Supercritical heat-insulated oil pipe production method

Abstract

The invention relates to a manufacturing method in the oil pipe processing field, in particular to a process for preparation of a supercritical heat insulated oil tube. The technical proposal is that the invention comprises material selecting and preprocessing of an inner tube and an outer tube, welding wires for nesting and welding are flux-cored wires, protective gas for welding is the mixture gas of argon gas and argon gas, autofrettage is done after being welded and heat preservation for a certain time, the control thermal conductivity factor of X-ray flaw on-line detection, heating vaccum pumping, vacuum blocking welding, and magnaflux inspection are 0.01W / m DEG C to 0.04 W / m DEG C, and normal temperature anti-inner pressure test pressure of screw cutting on two ends, coating sealinggrease for mounting sealing ring, an upper coupling, a path, and an integral test are more than 40MPa, a normal temperature anti-external crowded test pressure is more than 45MPa, and the invention also comprises an upper screw thread protector. Modification and tackling of the invention are from material selecting and technological condition to improve performance indicating of the insulated oiltube, the invention can satisfy steam injection pressure 26MPa, steam injection temperature 400 DEG C, the downhole depth can achieve a behavior with 2300m through process combination.

Description

Technical field: [0001] The invention relates to a manufacturing method in the field of oil pipe processing used in the steam injection production process of a heavy oil well, in particular to a manufacturing method of a supercritical heat-insulated oil pipe. Background technique: [0002] Insulated tubing is an important equipment used in the steam injection production process of heavy oil wells. It is used as a steam injection channel to inject high-temperature and high-pressure steam downhole, and protect oil well casing and cement sheath from thermal stress damage and reduce wellbore heat loss. , improve the effect of steam injection and oil recovery. Chinese patent (application number 97115719.7) discloses a "vacuum heat-insulated oil pipe and its manufacturing technology", which consists of a coupling, a heat-insulated bushing, a liner, an outer pipe, an inner pipe, a heat-insulating material, a centralizing block, a suction agent composition. The vacuum insulation o...

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Problems solved by technology

[0003] The problems of this technology include: (1) The steel grade used for the pipe is N80, which is convenient for processing, but the prestress is reduced; (2) The welding wire used in the welding process of the heat-insulated oil pipe is CO 2 Solid welding wire for fusion welding; (3) High-purity carbon dioxide gas is used for the welding of heat-insulated oil pipes; (4) The test pressure of heat-insulated oil pipes for internal pressure resistance at room temperature is 32MPa, and the test pressure for external extrusion resistance at room temperature is 26MPa; (5) Heat-insulated oil pipes Depending on the thermal conductivity, the thermal conductivity is ≤0.02W / m·℃; (6) The pipe fittings processed by this technology can only meet the well conditions where the injected steam temperature does not exceed 350℃, the injected steam pressure does not exceed 21MPa, and the well depth does not exceed 1600 meters