AGA: American Gas Association

AFV: Alternative-fuel vehicle. A vehicle designed to operate on an alternative fuel (e.g., compressed natural gas, methane blend, electricity).

Base Gas: The quantity of natural gas needed to maintain adequate reservoir pressures and deliverability rates throughout the withdrawal season.

Christmas Tree: The valves and fittings installed at the top of a gas or oil well to control and direct the flow of well fluids.

CNG: Compressed Natural Gas

Disposition: In natural gas applications, disposition is the removal of natural, synthetic, and/or supplemental gas, or any components or gaseous mixtures contained therein, from the responding company’s facilities within the report state by any means or for any purpose, including the transportation of such gas out of the report state.

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Dry Natural Gas: Natural gas which remains after: 1) the liquefiable hydrocarbon portion has been removed from the gas stream (i.e., gas after lease, field, and/or plant separation); and 2) any volumes of nonhydrocarbon gases have been removed where they occur in sufficient quantity to render the gas unmarketable.

Fossil Fuel: An energy source formed in the Earth’s crust from decayed organic material. The common fossil fuels are petroleum, coal, and natural gas.
Fractionation: The process by which saturated hydrocarbons are removed from natural gas and separated into distinct products, or “fractions,” such as propane, butane, and ethane.

Gas Well: A well completed for production of natural gas from one or more gas zones or reservoirs.

Improved Recovery: Extraction of crude oil or natural gas by any method other than those that rely primarily on natural reservoir pressure, gas lift, or a system of pumps.

Lease separator: A facility installed at the surface for the purpose of separating the full well stream volume into two or three parts at the temperature and pressure conditions set by the separator.

Natural Gas Liquids: NGL. A group of hydrocarbons including ethane, propane, normal butane, isobutane, and natural gasoline.

Shale Gas: Natural gas produced from wells that are open to shale rock formations.

Residue Gas: Natural gas from which natural gas processing plant liquid products and, in some cases, nonhydrocarbon components have been extracted.

The terms and definitions for this word search were abstracted from a resource by the U.S. EIA. Find the full glossary at