Well hole drill rod centralizer

Abstract

A plurality of sliding strip grooves extending in the axial direction are formed in the circumference of the outer wall of a pipe body in an array mode, the outer wall of the pipe body is slidably connected with an operation sleeve in a sleeved mode, and a plurality of protruding blocks connected with the sliding strip grooves in a sliding and inserted mode are arranged on the inner wall of the operation sleeve. The inner walls of the two axial ends of the sliding strip groove are connected with the side walls of the two ends of the convex block through springs, the head end and the tail end of the operation sleeve are each of a conical surface structure, and a plurality of flow channels extending in the axial direction are formed in the outer wall of the operation sleeve. According to the borehole drill rod centralizer, through the operation sleeve connected to the outer wall of the pipe body in a sliding and sleeving mode and the spring providing driving force, on the basis that spring energy storage is conducted through friction between the operation sleeve and the inner wall of a shaft, when oncoming falling blocks happen, the side wall of the operation sleeve is extruded by the falling blocks, and therefore energy storage is achieved. The elastic potential energy stored by the spring is rapidly released, the operation sleeve is driven to push the falling blocks to conduct falling block crushing operation, the falling blocks are cleaned in time, falling block crushing is conducted, and the problem that the centralizer is blocked by the falling blocks is solved.

Description

Technical Field

[0001] This invention belongs to the field of deep well exploration equipment technology, and specifically relates to a wellbore drill pipe centralizer. Background Technology

[0002] Centralizers are auxiliary tools installed on the drill string during drilling operations. Their main function is to keep the drill pipe centered and stabilize the drill string trajectory to ensure wellbore quality and drilling efficiency.

[0003] During drilling operations, especially in the deep sections of ultra-deep wells at depths of 10,000 meters, the operation faces harsh environments with ultra-high temperatures, ultra-high pressures, and complex geostress coupling. Because the stability of the wellbore is difficult to guarantee, wellbore instability can lead to large chunks falling and directly contacting the drill pipe and centralizer. Furthermore, the distance between the drill pipe centralizer and the inner wall of the wellbore is smaller than the distance between the drill pipe sidewall and the inner wall of the wellbore, which drastically reduces the effective flow area of ​​the wellbore annulus. This significantly increases the risk of blockage at the centralizer, directly affecting the improvement of drilling quality in ultra-deep wells at depths of 10,000 meters.

[0004] To resolve blockages caused by falling blocks, the drill string is typically moved by raising and lowering it. However, this method doesn't allow workers to promptly detect blockages or falling blocks, often leading to blockages being discovered by surface personnel only after the incident has occurred. Therefore, there is an urgent need for a tool that can quickly clear large blockages from the drill string stabilizer area. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a wellbore drill pipe stabilizer, comprising: a pipe body, with male threaded connectors and female threaded connectors at both ends of the pipe body, characterized in that the outer wall of the pipe body is circumferentially arrayed with a plurality of axially extending sliding grooves, a working sleeve is slidably sleeved on the outer wall of the pipe body, the inner wall of the working sleeve is provided with a plurality of protrusions that slidably insert into the sliding grooves, the inner walls of both ends of the sliding grooves and the side walls of both ends of the protrusions are connected by springs, the beginning and end ends of the working sleeve are both tapered structures and the outer wall of the working sleeve is provided with a plurality of axially extending flow channels.

[0006] Furthermore, the outer wall of the tube is provided with a number of axially extending limiting grooves in a circumferential array, and the inner wall of the working sleeve is provided with a number of limiting blocks that slide into the limiting grooves.

[0007] The distance between the end of the limiting block and the inner wall of the limiting groove in the same orientation is less than the distance between the end of the protruding block and the inner wall of the sliding groove in the same orientation.

[0008] Furthermore, the outer wall of the tube is provided with a ring sleeve, and the outer wall of the ring sleeve is provided with a sliding groove and a limiting groove, and the thickness of the ring sleeve is greater than the depth of the sliding groove and the limiting groove.

[0009] Furthermore, two limiting rings are fitted onto the outer wall of the tube. The two limiting rings are located at both ends of the working sleeve. When the limiting block moves to one end and abuts against the inner wall of the end that is in the same direction as the sliding groove, the working sleeve abuts against the limiting ring in the same direction.

[0010] Furthermore, the number of flow channels is 3 to 6, and the total number of limiting blocks and protrusion blocks is 4 to 12.

[0011] Furthermore, the flow channel adopts a spiral structure or a straight structure.

[0012] Furthermore, an annular block is fitted onto the outer wall of the pipe, and the annular block is located between the working sleeve and the male threaded connector. The annular block includes a collar block fitted onto the outer wall of the pipe and slit blocks arranged in a circumferential array on the outer wall of the collar block.

[0013] Furthermore, the slitting block includes a cutting section facing the male threaded connector and a guide section facing the working sleeve. The sidewall of the guide section facing the male threaded connector has a conical structure, and the cutting section has a wedge-shaped structure.

[0014] Furthermore, the sidewall of the guide section facing the male threaded joint adopts an external conical surface structure with an included angle of 30-45°, and the sidewall of the cutting section facing the inner wall of the well shaft adopts an internal conical surface structure with an included angle of 20-45°.

[0015] Furthermore, the surface of the work cover is coated with a non-stick coating.

[0016] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0017] The wellbore drill pipe centralizer of the present invention utilizes a working sleeve that is slidably fitted onto the outer wall of the drill pipe and a spring that provides driving force. Based on the energy stored in the spring through friction between the working sleeve and the inner wall of the wellbore, when faced with an oncoming block, the inherent phenomenon of the block pressing against the side wall of the working sleeve causes the elastic potential energy stored in the spring to be released rapidly. This drives the working sleeve to push the block and perform a block breaking operation, thus achieving timely clearing and breaking of the block and avoiding the problem of the centralizer being blocked by the block.

[0018] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a wellbore drill pipe stabilizer in an embodiment of the present invention is shown;

[0021] Figure 2 A schematic diagram of the tube body in an embodiment of the present invention is shown;

[0022] Figure 3 A schematic diagram of the working sleeve in an embodiment of the present invention is shown;

[0023] Figure 4 A cross-sectional view of the work sleeve in an embodiment of the present invention is shown. Figure 1 ;

[0024] Figure 5 A cross-sectional view of the work sleeve in an embodiment of the present invention is shown. Figure 2 ;

[0025] Figure 6 A schematic diagram of the ring block structure in an embodiment of the present invention is shown;

[0026] Figure 7 A cross-sectional schematic diagram of the wellbore drill pipe stabilizer in an embodiment of the present invention is shown;

[0027] Figure 8 A schematic diagram showing the usage state of the wellbore drill pipe stabilizer in an embodiment of the present invention is shown.

[0028] In the figure, 1-male threaded connector, 2-female threaded connector, 3-pipe body, 4-sliding groove, 5-working sleeve, 6-protruding block, 7-spring, 8-flow channel, 9-limiting groove, 10-limiting block, 11-ring sleeve, 12-limiting ring, 13-ring block, 14-ring block, 15-sliding block, 1501-cutting part, 1502-guide part. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a wellbore drill pipe stabilizer. Figure 1 A schematic diagram of a wellbore drill pipe stabilizer according to an embodiment of the present invention is shown. Figure 1 In the wellbore drill pipe stabilizer, there are: a pipe body 3, with male threaded connector 1 and female threaded connector 2 at both ends of the pipe body 3 respectively; a number of axially extending sliding grooves 4 are arranged in a circular array on the outer wall of the pipe body 3; a working sleeve 5 is slidably sleeved on the outer wall of the pipe body 3; a number of protrusions 6 are slidably inserted into the inner wall of the working sleeve 5 and are slidably inserted into the sliding grooves 4; the inner walls of the two ends of the sliding grooves 4 and the side walls of the two ends of the protrusions 6 are connected by springs 7; the beginning and end of the working sleeve 5 are both tapered structures and the outer wall of the working sleeve 5 is provided with a number of axially extending flow channels 8.

[0031] It should be noted that in horizontal or directional well operations, the drill pipe centralizer is first lowered vertically and then enters the directional or horizontal section. In the directional or horizontal section, the sidewall of the drill pipe centralizer of this application will abut against the inner wall of the wellbore, causing sliding friction between the inner wall of the wellbore and the sidewall of the drill pipe centralizer of this application.

[0032] Therefore, in the actual use of the device in this application, the outer wall of the working sleeve 5 abuts against the inner wall of the wellbore, and the inner wall of the wellbore will exert a frictional force on the drill pipe stabilizer in the opposite direction of the drill pipe's movement. Figure 8 In the example shown, the drill pipe stabilizer of this application moves from left to right. During this movement, the outer wall of the working sleeve 5 is subjected to a leftward frictional force from the inner wall of the wellbore, which in turn pushes the working sleeve 5 to move to the left relative to the pipe body 3 until the sum of the deformation forces of the several springs 7 is equal to the frictional force on the outer wall of the working sleeve 5.

[0033] During the subsequent lowering of the drill pipe stabilizer into the wellbore, existing debris inside the wellbore will collide with the outer wall of the working sleeve 5. Given that the working sleeve 5 has a conical structure at both its front and rear ends and several axially extending flow channels 8 on its outer wall, when a large debris is encountered, the debris will immediately compress against the conical surface or the inner cavity of the flow channel 8 at the end of the working sleeve 5 upon contact with its outer wall. This will push up the working sleeve 5 and the pipe body 3, instantly reducing the contact area between the outer wall of the working sleeve 5 and the inner wall of the wellbore. Consequently, the frictional force on the outer wall of the working sleeve 5 will be momentarily reduced, causing several springs 7 to immediately open. The initial reset motion quickly pushes the working sleeve 5 to move to the right relative to the pipe body 3, applying a force to the right to the fallen block, thus achieving the effect of clearing the fallen block and preventing blockage at the side wall of the working sleeve 5. After the working sleeve 5 pushes out the fallen block, it re-forms abutment against the inner wall of the wellbore. The working sleeve 5 moves to the left relative to the pipe body 3 until the total deformation force of several springs 7 is equal to the frictional force on the outer wall of the working sleeve 5, waiting for the next fallen block. This achieves timely clearing of fallen blocks. Only when the fallen block passes through the flow channel 8 will it not push up the working sleeve 5, achieving the effect of timely detection and timely breaking of fallen blocks.

[0034] Furthermore, it should be noted that the function of the centralizer is to maintain the drill pipe in a centered position within the wellbore. Therefore, when the centralizer is installed on the drill pipe via the male threaded connector 1 and the female threaded connector 2, and during the process of lowering the centralizer and drill pipe together into the wellbore, a standard distance of 5-15mm is maintained between the outer wall of the centralizer and the inner wall of the wellbore to ensure timely correction of the drill pipe position. After drilling fluid is injected into the wellbore, the centralizer occupies part of the annulus space, reducing the flow cross-section of the drilling fluid within the wellbore. The drilling fluid will be obstructed on the front side of the centralizer, resulting in a slower flow velocity, while the flow velocity will increase on the back side of the centralizer, especially in the narrow area between the centralizer and the wellbore wall, where the flow velocity will rise, enhancing turbulence and forming local vortices or eddies. Under the impact of the drilling fluid and the reverse thrust of the working sleeve 5, larger debris can be quickly broken into several smaller debris, which can then be discharged through the flow channel 8, further improving the efficiency of debris removal using the centralizer in this application.

[0035] The wellbore drill pipe centralizer of the present invention utilizes a working sleeve 5 slidably sleeved on the outer wall of the pipe body 3 and a spring 7 providing driving force. Based on the energy stored in the spring 7 through the friction between the working sleeve 5 and the inner wall of the wellbore, when facing an oncoming block, the inherent phenomenon of the block pressing against the side wall of the working sleeve 5 causes the elastic potential energy stored in the spring 7 to be released rapidly. This drives the working sleeve 5 to push the block and perform a block breaking operation, thus achieving timely clearing and breaking of the block and preventing the centralizer from being blocked by the block.

[0036] refer to Figure 2 The outer wall of the tube body 3 is also provided with a number of axially extending limiting grooves 9 arranged in a circular array, and the inner wall of the working sleeve 5 is provided with a number of limiting blocks 10 that slide and insert into the limiting grooves 9.

[0037] The distance between the end of the limiting block 10 and the inner wall of the end of the limiting groove 9 in the same orientation is less than the distance between the end of the protruding block 6 and the inner wall of the end of the sliding groove 4 in the same orientation.

[0038] exist Figure 2 , Figure 7 In the example shown, the limiting groove 9 and the sliding groove 4 have the same length, and the inner walls at both ends of the limiting groove 9 are coplanar with the inner walls at both ends of the sliding groove 4. Simultaneously, the central tangent of the limiting block 10 and the protruding block 6 remains coplanar, but the length of the limiting block 10 is greater than the axial extension length of the protruding block 6. This causes the working sleeve 5 to move relative to the tube body 3 towards one end. When the end of the limiting block 10 in the same orientation abuts against the inner wall of the end of the limiting groove 9, a predetermined gap is formed between the end of the protruding block 6 in the same orientation and the inner wall of the end of the sliding groove 4. This predetermined gap is used to accommodate the compressed spring 7, thereby protecting the spring 7 and limiting its deformation.

[0039] Meanwhile, several limiting grooves 9 and several sliding grooves 4 are arranged alternately. By adding limiting grooves 9 and limiting blocks 10, the firmness of the connection between the outer wall of the pipe body 3 and the inner wall of the working sleeve 5 is improved, further ensuring the stability of the working sleeve 5 as it rotates with the pipe body 3.

[0040] exist Figure 2 In the example shown, the outer wall of the tube body 3 is provided with a ring sleeve 11. The outer wall of the ring sleeve 11 is provided with a sliding groove 4 and a limiting groove 9. The thickness of the ring sleeve 11 is greater than the depth of the sliding groove 4 and the limiting groove 9, so as to avoid damage to the tube body 3 caused by the addition of the sliding groove 4 and the limiting groove 9, and to maintain the overall structural integrity of the tube body 3.

[0041] Specifically, two limiting rings 12 are sleeved on the outer wall of the pipe body 3. The two limiting rings 12 are located at both ends of the working sleeve 5. When the limiting block 10 moves to one end and forms abutment with the inner wall of the end of the sliding groove 4, the working sleeve 5 abuts with the limiting ring 12 in the same position.

[0042] By using the limiting rings 12 at both ends of the working sleeve 5, the sliding range of the working sleeve 5 is limited during the lowering or lifting of the device, thereby limiting the deformation of the spring 7 and protecting the spring 7, the limiting block 10, and the protruding block 6.

[0043] refer to Figure 2-5 The number of flow channels 8 is 3 to 6, and the total number of limit blocks 10 and protrusion blocks 6 is 4 to 12. In order to improve the stability of the flow channels 8 under force, in this example, the total number of limit blocks 10 and protrusion blocks 6 is twice the number of flow channels 8.

[0044] Specifically, the flow channel 8 adopts a spiral structure or a straight structure. The spiral structure of the flow channel 8 is selected to face the rotating drilling operation, while the straight structure of the flow channel 8 is selected to face the operation of cleaning the inner wall of the wellbore when the drill pipe is lowered. In actual use, the cross-section of the supporting rib between adjacent flow channels 8 can be rectangular, trapezoidal or I-shaped, etc., to further adapt to the complex environment of different wellbores.

[0045] refer to Figure 6 A ring block 13 is fitted onto the outer wall of the pipe body 3. The ring block 13 is located between the working sleeve 5 and the male threaded connector 1. The ring block 13 includes a collar block 14 fitted onto the outer wall of the pipe body 3 and slitting blocks 15 arranged in a circumferential array on the outer wall of the collar block 14. For example, the number of slitting blocks 15 is 3 to 9, and the number of ring blocks 13 is 1 to 3.

[0046] During the movement of the centralizer, the drilling fluid in the wellbore is first diverted and guided by the cutting block 15 on the annular block 13, reducing the direct impact of the drilling fluid on the working sleeve 5. At the same time, after the large block is squeezed by the working sleeve 5, it is pushed back by the working sleeve 5 under the action of the spring 7. The large block will collide with the cutting block 15, which will divide the large block into several small blocks, thus avoiding the same large block from repeatedly hitting the working sleeve 5 and affecting the progress of the drilling operation.

[0047] Based on the reverse impact crushing of the falling blocks by the working sleeve 5, the addition of ring block 13 to crush the falling blocks a second time further improves the efficiency of falling block cleaning and further avoids the phenomenon of the straightener being blocked by falling blocks.

[0048] Furthermore, the cutting block 15 includes a guide portion 1502 facing the male threaded connector 1 and a cutting portion 1501 facing the working sleeve 5. The sidewall of the guide portion 1502 facing the male threaded connector 1 has a conical structure. The sidewalls of several guide portions 1502 facing the male threaded connector 1 together form an outwardly expanding inclined surface, which guides the drilling fluid in the wellbore while facilitating the passage of the device through the blowout preventer (BOP) core installed on the inner wall of the wellbore. It should be noted that the BOP core is a key component of the BOP in the wellbore, mainly used to control blowouts and prevent runaway blowouts during oil and gas well drilling or workover operations. The BOP core is usually annular or bag-shaped, and it can form a seal around the wellhead. During the process of lowering the device into the wellbore, the outwardly expanding inclined surface compresses and deforms the BOP core to prevent the cutting block 15 from damaging the BOP core.

[0049] The cutting section 1501 adopts a wedge-shaped structure. Figure 6 In the example shown, the cross-section of the cutting section 1501 adopts a triangular structure with the tip facing the side of the working sleeve 5, so as to facilitate the cutting operation of the large block pushed back by the working sleeve 5.

[0050] Although the above description uses a wedge-shaped cutting section 1501 as an example, the present invention is not limited thereto. The cross-section of the cutting section 1501 can also adopt other structures, such as trapezoidal or semi-circular. Although the cutting section 1501 with a trapezoidal or semi-circular cross-section will directly affect the efficiency of the cutting section 1501 in breaking up pieces, it can greatly improve the service life of the cutting section 1501. Those skilled in the art can consider the connection principle of the present invention and the actual application situation, and can make decisions as long as the principle of the present invention can be realized.

[0051] Specifically, the side wall of the guide section 1502 facing the male threaded connector 1 adopts an external conical surface structure with an included angle of 30-45°, and the side wall of the cutting section 1501 facing the inner wall of the wellbore adopts an internal conical surface structure with an included angle of 20-45°. While further improving the smoothness of the device when passing through the blowout preventer rubber core, the structure of the cutting section 1501 is adjusted. It should be noted that the larger the included angle of the side wall of the cutting section 1501 facing the inner wall of the wellbore, the better the effect of the cutting section 1501 in breaking up large broken pieces, but the shorter the service life of the cutting section 1501. Adjustments need to be made according to the actual situation.

[0052] To improve the service life of the device, the surface of the work sleeve 5 is coated with a non-stick coating, for example, a Teflon coating, to prevent the mud-covered tool from affecting the cleaning efficiency of the device.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of multiple components or the interaction between multiple components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wellbore drill pipe stabilizer, for installation on the drill pipe and lowered together into the wellbore, comprising: The tube body (3) has a male threaded connector (1) and a female threaded connector (2) at both ends. The tube body (3) is characterized by having a plurality of axially extending sliding grooves (4) arranged in a circumferential array on the outer wall of the tube body (3). The outer wall of the tube body (3) is slidably fitted with a working sleeve (5). The inner wall of the working sleeve (5) is provided with a plurality of protrusions (6) that are slidably inserted into the sliding grooves (4). The inner walls of the two ends of the sliding grooves (4) and the side walls of the two ends of the protrusions (6) are connected by springs (7). The beginning and end of the working sleeve (5) are both tapered and the outer wall of the working sleeve (5) is provided with a plurality of axially extending flow channels (8).

2. The wellbore drill pipe centralizer according to claim 1, characterized in that, The outer wall of the tube body (3) is also provided with a number of axially extending limiting grooves (9) arranged in a circular array, and the inner wall of the working sleeve (5) is provided with a number of limiting blocks (10) that slide and insert into the limiting grooves (9). The distance between the end of the limiting block (10) and the inner wall of the end of the limiting groove (9) is less than the distance between the end of the protruding block (6) and the inner wall of the end of the sliding groove (4).

3. The wellbore drill pipe centralizer according to claim 2, characterized in that, The outer wall of the tube body (3) is provided with a ring sleeve (11), and the outer wall of the ring sleeve (11) is provided with a sliding groove (4) and a limiting groove (9). The thickness of the ring sleeve (11) is greater than the depth of the sliding groove (4) and the limiting groove (9).

4. The wellbore drill pipe centralizer according to claim 3, characterized in that, The outer wall of the tube body (3) is fitted with two limiting rings (12). The two limiting rings (12) are located at both ends of the working sleeve (5). When the limiting block (10) moves to one end and the end of the end abuts against the inner wall of the sliding groove (4), the working sleeve (5) abuts against the limiting ring (12) in the same position.

5. The wellbore drill pipe centralizer according to claim 2, characterized in that, The number of flow channels (8) is 3 to 6, and the total number of limiting blocks (10) and protrusion blocks (6) is 4 to 12.

6. The wellbore drill pipe centralizer according to claim 2, characterized in that, The flow channel (8) adopts a spiral structure or a straight structure.

7. The wellbore drill pipe centralizer according to claim 2, characterized in that, The outer wall of the tube body (3) is fitted with an annular block (13), which is located between the working sleeve (5) and the male threaded connector (1). The annular block (13) includes a collar block (14) fitted on the outer wall of the tube body (3) and slitting blocks (15) arranged in a circumferential array on the outer wall of the collar block (14).

8. The wellbore drill pipe centralizer according to claim 7, characterized in that, The cutting block (15) includes a cutting part (1501) facing the male threaded connector (1) and a guide part (1502) facing the working sleeve (5). The guide part (1502) has a conical structure on the side wall facing the male threaded connector (1), and the cutting part (1501) has a wedge-shaped structure.

9. The wellbore drill pipe centralizer according to claim 8, characterized in that, The guide part (1502) has an outer conical surface structure with an included angle of 30-45° on the side wall facing the male threaded connector (1), and the cutting part (1501) has an inner conical surface structure with an included angle of 20-45° on the side wall facing the inner wall of the well.

10. The wellbore drill pipe stabilizer according to any one of claims 1-9, characterized in that, The surface of the work sleeve (5) is coated with a non-stick coating.

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