The process of oil recovery is essentially the process of getting oil from the places where oil exists in the ground (whether onshore or offshore) and into processing plants for refining so the oil is suitable for industrial and residential purposes. The ways to recover oil through a conventional well bore are known as primary, secondary, and tertiary (enhanced), but some unconventional methods are also becoming popular.

Oil, which is usually called crude oil in its most basic form, is a valuable fuel whose chemical makeup is a mixture of hydrocarbon fuels: kerosene, dissolved natural gas, naphtha, light and heavy heating oils, diesel fuel, tars, benzene, and gasoline. It is formed over millions of years by the action of heat and pressure on organic material buried deep within rock, and typically exists in combination with salt water, natural gas, and soil. Most of the world's oil...