Application of oil casing: Oil casing is a kind of seamless steel pipe and an important piece of equipment for oil drilling. Its main equipment also includes drill pipe, core pipe and casing, drill collar, and steel pipe for small-diameter drilling. The domestic casing is made of steel for geological drilling through hot rolling or cold drawing, and the steel grade is represented by “geological” (DZ).
1. Oil casing application: used for oil well drilling.
2. According to SY/T6194-96 “Petroleum casing”, there are two types of oil casing: short threaded casing and its coupling, and long threaded casing and its coupling.
3. Oil casing specification and appearance quality
(1) The domestic casing is by the regulations of SY/T6194-96, the length of the casing is not fixed, and its range is 8-13m. But a casing not shorter than 6m can be provided, and its quantity shall not exceed 20%.
(2) The inner and outer surfaces of the oil casing shall not have folds, hairlines, delaminations, cracks, folds, and scabs. These defects shall be completely removed, and the removal depth shall not exceed 12.5% of the nominal wall thickness.
(3) The outer surface of the coupling must not have defects such as folds, hairlines, separation layers, cracks, rolling folds, and scarring. the
(4) The surface of the oil casing and coupling threads should be smooth, and burrs, tears, and other defects that can interrupt the thread and affect the strength and tight connection are not allowed. the
4. Chemical Composition Inspection
(1) According to the regulations of SY/T6194-96. The casing and its couplings shall be of the same steel grade. Sulfur content < 0.045%, phosphorus content < 0.045%.
(2) Take chemical analysis samples according to the provisions of GB222-84. Carry out chemical analysis according to the relevant part of GB223.
(3) The first edition of American Petroleum Institute ARISPEC5CT1988. The chemical analysis shall be prepared according to the latest version of ASTME59, and the chemical analysis shall be carried out according to the latest version of ASTME350.
5. Physical performance test
(1) According to the regulations of SY/T6194-96. For flattening test (GB246-97) tensile test (GB228-87) and hydraulic test.
(2) Hydrostatic pressure test, flattening test, sulfide stress corrosion cracking test, hardness test (ASTME18 or E10 latest version), tensile test, transverse impact test ( ASTMA370, ASTME23, and the latest version of relevant standards), grain size determination (the latest version of ASTME112 or other methods).
6. Main import and export situation
(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 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 specifications are mainly 139.77.72R-2, 177.89.19R-2, 244.58.94R-2, 244.510.03R-2, 244.511.05R-2, etc.
(2) There are three types of API-specified 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 the words LTC, that is, long threaded sleeves.
(4) In addition to adopting API standards for casings imported from Japan, there are also a small number of Japanese factory standards. The steel grades are NC-55E, NC-80E, NC-L80, NC-80HE, etc.
(5) In the claim cases, there have been appearance defects such as black buckle and threaded buckle damage, pipe body folding, broken buckle and thread close distance, coupling J value out of tolerance, etc., as well as internal casing brittle cracks and low yield strength. quality problem.
7. Packaging shall be by SY/T6194-96, domestic casing shall be bound with steel wire or steel belt. The exposed portion of each casing and coupling thread shall be screwed with a protective ring to protect the thread. 8. Others According to the first edition of American Petroleum Institute standard APISPEC5CT1988, casing steel grades H-40, J-55, K-55, N-80, C-75, L-80, C-90, C-95, P-110, Q-125 a total of 10 kinds.
Casing shall be supplied with threads and couplings, or with one of the following pipe ends: plain end, round thread without coupling or with coupling, buttress thread with or without coupling, direct connection Type thread, special end processing, sealing ring structure.
Post time: Jun-25-2023