Oil casing is used to support the oil, gas wells of steel pipe, in order to ensure the drilling process and the completion of the entire well after the normal operation. Each well has several layers of casing depending on the drilling depth and geology. Casing down to use cement cementing, it and the tubing, drill pipe is different, can not be reused, a one-time consumption of materials. Therefore, the casing of the total consumption of more than 70% of the wells. Casing according to the use can be divided into: catheter, surface casing, casing technology and oil casing.

Petroleum cracking pipe is a kind of hollow long circular seamless steel pipe. Petroleum cracking pipe uses: used to transport gasoline, kerosene, diesel and other oil products, corrosion resistance, anti-wear. Petroleum cracking pipe (gb9948-83) is suitable for geological drilling and industrial drilling of the first class steel pipe.