Hydrocarbons in gaseous form. Gas sold under the name natural gas mainly consists of methane (CH4), and some ethane and propane, small amounts of other, heavier hydrocarbons and traces of contaminants like CO2 and H2S.

A collective term for the petroleum qualities, ethane, propane, isobutane, normal butane and naphtha. NGL are partially liquid at normal pressure.

Natural gas produced from a reservoir that does not contain significant quantities of crude oil.