API 5CT is a standard on the oil casing by American Petroleum Institute, mainly for the oil pipe, tubing, and casing.

Special petroleum pipe is mainly used for drilling oil and gas Wells and oil and gas transportation. It includes oil drilling pipe, oil casing, extraction pipe. The oil drill pipe is used to connect the drill collar to the drill bit and transfer drilling power. The oil casing is mainly used to support the well wall during drilling and after completion to ensure the drilling process and the normal operation of the whole oil well after completion. The suction pipe mainly conveys oil and gas from the bottom of the well to the surface.

The oil casing is the lifeline to maintain the operation of oil well. Due to the different geological conditions, the downhole stress state is complex, and the comprehensive effect of tension, pressure, bending and torsion stress on the pipe body has put forward a higher demand on the quality of the casing itself. If the casing itself is damaged for some reason, it can lead to production loss or even abandonment of the entire well.

According to the strength of steel itself, casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Well conditions, different depths, the use of steel grade is also different. In corrosive environment, the casing itself is required to have corrosion resistance. In the complex geological conditions, it is also required that the casing has anti-collapse performance.

API 5CT oil casing is used in oil well drilling, which is mainly used for drilling and completion of the right wall of the support, to ensure the conduct and completion of the drilling process after the normal operation of the wells. The casing is to maintain the wells run lifeline. As different geological conditions, underground complex stress state, pulling, pressing, bending, torsional stress act on the combined effect of the tube, which the casing itself, the quality of the higher requirements. Once the casing itself is damaged for some reason, could lead to the whole production wells, or even scrapped.

Mechanical properties of API 5CT API 5CT Seamless steel tubing: