PDC tooth wheel and composite drill bit comprising PDC tooth wheels

Abstract

The invention provides a PDC tooth wheel. The conical face of the tooth wheel is regularly provided with a plurality of transversely-embedded PDC composite pieces in a staggered mode. The PDC tooth wheels are regularly fixed between cutting wings of a PDC drill bit to constitute a PDC tooth wheel composite drill bit. The transversely-embedded PDC composite pieces are adopted instead of an existingtooth wheel sharp tooth structure, so that on the one hand, the exposed height of cutting teeth is effectively decreased, diversified modes such as shearing, cutting and impacting are adopted insteadof an original single impacting rock breaking mode, the amplitude of longitudinal vibration of a tooth wheel drill bit is effectively decreased, the work mode of the tooth wheel drill bit in the composite drill bit is made to be matched with the PDC drill bit, and thus the attachment degree of the drill bit and the well bottom is increased, so that the drilling efficiency of the PDC drill bit isensured, and the mechanical drilling speed of the composite drill bit is advantageously increased; and on the other hand, by increasing the cutting chamfers of the PDC composite pieces, the work pressure of the PDC composite pieces is remarkably reduced, the invalid condition of the cutting teeth is advantageously relieved, and thus the service life of the drill bit is prolonged.

Description

technical field [0001] The invention relates to the technical field of oil drilling, in particular to a PDC cone and a composite drill bit containing the PDC cone. Background technique [0002] In routine operations, the service life of the drill bit and the ROP are two important indicators used to evaluate the cost performance of the drill bit. The service life of the drill bit determines the number of trips to replace the drill bit, and the ROP determines the operation time, so the above two parameters directly affect the drilling cost. Drill bit manufacturers continue to improve drill bit structure, cutter structure and other measures in order to meet the requirements of reducing the total cost of drilling. Among them, the Kymera composite drill bit technology launched by Baker Hughes is more representative - combining the roller cone bit and the PDC bit on the same bit body, so as to have the superior cutting ability and durable working performance of the PDC bit at the...

AI Technical Summary

Problems solved by technology

When the compound bit is used for drilling, the longitudinal vibration generated by the roller cone bit makes the depth of cut of the PDC bit extremely unstable on the one hand, resulting in the formation of repeated broken areas and bottom hole cushions at the bottom of the well, so that the ROP of the compound bit is affected. On the other hand, the reciprocating motion of the PDC bit with the roller cone bit in the vertical direction increases the vertical collision probability between the cutting layer of the PDC cutter and the rock formation, which can easily lead to broken teeth, chipping and tooth loss. Severe failure of cutting teeth, thereby affecting the service life of compound drill bits

Images