Composite shock absorber for PDC (polycrystalline diamond compact) bit

Abstract

The invention relates to a composite shock absorber for a PDC (polycrystalline diamond compact) bit. The composite shock absorber comprises a drilling tool body, an impact body, a disc spring set, a torsion bar spring and an annular pressing sleeve, wherein the bit vibration impact force is transmitted between the drilling tool body and the impact body through a torsion transmission joint, the impact body is arranged at the lower end of the drilling tool body and forms a shock absorption cavity, the drilling tool body is provided with a water inlet, the impact body is provided with a water outlet, the torsion bar spring is a cylindrical body, the upper end of the torsion bar spring is provided with an external thread, the lower part of the torsion bar spring is provided with a spline, thetorsion bar spring is positioned in the shock absorption cavity, the upper end of the torsion bar spring is connected to the drilling tool body in a threaded mode, the lower part of the torsion bar spring extends into an impactor and is connected to the impactor through the spline, the disc spring set sleeves the outer side of the torsion bar spring, the annular pressing sleeve is arranged at thelower end of the disc spring set, and a bearing set is arranged between the lower end surface of the annular pressing sleeve and an annular step, located in the drilling tool body, of the impact body.According to the composite shock absorber, the damage of the slippage effect to PDC cutting teeth can be weakened, the axial vibration from a drill string can be absorbed, and the service life of thebit can be effectively prolonged.

Description

technical field [0001] The invention relates to a drilling device in the technical field of petroleum drilling, in particular to a composite shock absorber for a PDC drill bit. Background technique [0002] PDC drill bits are widely used in oil drilling and other fields. The PDC composite sheet welded on the PDC drill bit has a very strong anti-abrasion ability, but its impact resistance is its fatal weakness. During the drilling process, the PDC bit should be able to cut rocks continuously and stably under normal conditions. However, this ideal state does not exist in actual drilling. The movement of the PDC bit in the downhole is extremely disordered, including lateral, axial The vibration of the drill bit can easily damage the PDC cutting teeth of the drill bit, which will cause damage to the drill bit, affect the life of the drill bit, and increase the drilling cost. Statistics show that this kind of damage accounts for 80% of PDC bit failure forms in drilling operation...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a kind of composite shock absorber for PDC drill bit, this composite shock absorber for PDC drill bit is used to overcome the problem that PDC diamond compact drill bit is impacted at the moment of drilling operation and causes the problem of PDC drill bit damage

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