A downhole drilling while plugging tool and a plugging method

Abstract

The application belongs to the technical field of oilfield downhole operation sealing, and discloses a downhole drilling plugging tool and a plugging method, wherein the lower end of the antenna device part is connected with the inner wall of the outer pipe through threads, the upper end of the electric control device is connected with the inner part of the outer pipe through threads, the inner wall of the lower end of the electric control device is connected with the outer wall of the upper end of the power device through threads, the inner wall of the upper end of the outer circulating sleeve is connected with the outer wall of the lower end of the power device through threads, the outer wall of the sliding sleeve is slidingly connected with the inner part of the outer circulating sleeve, the upper ball valve seat is only in contact with the reversing ball valve, and the outer wall of the joint is connected with the inner wall of the outer pipe through threads. The application can realize downhole non-drilling plugging in the case of leakage in the drilling process, reduce well control risk and shorten the drilling cycle, and the plugging vortex generated by the jet flow can reinforce the well wall.

Description

Technical Field

[0001] This invention relates to the field of wellbore sealing technology, specifically to a wellbore plugging tool and method. Background Technology

[0002] Drilling is an essential part of the exploration and development of resources such as oil and natural gas. However, a common technical challenge in drilling is lost circulation. Loss circulation refers to the phenomenon of drilling fluid or other working fluids leaking into the formation during drilling. It not only results in the loss of a large amount of drilling fluid and drilling time, but can also cause complex situations and major accidents such as well collapse, stuck pipe, and blowouts, leading to huge losses for the drilling project.

[0003] Well leakage typically requires three conditions: first, the existence of a leakage channel in the formation that allows drilling fluid to flow, such as pores, fractures, or caverns; second, a positive pressure differential between the wellbore and the formation that allows drilling fluid to flow through the leakage channel; and third, the existence of a space in the formation capable of holding a certain volume of drilling fluid. When all three conditions are met simultaneously, well leakage occurs. Well leakage is a common and complex phenomenon in oilfield drilling, affecting safe oil well production and severely restricting the development of petroleum drilling technology.

[0004] To address well leakage problems, the industry has developed various plugging technologies and methods. Traditional plugging methods often require stopping drilling operations after leakage is discovered, followed by sealing with specific plugging materials and tools. This method is not only inefficient but also increases the risks and costs of the operation.

[0005] In recent years, drilling-while-fuse technology has gradually become an effective means of solving well leakage problems. The basic principle of drilling-while-fuse technology is to plug leaks in the downhole fracturing section in real time during the drilling process using specific tools and methods. This method can significantly improve the efficiency of drilling operations, reduce plugging costs, and better ensure operational safety.

[0006] Existing wellbore leakage plugging technologies mainly include methods such as spraying specially reinforced concrete to form a tough tunnel gel and using downhole tools to divert a small portion of the pumped drilling fluid and apply it as a rotating jet to the leaking wellbore to form an impermeable wall layer. While these technologies have solved the wellbore leakage problem to some extent, they still have some shortcomings. For example, spraying specially reinforced concrete may cause additional damage to the wellbore, and the method of using drilling fluid to form an impermeable wall layer is more effective for low-velocity permeable and fractured leakage, but less effective for high-velocity leakage.

[0007] The typical procedure for plugging leaks involves pulling the drill string, replacing the specialized plugging tool, and then injecting plugging fluid to seal the leak. However, in deep and ultra-deep wells where leaks occur, frequent pulling of the drill string to replace the plugging tool can significantly extend non-productive operating time and severely impact drilling efficiency.

[0008] Therefore, developing a more efficient, safe, and economical downhole leakage plugging tool and method is of great significance for improving drilling efficiency, reducing operating costs, and ensuring operational safety. This patent is proposed against this backdrop, aiming to provide a novel downhole leakage plugging tool and method to better address well leakage problems during drilling.

[0009] The CN109931019A drilling circulating plugging device includes: an outer cylinder with at least one bypass nozzle; an open-ended sliding sleeve axially movable within the outer cylinder, capable of plugging at least one bypass nozzle, the open-ended sliding sleeve having a fluid flow orifice communicating with the bypass nozzle, a ball catcher and a ball seat connected inside the open-ended sliding sleeve, the ball catcher located at the upper end of the ball seat, and the fluid flow orifice located above the ball catcher; and a ball basket connected within the outer cylinder, located below the open-ended sliding sleeve, the ball basket having at least one set of open slots. This tool can effectively solve the technical problems of drilling leakage plugging and cuttings bed cleaning during drilling; however, the tool's structure is relatively complex, affecting drilling efficiency. Summary of the Invention

[0010] To overcome the shortcomings of existing technologies, this invention improves the success rate of plugging leaks and increases drilling efficiency through a downhole drilling plugging technology. This technology can achieve plugging without drilling, reduce well control risks, and shorten the drilling cycle.

[0011] The technical solution adopted by this invention to solve its technical problem is:

[0012] A downhole drilling plugging tool includes an antenna device whose lower end is threaded to the inner wall of an outer tube, an electrical control device whose upper end is threaded to the inside of the outer tube, an electrical control device whose lower inner wall is threaded to the upper outer wall of a power device, an outer circulation sleeve whose upper inner wall is threaded to the lower outer wall of a power device, a sliding sleeve whose outer wall is slidably connected to the inside of the outer circulation sleeve, an upper ball valve seat that only contacts a reversing ball valve, and a connector whose outer wall is threaded to the inner wall of the outer tube.

[0013] Furthermore, the leak-stopping tool used during drilling is electrically controlled.

[0014] Furthermore, the leak sealing tool is connected below the drill collar.

[0015] Furthermore, the lower end of the leak sealing tool is connected to the drill bit.

[0016] Furthermore, the leak-sealing tool is used in combination with the leak-sealing nozzle.

[0017] Furthermore, the sealing nozzle is selected based on the actual sealing agent.

[0018] Furthermore, when using the drilling plugging tool, an open-hole annulus is provided on the inner side of the well wall.

[0019] A downhole plugging method involves selecting a plugging agent based on the actual conditions of the lost formation, choosing a corresponding plugging nozzle based on the actual plugging agent, then dropping a plugging electrical control signal ball with the corresponding signal, switching the plugging tool to plugging mode, and after the plugging work is completed, dropping a drilling electrical control signal ball, switching the plugging tool to drilling mode, and continuing drilling work.

[0020] Specifically, when a leakage is discovered during construction, the first step is to stop the operation of the drilling-while-drilling (DWD) plugging tool. A plugging electrical control signal ball is then thrown into the DWD plugging tool. The antenna device identifies the plugging electrical control signal, activates the DWD plugging mode, and transmits the signal to the electrical control unit. The reversing ball valve is then closed, and the power unit is activated to control the sliding sleeve to move downwards, aligning the appropriate plugging nozzle with the bypass hole on the sliding sleeve. Subsequently, plugging agent is injected into the drill pipe, allowing the plugging fluid to be injected from the plugging nozzle into the lost formation, sealing the leakage channel. Finally, after the sealing work is completed, a drilling electrical control signal ball is thrown back into the tool. The antenna device identifies the drilling electrical control signal, and the signal is transmitted to the electrical control unit. The drilling mode of the DWD plugging tool is then activated again, the reversing ball valve is opened, and the power unit is activated to control the sliding sleeve to move upwards, continuing the drilling operation.

[0021] Furthermore, the selection of sealing agents is based on the analysis of rock crack opening patterns in conjunction with rock experimental results.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention can achieve downhole plugging in the event of leakage during drilling, thereby reducing well control risks and shortening the drilling cycle. Furthermore, the plugging vortex generated by the jet can reinforce the wellbore. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is a schematic diagram of the working process of a drilling leak sealing tool;

[0026] Figure 2 A simplified diagram of a leak-stopping tool used while drilling.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Wellbore; 2. Drill collar; 3. Drilling plugging tool; 4. Plugging nozzle; 5. Loss zone; 6. Open hole annulus; 7. Drill bit; 8. Antenna device; 9. Electrical control device; 10. Outer tube; 11. Power unit; 12. External circulation sleeve; 13. Sliding sleeve; 14. Upper ball valve seat; 15. Reversing ball valve; 16. Connector. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] Based on the actual geological conditions of the block, and to ensure drilling efficiency, a plugging-while-drilling (MWD) solution was selected. This WMD plugging tool has been modified in its mode switching between drilling and plugging, changing from a traditional mechanical switching to an electronically controlled switching. When encountering lost circulation during drilling, a suitable plugging agent is selected based on the actual conditions of the lost circulation formation. The corresponding nozzle is then chosen, and the corresponding plugging electronic control signal ball is deployed, switching the tool to plugging mode. After the plugging work is completed, the drilling electronic control signal ball is deployed, switching the tool back to drilling mode and continuing drilling operations.

[0032] Tool Connection Instructions: The leak-sealing tool 3 is connected below the drill collar 2. The lower end of the antenna device 8 is connected to the inner wall of the outer tube 10 by a thread. The upper end of the electronic control device 8 is connected to the inside of the outer tube 10 by a thread. The lower inner wall of the electronic control device 9 is connected to the upper outer wall of the power device 11 by a thread. The upper inner wall of the outer circulation sleeve 12 is connected to the lower outer wall of the power device 11 by a thread. The outer wall of the sliding sleeve 13 only contacts the inside of the outer circulation sleeve 12 and does not constitute a fixing function; it is a sliding connection. The upper ball valve seat 14 only contacts the reversing ball valve 15. The outer wall of the connector 16 is connected to the inner wall of the outer tube 10 by a thread.

[0033] Production conditions: Cementing operation.

[0034] The usage method is as follows:

[0035] When leakage is discovered during construction, the first step is to stop the operation of the leak-proof tool 3. Based on the leakage situation in the prone-to-leakage area and the results of rock experiments, analyze the rock fracture opening pattern and select a suitable plugging agent system. Then, a plugging electrical control signal ball is thrown into the leak-proof tool 3. The antenna device 8 identifies the plugging electrical control signal, activates the plugging mode of the leak-proof tool 3, transmits the signal to the electrical control device 9, closes the reversing ball valve 15, and opens the power unit 11 to control the sliding sleeve 13 to move downwards, thus placing the suitable plugging agent. The nozzle 4 is aligned with the bypass hole on the sleeve 13; then, the plugging agent is injected into the drill pipe, and the plugging liquid is injected from the plugging nozzle 4 into the lost formation 5 to seal the lost channel; after the sealing work is completed, the drilling control signal ball is thrown back into the tool, the antenna device 8 identifies the drilling control signal, and transmits the signal to the control device 9, restarts the drilling mode of the plugging tool 3, opens the reversing ball valve 15, and opens the power unit 11 to control the sleeve 13 to move upward and continue to complete the drilling work.

[0036] Example 2

[0037] Based on the actual geological conditions of a certain area, the narrow density window of the block leads to frequent wellbore instability in horizontal wells, which can easily cause drilling accidents such as well kicks, well collapses, and stuck pipe. For emergency accidents, it is necessary to quickly implement plugging measures for the lost formation. However, conventional plugging methods require pulling out the drilling tools before plugging, which not only prolongs the drilling cycle but also increases drilling risks. Therefore, it is proposed to use the plugging while drilling method. The plugging vortex generated by the jet of the plugging tool while drilling will form a solid mud cake on the wellbore. This mud cake has low permeability, which can effectively reduce the intrusion of drilling fluid into the formation, reduce the risk of secondary loss of the wellbore, and better protect the oil and gas reservoir.

[0038] During the drilling process, the drilling plugging tool 3 initially operates in drilling mode, at which time the reversing ball valve 15 is in the open state. When leakage occurs, the drilling plugging tool 3 is immediately stopped. The rock texture characteristics experiment, mineral composition analysis and physical property parameter test are carried out on the block. The internal mechanism of its collapse and leakage is analyzed. Based on the actual leakage situation, the rock fracture opening law is analyzed in combination with the rock test results. A suitable plugging agent system is selected and a plugging nozzle 4 of appropriate size is screened.

[0039] Subsequently, a leakage control signal ball corresponding to the signal is thrown into the drilling plugging tool 3. The signal recognition system in the antenna device 8 identifies the plugging signal ball, activates the power unit 11 to control the sliding sleeve 13 to move downward, closes the reversing ball valve 15, aligns the plugging nozzle 4 with the bypass hole on the sliding sleeve 13, and activates the plugging mode. Furthermore, the signal ball's recognition function has been further upgraded. For different geological leakage situations, we need to select plugging agent formulations of different densities and plugging agent particle sizes. Through analysis of the leakage situation, different signal balls can be thrown, corresponding to different sizes of plugging nozzles 4 aligned with the bypass hole of the sliding sleeve, to achieve the best plugging effect.

[0040] Subsequently, a plugging agent is injected into the drill pipe, and the plugging fluid is ejected from the plugging nozzle 4 in a jet manner, allowing the plugging material in the plugging agent to enter the lost zone 5, sealing the lost channel. Furthermore, due to the eddy effect, the plugging fluid ejected from the nozzle will form a solid mud cake on the well wall 1, further improving the well wall stability, reducing the risk of secondary loss, and better protecting the oil and gas reservoir.

[0041] Finally, after the sealing work is completed, the drilling control signal ball is thrown back into the drilling plugging tool 3. The antenna device 8 identifies the drilling tag signal and transmits the signal to the control device 9. The power device 11 is turned on to control the sliding sleeve 13 to move upward, the reversing ball valve 15 is opened, the drilling mode of the drilling plugging tool 3 is turned on again, and the drill bit 7 continues to complete the drilling work.

[0042] The terms "comprising," "including," or any other variations thereof used in this specification are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. It should be noted that, without conflict, embodiments and features in the embodiments of this invention can be combined with each other. This invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or substitution of these aspects and / or embodiments. Moreover, each aspect and / or embodiment of the invention can be used alone or in combination with one or more other aspects and / or embodiments thereof.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A downhole plugging tool, characterized in that, The lower end of the antenna device (8) is connected to the inner wall of the outer tube (10) by a thread. The upper end of the electronic control device (8) is connected to the inside of the outer tube (10) by a thread. The lower inner wall of the electronic control device (9) is connected to the upper outer wall of the power device (11) by a thread. The upper inner wall of the outer circulation sleeve (12) is connected to the lower outer wall of the power device (11) by a thread. The outer wall of the sliding sleeve (13) is slidably connected to the inside of the outer circulation sleeve (12). The upper ball valve seat (14) is only in contact with the reversing ball valve (15). The outer wall of the connector (16) is connected to the inner wall of the outer tube (10) by a thread.

2. The downhole plugging tool according to claim 1, characterized in that, The leak sealing tool (3) is electrically controlled.

3. The downhole plugging tool according to claim 1, characterized in that, The leak sealing tool (3) is connected below the drill collar (2).

4. The downhole plugging tool according to claim 1, characterized in that, The lower end of the leak sealing tool (3) is connected to the drill bit (7).

5. The downhole plugging tool according to claim 1, characterized in that, The leak-stopping tool (3) and the leak-stopping nozzle (4) are used together.

6. The downhole plugging tool according to claim 5, characterized in that, The sealing nozzle (4) is selected according to the actual sealing agent.

7. The downhole plugging tool according to claim 1, characterized in that, When the drilling plugging tool (3) is used, an open hole annulus (6) is provided on the inner side of the well wall (1).

8. A downhole plugging method, characterized in that, Based on the actual situation of the lost formation, the plugging agent is selected, and the corresponding plugging nozzle (4) is selected according to the actual plugging agent. Then, the plugging electrical control signal ball with the corresponding signal is thrown, and the plugging tool (3) is switched to plugging mode. After the plugging work is completed, the drilling electrical control signal ball is thrown, and the plugging tool (3) is switched to drilling mode to continue drilling work.

9. The downhole plugging method according to claim 8, characterized in that, The selection of sealing agents is based on the analysis of rock crack opening patterns using combined rock experimental results.

10. The downhole plugging method according to claim 8, characterized in that, After a leak is discovered during construction, the first step is to stop the working of the leak-stopping tool (3) while drilling, throw a leak-stopping electrical control signal ball into the leak-stopping tool (3), and have the leak-stopping electrical control signal identified by the antenna device (8). Then, the leak-stopping mode of the leak-stopping tool (3) while drilling is turned on, and the signal is transmitted to the electrical control device (9). The reversing ball valve (15) is closed, and the power device (11) is turned on to control the sliding sleeve (13) to move down and align the appropriate leak-stopping nozzle (4) with the bypass hole on the sliding sleeve (13). Subsequently, a plugging agent is injected into the drill pipe, and the plugging liquid is injected from the plugging nozzle (4) into the lost formation (5) to seal the lost channel. After the sealing work is completed, the drilling control signal ball is thrown back into the tool. The antenna device (8) identifies the drilling control signal and transmits the signal to the control device (9). The drilling mode of the plugging tool (3) is restarted, the reversing ball valve (15) is opened, and the power unit (11) is turned on to control the sliding sleeve (13) to move upward and continue to complete the drilling work.

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