Oil casing pipe
is a steel pipe used to support the wall of oil and gas wells to ensure the normal operation of the entire oil well during the drilling process and after completion.
According to the American Petroleum Institute standard APISPEC5CT first edition in 1988, casing steel grades H-40, J-55, K-55, N-80, C-75, L-80, C-90, C-95, P- There are 10 types of 110 and Q-125. The casing should be supplied with threads and couplings, or in the form of any of the following pipe ends: flat ends, round threads without couplings or couplings, partial trapezoidal threads with couplings or couplings, straight Thread, special end processing, seal ring structure.
(1) The main importing countries of petroleum casing are: Germany, Japan, Romania, Czech Republic, Italy, Britain, Austria, Switzerland, United States, Argentina, and Singapore. Import standards refer to API5A, 5AX, 5AC standards of the American Petroleum Institute. The steel grades are H-40, J-55, N-80, P-110, C-75, C-95 and so on. The specifications are mainly 139.77.72R-2, 177.89.19R-2, 244.58.94R-2, 244.510.03R-2, 244.511.05R-2 and so on.
(2) There are three types of API lengths: R-1 is 4.88 to 7.62m, R-2 is 7.62 to 10.36m, and R-3 is 10.36m to longer.
(3) Some imported goods are marked with the word LTC, that is, long threaded sleeves.
(4) In addition to API standards for casings imported from Japan, there are still a small number of implementations of Japanese factory standards (such as Nippon Steel, Sumitomo, Kawasaki, etc.). NC-80HE and so on.
(5) In the claim case, there have been appearance defects such as black buckle and wire buckle damage, pipe body folding, excess distance between broken buckle and thread, excessive J value of the coupling, and brittle fracture of the casing and low yield strength. Internal quality issues.