A near-bit torsional and oscillating coupled impactor

Abstract

The invention discloses a near-bit torsion and oscillation coupling impactor which comprises a drill collar pup joint, a splitter, a torsion impactor body, an impulse oscillation cavity and an impact transmission pup joint. The lower portion of the drill collar pup joint is connected with the impact transmission pup joint, the splitter, the torsion impactor body and the impulse oscillation cavity are installed on the inner circumference of the drill collar pup joint and a lower port of the splitter is communicated with an inlet of the torsion impactor body; an outlet of the torsion impactor body is communicated with an inlet of the impulse oscillation cavity and an outlet of the impulse oscillation cavity is communicated with the impact transmission pup joint; a pressure releasing flow channel and an impact flow channel are formed in the torsion impactor body. The near-bit torsion and oscillation coupling impactor has the advantages that due to the fact that high-frequency low-amplitude torsion which is stable in periodicity and oscillation coupling impact vibration can be generated, impact torque can effectively eliminate the phenomena of PDC bit stick slip and intermittent bit sticking; due to the fact that the near-bit torsion and oscillation coupling impactor is provided with no electronic part and is of a full-hydraulic mechanical structure, the size is small and the impact process has no interference to an electric instrument which conducts measurement while drilling. Parts which are prone to being damaged are few in the near-bit torsion and oscillation coupling impactor, and the near-bit torsion and oscillation coupling impactor is stable in work, long in service life and beneficial to lowering well drilling cost.

Description

technical field [0001] The invention relates to a downhole power tool used in the field of petroleum and natural gas drilling engineering, in particular to a torsion and vibration coupling impactor near a drill bit. Background technique [0002] In deep or ultra-deep formations, the rock hardness is high, the drillability level is high, the ROP is slow, and the drilling cost is high. In the process of oil and natural gas drilling and production, downhole power-assisted rock-breaking tools have become a useful supplement to efficient rock-breaking technology in deep formations. Field practice and indoor experimental research have shown that applying a certain period of impact force to the drill bit will improve the rock-breaking efficiency of the drill bit. Therefore, impact drilling tools are expected to become an important technical means to increase the speed of deep wells. [0003] When using the PDC bit to drill into the above formations, stick-slip effect and intermitt...

AI Technical Summary

Problems solved by technology

The stick-slip effect and intermittent sticking cause the irregular release of the torsional elastic energy accumulated in the drill string, causing the rock-breaking process of the PDC bit to become extremely unstable, accelerating the abnormal damage of the PDC bit, and reducing the service life of the PDC bit

[0004] The conventional hydraulic impactor belongs to the axial impact and cannot increase the rock-breaking torque of the PDC bit. For example, the patent CN200710056325.1 describes a jet impactor

[0005] In order to improve the ROP of deep wells, solve the stick-slip effect of PDC bits, intermittent sticking and other problems, promote the stable operation of PDC bits, and prolong the service life of the bits, the patent US6742609B2 designed a drilling fluid turbine-driven torsional impactor, but The drilling tool has complex structure, many wearing parts, high pressure loss, and limited service life

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