Casing centralizer for drilling

Abstract

The invention relates to the technical field of drilling casing installation, in particular to a casing centralizer for drilling, which comprises a casing I. A primary support assembly and a secondary support assembly are movably mounted on the outer side of the casing I. The primary support assembly comprises a movable cylinder and a plurality of support blocks, the movable cylinder movably sleeves the outer side of the casing I, and the support blocks are movably mounted on the outer side of the movable cylinder. The supporting block is installed on the side wall of the movable cylinder in a sliding mode. The supporting blocks and the protection plates abut against the inner wall of the mining hole to achieve first-stage supporting and second-stage supporting of the first casing pipe, the first casing pipe can be effectively prevented from being bent and deviated, the low-carbon mining effect is achieved, the longitudinal distance between every two protection plates is reduced through torsion and rotation of the protection plates, and the mining efficiency is improved. The problem that large stone particles in the mining hole fall between the first sleeve and the protective plate, and consequently the first sleeve cannot be recycled is solved, the twisted protective plate drives the rotating cylinder to rotate reversely, the diameter of the bent position of the protective plate is increased, and the stability of the first sleeve in the working process is improved.

Description

Technical Field

[0001] The invention relates to the technical field of drilling casing installation, in particular to a casing centralizer used for drilling. Background Art

[0002] A centralizer is an auxiliary tool used in the casing installation process in the oil and gas extraction industry. Its main function is to ensure that the casing is vertically placed underground or correctly placed according to a predetermined trajectory to improve extraction efficiency and safety. When setting the casing inside the extraction hole, the centralizer can prevent the casing from bending, deflecting or getting stuck on the well wall, thereby avoiding possible casing leakage and reduced extraction efficiency, and failing to achieve low-carbon extraction. For example, a casing centralizer disclosed in publication number CN117514031B, when in use, pressurizes the casing, the active sleeve slides backward, and the driven sleeve slides backward, forcing the elastic sheet to bend and contact the well wall, so that the casing is in the center of the well. When the casing centralizer needs to be removed, pressurize the casing again, and the active sleeve slides backward. The matching state of the fixed sleeve and the annular middle piece changes, and the elastic sheet returns to its original shape, so that the casing centralizer can be removed from the oil well. However, after the casing is pressurized, the driven sliding sleeve is not supported, so that the elastic sheet cannot bend. In the process of lowering the casing, only the middle part of the elastic sheet arches and contacts the oil well wall, so that the casing at the arched position of the middle part of the elastic sheet is located in the center of the oil well. The remaining parts may still bend and deviate, resulting in casing leakage, leading to the problem of being unable to low-carbon mining. In addition, after the elastic sheet is bent, if the stone particles on the side wall of the oil well fall between the elastic sheet and the casing, the elastic sheet cannot be reset, which not only makes it impossible to remove the casing, but also causes the stone particles to scratch the casing, making the casing unable to be used again, resulting in a waste of resource costs. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems in the background technology and to propose a casing centralizer for drilling.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A casing centralizer for drilling, comprising a first casing, a primary support assembly and a secondary support assembly movably mounted on the outer side of the first casing, the primary support assembly comprising a movable cylinder and a plurality of support blocks, the movable cylinder movably sleeved on the outer side of the first casing, the support blocks slidably mounted on the side walls of the movable cylinder, the side walls of the support blocks being integrally formed with a plurality of evenly distributed inclined convex teeth, the side walls of the inclined convex teeth being provided with a plurality of evenly distributed ball bearings;

[0006] The secondary support assembly is located above the primary support assembly, and includes a rotating cylinder and a plurality of guard plates. The rotating cylinder is rotatably mounted on the outside of the first sleeve. The bottom of the rotating cylinder is integrally formed with a plurality of evenly distributed mounting seats 1, and the top of the movable cylinder is integrally formed with a plurality of evenly distributed mounting seats 2. The mounting seats 1, 2 and the guard plates correspond one to one, and the guard plates are movably mounted between the mounting seats 1 and 2.

[0007] A limiting assembly is slidably mounted on the outer side of the guard plate, and the limiting assembly is used to release the support block and the guard plate for support, and to tighten the support block and the guard plate for storage.

[0008] In the above-mentioned casing centralizer for drilling, a plurality of evenly distributed slide tubes are integrally formed on the top of the movable tube, a rotating sleeve is rotatably installed on the outer side of the casing, and the rotating sleeve is located below the rotating tube. A plurality of evenly distributed slide plates are integrally formed on the bottom of the rotating sleeve, and the slide plates are slidably installed inside the slide tube.

[0009] In the above-mentioned casing centralizer for drilling, the outer peripheral wall of the slide tube is integrally formed with support ring 1 and support ring 2, the support ring 1 is located above the support ring 2, and the diameter of the support ring 1 is larger than the diameter of the support ring 2.

[0010] In the above-mentioned casing centralizer for drilling, a second spring is provided between each of the support blocks and the movable cylinder.

[0011] In the above-mentioned casing centralizer for drilling, a fixed cylinder is fixedly installed on the outer side of the casing 1, and the rotating cylinder is located below the fixed cylinder and is rotatably installed on the outer side of the fixed cylinder.

[0012] In the above-mentioned casing centralizer for drilling, the side wall of the fixed cylinder is provided with a plurality of evenly distributed movable grooves, a convex tooth 2 is slidably installed inside the movable groove, a spring 1 is provided between the convex tooth 2 and the movable groove, and the inner wall of the rotating cylinder is integrally formed with a plurality of evenly distributed convex teeth 1, and the convex teeth 1 and convex teeth 2 conflict with each other.

[0013] In the above-mentioned casing centralizer for drilling, the guard plate is in the shape of a square bar, and the cross section of the side wall of the guard plate is in the shape of an arc.

[0014] In the above-mentioned casing straightener for drilling, the limiting assembly includes a limiting cylinder and a second cone cylinder. The limiting cylinder is movably mounted on the outer side of the guard plate, and the second cone cylinder is slidably mounted on the outer side of the limiting cylinder. The top of the limiting cylinder is integrally formed with the first cone cylinder, and the first cone cylinder is located above the second cone cylinder.

[0015] Compared with the existing technology, the beneficial effects of the present invention are:

[0016] The first-level support assembly and the second-level support assembly are movably installed on the outside of the casing, so that when the casing is lowered, the spring 2 is released and the support block contacts the inner wall of the mining hole, and the first-level support of the casing is achieved by the contact of the support block with the inner wall of the mining hole. When the support block contacts the inner wall of the mining hole, the rotating cylinder and the movable cylinder squeeze the guard plate, and the guard plate bends and contacts the inner wall of the mining hole. The second-level support of the casing is achieved by the contact of the guard plate with the inner wall of the mining hole. The first-level support assembly and the second-level support assembly can effectively prevent the casing from bending and deflecting, playing the role of low-carbon mining, and the inclined convex The teeth contact the inner wall of the mining hole and drive the movable cylinder to rotate, causing the guard plate to twist and rotate with the movable cylinder. Through the twisting and rotation of the guard plate, the longitudinal distance between each guard plate is reduced, and large stones inside the mining hole are prevented from falling between the casing and the guard plate, causing the casing to be unable to be recovered and the stones to scratch the casing. When the casing is working, the support block contacts the inner wall of the mining hole and the movable cylinder stops rotating. At this time, the twisted guard plate drives the rotating cylinder to reverse, so that the diameter of the bending part of the guard plate is increased, thereby improving the stability of the casing during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0018] Figure 2 It is a cross-sectional view of the overall structure of the present invention;

[0019] Figure 3 For the present invention Figure 2 A magnified schematic diagram of point A in the middle;

[0020] Figure 4 Schematic diagram of the internal structure of the present invention as a whole;

[0021] Figure 5 It is a cross-sectional view of the structure of the rotating cylinder and the fixed cylinder in the present invention;

[0022] Figure 6 This is a disassembly diagram of the rotating cylinder and the fixed cylinder in the present invention;

[0023] Figure 7 This is a disassembly diagram of the rotating sleeve and the movable cylinder in the present invention;

[0024] Figure 8 This is a disassembled schematic diagram of the movable cylinder and the support block in the present invention;

[0025] Figure 9 It is a structural schematic diagram of the guard plate in the present invention.

[0026] In the figure: 1. Sleeve 1; 11. Limiting cylinder; 111. Conical cylinder 1; 112. Conical cylinder 2; 21. Rotating cylinder; 211. Protruding tooth 1; 212. Mounting seat 1; 22. Fixed cylinder; 221. Protruding tooth 2; 222. Spring 1; 223. Movable groove; 23. Rotating sleeve; 231. Guard plate; 232. Slide plate 1; 31. Movable cylinder; 311. Slide plate; 312. Support ring 1; 313. Support ring 2; 314. Mounting seat 2; 32. Support block; 321. Inclined protruding tooth; 322. Ball; 323. Spring 2. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0029] Reference Figure 1 - Figure 9 As shown, a casing centralizer for drilling includes a casing 1, with a primary support assembly and a secondary support assembly movably mounted on the outside of the casing 1. The primary support assembly includes a movable cylinder 31 and a plurality of support blocks 32. The movable cylinder 31 is movably mounted on the outside of the casing 1, and the support blocks 32 are slidably mounted on the side walls of the movable cylinder 31. The side walls of the support blocks 32 are integrally formed with a plurality of evenly distributed inclined protruding teeth 321. The side walls of the inclined protruding teeth 321 are provided with a plurality of evenly distributed ball bearings 322. A second spring 323 is provided between each support block 32 and the movable cylinder 31.

[0030] The secondary support assembly is located above the primary support assembly and includes a rotating cylinder 21 and several guard plates 231. The rotating cylinder 21 is rotatably mounted on the outside of the sleeve 1. The bottom of the rotating cylinder 21 is integrally formed with several evenly distributed mounting seats 1 212. The top of the movable cylinder 31 is integrally formed with several evenly distributed mounting seats 2 314. The mounting seats 1 212, the mounting seats 2 314 and the guard plates 231 correspond one to one. The guard plates 231 are movably mounted between the mounting seats 1 212 and the mounting seats 2 314.

[0031] A limiting assembly is slidably installed on the outer side of the guard plate 231. The limiting assembly is used to release the support block 32 and the guard plate 231 for support, and to tighten the support block 32 and the guard plate 231 for storage.

[0032] Among them, the working principle of the support block 32 is: in the process of lowering the casing 1 into the inside of the mining hole, when the support block 32 moves out of the limit assembly, the spring 2 323 is released, so that each support block 32 contacts the inner wall of the mining hole, and the movable cylinder 31 drives the casing 1 to move, so that the axis of the casing 1 coincides with the axis of the mining hole. At this time, the first-level support of the casing 1 is achieved by the contact of the support block 32 with the inner wall of the mining hole. At the same time, in the process of the casing 1 moving into the inside of the mining hole, the movable cylinder 31 follows the casing 1 to move into the inside of the mining hole, and the movable cylinder 31 drives the support block 32 to move, so that the inclined convex teeth 321 contact the inner wall of the mining hole, and drive the movable cylinder 31 to rotate. The inclined convex teeth 321 reduce the friction with the inner wall of the mining hole through the ball 322, thereby improving the working efficiency of the casing 1.

[0033] like Figure 4 and Figure 9 As shown, the guard plate 231 is in the shape of a square bar, and the cross section of the side wall of the guard plate 231 is in the shape of an arc.

[0034] The working principle of the guard plate 231 is as follows: in the process of lowering the casing 1 into the inside of the mining hole, after the support block 32 hits the inner wall of the mining hole, the casing 1 drives the rotating cylinder 21 to move. At this time, the movable cylinder 31 stops moving, so that the rotating cylinder 21 and the movable cylinder 31 squeeze the guard plate 231, and the guard plate 231 bends and hits the inner wall of the mining hole. At this time, the axis of the rotating cylinder 21 and the axis of the movable cylinder 31 coincide, thereby improving the stability of the casing 1 during the lowering process, and realizing secondary support of the casing 1 through the hit of the guard plate 231 against the inner wall of the mining hole. When the guard plate 231 hits the inner wall of the mining hole, the movable cylinder 31 continues to move with the casing 1. When the movable cylinder 31 rotates, the movable cylinder 31 drives the guard plate 231 to rotate. Through the rotation of the guard plate 231, large pieces of stone inside the mining hole are prevented from falling between the casing 1 and the guard plate 231, causing the problem that the casing 1 cannot be recovered.

[0035] like Figure 4 、 Figure 7 and Figure 8 As shown, the top of the movable cylinder 31 is integrally formed with several evenly distributed slide cylinders 311, the outer side of the sleeve 1 is rotatably installed with a rotating sleeve 23, the rotating sleeve 23 is located below the rotating cylinder 21, and the bottom of the rotating sleeve 23 is integrally formed with several evenly distributed slide plates 232, which are slidably installed inside the slide cylinder 311.

[0036] Among them, the working principle of the rotating sleeve 23 is: during the rotation of the movable cylinder 31, the slide cylinder 311 drives the slide plate 232 to rotate, so that the rotating sleeve 23 rotates, and the slide cylinder 311 and the slide plate 232 rotate between the guard plate 231 and the casing 1, thereby preventing small pieces of stone inside the mining hole from falling between the casing 1 and the guard plate 231, causing the casing 1 to be unable to be recovered.

[0037] like Figure 4 、 Figure 7 and Figure 8 As shown, the outer peripheral wall of the slide tube 311 is integrally formed with a support ring 1 312 and a support ring 2 313 . The support ring 1 312 is located above the support ring 2 313 , and the diameter of the support ring 1 312 is larger than the diameter of the support ring 2 313 .

[0038] Among them, support ring 1 312 and support ring 2 313 respectively support the inner wall of the guard plate 231, so that when the guard plate 231 bends, the guard plate 231 bends at the position where the support ring 1 312 resists, avoiding the problem of bending failure and bending deviation of the guard plate 231.

[0039] like Figure 3 、 Figure 5 and Figure 6 As shown, a fixed cylinder 22 is fixedly installed on the outside of the sleeve 1, and the rotating cylinder 21 is located below the fixed cylinder 22 and is rotatably installed on the outside of the fixed cylinder 22. The side wall of the fixed cylinder 22 is provided with a plurality of evenly distributed movable grooves 223, and a convex tooth 221 is slidably installed inside the movable groove 223. A spring 1 222 is provided between the convex tooth 221 and the movable groove 223. The inner wall of the rotating cylinder 21 is integrally formed with a plurality of evenly distributed convex teeth 1 211, and the convex teeth 1 211 and the convex teeth 221 conflict with each other.

[0040] The working principle of the rotating cylinder 21 is as follows: when the movable cylinder 31 drives the guard plate 231 to rotate, the convex tooth 1 211 and the convex tooth 2 221 conflict with each other, causing the rotating cylinder 21 to stop rotating. At this time, the curved guard plate 231 is twisted, so that the diameter of the curved part of the guard plate 231 is reduced. The movable cylinder 31 and the rotating cylinder 21 squeeze the guard plate 231 again, so that the curvature of the guard plate 231 increases and conflicts with the inner wall of the mining hole again. At this time, the convex tooth 1 211 squeezes the convex tooth 221, and the convex tooth 221 contracts. , so that the movable cylinder 31 drives the rotating cylinder 21 to rotate through the guard plate 231. Through the torsion of the guard plate 231, the longitudinal distance between each guard plate 231 is reduced, and the interception of large stone particles by the guard plate 231 during the rotation process is improved. When the casing 1 is working, the support block 32 contacts the inner wall of the mining hole, and the movable cylinder 31 stops rotating. At this time, the twisted guard plate 231 drives the rotating cylinder 21 to reverse, so that the diameter of the bending part of the guard plate 231 is increased, thereby improving the stability of the casing 1 during operation.

[0041] Further references Figure 4 、 Figure 5 and Figure 7 To explain, when the casing 1 inside the mining hole is taken out, the casing 1 drives the rotating cylinder 21 to move, and the support block 32 contacts the inner wall of the mining hole, so that the movable cylinder 31 and the rotating cylinder 21 stretch the guard plate 231, and the guard plate 231 is released from the twisted state and the bent state by stretching. When the guard plate 231 is released from the twisted state, the side walls of the slide cylinder 311 and the slide 1 232 contact the stone particles that failed to be intercepted between the casing 1 and the guard plate 231, so that the stone particles move out from between the casing 1 and the guard plate 231, avoiding the stone particles being stuck between the casing 1 and the guard plate 231, affecting the guard plate 231 from releasing the bent state.

[0042] like Figure 1 and Figure 2 As shown, the limiting assembly includes a limiting cylinder 11 and a second cone cylinder 112. The limiting cylinder 11 is movably mounted on the outside of the guard plate 231, and the second cone cylinder 112 is slidably mounted on the outside of the limiting cylinder 11. The top of the limiting cylinder 11 is integrally formed with a first cone cylinder 111, and the first cone cylinder 111 is located above the second cone cylinder 112.

[0043] Among them, the working principle of cone cylinder 111 and cone cylinder 2 112 is: cone cylinder 2 112 is fixedly installed on the outside of the mining hole, and when the support block 32 and the guard plate 231 contact the inner wall of cone cylinder 111 and cone cylinder 2 112, it shrinks, so that only one limiting component is required when casing 1 is installed below.

[0044] The specific working principle and method of use of the present invention are explained in detail below: After the worker fixes the cone cylinder 2 112 on the outside of the mining hole, he lowers the casing 1 to the inside of the mining hole, and the limiting cylinder 11 passes through the cone cylinder 2 112, so that the bottom of the cone cylinder 111 contacts the top of the cone cylinder 2 112. At this time, as the casing 1 moves, the support block 32 and the guard plate 231 move out of the interior of the limiting cylinder 11, so that the support block 32 contacts the inner wall of the mining hole for primary support, and the movable cylinder 31 stops moving. At this time, the movable cylinder 31 and the rotating cylinder 21 squeeze the guard plate 231, so that the guard plate 231 bends and contacts the inner wall of the mining hole for secondary support. After the guard plate 231 contacts the inner wall of the mining hole, the movable cylinder 31 continues to follow the casing through the guard plate 231. When the pipe 1 moves, the inclined convex teeth 321 slide inside the mining hole, so that the support block 32 drives the movable cylinder 31 to rotate, and the movable cylinder 31 drives the rotating sleeve 23 to rotate, so that the slide cylinder 311 and the slide plate 232 rotate between the guard plate 231 and the casing 1, so as to prevent small stones inside the mining hole from falling between the casing 1 and the guard plate 231, causing the casing 1 to be unable to be recovered. At the same time, the movable cylinder 31 drives the rotating cylinder 21 to rotate through the guard plate 231, and the rotation of the guard plate 231 prevents large stones inside the mining hole from falling between the casing 1 and the guard plate 231, causing the casing 1 to be unable to be recovered. When the convex teeth 1 211 and the convex teeth 2 21 conflict with each other, the rotating cylinder 21 stops rotating, so that The bent guard plate 231 is twisted. At this time, the diameter of the bent part of the guard plate 231 is reduced, and the movable cylinder 31 and the rotating cylinder 21 squeeze the guard plate 231 again, so that the guard plate 231 hits the inner wall of the mining hole again. At this time, the convex tooth 1 211 squeezes the convex tooth 221, and the convex tooth 221 contracts, so that the movable cylinder 31 continues to drive the rotating cylinder 21 to rotate. The longitudinal distance between each guard plate 231 is reduced by the twisting of the guard plate 231, and the interception of large stones by the guard plate 231 during the rotation process is improved, further preventing large stones inside the mining hole from falling between the casing 1 and the guard plate 231, causing the casing 1 to be unable to be recovered. When the casing 1 is working, the support block 32 hits the inner wall of the mining hole, and the movable cylinder 31 stops rotating. At this time, the twisted guard plate 231 drives the rotating cylinder 21 to reverse, so that the diameter of the bending part of the guard plate 231 increases, thereby improving the stability of the casing 1 during operation. When the casing 1 inside the mining hole is taken out, the casing 1 drives the rotating cylinder 21 to move, and the support block 32 contacts the inner wall of the mining hole, so that the movable cylinder 31 and the rotating cylinder 21 stretch the guard plate 231, and the guard plate 231 is released from the twisted state and the bent state by stretching. When the guard plate 231 is released from the twisted state, the side walls of the slide cylinder 311 and the slide plate 232 contact the stone particles that failed to be intercepted between the casing 1 and the guard plate 231, so that the stone particles move out from between the casing 1 and the guard plate 231, thereby preventing the stone particles from being stuck between the casing 1 and the guard plate 231 and affecting the release of the bent state of the guard plate 231.When the guard plate 231 and the support block 32 contact the inner wall of the second cone cylinder 112, the guard plate 231 and the support block 32 shrink and move to the inside of the limiting cylinder 11.

[0045] It is further explained that the above-mentioned fixed connection should be understood in a broad sense unless otherwise clearly specified and limited. For example, it can be welding, gluing, or one-piece molding, etc., which are common means well known to those skilled in the art.

[0046] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A casing centralizer for drilling, comprising a casing (1), characterized in that: A primary support assembly and a secondary support assembly are movably mounted on the outer side of the sleeve (1), the primary support assembly comprising a movable cylinder (31) and a plurality of support blocks (32), the movable cylinder (31) being movably mounted on the outer side of the sleeve (1), the support blocks (32) being slidably mounted on the side walls of the movable cylinder (31), the side walls of the support blocks (32) being integrally formed with a plurality of evenly distributed inclined convex teeth (321), and the side walls of the inclined convex teeth (321) being provided with a plurality of evenly distributed rolling balls (322); The secondary support assembly is located above the primary support assembly, and the secondary support assembly includes a rotating cylinder (21) and a plurality of guard plates (231). The rotating cylinder (21) is rotatably mounted on the outside of the sleeve (1). The bottom of the rotating cylinder (21) is integrally formed with a plurality of evenly distributed mounting seats (212). The top of the movable cylinder (31) is integrally formed with a plurality of evenly distributed mounting seats (314). The mounting seats (212), the mounting seats (314) and the guard plates (231) correspond to each other one by one, and the guard plates (231) are movably mounted between the mounting seats (212) and the mounting seats (314). A limiting assembly is slidably mounted on the outer side of the guard plate (231), and the limiting assembly is used to release the support block (32) and the guard plate (231) for support, and to tighten the support block (32) and the guard plate (231) for storage.

2. The casing centralizer for drilling according to claim 1, characterized in that: The top of the movable cylinder (31) is integrally formed with a plurality of evenly distributed slide cylinders (311); the outer side of the sleeve (1) is rotatably mounted with a rotating sleeve (23); the rotating sleeve (23) is located below the rotating cylinder (21); the bottom of the rotating sleeve (23) is integrally formed with a plurality of evenly distributed slide plates (232); the slide plates (232) are slidably mounted inside the slide cylinder (311).

3. The casing centralizer for drilling according to claim 2, characterized in that: The outer peripheral wall of the slide tube (311) is integrally formed with a support ring 1 (312) and a support ring 2 (313), wherein the support ring 1 (312) is located above the support ring 2 (313), and the diameter of the support ring 1 (312) is larger than the diameter of the support ring 2 (313).

4. The casing centralizer for drilling according to claim 1, characterized in that: A second spring (323) is provided between each of the support blocks (32) and the movable cylinder (31).

5. The casing centralizer for drilling according to claim 1, characterized in that: A fixed cylinder (22) is fixedly installed on the outer side of the sleeve (1), and the rotating cylinder (21) is located below the fixed cylinder (22) and is rotatably installed on the outer side of the fixed cylinder (22).

6. The casing centralizer for drilling according to claim 5, characterized in that: The side wall of the fixed cylinder (22) is provided with a plurality of evenly distributed movable grooves (223), a convex tooth (221) is slidably mounted inside the movable groove (223), a spring (222) is provided between the convex tooth (221) and the movable groove (223), and the inner wall of the rotating cylinder (21) is integrally formed with a plurality of evenly distributed convex teeth (211), and the convex teeth (211) and the convex teeth (221) are in conflict with each other.

7. The casing centralizer for drilling according to claim 1, characterized in that: The guard plate (231) is in the shape of a square strip, and the cross section of the side wall of the guard plate (231) is in the shape of an arc.

8. The casing centralizer for drilling according to claim 1, characterized in that: The limiting assembly comprises a limiting cylinder (11) and a second cone cylinder (112), wherein the limiting cylinder (11) is movably mounted on the outer side of the guard plate (231), and the second cone cylinder (112) is slidably mounted on the outer side of the limiting cylinder (11), and the top of the limiting cylinder (11) is integrally formed with the first cone cylinder (111), and the first cone cylinder (111) is located above the second cone cylinder (112).

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