PDC drill bit composite impact device

Abstract

The invention provides a PDC drill bit composite impact device. The PDC drill bit composite impact device comprises a hammer seat, a punch hammer and a reversing valve, wherein the hammer seat is arranged in an inner cavity of a drill bit, and a hammer seat inner cavity is formed in the hammer seat; the punch hammer is arranged in the hammer seat inner cavity of the hammer seat and can do reciprocating motion in the hammer seat inner cavity, a punch hammer inner cavity is formed in the punch hammer, and a punch hammer bypass port is formed in the punch hammer; the reversing valve is arranged in the punch hammer inner cavity and can do reciprocating motion in the punch hammer inner cavity, and a reversing valve bypass port is formed in the reversing valve; and the reversing valve is hydraulically driven to do reciprocating motion relative to the punch hammer, a bypass channel formed by the reversing valve bypass port and the punch hammer bypass port is periodically opened and closed, and periodic hydraulic pulses are formed. By the adoption of the structure, the PDC drill bit composite impact device has the following beneficial effects that the forward impact energy of the punch hammer is increased through the periodic hydraulic pulses, meanwhile, the pressure loss of the PDC drill bit composite impact device is not increased, and the rock breaking efficiency of the PDC drill bit is greatly improved.

Description

technical field [0001] The invention belongs to the fields of oil, natural gas, geothermal, geomineral and other resources mining, and in particular relates to a PDC drill bit composite impact device. Background technique [0002] As it becomes more and more difficult to exploit resources such as oil, natural gas, geothermal, and geological minerals, the hardness of the rock formations encountered during the drilling process is increasing, and the drilling efficiency is reduced. [0003] In order to solve the problem of low drilling efficiency in hard formations, an axial or circumferential impactor is usually installed in the drill string. During the drilling process, the impactor applies a periodic axial and circumferential impact energy to the drill bit to assist rock breaking and improve rock breaking efficiency. The axial impactor acts on the drill bit through the axial impact load generated to increase the cutting depth of the cutting teeth; the torsional impactor act...

AI Technical Summary

Problems solved by technology

However, the impact energy of the existing axial impactors and circumferential impactors is relatively small. In order to increase the impact energy, the only way to increase the pressure loss on both sides of the hammer is to increase the pressure loss of the impactor. However, due to the limitation of drilling equipment, the pressure loss of the impactor is limited, so the impact energy is limited, and the impact energy of the impactor cannot be further increased.

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