An adaptive gauge coring bit

Abstract

The application discloses a self-adapting hole-diameter coring bit, and relates to the technical field of coring bits, mainly comprising a variable pin joint, a guide rail steel body, an axial spring, a sliding block and a shoe block; the shoe block is embedded or welded at the end of the independent sliding block which can move axially; the sliding block can axially stretch and shrink under the guidance of the guide rail steel body, so that the inner and outer diameters of the coring bit can be self-adaptively adjusted; in a non-working state, the inner and outer diameters of the coring bit are reduced to meet the requirement of passing through the irregular well wall or the well section with a smaller hole diameter, so that the wear caused by reaming can be avoided; when the coring bit contacts the well bottom, the coring bit is self-adaptively adjusted to the target hole diameter under the action of the drilling pressure, so that the drilling requirement can be met. The self-adapting hole-diameter coring bit can solve the problems of sticking and wear during the tripping of the coring bit in the drilling engineering, because the shoe block at the bottom of the coring bit cannot move, so that the outer diameter of the coring bit cannot adapt to the change of the hole diameter.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coring bits, in particular to a self-adaptive hole diameter coring bit. BACKGROUND

[0002] In drilling engineering such as oil and gas resource investigation, geothermal exploration and scientific drilling, obtaining core of target formation is an important engineering purpose of engineering implementation, and the core is mainly obtained by drilling in the target formation in the well by using a coring tool, wherein the coring bit is a component of the coring tool for directly drilling the core. At present, the coring tasks required by different types of drilling engineering are not the same, mainly including coring of local target formation in the well and continuous coring in the well, and therefore the bits used in different well sections are also different. Influenced by the bit types, structural features and well formation pressure release used in different well sections, irregular well wall (spiral well wall, local bulge, pit or step, etc.) and irregular hole diameter size are easily caused, and the coring tool is often blocked during running in and tripping out during coring operation, and therefore the coring tool needs to be continuously reamed in the blocked well section to trim the well wall and hole diameter, which directly causes damage of the bit blocks of the coring bit mainly used for grinding rock, and easily deteriorates the well quality and greatly reduces the service life of the coring bit.

[0003] The existing coring bit mainly includes a bit block and a steel body, wherein the bit block is formed by hard alloy or PDC composite sheet by welding or diamond powder hot pressing, and then a plurality of bit blocks are fixed to the steel body by embedding or welding to form an integrated coring bit. The inner and outer diameters of the coring bit of different sizes are fixed values, and therefore the bit blocks are easily damaged abnormally when the irregular well wall or the hole diameter smaller than the outer diameter of the coring bit is encountered during running in and tripping out.

[0004] The existing coring bit mainly includes a bit block and a steel body, wherein a certain number of bit blocks are fixed to the end of the steel body by embedding or welding to form an integrated coring bit. The outer diameter of the coring bit is fixed and consistent with the hole diameter of the drilled well section, and the inner diameter is the diameter of the drilled core. When the coring operation is performed, the coring bit is easily blocked and needs to be reamed for a long time when the irregular well wall or the small hole diameter is encountered. Due to the fixed structure of the inner and outer diameters of the coring bit, the outer diameter of the coring bit is easily reduced during reaming, which reduces the service life of the coring bit and has the risk of drilling a small diameter hole. SUMMARY

[0005] To solve the above technical problems, the present application provides a self-adaptive hole diameter coring bit to solve the problems of sticking and wear of the coring bit during running in and tripping out of the existing coring tool in drilling engineering.

[0006] To achieve the above object, the present application provides the following scheme:

[0007] The present application provides a self-adaptive hole diameter coring bit, comprising a variable pin joint, a guide rail steel body, an axial spring, a sliding block and a tire block.

[0008] The variable pin joint is a tubular body, a first thread is arranged on the outer wall of one end of the variable pin joint, the first thread is used for connecting with a coring drilling tool, a second thread is arranged on the middle part of the variable pin joint close to the other end, the second thread is used for connecting with one end of the guide rail steel body, a limiting stepped hole is arranged on the other end of the variable pin joint, the limiting stepped hole is used for connecting with one end of the axial spring, and the limiting stepped hole is used for limiting the axial and radial directions of the axial spring.

[0009] The guide rail steel body is a cylindrical structure, an internal thread is arranged on the inner wall of one end of the guide rail steel body, the internal thread is matched with the second thread to realize the detachable connection between the variable pin joint and the guide rail steel body, a plurality of through hole grooves are circumferentially and uniformly arranged on the inner wall of the other end of the guide rail steel body, the opening end of the through hole groove faces the axis of the guide rail steel body, and the opening end of the through hole groove is provided with a limiting part for reducing the opening size of the through hole groove.

[0010] The sliding block is a 7-shaped structure, the sliding block comprises a vertically arranged sliding channel, the cross section of the sliding channel is matched with the shape of the through hole groove, one end of the sliding channel is in contact with the other end of the axial spring, the other end of the sliding channel is connected with one end of a transverse mounting part, the other end of the mounting part is provided with a mounting groove, a gauge block is arranged in the mounting groove, the gauge block is used for protecting the coring bit and preventing the outer diameter of the coring bit from being worn and reduced during drilling, and the mounting part away from the sliding channel is provided with the tire block.

[0011] Optionally, an inner step is arranged on the inner wall of the variable pin joint, and the inner step is used for limiting the core tube of the coring drilling tool.

[0012] Optionally, a column hole is arranged at one end of the sliding channel parallel to the mounting part, the column hole is used for mounting an anti-slip block, and the anti-slip block is used for preventing the sliding block from falling off from the through hole groove.

[0013] Optionally, the column hole is a limiting hole, the cross section of the anti-slip block is the same as the cross section shape of the column hole, one end of the anti-slip block is provided with a containing hole along the axial direction of the anti-slip block, a radial spring is arranged in the containing hole, and the radial spring is used for keeping the other end of the anti-slip block in contact with the inner wall of the guide rail steel body.

[0014] Optionally, the column hole comprises a rectangular hole, a trapezoidal hole is arranged at the top of the rectangular hole, and the top opening of the trapezoidal hole is arranged; the anti-escape slide block has the same shape as the column hole.

[0015] Optionally, a key groove through hole is arranged at one end of the anti-escape slide block, the key groove through hole is communicated with the accommodating hole, and the key groove through hole is used for sand discharge and anti-jamming.

[0016] Optionally, the gauge block is formed by hot pressing of mixed wear-resistant metal powder and hard alloy.

[0017] Optionally, the gauge block has a trapezoidal structure.

[0018] Optionally, the block comprises a plurality of first blocks and a plurality of second blocks, the first blocks and the second blocks are arranged at intervals, the plurality of first blocks and the plurality of second blocks are fan-shaped blocks, the plurality of first blocks and the plurality of second blocks are provided with a plurality of strip-shaped arc-shaped liquid flow grooves at one end away from the variable buckle joint, and the plurality of first blocks and the plurality of second blocks are complementarily arranged at one end towards the variable buckle joint.

[0019] Optionally, the through hole groove is a dovetail type groove.

[0020] The present application has the following technical effects relative to the prior art:

[0021] The adaptive hole diameter coring bit in the application adopts a split structure of a variable pin joint thread connecting a guide rail steel body, the independent variable pin joint can be processed into different pin types to facilitate the connection of external coring drilling tools of different structures, and the adaptability of the coring bit is expanded. Meanwhile, the blocks for grinding the bottom rock and the gauge blocks are fixed on the movable slider end by the inlaying mode, and the slider slides in the inclined "dove tail" type through hole groove type guide rail of the guide rail steel body, and the size of the adaptive hole diameter is adjusted, so that the problem that the blocks are inevitably worn by the irregular well wall of the non-working well section and the service life is reduced is solved. The working characteristics are that the slider extends out of the guide rail steel body under the action of the axial spring during the drilling process of the coring well section, at this time, all the blocks are contracted to the minimum inner and outer diameters along with the extension of the slider, the outer diameter of the block part of the coring bit with the largest outer diameter in the coring drilling tool is effectively reduced to ensure the smooth passing through the irregular well wall or the well section with small well diameter, and the blocks are protected from being worn; when the coring bit contacts the bottom hole to perform normal coring drilling work, the slider is contracted to the inside of the guide rail steel body under the action of the drilling pressure, and the blocks are expanded, the outer diameter of the coring bit is adaptively adjusted to the target well diameter size to start normal drilling; after the coring work of the target layer section is completed, the coring drilling tool is pulled up, the slider is extended again to contract the blocks, and the inner and outer diameters of the coring bit blocks are reduced to prevent the sticking during the pulling up. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Fig. 1 The structure schematic diagram of the self-adaptive hole diameter coring bit in the application in the well and out of the well state;

[0024] Fig. 2 The structure schematic diagram of the self-adaptive hole diameter coring bit in the application in the well and out of the well state;

[0025] Fig. 3 The structure schematic diagram of the self-adaptive hole diameter coring bit in the application in the well and out of the well state;

[0026] Fig. 4 The structure schematic diagram of the self-adaptive hole diameter coring bit in the application in the well and out of the well state;

[0027] Fig. 5It is a structure diagram of the anti-slip block in the self-adapting gauge coring bit.

[0028] Marked as: 1, variable buckle joint; 2, guide rail steel body; 2-1, through hole groove; 3, axial spring; 4, radial spring; 5, sliding block; 5-1, sliding way; 5-2, column hole; 6, gauge block; 7, first pad; 8, second pad; 9, anti-slip block; 9-1, accommodating hole; 9-2, key groove through hole. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] As shown in the drawings, Figs. 1 to 5 The present embodiment provides a self-adapting gauge coring bit, which comprises a variable buckle joint 1, a guide rail steel body 2, an axial spring 3, a sliding block 5 and a pad, and the pad comprises a first pad 7 and a second pad 8.

[0031] The variable buckle joint 1 is a tubular body, a first thread is arranged on the outer wall of one end of the variable buckle joint 1, the first thread is an external thread, and the first thread is used for connecting with a coring tool. The first thread can be processed into different types of threads according to different coring tools, thereby expanding the adaptability of the coring bit. A second thread is arranged on the middle part of the variable buckle joint 1 close to the other end, the second thread is an external thread, and the second thread is used for connecting with one end of the guide rail steel body 2. The other end of the variable buckle joint 1 is provided with a limiting stepped hole, the limiting stepped hole is used for connecting with one end of the axial spring 3, and the limiting stepped hole is used for limiting the axial and radial directions of the axial spring 3.

[0032] The guide rail steel body 2 is a cylindrical structure, an internal thread is arranged on the inner wall of one end of the guide rail steel body 2, the internal thread is used for matching with the second thread to realize the detachable connection between the variable buckle joint 1 and the guide rail steel body 2. A plurality of through hole grooves 2-1 are arranged on the inner wall of the other end of the guide rail steel body 2 in the circumferential direction, the opening end of the through hole groove 2-1 faces the axis of the guide rail steel body 2, and the opening end of the through hole groove 2-1 is provided with a limiting part for reducing the opening size of the through hole groove 2-1. The part between the two ends of the guide rail steel body 2 is a smooth inner wall, the diameter of which is greater than the outer diameter of the axial spring 3, and this section is the sliding space of the sliding block 5. In a more specific embodiment, 12 through hole grooves 2-1 are arranged on the guide rail steel body 2, the through hole grooves 2-1 are dovetail grooves, and the side of the through hole groove 2-1 facing the axis of the guide rail steel body 2 is parallel to the axis of the guide rail steel body 2. The side of the through hole groove 2-1 away from the axis of the guide rail steel body 2 gradually moves away from the axis of the guide rail steel body 2 from the guide rail steel body 2 to the variable buckle joint 1.

[0033] The slider 5 is a 7-shaped structure, the slider 5 includes a vertically arranged slide 5-1, the cross section of the slide 5-1 matches the shape of the through hole groove 2-1, one end of the slide 5-1 is in contact with the other end of the axial spring 3, the other end of the slide 5-1 is connected with one end of the transverse mounting part, the other end of the mounting part is provided with a mounting groove, the mounting groove is provided with a diameter block 6, the diameter block 6 is a trapezoidal structure. The diameter block 6 is made of wear-resistant metal powder and hard alloy mixed and hot-pressed. The diameter block 6 is used to protect the core drill bit, prevent the outer diameter of the core drill bit from being worn and reduced during drilling, and the side of the mounting part away from the slide 5-1 is provided with a tire block.

[0034] In a more specific embodiment, one end of the slide 5-1 is provided with a column hole 5-2 parallel to the mounting part, the column hole 5-2 is used to install an anti-slip block 9, the anti-slip block 9 is used to prevent the slider 5 from falling out of the through hole groove 2-1. The column hole 5-2 includes a rectangular hole, the top of the rectangular hole is provided with a trapezoidal hole, the top of the trapezoidal hole is open, and the cross section of the anti-slip block 9 is the same as the shape of the column hole 5-2.

[0035] One end of the anti-slip block 9 is provided with a containing hole 9-1 along the axial direction of the anti-slip block 9, the containing hole 9-1 is provided with a radial spring 4, the radial spring 4 is used to keep the other end of the anti-slip block 9 in contact with the inner wall of the guide rail steel body 2. The end of the anti-slip block 9 towards the variable buckle joint 1 is provided with a key groove through hole 9-2, the key groove through hole 9-2 is communicated with the containing hole 9-1, the key groove through hole 9-2 is used for sand discharge and anti-jamming. After the anti-slip block 9 is installed with the radial spring 4, the anti-slip block 9 is integrally installed in the trapezoidal column hole 5-2 at the small end of the slider 5 and can slide radially under the action of the radial spring 4, while preventing the slider 5 from falling out of the guide rail steel body 2 during sliding.

[0036] The cross section of the slide 5-1 includes a rectangular structure, one end of the rectangular structure is provided with a dovetail type structure, the dovetail type structure matches the dovetail type part of the through hole groove 2-1, the height of the rectangular structure gradually decreases from the column hole 5-2 to the mounting part, and the end face of the slider 5 towards the axis is perpendicular to the end face provided with the column hole 5-2.

[0037] The inner wall of the variable buckle joint 1 is provided with an inner step, the inner step is used for limiting the core barrel of the coring tool.

[0038] The tire block includes six first tire blocks 7 and six second tire blocks 8, the first tire blocks 7 and the second tire blocks 8 are arranged alternately; the first tire blocks 7 and the second tire blocks 8 are both fan-shaped blocks; the first tire blocks 7 and the second tire blocks 8 are provided with a plurality of strip-shaped arc-shaped liquid flow grooves away from one end of the variable buckle joint 1; the first tire blocks 7 and the second tire blocks 8 are complementarily arranged towards one end of the variable buckle joint 1. The first tire blocks 7 and the second tire blocks 8 are fixed on the front end of the slider 5 by inlaying or welding.

[0039] The first block 7, the second block 8 and the gauge block 6 are assembled with the sliding block 5 to form an independent sliding block assembly, which is beneficial to the repair or quick replacement of the core drill bit.

[0040] The self-adapting gauge core drill bit solves the problems of sticking and abrasion of the core drill bit during tripping caused by the fixed and immovable core drill bit blocks at the bottom of the core drill bit for grinding rocks, and the non-adapting of the outer diameter of the core drill bit to the gauge change.

[0041] In the self-adapting gauge core drill bit, the blocks are respectively embedded or welded at the end of the independent sliding block which can axially move, and the sliding block can axially stretch and shrink under the guidance of the guide rail steel body to realize the self-adapting adjustment of the inner and outer diameters of the core drill bit, that is, the inner and outer diameters of the core drill bit are reduced in the non-working state to meet the through-wall irregular or small gauge well section to avoid reaming abrasion, and the core drill bit is self-adapted to the target gauge size when contacting the bottom of the well to meet the drilling requirements.

[0042] It should be noted that, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be regarded as limiting the claims.

[0043] The principles and implementation modes of the present application are described in specific examples in the specification, and the above embodiment descriptions are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in specific implementation modes and application scope. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A self-adapting gauge coring bit, characterized by, The variable buckle joint, the guide rail steel body, the axial spring, the sliding block and the block are included. The variable buckle joint is a tubular body, a first thread is arranged on the outer wall of one end of the variable buckle joint, the first thread is used for being connected with a coring drill, a second thread is arranged on the middle part of the variable buckle joint close to the other end, the second thread is used for being connected with one end of the guide rail steel body, the other end of the variable buckle joint is provided with a limiting stepped hole, the limiting stepped hole is used for being connected with one end of the axial spring, and the limiting stepped hole is used for limiting the axial spring in the axial and radial directions. The guide rail steel body is a cylindrical structure, an inner thread is arranged on the inner wall of one end of the guide rail steel body, the inner thread is matched with the second thread to realize detachable connection of the variable buckle joint and the guide rail steel body, and a plurality of through hole grooves are uniformly arranged on the inner wall of the other end of the guide rail steel body in the circumferential direction, the opening end of the through hole groove faces the axis of the guide rail steel body, and the opening end of the through hole groove is provided with a limiting part for reducing the opening size of the through hole groove. The sliding block is a 7-shaped structure, the sliding block includes a vertically arranged sliding channel, the cross section of the sliding channel is matched with the shape of the through hole groove, one end of the sliding channel is in contact with the other end of the axial spring, the other end of the sliding channel is connected with one end of a transverse mounting part, the other end of the mounting part is provided with a mounting groove, a gauge block is arranged in the mounting groove, the gauge block is used for protecting a coring bit, preventing the outer diameter of the coring bit from being worn and reduced during drilling, and the mounting part away from the sliding channel is provided with the block.

2. The self-adapting gauge coring bit of claim 1, wherein, An inner step is arranged on the inner wall of the variable buckle joint, and the inner step is used for limiting a coring drill core tube.

3. The self-adapting gauge coring bit of claim 1, wherein, One end of the sliding channel is provided with a column hole parallel to the mounting part, the column hole is used for mounting an anti-slip block, and the anti-slip block is used for preventing the sliding block from falling off from the through hole groove.

4. The self-adapting gauge coring bit of claim 3, wherein, The column hole is a limiting hole, the cross section of the anti-slip block is the same as the cross section shape of the column hole, one end of the anti-slip block is provided with a containing hole along the axial direction of the anti-slip block, a radial spring is arranged in the containing hole, and the radial spring is used for keeping the other end of the anti-slip block in contact with the inner wall of the guide rail steel body.

5. The under-reaming bit of claims 3 or 4, wherein, The column hole includes a rectangular hole, the top of the rectangular hole is provided with a trapezoidal hole, the top opening of the trapezoidal hole is arranged, and the cross section of the anti-slip block is the same as the shape of the column hole.

6. The self-adapting gauge coring bit of claim 4, wherein, One end of the anti-slip block towards the variable buckle joint is provided with a key groove through hole, the key groove through hole is communicated with the containing hole, and the key groove through hole is used for sand discharge and anti-jamming.

7. The self-adapting gauge coring bit of claim 1, wherein, The gauge block is formed by hot pressing of a mixture of wear-resistant metal powder and hard alloy.

8. The self-adapting gauge coring bit of claim 1, wherein, The gauge block is a trapezoidal structure.

9. The self-adapting gauge coring bit of claim 1, wherein, The block includes a plurality of first blocks and a plurality of second blocks, the first blocks and the second blocks are arranged alternately, the first blocks and the second blocks are all fan-shaped blocks, the first blocks and the second blocks away from one end of the variable buckle joint are provided with a plurality of strip-shaped arc-shaped liquid flow grooves, and the first blocks and the second blocks towards one end of the variable buckle joint are complementarily arranged.

10. The self-adapting gauge coring bit of claim 1, wherein, The through hole slot is a dovetail type slot. The through hole slot is a dovetail type slot.

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