Natural Gas 05 : A fuel gas occurring naturally in certain geologic formations. Natural gas is usually a combustible mixture of methane and other hydrocarbons. (Bul D11).
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}