Friction welding type kelly bar

Abstract

The invention relates to an oil drilling tool, and in particular to a friction welding type kelly bar, which comprises a pipe body and a first joint and a second joint respectively positioned at two ends of the pipe body; the shape of the section of the pipe body is a square or hexagon; the pipe body is connected with the first joint and the second joint in a friction welding mode; and the welding parameters are that: the first-level friction pressure is between 3 and 5MPa and the time is 20 to 60 seconds; the second-level friction pressure is between 4 and 8MPa and the time is 60 to 180 seconds; and the upsetting force is between 10 and 18MPa. The friction welding type kelly bar has the advantages that: the friction welding type kelly bar is manufactured in segments, the manufacture is simple and the production efficiency is high; raw materials and energy are saved, and the cost is greatly reduced; and the processing quality is easily guaranteed and the processing accuracy is high. For the manual welding mode adopted by the conventional kelly bar, welding lines generated easily have crystal defects such as bubbles, segregation, inclusion, cracks and the like so as to severely influence the strength and service life of a kelly bar; and compared with the manual welding, the friction welding ensures that the joints have good and stable quality and are not melted in the welding process, and belongs to solid-phase hot-pressure welding, and the joints have forging textures, so the welding lines do not have the crystal defects such as bubbles, segregation, inclusion, cracks and the like, and the strength of the joints by the friction welding is far greater than that by fusion welding and braze welding, and reaches or even surpass the strength of a base metal.

Description

technical field [0001] The invention relates to a drill pipe, in particular to a drill pipe used for oil, natural gas or other geological engineering drilling. Background technique [0002] The kelly is made of AISI 4142H~4145H forged or precision-rolled alloy structural steel. It is a square or hexagonal steel pipe connecting the swivel and the drill pipe. The kelly transmits the torque to the drilling rigging through the rotation of the turntable. It is the driving part of the entire drill string. With the rapid development of my country's economy, the demand for oil has increased sharply, and land oil sources can no longer meet the needs, and the depth of oil drilling is getting deeper and deeper. At present, with the improvement of deep well operation technology, the consumption of kelly is increasing significantly. Since the length of the kelly is required to be more than 12 meters or even as long as 16 meters, the current domestic raw material suppliers cannot provid...

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Problems solved by technology

[0003] Aiming at the deficiencies in the above-mentioned prior art, the present invention designs a friction-welded kelly to solve the manufacturing troubles existing in the prior art, such as uncontrollable welding precision and welding quality, long production cycle, large waste of materials, and high cost The problem

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