The properties of petroleum vary from place of origin, with a density of 0.8-1.0g /cm3, a wide range of viscosity, a great difference in freezing point (30-60 degrees Celsius), a range of boiling point of normal temperature to more than 500 degrees Celsius, soluble in a variety of organic solvents, insoluble in water, but can form emulsion with water. But the composition and appearance of oil in different fields can be very different. Petroleum is mainly used as fuel oil and gasoline, which constitute one of the most important secondary energy sources in the world in 2012. Petroleum is also the raw material for many chemical industrial products such as solvents, fertilizers, pesticides and plastics. In 2012 88% of the oil produced was used as fuel and 12% as raw material for the chemical industry. In fact, oil is a non-renewable raw material