API 5CT welded casing seamless carbon steel oil pipe API oil casing is mainly used for oil and gas well drilling and oil and gas transmission. It includes oil drill pipe, oil casing and oil extraction pipe. API oil casing oil drill pipe is mainly used to connect drill collar and bit and transmit drilling power. The oil casing is mainly used to support the well wall during drilling and after well completion, so as to ensure the normal operation of the whole well during drilling and after well completion. Tubing is pipe used for the transportation of crude oil and natural gas from an oil or gas layer to the surface after drilling is complete. It is made to withstand the pressure generated from the extraction process. Standard API 5CT Size 2 3/8", 2 7/8", 3 1/2", 4 1/2" Steel grade J-55, L-80, N-80, C-90, T-95, P-110…