Processing method of end upsetting of drill pipe

Abstract

The invention discloses a processing method for thickening a drill pipe end; a thickening device adopted is a hydraulic pipe end upsetting machine, and three-time heating and twice thickening steps orfour-time heating and three-time thickening steps are adopted according to the different thickening ratios, wherein, the previous twice heating is respectively performed in two heating furnaces in sequence, and in each thickening process, the simultaneous process of internal thickening and external thickening is avoided. By adopting the processing method disclosed in the invention and under the condition of using the hydraulic pipe end upsetting machine, the production efficiency is improved, besides, the destabilization is minimized during the processing, and the smooth transition of the internal thickening transition zone and the large enough R radius are ensured, thus improving the anti-fatigue life of the drill pipe body, and effectively avoiding the occurrence of piercing accidents.

Description

technical field [0001] The invention relates to a method for thickening the pipe end of a steel pipe, in particular to a processing method for thickening the pipe end of a drill pipe. Background technique [0002] The drill pipe used for oil drilling is manufactured according to the API standard, and its main structure is to weld an external threaded joint and an internal threaded joint at both ends of the drill pipe body. Since the wall thickness of the pipe body itself is small, in order to increase the strength of the connection between the pipe body and the joint, the parts connected to the joint at both ends of the pipe body are thickened. There are three types of thickening of the drill pipe body: inner thickening, outer thickening and inner and outer thickening, among which the outer thickening and inner and outer thickening of the drill pipe body are commonly used thickening forms. [0003] like figure 1 As shown, for inner and outer thickened drill pipes, D is the...

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Problems solved by technology

[0006] However, when the hydraulic pipe end thickening machine is used to thicken the end of the drill pipe, due to the method of large deformation processing on the inside and outside at the same time, the drill pipe is prone to instability, and the smoothness of the inner thickening transition zone It is difficult to guarantee the degree of thickening. When the last thickening is completed, the inner thickening transition zone must be ground, which not only reduces the strength of the drill pipe, but also reduces the processing efficiency of the drill pipe.

In addition, all heating steps are carried out on a heating furnace, and only after completing all the processing steps of the previous drill pipe, can the processing of the next drill pipe be carried out, and the efficiency of continuous production is low

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