The petroleum industry is divided into upstream, midstream and downstream. The relationship between the upstream and downstream industrial chains is very close, with a very distinctive industrial chain structure and industrial chain information transmission effect. Among them, the upstream business includes the exploration and development of crude oil and natural gas, the midstream is mainly the storage and transportation of oil and gas, and the downstream includes process-based businesses such as oil refining, chemical industry, and natural gas processing, and product distribution and sales businesses such as gas station retail. Under normal circumstances, the processing industry that uses petroleum and natural gas as raw materials to produce petroleum products and petrochemical products is called the petrochemical industry (referred to as the petrochemical industry), and the rest are collectively called the petroleum industry. The main production and operation activities of the petroleum industry include oil and gas exploration, oil and gas field development, drilling engineering, ground construction, petrochemicals, storage, transportation and sales, and operation management.