Gallon A volumetric measure equal to 4 quarts (231 cubic inches) used to measure fuel oil. One barrel equals 42 gallons. Gas A non-solid, non-liquid combustible energy source that includes natural gas, coke-oven gas, blast-furnace gas, and refinery gas. Gas oil European and Asian designation for No. 2 heating oil and No. 2 diesel fuel. Gas plant operator Any firm, including a gas plant owner, which operates a gas plant and keeps the gas plant records. A gas plant is a facility in which natural gas liquids are separated from natural gas or in which natural gas liquids are fractionated or otherwise separated into natural gas liquid products or both. Gas processing unit A facility designed to recover natural gas liquids from a stream of natural gas that may or may not have passed through lease separators and/or field separation facilties. Another function of natural gas processing plants is to control the quality of the processed natural gas stream. Cycling plants are considered natural gas processing plants. Gas to liquid (GTL) The process of refining natural gas and other hydrocarbons into longer-chain hydrocarbons, which can be used to convert gaseous waste products into fuels. Gas turbine plant A plant in which the prime mover is a gas turbine. A gas turbine consists typically of an axial-flow air compressor and one or more combustion chambers where liquid or gaseous fuel is burned and the hot gases are passed to the turbine and where the hot gases expand drive the generator and are then used to run the compressor. Gas well A well completed for production of natural gas from one or more gas zones or reservoirs. Such wells contain no completions for the production of crude oil. Gas well productivity Derived annually by dividing gross natural gas withdrawals from gas wells by the number of producing gas wells on December 31 and then dividing the quotient by the number of days in the year. Gasification A chemical or heat process used to convert carbonaceous material -- coal, petroleum, biomass -- into its gaseous components, carbon monoxide and hydrogen. Gatherer A company primarily engaged in the gathering of natural gas from well or field lines for delivery, for a fee, to a natural gas processing plant or central point. Gathering companies may also provide compression, dehydration, and/or treating services. Gel point The point at which a liquid fuel cools to the consistency of petroleum jelly. Glycerin The "thick" component of all biodiesel feedstocks. It is separated from the esters during the biodiesel reaction process, combining together with the catalyst to form glycerin soap, the by-product of making biodiesel. GOR Gas to oil ratio. The volume of gas at atmospheric pressure produced per unit volume of oil produced. Government-owned stocks Oil stocks owned by the national government and held for national security. In the United States, these stocks are known as the Strategic Petroleum Reserve. Greasecar A diesel-powered automobile rigged post-production to run on used vegetable oil. Gross input to atmospheric crude oil distillation units Total input to atmospheric crude oil distillation units. Includes all crude oil, lease condensate, natural gas plant liquids, unfinished oils, liquefied refinery gases, slop oils, and other liquid hydrocarbons produced from tar sands, gilsonite, and oil shale.