According to the American Petroleum Institute standard APISPEC5CT 1988 1st edition, casing steel grades are 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 any of the following pipe end forms: plain end, round thread without or with couplings, trapezoidal thread with or without couplings, direct connection Type thread, special end processing, sealing ring structure.
Origin of oil casing
(1) The main importing countries of oil casing are Germany, Japan, Romania, the Czech Republic, Italy, the United Kingdom, Austria, Switzerland, the United States, Argentina and Singapore. Import standards mostly refer to the American Petroleum Institute standards API5A, 5AX, and 5AC. Steel grades are H-40, J-55, N-80, P-110, C-75, C-95, etc. The main specifications are 139.77.72R-2, 177.89.19R-2, 244.58.94R-2, 244.510.03R-2, 244.511.05R-2, etc.
(2) API specifies three lengths: R-1 is 4.88~7.62m, R-2 is 7.62~10.36m, and R-3 is 10.36m or longer.
(3) Some imported goods are marked with LTC, which means long threaded casing.
(4) In addition to API standards, casing imported from Japan also adopts Japanese factory standards (such as Nippon Steel, Sumitomo, Kawasaki, etc.). The steel numbers are NC-55E, NC-80E, NC-L80. NC-80HE etc.
(5) In the claim cases, there have been appearance defects such as black buckles and threaded buckle damage, folding of the pipe body, broken buckles, excessive thread tightness, excessive coupling J value, and internal defects such as casing brittleness and low yield strength. quality problem.
Packaging of oil casing
According to SY/T6194-96, domestic casing should be bundled with steel wire or steel belt. A protective ring should be screwed on the exposed portion of each casing and coupling thread to protect the threads.
Post time: Apr-12-2024