Liquefied natural gas. Natural gas may be extracted from oilfields or produced from fields containing only gas. It is also found in association with very light oil, termed condensate. Light hydrocarbons extracted from natural gas are referred to as natural gas liquids (NGL). Natural gas main component is methane. It can be liquefied, for transport or storage, by cooling to about -160ÂșC and is then referred to as liquefied natural gas