measure of gravity (i.e., density) of liquid petroleum product.  The formula for °API in terms of specific gravity (g) is (141.5 ¸ g at 60°F) – 131.5.  Very light crude oils and gasoline have °API in the range of 50° to 60°.  Light crude oils' °API range from about 35° to 45°.   Heavy (dense) crude oils °API range from about 6° to 25°.  Water has an °API of 10° and a specific gravity of 1.

A distinct twelve-digit number assigned to a U.S. well. Digits 1 and 2 are state codes, digits 3 thru 5 are county/parish or offshore codes, digits 6 through 10 identify the well, and digits 11 and 12 identify special well conditions such as a sidetracking.

Natural gas, occurring in the form of a gas cap, overlying an oil zone [as opposed to non associated gas (from a gas reservoir with no oil) and dissolved (or casinghead or solution) contained in the reservoir's crude oil gas].

A standard measure of volume for crude oil and liquid petroleum products.  One barrel equals 42 U.S. gallons.

Impurities contained in produced oil.  Purchasing companies will ordinarily not accept oil having more than one percent of BS&W.  If the fluid as produced contains more than this proportion of foreign matter, some of the impurities such as sand and water may be removed from the crude by settling in the bottom of the lease storage.  The impurities gradually settle and thicken in the bottom of the tank as an emulsion.

Group of lease storage tanks.

Bbl or bbl, the abbreviation for barrel.

Barrels per day.

Billion Cubic Feet.

Barrels of Oil Per Day.

A measure of the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.  Dry natural gas averages 1.03 MMBtu/mcf; wet natural gas 1.110 MMBtu/mcf.  Natural gas in pipelines has from .95 o 1.05 MMBtu/mcf.  An average oil barrel has the energy content of approximately 5.6 mcf dry natural gas of 1.03 MMBTU/MCF.

See basic sediment and water.

See British Thermal Unit.

A wet gas produced along with crude oil from oil wells.  The dissolved gas or solution gas is dissolved in the reservoir's crude oil but bubbles out of the oil when exposed to normal atmospheric pressures.  Casinghead refers to the top of the well's casing.

A high-methane natural gas adsorbed to underground coal and not substantially produced until the late 1980s when special federal income tax credits (IRC Section 29 tax credits) sparked a drilling boom.

A light hydrocarbon liquid, generally natural gasolines (C5 to C10), that condenses to a liquid (i.e., falls out of wet gas) as the wet gas is sent through a mechanical separator near the well.

Water in the producing formation.

Liquid petroleum as it comes out of the ground, as distinguished from refined oils manufactured from it.  

The pressure of the gas from a well to be delivered into a pipeline.  

A well through which salt water is pumped to subsurface reservoirs to dispose of salt water produced with oil and gas.

Codes established by state regulatory agencies that indicate how a product was disposed of.

Natural gas mixed with crude oil in a producing formation.

Natural gas composed of over 90 percent (some say 95 percent) methane and suitable for use by customers of local gas distribution companies.

A well that simultaneously drains two reservoirs of oil or gas at different depths, with the production from each zone separated from the other by some type of tubing installation.

Equal daily quantities.  An average daily volume used for pricing crude oil, by allocating volumes from multiple run tickets in a month.

An method used to drive oil from reservoirs into a well in excess of that which may be produced through natural reservoir pressure, energy, or drive (primary recovery).  (See Secondary and Tertiary Recovery)

An area consisting of a single reservoir or multiple reservoirs all grouped on or related to the same individual geologic structural feature and/or stratigraphic feature.

To burn unmarketable gas from a lease.

High BTU content gas that is vented from a low-pressure separator.

A well that lifts oil and gas to the surface with natural reservoir pressure.

Inducing gas or liquids into a reservoir to move oil toward the well bore.

A bed or deposit composed substantially of the same minerals throughout.

Bottom hole pressure of a shut-in-well.

Artificial means of extracting oil.  Gas is injected down hole between the casing and production tubing.  The injected gas then aerates the liquid and floats up the tubing to the surface.  Commonly used on offshore wells.

A measure of the volume of gas produced along with oil from the same well.  

Statement provided to record the amount of gas transferred from the well to the pipeline.  Statements generally include purchaser and seller identification, well identification, volume accepted, BTU content, pressure base, water content (i.e. saturated or dry), and gross value due seller.

A well producing primarily natural gas.

A form on which the measurement of oil in lease tanks is recorded.

The individual responsible for the measurement of quantity and quality of oil and gas on a lease.

Short for API gravity which expresses the density of a given petroleum fluid.

A well used to inject gas, water, or LPG under high pressure into a producing formation to maintain sufficient pressure to produce the recoverable reserves.

Pressure at which gas, water or LPG is injected into a producing formation.

An automatic device for moving and measuring oil from lease storage to the pipeline.  This requires a pump, an oil meter, and a BS&W measuring device.

Gas or natural gasoline used at the well site to operate production equipment.

The standard measure of volume for natural gas; 1,000 cubic feet.

Meter accuracy factor usually determined through a meter proving process.

A tertiary recovery process similar to a water flood but involving the injection of a solvent that mixes with crude oil.

The abbreviation for 1,000,000 cubic feet of gas used to measure large quantities.

Hydrocarbons that exist in the gaseous phase under certain atmospheric and temperature conditions.

A well that can and does produce crude oil with minimal natural gas.  Usually state regulations would classify a well as an oil well (as opposed to being a gas well) if it produced less than 15 mcf per barrel of oil.

An underground reservoir having a common accumulation of oil or gas.

The published price that a crude oil purchaser will pay for a specific grade of crude at the point that it is delivered by the seller and accepted by the purchaser on or after a stated date.

A posting of the price per barrel the purchaser will pay for each grade of crude oil in a geographic area.

Taxes levied by state governments on mineral production based on the value and/or quantity of production.  Also called severance taxes.

A system of allocating production from a well permitted to be produced during a period of time.

The individual responsible for all equipment contained on the lease.

A record of the quantity of oil removed out of a stock tank into a pipeline or tank truck.  A run ticket will generally have opening and closing volumes, observed gravity and temperature, BS&W, and date and time of delivery.  It is usually made in triplicate and filled out by the gauger employed by the purchaser and sometimes witnessed by the pumper or employee of the company operating the well.

Now refers to water flooding.  Used to refer to any process of injecting water, gas, etc., into a formation to build up pressure in order to produce additional oil otherwise unobtainable by primary recovery.

A well that is capable of producing oil or gas but which is not on production.

The regulation of the number of wells that can be drilled on a given area of land.

A well with marginally economic production.

A group of storage tanks to which crude oil flows from producing oil wells.

The individual who measures a tank and prepares a tank table.

A table showing the volume of a tank at various levels based on one-fourth-inch intervals.

A well, that is deemed nonproductive, but that is not permanently plugged as there is intent to use it for some other purpose or to reestablish production if economics improve.

The use of sophisticated techniques such as flooding the reservoir with steam to increase the production of oil or gas.

The secondary recovery method in which water is forced down injection wells laid out in various patterns around the producing wells.  The water injected displaces the oil and forces it to the producing wells.

Gas that contains a large quantity of liquids.