Oil & Gas with reference to productios extracted from inside the earth, after extraction and purification are used as energy generating elements is made. The term oil is meant both crude oil and products derived therefrom.

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, usually it contains 84% carbon, 14% hydrogen, 1 to 3% sulfur and nitrogen, oxygen, heavy metals and salts with a total less than 1%. Crude oil ranges from light volatile oils, highly fluid, oils confluid as waste oil, heavy oil, and some high paraffin oils. To remove a surface crude oil may also contain natural gas fluids and products such as salt water from the extraction.