A downhole tubing joint leak stoppage device and method

Abstract

The application discloses a leak-stopping device and method for downhole tubing joint leakage, a first pipe element is provided with a first plug at the bottom, a first piston is arranged in the first pipe element, a first telescopic driving device is connected to the top of the first piston, a pressurized medium containing cavity is formed between the first piston and the first plug, a hollow first inflatable sealing ring is arranged on the outer wall of the first pipe element close to the bottom, and the first inflatable sealing ring is communicated with the pressurized medium containing cavity; the bottom of the first plug is connected with a leak-stopping agent container, the bottom of the leak-stopping agent container is provided with a leak-stopping agent sprayer communicated with the leak-stopping agent container; a hollow second inflatable sealing ring is arranged right below the leak-stopping agent sprayer, the lower end of a second pipe element is communicated with the second inflatable sealing ring, and the upper end is communicated with the pressurized medium containing cavity; a noise detection device, a camera and a heating device are arranged on the second pipe element. The application can meet the plugging of the tubing joint leakage and does not affect the subsequent tubing pulling operation.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas development technology, and specifically relates to a leak-sealing device and method for downhole tubing joint leakage. Background Technology

[0002] Currently, there is no effective technology for sealing oil pipe leaks. In most cases, the oil pipe needs to be pulled out, so the pipe joint cannot be firmly bonded. To seal the leak path at the pipe joint, the solution must be to both stop the leak and not hinder the subsequent pipe pulling. In other words, the sealing agent must be able to penetrate along the leak path in the pipe joint threads without forming a large solidified layer inside the joint. If the sealing agent is squeezed into the annulus, a small amount may not be enough to prevent gas from leaking out of the pipe under high internal pressure. A larger solidified volume of sealing agent provides better sealing, but it will affect the subsequent pipe pulling operation. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a plugging device and method for leaking downhole tubing joints, which can satisfy the need to plug leaks in tubing joints without affecting subsequent tubing extraction operations.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] A leak-sealing device for downhole tubing joint leakage includes a first pipe fitting and a second pipe fitting. The first pipe fitting has a first plug at its bottom and a first piston inside. A first telescopic drive device is connected to the top of the first piston. A pressurizing medium receiving cavity is formed between the first piston and the first plug. A hollow first expandable sealing ring is fitted onto the outer wall of the first pipe fitting near its bottom, and the first expandable sealing ring communicates with the pressurizing medium receiving cavity. A leak-sealing agent container is connected to the bottom of the first plug, and a leak-sealing agent sprayer is located at the bottom of the leak-sealing agent container, communicating with the leak-sealing agent container. A hollow second expandable sealing ring is located directly below the leak-sealing agent sprayer. The lower end of the second pipe fitting communicates with the second expandable sealing ring, and the upper end of the second pipe fitting passes through the leak-sealing agent container and the first plug sequentially before communicating with the pressurizing medium receiving cavity. A noise detection device, a camera, and a heating device are installed on the second pipe fitting.

[0006] Furthermore, it also includes a third fitting located directly below the sealant sprayer. A second plug is positioned at the top of the third fitting, and a second expandable sealing ring is fitted onto the outer wall of the third fitting near its top. A first channel is formed on the second plug, with one end communicating with the second expandable sealing ring and the other end communicating with the second fitting. A second piston is installed inside the third fitting, forming a cleaning agent receiving cavity between the top of the second piston and the second plug. A second telescopic drive device is connected to the bottom of the second plug. A cavitation jet nozzle communicating with the cleaning agent receiving cavity is connected to the second plug, and the cavitation jet nozzle is upward-facing and bent outwards.

[0007] Furthermore, a cleaning agent return pipeline is provided from the top to the bottom of the second plug.

[0008] Furthermore, the first telescopic drive device, the second telescopic drive device, the noise detection device, the camera, the sealant sprayer, and the heating device are all connected to a controller.

[0009] Furthermore, the outer diameters of the first and second expandable sealing rings are 3mm to 6mm smaller than the inner diameter of the oil pipe to be plugged.

[0010] Furthermore, a cover plate is provided on the top of the first pipe fitting, and a connecting rod is connected to the cover plate.

[0011] A method for sealing leaks in downhole tubing joints, using the aforementioned sealing device, includes: lowering the sealing device into the tubing to be sealed; when a leak is detected at the tubing joint using a noise detection device; determining the specific leak location using a camera; pushing the first piston downwards using a first telescopic drive device to pressurize the pressurized medium in the pressurized medium container into the first expandable sealing ring, and pressing the second expandable sealing ring into the second expandable sealing ring through the second fitting; the first and second expandable sealing rings contacting the inner wall of the tubing to form a sealing space; spraying the sealing agent in the sealing agent container onto the leak location using a leak agent sprayer; and heating and curing the sprayed sealing agent using a heating device.

[0012] Furthermore, it also includes: after determining the specific leak location and sealing the oil pipe with the first expandable sealing ring and the second expandable sealing ring, using the second telescopic drive device to push the second piston upward, and spraying the cleaning agent in the cleaning agent containment chamber through the cavitation jet nozzle to the leak location to clean the leak location.

[0013] Furthermore, after the leak is plugged, the first piston is pulled upward using the first telescopic drive device to draw the pressurized medium in the first expandable sealing ring and the second expandable sealing ring back into the pressurized medium receiving cavity.

[0014] Furthermore, after cleaning is completed, the second piston is pulled down using the second telescopic drive device to draw the cleaning agent back into the cleaning agent receiving cavity through the cleaning agent return pipeline.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] This invention provides a leak-sealing device for downhole tubing joints. When a leak is detected in the tubing joint using a noise detection device, a camera determines the specific leak location. A first telescopic drive device pushes a first piston downward, forcing pressurized medium from the pressurized medium container into a first expandable sealing ring. A second expandable sealing ring is then pressed in through a second fitting. The first and second expandable sealing rings contact the inner wall of the tubing to form a sealed space. A leak-sealing agent sprayer applies the sealant from the sealant container to the leak location. A heating device heats and cures the sprayed sealant, thus completing the leak sealing. This invention ensures that a specific sealant penetrates along the leak path and then cures, sealing the leak. Because the leak-sealing device of this invention can accurately locate the specific leak location and precisely apply the sealant, very little sealant cures within the leak path of the tubing thread joint. Furthermore, a small amount of thread grease remains inside the threads, resulting in minimal sealant usage. The limited adhesion to the surface after curing does not affect the uncoupling operation after the tubing thread joint is removed.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments 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 from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a leak-sealing device for a downhole tubing joint according to the present invention.

[0020] In the diagram: 1-Noise detection device; 2-First expandable sealing ring; 3-Second telescopic drive device; 4-Camera; 5-Cleaning agent return pipeline; 6-Cleaning agent containment chamber; 7-Cavitation jet nozzle; 8-Leak sealant sprayer; 9-Heating device; 10-Connecting rod; 11-First telescopic drive device; 12-Pressurized medium containment chamber; 13-Leak sealant containment; 14-First fitting; 15-Second fitting; 16-Third fitting; 17-First piston; 18-First plug; 19-Second plug; 20-Second expandable sealing ring; 21-Second piston; 22-First channel; 23-Cover plate. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions 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.

[0022] As a specific embodiment of the present invention, such as Figure 1As shown, the present invention discloses a leak-sealing device for a downhole tubing joint, comprising a first fitting 14 and a second fitting 15. A first plug 18 is provided at the bottom of the first fitting 14, and a first piston 17 is provided inside the first fitting 14. A first telescopic drive device 11 is connected to the top of the first piston 17. A pressurizing medium receiving cavity 12 is formed between the first piston 17 and the first plug 18. Specifically, the pressurizing medium receiving cavity 12 contains a pressurizing medium. In this embodiment, the pressurizing medium is hydraulic oil. A hollow first expandable sealing ring 2 is fitted onto the outer wall of the first pipe fitting 14 near the bottom. The inner ring of the first expandable sealing ring 2 is fixed to the outer wall of the first pipe fitting 14 near the bottom. The first expandable sealing ring 2 communicates with the pressurizing medium receiving cavity 12. Specifically, a channel is provided on the first plug 18 to connect the first expandable sealing ring 2 to the pressurizing medium receiving cavity 12. After the pressurizing medium in the pressurizing medium receiving cavity 12 enters the first expandable sealing ring 2, the first expandable sealing ring 2 expands, achieving a seal with the inner wall of the oil pipe. A sealing agent container 13 is connected to the bottom of the first plug 18. A sealing agent sprayer 8 is provided at the bottom of the sealing agent container 13 and communicates with the sealing agent container 13. Specifically, the sealing agent sprayer 8 contains sealing agent. The nozzle end of the sealing agent sprayer 8 is in the same vertical plane as the outer wall of the first pipe fitting 14. The sealing agent is sprayed onto the location where sealing is required through the sealing agent sprayer 8. A hollow second expandable sealing ring 20 is positioned directly below the sealant sprayer 8. The lower end of the second pipe 15 is connected to the second expandable sealing ring 20, and the upper end of the second pipe 15 passes through the sealant container 13 and the first plug 18 in sequence before connecting to the pressurizing medium container 12. The pressurizing medium in the pressurizing medium container 12 enters the second expandable sealing ring 20 through the second pipe 15, causing the second expandable sealing ring 20 to expand and achieve a seal with the inner wall of the oil pipe. A noise detection device 1, a camera 4, and a heating device 9 are installed on the second pipe 15. Specifically, the noise detection device 1 detects the leak location, and the image captured by the camera 4 is transmitted to the ground for manual identification to determine the specific leak location (of course, an artificial intelligence identification method can also be used for intelligent identification). After the sealant is sprayed, the heating device 9 heats and cures the sealant. Preferably, the outer diameter of the first expandable sealing ring 2 and the second expandable sealing ring 20 is 3mm to 6mm smaller than the inner diameter of the tubing to be plugged. This avoids the plugging device getting stuck downhole and ensures that the plugging device can establish a sealing space in the tubing string with a small expansion amount.

[0023] Based on the above implementation methods, as a more preferred implementation method, such as... Figure 1As shown, the leak-sealing device for a downhole tubing joint of the present invention further includes a third pipe fitting 16, which is located directly below the leak-sealing agent sprayer 8. A second plug 19 is provided at the top of the third pipe fitting 16. The inner ring of the second expandable sealing ring 20 is fixedly sleeved on the outer wall of the third pipe fitting 16 near the top. A first channel 22 is provided on the second plug 19. One end of the first channel 22 is connected to the second expandable sealing ring 20, and the other end of the first channel 22 is connected to the second pipe fitting 15. Specifically, the pressurizing medium in the pressurizing medium receiving cavity 12 enters the second expandable sealing ring 20 through the second pipe fitting 15 and the first channel 22. A second piston 21 is provided inside the third pipe fitting 16. A cleaning agent receiving cavity 6 is formed between the top of the second piston 21 and the second plug 19. A second telescopic drive device 3 is connected to the bottom of the second plug 19. A cavitation jet nozzle 7, which is connected to the second plug 19 and communicates with the cleaning agent receiving cavity 6, is connected to the second plug 19. The cavitation jet nozzle 7 is upward and bent outward. Specifically, the cleaning agent containing the cleaning agent cavity 6 is used to locate the leak. After the leak location is found, the second piston 21 is pushed upward by the second telescopic drive device 3 to spray the cleaning agent in the cleaning agent cavity 6 through the cavitation jet nozzle 7 to the leak location for cleaning. During cleaning, the main focus is on cleaning the thread grease between the internal and external threaded joints, ensuring that the applied sealant can bond well with the surface of the oil pipe substrate, thereby increasing the sealing ability.

[0024] Preferred, such as Figure 1 As shown, a cleaning agent return pipeline 5 is provided from the top to the bottom of the second plug 19. After cleaning, the second piston 21 is pulled down by the second telescopic drive device 3 to draw the cleaning agent between the first expandable sealing ring 2 and the second expandable sealing ring 20 back into the cleaning agent receiving cavity 6.

[0025] This invention connects a first telescopic drive device 11, a second telescopic drive device 3, a noise detection device 1, a camera 4, a sealant sprayer 8, and a heating device 9 to a controller. The controller controls the sealant application process. Specifically, after the noise detection device 1 detects a leak and the camera 4 locates the leak, the controller controls the first telescopic drive device 11 to push the first piston 17 downwards, causing the first expandable sealing ring 2 and the second expandable sealing ring 20 to expand and seal against the inner wall of the oil pipe. After sealing, the controller controls the second telescopic drive device 3 to push the second piston 21, causing the cleaning agent in the cleaning agent chamber 6 to be sprayed onto the leak location through the cavitation jet nozzle 7, thus cleaning the leak. After cleaning, the sealant sprayer 8 is controlled to spray sealant onto the leaking oil pipe joint to seal it. After spraying the sealant, the heating device 9 is controlled to heat and cure the sealant.

[0026] Preferred, such as Figure 1As shown, the present invention has a cover plate 23 on the top of the first pipe fitting 14, and a connecting rod 10 is connected to the cover plate 23. The connecting rod 10 and the rope are used to lower the leak-sealing device into the oil pipe.

[0027] This invention discloses a method for sealing leaks in downhole tubing joints, specifically comprising: lowering a sealing device into the tubing to be sealed; when a leak is detected in the tubing joint using a noise detection device 1; determining the specific leak location using a camera 4; pushing a first piston 17 downward using a first telescopic drive device 11 to pressurize the pressurized medium in the pressurized medium receiving chamber 12 into a first expandable sealing ring 2; and pressing a second expandable sealing ring 20 into the first expandable sealing ring 2 through a second fitting 15; the first expandable sealing ring 2 and the second expandable sealing ring 20 contacting the inner wall of the tubing to form a sealing space; after determining the specific leak location and sealing the tubing using the first expandable sealing ring 2 and the second expandable sealing ring 20; pushing a second piston 21 upward using a second telescopic drive device 3 to spray cleaning agent in the cleaning agent receiving chamber 6 through a cavitation jet nozzle 7 onto the leak location; rotating once to clean the leak location; and after cleaning, pulling the second piston 21 downward using the second telescopic drive device 3 to draw the cleaning agent back into the cleaning agent receiving chamber 6 through the cleaning agent return line 5. Finally, the sealant in the sealant container 13 is sprayed onto the leak location using the sealant sprayer 8, and the sealant is heated and cured using the heating device 9 to complete the sealant application. After the sealant application is completed, the first piston 17 is pulled upward by the first telescopic drive device 11 to draw the pressurized medium in the first expandable sealing ring 2 and the second expandable sealing ring 20 back into the pressurized medium container 12, and the process continues to search for the next leak location and perform the above sealant operation.

[0028] In this embodiment, the cleaning pressure during cleaning using the cavitation jet nozzle 7 is not less than 10 MPa, and the highest vibration frequency of the jet pressure achievable by the cavitation jet nozzle 7 on the surface of the threaded joint is not less than 50 kHz.

[0029] In this embodiment, a high-temperature curing sealant with low viscosity and good penetration is selected, such as low-viscosity epoxy resin, acrylic resin, polysilazane, etc. It is applied to the upper side of the leak gap using a sealant sprayer 8 and gradually penetrates into the leak channel.

[0030] In this embodiment, the heating device 9 is a resistance heating device. In order to ensure that the sealing agent flows into the leakage channel as much as possible, the heating rate is controlled to be no more than 10℃ / m22n. After reaching the set curing temperature, the heating is stopped and maintained for a certain time according to the resin curing requirements.

[0031] In this embodiment, before using the leak-sealing device, it is recommended to use other detection methods to preliminarily determine the location of the oil pipe leak, and then apply the leak-sealing device of the present invention to seal the oil pipe joint leak in order to speed up the construction. When approaching the estimated leak location, the lowering speed of the leak-sealing device is controlled within 0.5m / s, and the noise detection device 1 is turned on to detect the noise signal in the oil pipe to determine whether a leak has occurred.

[0032] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, 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, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A leak-sealing device for downhole tubing joint leakage, characterized in that, The system includes a first pipe fitting (14) and a second pipe fitting (15). The bottom of the first pipe fitting (14) is provided with a first plug (18). A first piston (17) is disposed inside the first pipe fitting (14). The top of the first piston (17) is connected to a first telescopic drive device (11). A pressurizing medium receiving cavity (12) is formed between the first piston (17) and the first plug (18). A hollow first expandable sealing ring (2) is fitted onto the outer wall of the first pipe fitting (14) near its bottom. The first expandable sealing ring (2) communicates with the pressurizing medium receiving cavity (12). The bottom of the first plug (18) is connected to... There is a sealant container (13), and a sealant sprayer (8) connected to the sealant container (13) is provided at the bottom of the sealant container (13); a hollow second expandable sealing ring (20) is provided directly below the sealant sprayer (8); the lower end of the second pipe (15) is connected to the second expandable sealing ring (20); the upper end of the second pipe (15) passes through the sealant container (13) and the first plug (18) in sequence and is connected to the pressurizing medium receiving chamber (12); a noise detection device (1), a camera (4) and a heating device (9) are provided on the second pipe (15).

2. The leak-sealing device for downhole tubing joint leakage according to claim 1, characterized in that, It also includes a third fitting (16), which is located directly below the sealant sprayer (8). The top of the third fitting (16) is provided with a second plug (19). The second expandable sealing ring (20) is sleeved on the outer wall of the third fitting (16) near the top. The second plug (19) is provided with a first channel (22). One end of the first channel (22) is connected to the second expandable sealing ring (20), and the other end of the first channel (22) is connected to the second fitting (15). The third fitting (16) is provided with a second piston (21). The top of the second piston (21) and the second plug (19) form a cleaning agent receiving cavity (6). The bottom of the second plug (19) is connected with a second telescopic drive device (3). The second plug (19) is connected with a cavitation jet nozzle (7) that is connected to the cleaning agent receiving cavity (6). The cavitation jet nozzle (7) is upward and bent outward.

3. A leak-sealing device for downhole tubing joint leakage according to claim 2, characterized in that, The top of the second plug (19) is provided with a cleaning agent return line (5) extending from the bottom.

4. A leak-sealing device for downhole tubing joint leakage according to claim 2, characterized in that, The first telescopic drive device (11), the second telescopic drive device (3), the noise detection device (1), the camera (4), the sealant sprayer (8), and the heating device (9) are all connected to a controller.

5. A leak-sealing device for downhole tubing joint leakage according to claim 1, characterized in that, The outer diameters of the first expandable sealing ring (2) and the second expandable sealing ring (20) are 3mm to 6mm smaller than the inner diameter of the oil pipe to be plugged.

6. A leak-sealing device for downhole tubing joint leakage according to claim 1, characterized in that, The top of the first pipe fitting (14) is provided with a cover plate (23), and a connecting rod (10) is connected to the cover plate (23).

7. A method for sealing leakage at a downhole tubing joint, characterized in that, The application of the leak-sealing device according to any one of claims 1 to 6 includes: lowering the leak-sealing device into the oil pipe to be sealed; when the noise detection device (1) detects a leak in the oil pipe joint, determining the specific leak location using the camera (4); pushing the first piston (17) downward using the first telescopic drive device (11) to press the pressurizing medium in the pressurizing medium receiving chamber (12) into the first expandable sealing ring (2), and pressing the second expandable sealing ring (20) into the second pipe fitting (15); the first expandable sealing ring (2) and the second expandable sealing ring (20) contacting the inner wall of the oil pipe to form a sealing space; spraying the leak-sealing agent in the leak-sealing agent receiving chamber (13) onto the leak location using the leak-sealing agent sprayer (8); and heating and curing the sprayed leak-sealing agent using the heating device (9).

8. A method for sealing leakage at a downhole tubing joint according to claim 7, characterized in that, The leak-sealing device is the leak-sealing device according to claim 2; after determining the specific leak location and sealing the oil pipe with the first expandable sealing ring (2) and the second expandable sealing ring (20), the second piston (21) is pushed upward by the second telescopic drive device (3) to spray the cleaning agent in the cleaning agent containment chamber (6) through the cavitation jet nozzle (7) to the leak location to clean the leak location.

9. A method for sealing leakage at a downhole tubing joint according to claim 8, characterized in that, After the leak is plugged, the first piston (17) is pulled upward by the first telescopic drive device (11) to draw the pressurized medium in the first expandable sealing ring (2) and the second expandable sealing ring (20) back into the pressurized medium receiving cavity (12).

10. A method for sealing leakage at a downhole tubing joint according to claim 8, characterized in that, The leak-sealing device is the leak-sealing device according to claim 3; after cleaning, the second piston (21) is pulled down by the second telescopic drive device (3) to draw the cleaning agent back into the cleaning agent receiving cavity (6) through the cleaning agent return pipeline (5).

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