Steel pipes can be divided into different steel grades according to the strength of the steel itself. The well conditions and well depth are different, and the steel grades used are also different. The casing itself is also required to have corrosion resistance in a corrosive environment. API seamless steel pipes also require casing resistance to crushing in places with complex geological conditions. Oil casing is the lifeline for maintaining oil well operations. Due to different geological conditions, the state of the downhole is complicated, and the combined action of tension, compression, bending and torsion stress acts on the pipe body, which puts high requirements on the quality of the casing itself. Once the casing itself is damaged for some reason, it may result in a reduction in production and even scrapping of the entire well.

API casing pipe is mainly used for drilling oil, gas and water wells and conveying oil, gas and water. It is mainly used for supporting the well wall during and after drilling to ensure the drilling process and the normal operation of the entire well after completion. The API casing pipe protects the well during use to avoid contamination by shallow water and shallow gas layers, supports wellhead equipment and maintains the weight of other layers of the casing for protection of the well.