General purpose of this lecture is to focus on Crude Oil. Crude oil is obtained from the Earth’s crust. It was formed from the remains of organisms which lived millions of years ago. Basically it is a fossil fuel. The fossil fuels coal, oil and natural gas have resulted from the action of heat and pressure over millions of years, in the absence of air, on material from animals and plants (organic material) which has been covered by layers of sedimentary rock.