Petroleum refers to the mixture of natural gaseous, liquid and solid hydrocarbons. Petroleum is divided into crude oil, natural gas, natural gas liquid and natural tar, but it is customary to use "oil" as the definition of "crude oil". Petroleum is a thick dark brown liquid, which is called "industrial blood". There are oil reserves in some parts of the upper crust.
The main components are mixtures of alkanes, cycloalkanes and aromatic hydrocarbons. It is one of the main targets of geological exploration. There are two theories about the mechanism of petroleum formation, namely, biological deposition and petrochemical formation. The former is widely accepted that oil is formed by the long evolution of organisms in ancient oceans or lakes, which belongs to biological deposition and cannot be regenerated.
The latter thinks that oil is generated by carbon in the earth's crust, which has nothing to do with living things and is renewable. Petroleum is mainly used as fuel oil and gasoline, and it is also the raw material of many chemical industrial products, such as solutions, fertilizers, pesticides and plastics. The ancient Egyptians and Babylonians developed and utilized oil a long time ago. The Chinese name "Petroleum" was first named by Shen Kuo, a scientist in the Northern Song Dynasty.
Petroleum is an industrial term, but relative to mineral resources, petroleum industry is a mineral resources industry. In the process of oil exploration, according to the degree of exploration and proven situation, the oil reserves are calculated and determined. Oil reserves are the results of geological exploration and a kind of original mineral resources to be developed.
Refer to the above content: Baidu Encyclopedia-Petroleum