Crude oil is a natural resource found underground in land or sea. Crude oil that is pumped out from wells is not fit for use at first. It has to be refined into useable products such as gasoline, engine oil, diesel, kerosene, and many other products.

Crude oil is located, drilled, pumped out and refined. Oil exploration, drilling and refining is one of the most prominent industries in the world and uses some of the most advanced and sophisticated technology.