Oil casing pipe has many different grades.The main casing pipe grade is shown as below: H40, J55, K55, M65, L80, C90, N80, C90, C95,T95, P110, Q125. Oil casing pipe is large diameter pipes, which to promote the drilling and fixed the role of oil and gas oil casing or hole. Casing pipe is inserted into the hole and fixed with cement, in order to prevent the borehole and separated strata borehole collapse, and ensure the drilling mud circulating flow.
Oil special pipe is mainly used in oil and gas well drilling and oil and gas transportation. It includes petroleum drill pipe, oil tubing and casing. Oil casing pipe is mainly used in the drilling process and after the completion of borehole wall support, to ensure that the drilling process and after completion of the normal operation of the oil Wells. Main pipe will be well at the bottom of the oil and gas transmission to the ground.With the casing set depths determined, hole sizes and casing sizes must follow. The hole drilled for each casing string must be large enough to easily fit the oil well casing inside it, allowing room for cement between the outside of the casing and the hole.
Casing design for each size is done by calculating the worst conditions that may be faced during drilling and production. Mechanical properties of designed pipes such as collapse resistance, burst pressure, and axial tensile strength must be sufficient for the worst conditions.