Crude Oil is a naturally occurring πετρέλαιο product found beneath the earth’s surface. Crude oil can be refined to produce usable products such as gasoline, diesel and various forms of petrochemicals. It is a nonrenewable resource, also known as a fossil fuel, which means that it can’t be replaced naturally at the rate we consume it and is therefore a limited resource.
The major hydrocarbons in Crude Oil are PAH, Aliphatics and Alicyclic. Oil drilling is done to recover crude oil from the earth’s surface. This is done after a systematic study of geological aspects and reservoir characteristics. Crude Oil is separated from water, gas, sand, and debris, etc., at crude handling stations and then it is transported to refineries for distillation process. After the distillation process it is converted into more useful fractions for industrial purposes such as LPG, Naphtha, Motor Spirit, Diesel, Kerosene, Jet Kero, Lubes, Bitumen, Asphalt, etc.
The value or the quality of Crude Oil when produced is determined by its API gravity or viscosity or ease of flow, and the sulfur content (impurities) in it. Crude oil is divided into four categories based on its API gravity:
- Light Crude Oil – API gravity > 31.1 degree
- Medium Crude Oil – API gravity between 22.3 and 31.1 degree
- Heavy Crude Oil – API gravity < 22.3 degree
- Extra Heavy Crude Oil – API gravity < 10.0 degree