Heat treatment process for hollow drill collar

Abstract

The invention discloses a heat treatment process for a hollow drill collar and belongs to the technical field of production of tubes special for petroleum. The heat treatment process comprises the steps of machining an inner bore on a workpiece, and then quenching and tempering, and is characterized in that: rock wool is filled in the inner bore before the inner bore is quenched, and then a port is blocked by fire clay. In the heat treatment process for the drill collar, drilling after heat treatment changes into drilling before heat treatment, so that original machining twice changes into molding at one time, and machining procedure of the drill collar is simplified; meanwhile, the rigidity of the workpiece before the workpiece is tempered is much lower than that of the workpiece after the workpiece is tempered, therefore the difficulty of drilling is reduced greatly, the times of cutter hitting and working loss are reduced. By using the heat treatment process, the forged workpiece changes into a round rod shape from a step axle shape; and machining difficulty and raw material consumption are reduced. In addition, the solid heat treated workpiece changes into the hollow heat treated workpiece, the heating time and cooling time of quenching and tempering the drill collar are shortened greatly, and the production schedule is accelerated, so that the whole production cycle of the drill collar is shortened greatly.

Description

technical field [0001] The invention belongs to the technical field of oil special pipe production, and in particular relates to a hollow drill collar heat treatment process. Background technique [0002] With the increasingly tense global energy supply, countries are stepping up drilling and exploitation of underground energy, and the demand for drill collar consumable products is also expanding, which puts forward higher requirements for the quality and diversity of drill collars. According to statistics, the world needs about 1.7 million tons of various drill collars every year, while the actual supply in the drilling tool market is only 700,000 tons, which can only supply 41.2% of the market demand. Therefore, the demand side often needs to book half a year in advance. Drill collar products are in short supply, and orders continue to come in one after another. How to improve the production capacity of drill collars and expand market share is an urgent problem that every ...

AI Technical Summary

Problems solved by technology

The crack rate can reach 100% during the test, which seriously affects the production progress and product quality

[0005] In addition, after heat treatment, the inner hole will expand to a certain extent (that is, the phenomenon of hole expansion), which does not match the actual design size, and will also affect the quality of the drill collar.

[0006] 2) All manufacturers generally use pit furnace or trolley furnace to heat drill collars. This heat treatment method has mature technology and good quality stability, but it has large investment, high production cost and long product production cycle. Many manufacturers do not Make it your first choice for expanding production capacity

However, electromagnetic induction heat treatment technology also has certain defects, such as poor process stability, shallow heating layer, etc.

At present, intermediate frequency heat treatment technology has not been applied to the production of drill collars at home and abroad, and there is a lack of mature technology for reference. How to improve production efficiency while ensuring quality is still a problem to be solved

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