Torsion pendulum type low-pressure-loss backing-pressure-reducing while-drilling tool and work method thereof

Abstract

The invention discloses a torsion pendulum type low-pressure-loss backing-pressure-reducing while-drilling tool and a work method thereof. The tool is composed of a torsion pendulum-axial vibration spline assembly, a balance piston assembly and a pressurizing piston assembly. The torsion pendulum-axial vibration spline assembly comprises a spline mandrel (1), wherein an outer spline cylinder (2) is arranged outside the spline mandrel (1), the inner surface of the front end of the outer spline cylinder (2) is provided with a front end wiper plug assembly (101) and a first M-shaped wiper plug seal ring (304), the lower end of the spline mandrel (1) is provided with a disc spring assembly (3). The tool adopts the pressurizing piston structure, the tool can generate high oscillating force at asmall oscillating pressure, and the pressurizing piston assembly adopts a modular type structure and can adopt multiple-stage series connection; in this way, the tool can be installed at the positionfarther away from a drill bit, generates oscillating force on a longer drill stem, and improves the backing pressure reducing effect.

Description

technical field [0001] The invention relates to the technical field of oil drilling and production downhole tools, in particular to a torsion-type low-pressure consumption-reducing pressure-reducing tool while drilling, which is mainly used for increasing the speed of oil drilling. Background technique [0002] With the increase in the number of extended-reach wells and the continuous extension of horizontal displacement, the drilling mode is facing greater challenges. The hydraulic oscillator solves this problem in a simple and effective way, and proposes a unique and effective way. Stable weight-on-bit transmission, even in complex formations with large azimuth changes, improve the ability to adjust the tool face of the drill bit, so that drilling can reach farther target layers; it does not require too much work to adjust the tool during drilling face, keep the tool face stable, and increase the ROP. [0003] However, the currently commonly used drill string oscillating ...

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Problems solved by technology

[0004] 1) With a single axial oscillating force output, the ability to reduce frictional resistance in the horizontal section is limited;

[0005] 2) Due to the performance requirements of the seal, the tolerance of the shaft-hole steel body is too small, and the rock debris particles are easy to jam the mandrel, resulting in the tool not vibrating;

[0006] 3) There is no oil seal structure inside the tool, and the mud enters the tool spline and disc spring cavity, causing the oscillation space to be filled and the tool not to oscillate;

[0008] 5) The area of ​​the oscillating piston is small, and a larger oscillating pressure is required to drive a longer drill string, which leads to a higher cycle pressure loss, reaching the limit of the mud pump in the middle and late stages of the long horizontal section of a deep well;

[0009] 6) The friction between the internal seal of the tool and the mandrel is relatively large, which greatly reduces the effective value of the oscillation force on the one hand, and causes rapid failure of the seal on the other hand;

[0010] 7) The liquid migration in the tool is damped, resulting in a weaker high-frequency oscillation response capability, and the effective value of the high-frequency oscillation force caused by the damping force in the tool is low

[0011] In short, the existing drill string oscillating force output tools have serious defects such as damping, jamming, large friction, large wear, poor chemical resistance, poor high temperature resistance, and poor high pressure resistance, which lead to poor field application results

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