Production method for drawing type expanded extra-large-caliber J55 casing pipes

Abstract

The invention relates to the technical field of seamless steel pipe production and provides a production method for drawing type expanded extra-large-caliber J55 casing pipes. The method includes the steps that pipe blanks with the diameter being 356*15.5 mm are produced; each pipe end is heated and expanded to form a horn-shaped opening; primary heating expansion is conducted and comprises three passes of heating expansion; and secondary heating expansion is conducted and comprises three passes of heating expansion. By the adoption of the technical scheme, the problems that a drawing type pipe expanding unit is low in geometric dimension accuracy, poor in surface quality and low in yield are solved, the curvature, the outer diameter, the wall thickness size and the mechanical performance of the produced J55 casing pipes with the diameter being 508 mm can meet the API 5CT standard, the J55 casing pipes with the diameter being 508 mm can be produced through the drawing type pipe expanding unit in batches, and the expanding yield reaches 89%.

Description

technical field [0001] The invention belongs to the technical field of seamless steel pipe production, and in particular relates to a production method of a drawing-type expanded J55 sleeve pipe with a large diameter. Background technique [0002] The surface casing is the outermost casing in the oil and gas well casing program. In the process of oil and gas field development, after the drilling is drilled to the bedrock below the surface soil layer or to a certain depth, the surface casing is lowered, specifically , the surface casing has the following functions: [0003] (1) Isolate the upper aquifer to prevent surface water and surface groundwater from seeping into the wellbore; [0004] (2) Protect the wellhead and reinforce the well wall of the topsoil well section; [0005] (3) For the situation of encountering high-pressure oil and gas layers during drilling, installing a blowout preventer on the surface casing can prevent blowout. All the gaps between the surface ...

AI Technical Summary

Problems solved by technology

The push-type tube expansion has low production efficiency and cannot achieve obvious wall reduction; the roll-type cross-rolling tube expansion unit has a large investment and is not suitable for frequent specification changes; the pull-type tube expansion can not only achieve diameter expansion, but also achieve wall reduction and flexible specification replacement , but the steel tubes produced by the traditional drawing-type expansion process have poor bending degree, wall thickness and outer diameter accuracy (bending degree: pipe end ≤ 6mm / 1.5m, D±1.0%, S±20.0%), and it is difficult to meet API5CT and The API5B standard stipulates the geometric tolerance of the casing

[0009] At present, when the 650mm pull-type pipe expansion unit is used for pipe expansion, the original pull-type pipe expansion process is performed by Expansion The specification adopts one-time heating expansion (5-pass expansion). In order to ensure the final expansion temperature, the heating temperature is heated at 1040-1060°C. The oxidation is serious and the surface quality is poor. At the same time, one-time heating expansion is adopted. The diameter expansion rate of each pass Large, poor accuracy of wall thickness and outer diameter, and the bending of the pipe end is too large, it is difficult to improve significantly after straightening

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