FOSSIL FUEL: An energy source formed in the Earth’s crust from decayed organic material.

GAS: A non-solid, non-liquid combustible energy source that includes natural gas, coke-oven gas, blast-furnace gas, and refinery gas.

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

GEOTHERMAL ENGERGY: Hot water or steam extracted from geothermal reservoirs in the earth’s crust.

HYDROCARBON: Organic compound of hydrogen and carbon in the gaseous, liquid, or solid phase.

LIQUEFIED NATURAL GAS: (LNG) Natural gas (primarily methane) that has been liquefied by reducing its temperature to -260 degrees Fahrenheit at atmospheric pressure.

METHANE: A colorless, flammable, odorless hydrocarbon gas (CH4) which is a major component of natural gas.

NATURAL GAS: A gaseous mixture of hydrocarbon compounds, the primary one being methane.

OIL: A mixture of hydrocarbons usually existing in the liquid state in natural underground pools or reservoirs.

OIL SHALE: A sedimentary rock containing kerogen, a solid organic material.

PETROCHEMICALS: Organic and inorganic compounds and mixtures of petroleum-based chemicals.

PETROLEUM: A broadly defined class of liquid hydrocarbon mixtures. Included are crude oil, lease condensate, unfinished oils, refined products obtained from the processing of crude oil, and natural gas plant liquids.

PIPELINE: (Natural Gas) A continuous pipe conduit, complete with such equipment as valves, compressor stations, communications systems, and meters for transporting natural and/or supplemental gas from one point to another.

REFINERY: An installation that manufactures finished petroleum products from crude oil, unfinished oils, natural gas liquids, other hydrocarbons, and oxygenates.

This glossary of terms and definitions was compiled by Flow Research Inc. based on material produced by the U.S. Energy Information Administration.