Thickening method of petroleum and natural gas drill rod formed by thickening and extrusion

Abstract

The invention relates to the field of manufacturing of petroleum and natural gas drill rods, in particular to a thickening method of a petroleum and natural gas drill rod formed by thickening and extrusion. The method is characterized in that the sizes of intermediate section semi-finished products are sequentially calculated according to the finished product size of the thickened end of the drillrod, and then the finished product of the thickened end of the drill rod meeting requirements is obtained through combination of external thickening operation and extrusion forming operation and post-processing treatment. By adopting the method, the thickened end of the drill rod needing internal thickening or internal and external thickening is thickened and extruded, the size and shape of an internal transition zone can be controlled, the performance of the drill rod can be effectively improved, and the fatigue service life of the drill rod can be prolonged.

Description

technical field [0001] The invention relates to the field of oil and gas drill pipe manufacturing, in particular to a method for thickening oil and gas drill pipes combined with extrusion. Background technique [0002] The drill pipe used for oil and gas drilling consists of a drill pipe body and a pair of male and female joints that are friction welded at both ends of the drill pipe body. The tensile yield strength of the weld is lower than that of the base material to be welded , in order to increase the load-bearing capacity of the weld, it is necessary to thicken both ends of the drill pipe body, increase the cross-sectional area of ​​the weld, improve its load-bearing capacity, and match the load-bearing capacity of the weld with the pipe body and the joint . Therefore, thickening is an important process in the production of drill pipe used in oil and gas drilling, thickened tubing and casing for oil and gas, and drill pipe for non-excavation construction. The purpose...

AI Technical Summary

Problems solved by technology

In this way of thickening the inside and outside at the same time, during the operation, the inner transition zone is neither in contact with the thickening die nor with the punch. The inner transition zone is produced in a free-forming way, and its size and shape uncontrollable

Taking the drill pipe with three times of internal and external thickening as an example, it is an impossible task to lengthen the inner transition zone without using one thickening and another thickening to lengthen the inner transition zone; Thick and another thickening method to thicken and lengthen the inner transition zone, and it is difficult to ensure the smoothness of the inner transition zone

The inner transition zone thickened in this way is short, irregular in shape, uneven in potholes, serious in stress concentration, and low in fatigue life of the drill pipe

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