CN-122014101-A - Variable pitch all-metal screw drilling tool with self-adaptive wear compensation function

CN122014101ACN 122014101 ACN122014101 ACN 122014101ACN-122014101-A

Abstract

The invention discloses a variable pitch all-metal screw drilling tool with a self-adaptive wear compensation function, which comprises a stator made of all-metal materials, a rotor, a transmission mechanism, a self-adaptive compensation driving mechanism and a mechanical limiting mechanism, wherein the inner cavity of the stator and the outer profile of the rotor are of variable-section cone conical spiral structures with tiny cone angles, the axial displacement of the rotor can linearly adjust the radial sealing gap between the stator and the rotor, the transmission mechanism is a long-stroke hollow porous spline transmission shaft for realizing torque transmission and axial micro-sliding of the rotor, the self-adaptive compensation driving mechanism is a disc spring and hydraulic cooperative driving structure and is arranged in a universal shaft assembly for providing power for axial compensation of the rotor, and the mechanical limiting mechanism is an adjustable limiting ring and is arranged at the tail end of the rotor or the transmission shaft for limiting the maximum axial displacement of the rotor.

Inventors

XU RUI
LU ZHENGYANG
WANG BIAO
SUN XIAOFENG
BI XUELIANG
HOU ZHAOKAI
QU JINGYU
YAO DI
HU QIAOBO

Assignees

东北石油大学

Dates

Publication Date: 20260512
Application Date: 20260407

Claims (8)

1. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function is characterized by comprising a stator, a rotor, a transmission mechanism, a self-adaptive compensation driving mechanism and a mechanical limiting mechanism which are all made of metal materials; The inner cavity of the stator and the outline of the rotor are of a variable-section cone conical spiral structure with a tiny cone angle, and the axial displacement of the rotor can linearly adjust the radial sealing gap between the stator and the rotor; the transmission mechanism is a long-stroke hollow porous spline transmission shaft and is used for realizing torque transmission and rotor axial micro-sliding; the self-adaptive compensation driving mechanism is a disc spring and hydraulic cooperative driving structure and is arranged in the universal shaft assembly to provide power for axial compensation of the rotor; The mechanical limiting mechanism is an adjustable limiting ring and is arranged at the tail end of the rotor or the transmission shaft to limit the maximum axial displacement of the rotor.
2. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the variable section cone conical spiral structure converts radial wear which is difficult to control between a stator and a rotor into controllable axial displacement of the rotor through geometric topological transformation, and when the radial clearance is increased due to wear, the rotor moves in the direction of increasing the axial cone diameter so as to tighten the radial clearance, and the sealing performance is recovered.
3. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the effective meshing length of the spline of the long-stroke hollow porous spline transmission shaft covers the whole preset wear compensation stroke, the inside of the spline shaft is hollow, radial flow guide holes are arranged at the root parts of tooth surfaces, drilling fluid or lubricating oil can be introduced into the spline meshing surfaces to form a high-pressure fluid film, hydrostatic lubrication is realized, meanwhile, the spline shaft can balance internal and external fluid pressure, and additional axial force interference is eliminated.
4. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the disc spring group in the disc spring and hydraulic cooperative driving structure is made of a high-temperature-resistant nickel-based alloy and is in a pre-compression state to provide a basic pre-tightening force, hydraulic thrust is provided by pressure difference generated by drilling fluid flowing through the rotor, the resultant force of the spring force and the hydraulic force is a power source for axial compensation of the rotor, and when the contact counter force of the stator and the rotor is reduced, the resultant force pushes the rotor to move axially.
5. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the adjustable limiting ring is of a mechanical hard limiting structure, and when the axial displacement of the rotor reaches a preset limit value, the limiting ring physically blocks the rotor from continuing to move downwards, and the pressure of the vertical pipe is naturally attenuated or fluctuated at the moment and can be used as a ground prompting signal for the service life exhaustion of the stator.
6. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the long-stroke hollow porous spline transmission shaft can convert dry friction between metals into fluid lubrication when the drilling tool works, so that the rotor can maintain an axial floating state while transmitting torque, and friction self-locking is avoided.
7. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the self-adaptive compensation driving mechanism has the compensation triggering condition that the wear of metal matching surfaces of the stator and the rotor causes the increase of radial clearance, the decrease of tool volumetric efficiency and the decrease of contact surface reaction force, and at the moment, the belleville spring group releases potential energy and adds hydraulic thrust to push the rotor to axially jog advance.
8. The variable pitch all-metal screw drilling tool with the self-adaptive wear compensation function according to claim 1, wherein the drilling tool is of a pure metal structural design, has a theoretical temperature resistance of more than 300 ℃, can adapt to high-temperature and high-pressure extreme well bottom working conditions of deep and ultra-deep oil-gas drilling and dry hot rock drilling, and is not influenced by oil-based mud swelling.

Description

Variable pitch all-metal screw drilling tool with self-adaptive wear compensation function Technical Field The invention relates to the field of petroleum and natural gas exploration and geothermal resource development, in particular to a downhole power drilling tool technology, and more particularly relates to an all-metal screw drilling tool and a sealing gap control technology. Background In modern deep and ultra-deep oil and gas and dry hot rock drilling engineering, the well bottom working condition is extreme, and the temperature is often over 180 ℃ and even reaches 300 ℃. The traditional positive displacement screw drilling tool realizes sealing by means of interference fit of a rubber bushing stator and a metal rotor, however, the rubber material can have serious problems of delayed heat generation and aging embrittlement under a high-temperature environment, and swelling phenomenon is easy to occur in oil-based mud, so that the service life of the drilling tool is extremely short, and the operation requirement of a high-temperature deep well cannot be met. In order to overcome the temperature-resistant bottleneck of the rubber stator, an all-metal screw drilling tool is developed in the industry, and the stator material is changed into metal as well, so that a metal-metal matching structure is formed. The existing all-metal screw drilling tool technical scheme is mainly divided into two types, one type adopts a common all-metal structure with high-precision micro-clearance fit, the other type adopts a ground pump technology with conical stator and rotor, and the technology needs to stop and recover the fit clearance in a mode of manually adjusting a gasket after the stator and the rotor are worn. The existing all-metal screw drilling tool still has the technical defects that firstly, an all-metal structure lacks an elastic compensation mechanism, high-pressure leakage and torque failure can be rapidly caused by the increase of a clearance after the stator and the rotor are worn, secondly, the micron-sized matching precision is extremely sensitive to temperature, the situation of expansion jamming or shrinkage leakage easily occurs in a high-temperature underground environment, thirdly, the existing scheme relies on manual adjustment, the existing scheme cannot be completed underground, and the existing automatic adjustment scheme cannot realize effective clearance compensation due to rotor self-locking caused by spline friction under high-torque transmission. Disclosure of Invention In order to meet the above-mentioned needs, the present invention provides a variable pitch all-metal screw drill with adaptive wear compensation to at least partially solve the above-mentioned problems. The invention provides a variable pitch all-metal screw drilling tool with a self-adaptive wear compensation function, which comprises a stator, a rotor, a transmission mechanism, a self-adaptive compensation driving mechanism and a mechanical limiting mechanism, wherein the stator is made of all-metal materials; The inner cavity of the stator and the outline of the rotor are of a variable-section cone conical spiral structure with a tiny cone angle, and the axial displacement of the rotor can linearly adjust the radial sealing gap between the stator and the rotor; the transmission mechanism is a long-stroke hollow porous spline transmission shaft and is used for realizing torque transmission and rotor axial micro-sliding; the self-adaptive compensation driving mechanism is a disc spring and hydraulic cooperative driving structure and is arranged in the universal shaft assembly to provide power for axial compensation of the rotor; The mechanical limiting mechanism is an adjustable limiting ring and is arranged at the tail end of the rotor or the transmission shaft to limit the maximum axial displacement of the rotor. Preferably, the variable-section conical spiral structure converts the radial abrasion which is difficult to control between the stator and the rotor into controllable axial displacement of the rotor through geometric topological transformation, and when the radial clearance is increased due to abrasion, the rotor moves along the axial direction to the direction of increasing the conical diameter so as to tighten the radial clearance, and the sealing performance is recovered. The spline effective engagement length of the long-stroke hollow porous spline transmission shaft covers the whole preset abrasion compensation stroke, the spline shaft is hollow, a radial flow guide hole is arranged at the root of the tooth surface, drilling fluid or lubricating oil can be introduced into the spline engagement surface to form a high-pressure fluid film, hydrostatic lubrication is realized, meanwhile, the spline shaft can balance internal and external fluid pressure, and additional axial force interference is eliminated. Preferably, the disc spring group in the disc spring and hydraulic cooperative driving structure is