P110 Oil Casing

Oil casing is a steel pipe used to support the well wall of oil and gas wells to ensure that the drilling process is carried out and that the entire well operates properly after completion. Several layers of casing are used in each well depending on the drilling depth and geological conditions. The casing is cemented after the well is drilled, and unlike tubing and drill pipe, it is not reusable and is a one-time consumable material. Therefore, the consumption of casing accounts for more than 70% of all oil well tubing.

Oil casing can be divided into: conduit, surface casing, technical casing and oil casing according to the usage. Oil special pipe is mainly used for drilling of oil and gas wells and transmission of oil and gas. It includes oil drilling pipe, oil casing and oil pumping pipe. Oil drill pipe is mainly used to connect drill collar and drill bit and transfer drilling power. Oil casing is mainly used to support the well wall during the drilling process and after completion to ensure the drilling process and the normal operation of the whole well after completion. The pumping tubing is mainly used to transport oil and gas from the bottom of the well to the surface.

Oil casing is the lifeline that keeps the well running. Due to the different geological conditions, the downhole stress state is complex, with tensile, compressive, bending and torsional stresses acting on the tubing body in an integrated manner, which places high demands on the quality of the casing itself. Once the casing itself is damaged for some reason, it may lead to production reduction of the whole well or even scrapping.

According to the strength of the steel itself, casing can be divided into different steel grades, i.e. J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Different well conditions and depths require different steel grades. In corrosive environments, the casing itself is required to have corrosion resistance. In places with complex geological conditions, the casing is also required to have anti-crush performance.