Oil well plugging device and grouting method

Abstract

This invention discloses an oil well plugging device, including a base, a slurry mixing tank fixedly connected to the top of the base, a feeding port on the top of the slurry mixing tank, and a base slurry injection port on one side of the slurry mixing tank. A stirring assembly is installed inside the slurry mixing tank. A mixing pump and a plugging pump are respectively installed on both sides of the slurry mixing tank on the top of the base. The mixing pump is connected to the slurry mixing tank via a pipeline, and a first butterfly valve is installed on the pipeline connecting the two. The output end of the mixing pump is connected to a mixer via a pipeline, and a second butterfly valve is installed on this pipeline. The mixer is connected to the slurry mixing tank via a pipeline. The input end of the plugging pump is connected to the slurry mixing tank via a pipeline, and a third butterfly valve is installed on the pipeline connecting the two. The invention also discloses a method for injecting plugging slurry using this device. This invention solves the problems of poor plugging effect and long operation time caused by using mud pumps and solids control systems for mixing and injecting plugging slurry in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas drilling and production equipment technology, and relates to an oil well plugging device, as well as a plugging grout injection method using the device. Background Technology

[0002] During oil extraction, wellbore leakage can occur when drilling fluid or other media (such as cement slurry) leaks into formation pores and fractures during downhole operations such as drilling, cementing, testing, or workover. The conventional approach is to inject a high-viscosity, large-particle, high-solids-content plugging slurry into the well to seal the leakage.

[0003] However, existing drilling equipment lacks a dedicated device for injecting plugging slurry. Current production processes utilize drilling fluid injection mud pumps and solids control systems for mixing and injecting plugging slurry. Because drilling fluid and plugging slurry have different compositions, mixing them can reduce plugging effectiveness. Furthermore, using a single mud tank within the solids control system makes it difficult to mix high-viscosity plugging materials, and after plugging, the solids control system needs cleaning and drilling fluid re-mixing, significantly extending operation time. Therefore, a plugging device specifically designed for mixing and injecting plugging slurry is needed. Summary of the Invention

[0004] The purpose of this invention is to provide an oil well plugging device to accommodate the injection of plugging slurry with high viscosity, large particles, and high solids content.

[0005] The technical solution adopted in this invention includes a base, a slurry mixing tank fixedly connected above the base, a feeding port on the top of the slurry mixing tank, a base slurry injection port on one side of the slurry mixing tank, a stirring assembly inside the slurry mixing tank, a mixing pump and a plugging pump respectively installed on both sides of the slurry mixing tank above the base, the mixing pump being connected to the slurry mixing tank through a pipe, and a first butterfly valve being installed on the pipe connecting the two, the output end of the mixing pump being connected to a mixer through a pipe, and a second butterfly valve being installed on the pipe, the mixer being connected to the slurry mixing tank through a pipe, and the input end of the plugging pump being connected to the slurry mixing tank through a pipe, and a third butterfly valve being installed on the pipe connecting the two.

[0006] The invention is further characterized by: The output end of the plugging pump is connected to a first gate valve via a pipeline, and the plugging pump is fixedly connected to a direct drive motor.

[0007] A drain valve is provided on the side wall of the mixing tank near the base. An inclined bottom plate that slopes toward the drain valve is fixedly connected to the bottom of the inner wall of the mixing tank. The inclined bottom plate and the inner wall of the mixing tank are connected by an arc.

[0008] The mixing assembly includes a permanent magnet direct-drive agitator installed inside the mixing tank, and a pneumatic agitator fixedly connected to the bottom of the inner wall of the mixing tank.

[0009] A cleaning pipe is provided between the mixing pump and the first butterfly valve. A fourth butterfly valve is fixedly connected to the cleaning pipe. A branch pipe is provided on the pipe connecting the mixing pump and the second butterfly valve, which is connected to a reducing joint. The reducing joint is connected to a first ball valve through a pipe. A second gate valve is connected to the pipe connecting the output end of the plugging pump and the first gate valve through a branch pipe. A cleaning gun is fixedly connected to the top of the inner wall of the slurry tank. The second gate valve and the first ball valve merge into a pipe connected to the cleaning gun, and a second ball valve is provided on this pipe.

[0010] The pipeline connecting the mixing pump and the second butterfly valve is connected to the input end of the plugging pump via a branch pipeline, and a fifth butterfly valve is installed on this pipeline. A safety valve is connected between the second gate valve and the slurry mixing tank via a branch pipe, and the safety valve is connected to the slurry mixing tank via a pipeline.

[0011] A loading platform is fixedly connected above the mixing tank. An anti-slip grid is fixedly connected to the upper surface of the loading platform, and an opening is provided at the position corresponding to the feeding port of the loading platform. A guardrail is rotatably connected around the loading platform, and the guardrail can rotate to one side of the loading platform. A lighting lamp is fixedly connected to the loading platform.

[0012] Several telescopic rods perpendicular to the base are fixedly connected around the mixing pump on the base surface. A truss is fixedly connected to the top of the telescopic rod, and a hoisting rail is fixedly connected to the bottom of the truss. An electric hoist is slidably connected to the hoisting rail, and an electric bag breaker is fixedly connected to one side of the feeding port.

[0013] Another technical solution adopted in this invention is to use the grouting method of the above system, specifically implemented according to the following steps: Step 1: Keep all valves closed, then inject base slurry into the mixing tank through the base slurry injection port, and start the mixing assembly. After that, add the sealing material into the mixing tank through the feeding port. Step 2: Start the mixing pump and mixer and open the first and second butterfly valves, and add the additives from the mixer to mix with the base slurry and the sealing material to form the sealing slurry; Step 3: After the sealing grout is prepared, close the first and second butterfly valves and turn off the mixing pump and mixer. Then open the third butterfly valve and the sealing pump to inject grout.

[0014] The beneficial effects of this invention are: 1. This invention separates the mixing pump for the mixed plugging slurry and the grouting pump for grouting on both sides of the slurry mixing tank, thus separating the plugging agent filling area and the high-pressure pumping area for the operators, making the operators safer. At the same time, the plugging device involved in this invention is a skid-mounted integrated design, which is easy to transport, and one device can meet the grouting needs of well leaks in different locations.

[0015] 2. This invention combines pneumatic and mechanical stirring, enabling stirring even in dead corners of the tank. This promotes effective mixing of the base slurry and the sealing agent, making the proportions of each component in the actual prepared sealing slurry closer to the expected values, improving the sealing effect and reducing material waste.

[0016] 3. The present invention, through the setting of a safety valve and a fifth butterfly valve, can assist the normal operation of the plugging pump when the wellhead pressure is too high or the viscosity of the plugging slurry is too high, so that the plugging pump can stably deliver the plugging slurry into the oil well. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the oil well plugging device of the present invention; Figure 2 This is a schematic diagram of the pipeline connection structure of the oil well plugging device of the present invention; Figure 3 This is a top view of the oil well plugging device of the present invention; Figure 4 This is a schematic diagram of the slurry mixing tank in this invention; Figure 5 yes Figure 4 Enlarged structural diagram at point A; Figure 6 This is a schematic diagram of the structure at the bottom of the inner wall of the slurry mixing tank in this invention.

[0018] In the diagram: 1. Base; 2. Mixing tank; 3. Feed port; 4. Base slurry injection port; 5. Mixing assembly; 6. Mixing pump; 7. Leak-stopping pump; 8. First butterfly valve; 9. Second butterfly valve; 10. Mixer; 11. Third butterfly valve; 12. First gate valve; 13. Direct drive motor; 14. Drain valve; 15. Inclined base plate; 16. Permanent magnet direct drive agitator; 17. Pneumatic agitator; 18. Cleaning pipe; 19. Fourth butterfly valve; 20. Reducing joint; 21. First ball valve; 22. Second gate valve; 23. Cleaning gun; 24. Second ball valve; 25. Fifth butterfly valve; 26. Safety valve; 27. Loading platform; 28. Anti-slip grid; 29. ​​Guardrail; 30. Lighting; 31. Telescopic pole; 32. Truss; 33. Lifting rail; 34. Electric hoist; 35. Electric bag breaker. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1: like Figure 1 , Figure 2 and Figure 3As shown, the system includes a base 1, a mixing tank 2 fixedly connected to the top of the base 1, a feeding port 3 on the top of the mixing tank 2, a base slurry injection port 4 on one side of the mixing tank 2, a stirring assembly 5 inside the mixing tank 2, a mixing pump 6 and a plugging pump 7 respectively installed on both sides of the mixing tank 2 above the base 1, the mixing pump 6 is connected to the mixing tank 2 through a pipe, and a first butterfly valve 8 is installed on the pipe connecting the two, the output end of the mixing pump 6 is connected to a mixer 10 through a pipe, and a second butterfly valve 9 is installed on the pipe connecting the two, the mixer 10 is connected to the mixing tank 2 through a pipe, and a third butterfly valve 11 is installed on the pipe connecting the two.

[0021] The mixing tank 2 is used to mix and prepare the base slurry and plugging material for the plugging slurry. The stirring component 5 agitates the two to ensure thorough mixing. The mixing pump 6 delivers the pre-mixed mud into the mixer 10, from which chemical agents can be added to improve the plugging effect of the slurry and ensure thorough mixing. After the plugging slurry is prepared, it can be pumped into the lost circulation zone by the plugging pump 7 to repair the well leakage in the oil well.

[0022] Example 2: Based on Example 1: like Figure 1 and Figure 2 As shown, the output end of the plugging pump 7 is connected to the first gate valve 12 through a pipeline, and the plugging pump 7 is fixedly connected to the direct drive motor 13.

[0023] Due to the high viscosity, large particles, and high solid content of the plugging slurry, the plugging pump 7 needs to have a high suction capacity. Therefore, the plugging pump 7 is directly connected to the direct drive motor 13 to reduce the intermediate transmission mechanism and reduce power loss and energy consumption.

[0024] The connection between the plugging pump 7 and the wellhead can be controlled by the first gate valve 12, and the injection of plugging slurry can be stopped in time when needed to avoid excessive injection of plugging slurry.

[0025] Example 3: Based on Example 1: like Figure 1 , Figure 4 , Figure 5 and Figure 6 As shown, a drain valve 14 is provided on the side wall of the mixing tank 2 near the base 1. An inclined bottom plate 15 that is inclined toward the drain valve 14 is fixedly connected to the bottom of the inner wall of the mixing tank 2. The inclined bottom plate 15 and the inner wall of the mixing tank 2 are connected by an arc transition.

[0026] The drain valve 14 and the inclined bottom plate 15 can discharge excess plugging slurry in a timely manner, preventing the plugging slurry from clumping in the mixing tank 2 and affecting the normal use of the device. The arc transition between the inclined bottom plate 15 and the inner wall of the mixing tank 2 can promote the discharge of plugging slurry through the inclined design.

[0027] Example 4: Based on Example 1: like Figure 1 , Figure 2 and Figure 5 As shown, the mixing assembly 5 includes a permanent magnet direct drive agitator 16 installed in the mixing tank 2, and a pneumatic agitator 17 is fixedly connected to the bottom of the inner wall of the mixing tank 2.

[0028] The permanent magnet direct-drive agitator 16 is used to mix the base slurry and the plugging material, so that the two are fully integrated. At the same time, the pneumatic agitator 17, which is set on the inner wall of the mixing tank 2, creates a vortex near the inner wall of the mixing tank 2, preventing the plugging material from settling in the dead corners of the mixing tank 2, promoting the effective mixing of the base slurry and the plugging material, making the proportion of each component of the plugging slurry closer to the expected value, improving the plugging effect and reducing material waste.

[0029] Example 5: Based on Example 1: like Figure 2 As shown, a cleaning pipe 18 is provided between the mixing pump 6 and the first butterfly valve 8. A fourth butterfly valve 19 is fixedly connected to the cleaning pipe 18. A branch pipe is provided on the pipe connecting the mixing pump 6 and the second butterfly valve 9, which is connected to a reducing joint 20. The reducing joint 20 is connected to a first ball valve 21 through a pipe. A second gate valve 22 is connected to the pipe connecting the output end of the plugging pump 7 and the first gate valve 12 through a branch pipe. A cleaning gun 23 is fixedly connected to the top of the inner wall of the slurry tank 2. The second gate valve 22 and the first ball valve 21 merge into a pipe connected to the cleaning gun 23, and a second ball valve 24 is provided on this pipe.

[0030] After the leak sealing is completed, clean water can be introduced into the device through the cleaning pipe 18 and the base slurry injection port 4. The mixing pump 6 pumps the clean water into the slurry mixing pipe to flush the inner wall of the pipe. When the clean water flows through the reducing joint 20, the flow rate increases, and the high-speed water flow is sprayed out through the cleaning gun 23 to flush the inside of the slurry mixing tank 2. At the same time, the leak sealing pump 7 can also pump the water in the slurry mixing tank 2 into the leak sealing slurry output pipe for cleaning. The mixing pump 6, the leak sealing pump 7, and the cleaning gun 23 work together to clean the pipes and the slurry mixing tank 2 in the device, preventing the leak sealing slurry from clumping in the device and affecting subsequent use.

[0031] Example 6: Based on Example 5: like Figure 2As shown, the pipeline connecting the mixing pump 6 and the second butterfly valve 9 is connected to the input end of the plugging pump 7 via a branch pipeline, and a fifth butterfly valve 25 is installed on this pipeline. A safety valve 26 is connected between the second gate valve 22 and the slurry mixing tank 2 via a branch pipe, and the safety valve 26 is connected to the slurry mixing tank 2 via a pipeline.

[0032] When the viscosity of the plugging grout is too high, the suction of the plugging pump 7 is insufficient to transfer the grout. In this case, the fifth butterfly valve 25 and the mixing pump 6 can be opened to assist in the transfer of the plugging grout and improve the transfer efficiency of the grout.

[0033] If the wellhead pressure is too high during the injection of plugging slurry, safety valve 26 and second gate valve 22 can be opened to allow a portion of the plugging slurry to flow out from safety valve 26 and back into the slurry mixing tank 2, thus preventing the pressure inside the oil well from continuing to rise.

[0034] Example 7: Based on Example 1: like Figure 1 and Figure 3 As shown, a loading platform 27 is fixedly connected above the mixing tank 2. An anti-slip grid 28 is fixedly connected to the upper surface of the loading platform 27. The loading platform 27 has an opening at the position corresponding to the feeding port 3. A guardrail 29 is rotatably connected around the loading platform 27. The guardrail 29 can rotate to one side of the loading platform 27. A lighting lamp 30 is fixedly connected to the loading platform 27.

[0035] When preparing the sealing grout, workers need to add the sealing material to the top of the grout mixing tank 2 and the loading platform 27. The design of the guardrail 29 and anti-slip grid 28 ensures the safety of the workers. At the same time, the lighting 30 allows workers to prepare the sealing grout in dim environments. When the sealing device needs to be transported as a whole, the guardrail 29 can be folded and stored to reduce the size of the device, avoid conflict with other components, and facilitate transportation.

[0036] Example 8: Based on Example 1: like Figure 1 As shown, several telescopic rods 31 perpendicular to the base 1 are fixedly connected to the surface of the base 1 around the mixing pump 6. A truss 32 is fixedly connected to the top of the telescopic rods 31. A hoisting rail 33 is fixedly connected to the bottom of the truss 32. An electric hoist 34 is slidably connected to the hoisting rail 33. An electric bag breaker 35 is fixedly connected to one side of the feeding port 3.

[0037] The preparation of the sealing grout requires a large amount of sealing material, but the transportation of this material is difficult. Therefore, a hoisting track 33 and an electric hoist 34 are additionally installed. During use, the sealing material, along with its packaging bag, can be transported to the feeding port 3, where an electric bag breaker 35 opens the packaging bag to add the sealing material, reducing the difficulty of transporting the material. Furthermore, the telescopic rod 31 allows for adjustment of the height of the truss 32, facilitating the transport of the device.

[0038] This invention employs an integrated design approach, combining all functional modules requiring leak sealing onto a single skid. To achieve this integration, the structure has been simplified, enabling the leak sealing device to perform functions such as grout mixing, grout pumping, and cleaning of tanks, pipelines, and equipment. Furthermore, the integrated design facilitates the overall transport of the device, allowing a single unit to meet grouting needs at different locations.

[0039] How to use: Grouting process: First, keep all valves closed and extend the telescopic rod 31. Then, inject the base slurry into the mixing tank 2 through the base slurry injection port 4. Afterward, use the electric hoist 34 to lift the sealing material and transport it to the feeding port 3. At this time, the electric bag breaker 35 breaks open the packaging bag of the sealing material, allowing the sealing material to enter the mixing tank 2. While adding the sealing material, turn on the permanent magnet direct drive agitator 16 and the pneumatic agitator 17 to stir, so that the sealing material and the base slurry are fully mixed to form the sealing slurry. Then open the first butterfly valve 8 and the second butterfly valve 9, and start the mixing pump 6 and the mixer 10. The mixing pump 6 pumps the base slurry into the mixer 10. At this time, the workers add other special sealing materials into the mixer 10. The sealing slurry and other special sealing materials are mixed in the mixer 10 and discharged to the slurry preparation tank 2. After stirring evenly, the mixing and preparation of the sealing slurry is completed. After the plugging slurry is prepared, close the first butterfly valve 8, the second butterfly valve 9, the mixing pump 6, the mixer 10, and the stirring assembly 5. Open the third butterfly valve 11, the plugging pump 7, and the first gate valve 12. The plugging pump 7 will pump the plugging slurry to the well layer where the well leakage has occurred to complete the grouting.

[0040] Venting conditions: During the grouting process, the second gate valve 22 is kept open. When the wellhead pressure is higher than the set value of the safety valve 26, the safety valve 26 is automatically opened, and the plugging grout is reinjected from the safety valve 26 into the grout mixing tank, stopping the injection of the plugging grout and avoiding unnecessary losses caused by excessive pressure in the well.

[0041] Auxiliary grouting conditions: When the viscosity of the prepared sealing slurry is too high, open the first butterfly valve 8 and the fifth butterfly valve 25, and start the mixing pump 6. The mixing pump 6 transports the sealing slurry to the inlet of the sealing pump 7 to assist the sealing pump 7 in sucking in the sealing slurry and improve the sealing efficiency when the sealing slurry is viscous.

[0042] Cleaning conditions: After the leak is plugged, keep all valves open and introduce clean water through the cleaning pipe 18. The mixing pump 6 and the leak plugging pump 7 will pump the clean water into the pipes in the device to clean the pipes.

[0043] When the clean water passes through the reducing joint 20, the flow rate increases and it is sprayed out by the cleaning gun 23 to clean the inner wall of the mixing tank 2. After the cleaning is completed, the wastewater is discharged through the drain valve.

Claims

1. A well plugging device, characterized in that The system includes a base (1), a mixing tank (2) is fixedly connected above the base (1), a feeding port (3) is provided above the mixing tank (2), a base slurry injection port (4) is provided on one side of the mixing tank (2), a stirring assembly (5) is provided inside the mixing tank (2), a mixing pump (6) and a plugging pump (7) are respectively provided on both sides of the mixing tank (2) above the base (1), the mixing pump (6) is connected to the mixing tank (2) through a pipe, and a first butterfly valve (8) is provided on the pipe connecting the two, the output end of the mixing pump (6) is connected to a mixer (10) through a pipe, and a second butterfly valve (9) is provided on the pipe, the mixer (10) is connected to the mixing tank (2) through a pipe, the input end of the plugging pump (7) is connected to the mixing tank (2) through a pipe, and a third butterfly valve (11) is provided on the pipe connecting the two.

2. The oil well packer of claim 1, wherein, The output end of the plugging pump (7) is connected to a first gate valve (12) via a pipeline, and the plugging pump (7) is fixedly connected to a direct drive motor (13).

3. The oil well plugging device according to claim 1, characterized in that, The mixing tank (2) has a drain valve (14) on its side wall near the base (1). The bottom of the inner wall of the mixing tank (2) is fixedly connected to an inclined bottom plate (15) that is inclined toward the drain valve (14). The inclined bottom plate (15) and the inner wall of the mixing tank (2) are connected by an arc transition.

4. The oil well plugging device according to claim 1, characterized in that, The stirring assembly (5) includes a permanent magnet direct drive stirrer (16) installed in the mixing tank (2), and a pneumatic stirrer (17) is fixedly connected to the bottom of the inner wall of the mixing tank (2).

5. The oil well plugging device according to claim 2, characterized in that, A cleaning pipe (18) is provided between the mixing pump (6) and the first butterfly valve (8). A fourth butterfly valve (19) is fixedly connected to the cleaning pipe (18). A branch pipe is provided on the pipe connecting the mixing pump (6) and the second butterfly valve (9) and a reducing joint (20) is connected to it. A first ball valve (21) is connected to the reducing joint (20) through a pipe. A second gate valve (22) is connected to the pipe connecting the output end of the plugging pump (7) and the first gate valve (12) through a branch pipe. A cleaning gun (23) is fixedly connected to the top of the inner wall of the slurry tank (2). The second gate valve (22) and the first ball valve (21) merge into a pipe and are connected to the cleaning gun (23). A second ball valve (24) is provided on this pipe.

6. The oil well plugging device according to claim 5, characterized in that, The pipeline connecting the mixing pump (6) and the second butterfly valve (9) is connected to the input end of the plugging pump (7) via a branch pipeline, and a fifth butterfly valve (25) is installed on the pipeline. A safety valve (26) is connected between the second gate valve (22) and the slurry mixing tank (2) via a branch pipe. The safety valve (26) is connected to the slurry mixing tank (2) via a pipeline.

7. The oil well plugging device according to claim 1, characterized in that, A loading platform (27) is fixedly connected above the mixing tank (2). An anti-slip grid (28) is fixedly connected to the upper surface of the loading platform (27). The loading platform (27) has an opening at the position corresponding to the feeding port (3). A guardrail (29) is rotatably connected around the loading platform (27). The guardrail (29) can rotate to one side of the loading platform (27). A lighting lamp (30) is fixedly connected to the loading platform (27).

8. The oil well plugging device according to claim 1, characterized in that, The base (1) has several telescopic rods (31) fixedly connected around the mixing pump (6) and perpendicular to the base (1). A truss (32) is fixedly connected to the top of the telescopic rod (31). A hoisting rail (33) is fixedly connected to the bottom of the truss (32). An electric hoist (34) is slidably connected to the hoisting rail (33). An electric bag breaker (35) is fixedly connected to one side of the feeding port (3).

9. A grouting method for sealing leaks, characterized in that, The leak-sealing device according to any one of claims 1 to 8 is implemented specifically according to the following steps: Step 1: Keep all valves closed, then inject base slurry into the mixing tank (2) through the base slurry injection port (4), and start the stirring assembly (5). Then add the sealing material into the mixing tank (2) through the feeding port (3). Step 2: Start the mixing pump (6) and mixer (10) and open the first butterfly valve (8) and the second butterfly valve (9), and add the additive from the mixer (10) to mix with the base slurry and the plugging material to form the plugging slurry; Step 3: After the original grout for plugging is prepared, close the first butterfly valve (8) and the second butterfly valve and turn off the mixing pump (6) and the mixer (10). Then open the third butterfly valve (11) and the plugging pump (7) to inject grout.

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