Traditionally, crude oil is called crude oil. Dark brown viscous oily liquid with green fluorescence and special smell. It is a mixture of alkanes, cycloalkanes, aromatic hydrocarbons and olefins.

The main components are carbon and hydrogen, accounting for 83 ~ 87% and 1 1 ~ 14% respectively. There are also a small amount of sulfur, oxygen, nitrogen and trace elements such as phosphorus, arsenic, potassium, sodium, calcium, magnesium, nickel, iron and vanadium. Specific gravity 0.78 ~ 0.97, molecular weight 280 ~ 300, freezing point -50 ~ 24℃. Crude oil can be refined to obtain various products, such as fuel oil, solvent oil, lubricating oil, grease, paraffin, asphalt, liquefied gas, aromatic hydrocarbons and so on. , and provide fuel, raw materials and chemical products for all sectors of the national economy.