A variety of pdc drill bits with integrally detachable rear teeth

Abstract

The invention provides a diversified PDC (polycrystalline diamond compact) drill bit with the whole rear row teeth detachable. The drill bit comprises front row PDC cutting teeth, rear row PDC cutting teeth, a drill bit body, a joint, blades, a gauge, a nozzle, a hard alloy block and chip grooves, wherein the drill bit body is connected with the joint, the nozzle is embedded in the drill bit body, a plurality of blades are uniformly fixed on the drill bit body, the front row PDC cutting teeth are brazed on each blade, each chip groove is formed between every two adjacent blades, the rear row PDC cutting teeth are welded on the hard alloy block, and the hard alloy block is connected with the blades through screw threads. When stratum is soft and does not have strong destructive effect on the drill bit, the rear row PDC cutting teeth can be detached and single row teeth drilling is adopted to improve the drilling rate; and when the stratum is hard and has strong destructive effect, the rear row PDC cutting teeth are mounted, so that the service life of the drill bit is prolonged, adaptability of the drill bit to complex stratums is improved, usage cost and transportation cost of drilling crew on the drill bit are greatly reduced, a drilling operation period can be shortened and the drilling cost can be saved.

Description

technical field [0001] The invention relates to a rotary drilling bit for petroleum and geology, in particular to a diversified PDC bit whose rear teeth can be disassembled as a whole. Background technique [0002] At present, in drilling operations in fields such as petroleum and geological exploration, sudden formation changes often occur. For example, in two wells that are very close to each other, theoretically speaking, the formation and lithology should be very similar, but sometimes there will be a sudden change, which will cause the drill bit model that performed well in the previous well to perform well in the current well. Extremely poor, and even cause certain downhole accidents. [0003] Aiming at the drillability of the formation and the destructive mutation of the drill bit, we usually deal with it by increasing or decreasing the tooth density and increasing or decreasing the double row of teeth. However, preparing the same type of single-row tooth drill bit ...

AI Technical Summary

Problems solved by technology

However, preparing the same type of single-row tooth drill bit and double-row tooth drill bit in one well will greatly increase the drilling cost of the well team and the delivery cost of the manufacturer.

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