Oil & Gas, with reference to materials extracted from the earth, once extracted and purified, are used as energy generating elements. The term oil is meant to reference both crude oil, and other products derived from them.
Crude oil and natural gas are non-renewable energy sources, also called fossil fuels. Crude oil is a mixture of several hydrocarbon compounds and other materials, normally containing 84% carbon, 14% hydrogen, 1 to 3% sulfur and nitrogen, oxygen, heavy metals and salts with a total of less than 1%. Crude oil ranges from light volatile oils, which are highly fluid, to converged oils such as waste oil, heavy oil, and some high paraffin oils. Once extracted, crude oil may also contain natural gases and other products such as salt water.