The oil casing is used to support the oil and gas well walls to ensure the normal operation of the entire well after the drilling process is completed. Each well is based on different depths of drilling and geology, using several layers of casing. After the casing is down, the cement cementing should be adopted. It is different from the oil pipe and the drill pipe and cannot be reused. It is a disposable material. Therefore, the consumption of casing accounts for more than 70% of all oil well pipes.
Casing can be divided into: conduit, surface casing, technical casing and oil casing.