Cement retainer

Abstract

The present application belongs to the field of downhole tools, and particularly relates to a cement retainer. The conventional plugging method has great risk in engineering construction and cannot guarantee that the oil layer is not blocked by cement slurry, especially for high-pressure water layer squeeze plugging. The cement slurry may be squeezed out of the high-pressure water layer, which may cause the failure of squeeze plugging. The present application includes a fixed pipe, a soft rubber pipe and a connecting cover. The fixed pipe and the connecting cover are fixedly connected with the left side and the right side of the soft rubber pipe, respectively. A fixing assembly is installed on the right side of the connecting cover. A baffle is fixedly installed in the fixed pipe. A connecting assembly is connected with the right side of the baffle. In the present application, the connecting screw rod can be connected with the setting tool by rotating the driving cover, and the cement can be squeezed at the same time. The soft rubber pipe is deformed, so that the casing can be tightly plugged. Therefore, the present application has good practicability.

Description

Technical Field

[0001] This invention relates to the field of downhole tool technology, and more particularly to a cement retainer. Background Technology

[0002] In the mid-to-late stages of oilfield development, corrosion and perforation of the casing above the cement return point in oil wells can lead to leakage in the cemented section. This allows formation water from adjacent high-pressure water layers to flow into the wellbore, or a decrease in oil layer energy can cause water ingress or water flooding of the oil layer due to cross-contamination between the adjacent high-pressure water layer and the oil layer, posing serious challenges to oilfield development. Currently, some old oil wells that have been in production for many years have been shut in with high water cuts for extended periods. Analysis suggests three possibilities: first, long-term production may have caused casing corrosion and perforation, leading to casing leakage and water flooding; second, long-term high-pressure water injection in high-pressure injection wells may have created a water head cone with the oil layer, resulting in water flooding; and third, cross-contamination of high-pressure water layers near the oil layer may have caused water flooding. For these wells, packer leak detection ruled out the possibility of casing corrosion and perforation leakage. Isotope logging revealed a high-pressure water layer below the oil layer that was causing cross-contamination, resulting in water production in the entire well.

[0003] In this situation, the conventional approach is to first perforate the well in the high-pressure water layer, then chemically seal the water layer—primarily with cement slurry. After sealing, the cement plug is drilled out, and oil production resumes. However, in this well, the producing oil layer is above and very close to the high-pressure water layer. Using conventional sealing methods not only carries significant risks during construction but also makes it difficult to guarantee that the oil layer will not be blocked by cement slurry. In particular, when attempting to plug the high-pressure water layer, cement slurry may leak out, causing the plugging to fail. Therefore, we propose a cement retainer to address the aforementioned problems. Summary of the Invention

[0004] Given the existing technical problems that conventional sealing methods not only carry significant risks during engineering construction, but also make it difficult to ensure that the oil layer is not blocked by cement slurry, especially when squeezing and blocking high-pressure water layers, which may result in cement slurry escaping from the high-pressure water layer and causing the squeezing and blocking to fail, this invention proposes a cement retainer.

[0005] The cement retainer proposed in this invention includes a fixed pipe, a flexible rubber tube, and a connecting cover. The fixed pipe and the connecting cover are fixedly connected to the left and right sides of the flexible rubber tube, respectively. A fixing component is installed on the right side of the connecting cover. A baffle is fixedly installed inside the fixed pipe, and a connecting component is connected to the right side of the baffle. The right side of the connecting component extends into the connecting cover and is connected to the inner wall of the connecting cover. A pressure plate is connected to the right side of the connecting component. Multiple rubber rings are fixedly installed at equal intervals inside the flexible rubber tube.

[0006] A transmission component is connected inside the fixed tube, and the left side of the transmission component extends to the left side of the fixed tube. The right side of the baffle and the left side of the pressure plate are provided with putty, and the right end of the transmission component extends into the connecting cover and connects to the inner wall of the connecting cover. The left end of the fixed component extends into the connecting cover and connects to the transmission component.

[0007] With the above structure, the fixed component can be driven to operate by the drive transmission component, so that the fixed component can be stably connected with the setting tool. When the transmission component moves, it can drive the pressure plate to move, so as to squeeze the putty and move it into the soft rubber tube, which can expand the soft rubber tube and facilitate the squeezing of the inner wall of the sleeve, thereby sealing the sleeve and effectively preventing leakage.

[0008] Preferably, the fixing component includes a support ring, a connecting screw, and a driving component;

[0009] The support ring is fixedly installed on the left side of the connecting cover, and the left end of the connecting screw extends into the support ring and is rotatably connected to the inner wall of the support ring. The left end of the connecting screw is provided with a transmission groove, and the driving component is installed in the transmission groove. The left end of the transmission component extends into the connecting cover and is connected to the right side of the transmission assembly.

[0010] Furthermore, after the driving component receives power from the transmission assembly, it can drive the connecting screw to rotate, which facilitates a stable connection between the connecting screw and the setting tool.

[0011] Preferably, the driving component includes a drive shaft, a drive ring, and a stop block;

[0012] The drive shaft is connected to the right side of the transmission assembly, and the transmission ring is fixedly installed in the transmission groove. The right end of the drive shaft passes through the transmission ring and extends into the transmission groove. The stop block is fixedly installed on the inner wall of the transmission ring, and a spiral groove is opened on the drive shaft. One side of the stop block extends into the spiral groove and is connected to the inner wall of the spiral groove.

[0013] Furthermore, after the drive shaft receives power from the transmission component, it can move. At this time, under the transmission cooperation of the spiral groove and the stop, the transmission ring can rotate, thereby enabling the connecting screw to rotate.

[0014] Preferably, the connecting assembly includes two telescopic members and a limiting ring;

[0015] Two telescopic components are symmetrically fixedly installed on the right side of the baffle, and the limiting ring is fixedly installed inside the connecting cover. The telescopic components pass through the limiting ring and are connected to the limiting ring. The right ends of the two telescopic components are connected to the left side of the pressure plate.

[0016] Furthermore, two telescopic members and a limiting ring are used for connection, so as to enable the fixed pipe and the connecting cover to be stably connected.

[0017] Preferably, the telescopic member includes a support cover, a moving rod and a compression spring;

[0018] The support cover is fixedly installed on the right side of the baffle, and the moving rod is slidably connected in the support cover. The right end of the moving rod passes through the limiting ring and is fixedly connected to the left side of the pressing plate. The moving rod is slidably connected to the limiting ring, and the compression spring is fixedly installed on the left inner wall of the support cover. The right end of the compression spring is fixedly connected to the left end of the moving rod.

[0019] Furthermore, by using the sliding connection between the moving rod and the support cover, the connecting cover can be slidably limited, so as to enable the stable connection between the connecting cover and the fixed pipe.

[0020] Preferably, the transmission component includes a driving cover, a sliding member, a transmission joint, a threaded member, a connecting shaft and a pushing plate;

[0021] The driving cover is rotatably connected in the fixed pipe, and the left side of the driving cover extends to the left side of the fixed pipe and is fixedly connected to the transmission joint. The sliding member is installed in the driving cover. The threaded member is installed in the fixed pipe, and the left end of the threaded member extends into the driving cover and is connected to the sliding member. The right end of the threaded member is connected to the connecting shaft, and the right end of the connecting shaft passes through the baffle and the pressing plate respectively and extends to the right side of the pressing plate. The right end of the connecting shaft is fixedly connected to the pushing plate, and the pushing plate is slidably connected to the inner wall of the connecting cover. The left end of the pushing plate is fixedly connected to the transmission shaft. The connecting shaft is hermetically and slidably connected to the baffle and the pressing plate respectively.

[0022] Furthermore, by rotating the driving cover, the threaded member can be driven to operate through the sliding member. At this time, the pushing plate can be moved through the connecting shaft, so that the transmission shaft can be moved. And after the pushing plate contacts the pressing plate, the pressing plate can be pushed to move, so as to extrude the clay.

[0023] Preferably, the sliding member includes two limiting strips and a connecting plate;

[0024] The two limiting strips are respectively fixedly installed on the top inner wall and the bottom inner wall of the driving cover, and the connecting plate is slidably connected to the two limiting strips respectively. The connecting plate is connected to the right end of the threaded member.

[0025] Furthermore, when the connecting plate is slidably connected to the two limiting strips, a driving force can be continuously applied to the threaded member when the driving cover is rotated.

[0026] Preferably, the threaded member includes a threaded plate and a driving screw;

[0027] The threaded plate is fixedly installed inside the fixed pipe, and the driving screw rod penetrates through the threaded plate and is threadedly connected to the threaded plate. The left end of the driving screw rod extends into the driving cover and is fixedly connected to the right side of the connecting plate, and the right end of the driving screw rod is fixedly connected to the left end of the connecting shaft.

[0028] Furthermore, when the driving screw rod rotates along with the connecting plate, under the threaded transmission of the threaded plate, it can move, thereby带动 the connecting shaft to move.

[0029] The beneficial effects of the present invention are:

[0030] 1. In the present invention, when the device is lowered to the position in the casing that needs to be blocked, at this time, an external starting tool can be connected to the transmission joint to drive the driving cover to rotate. When the driving cover rotates, it can带动 the connecting plate to rotate. At this time, the driving screw rod can be rotated. Thus, under the threaded transmission of the threaded plate, the driving screw rod can move to the left, and then the push plate can be带动 to move to the left through the connecting shaft. At this time, the transmission shaft can be带动 to move. Under the transmission cooperation of the spiral groove and the stop block, the connecting screw rod can be带动 to rotate, so that the connecting screw rod is connected to the setting tool;

[0031] 2. In the present invention, when the push plate moves to the left along the connecting cover and contacts the pressing plate, at this time, the pressing plate can be带动 to move to the left, thereby挤压 the clay, making the clay move into the soft rubber tube, causing the soft rubber tube to expand until the soft rubber tube is tightly fitted to the inner wall of the casing, thereby实现 the blocking of the casing;

[0032] In the present invention, by rotating the driving cover, the connecting screw rod can be connected to the setting tool, and at the same time, the clay can be挤压, causing the soft rubber tube to deform, thereby实现 the tight blocking of the casing. Therefore, it has good practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the main structural view of the cement retainer proposed by the present invention;

[0034] Figure 2 is the main cross-sectional view of the cement retainer proposed by the present invention;

[0035] Figure 3 is the schematic diagram of the structure of part A in the appendix of the cement retainer proposed by the present invention; Figure 2 in the appendix;

[0036] Figure 4 is the schematic diagram of the structure of part B in the appendix of the cement retainer proposed by the present invention; Figure 2 in the appendix;

[0037] Figure 5This is a side sectional view of the connection structure of the connecting screw, transmission ring and transmission shaft of the cement retainer proposed in this invention;

[0038] Figure 6 This is a main sectional view of the connection structure between the support cover and the movable rod of the cement retainer proposed in this invention.

[0039] In the diagram: 1. Fixed tube; 2. Soft rubber tube; 3. Connecting cover; 4. Support ring; 5. Connecting screw; 6. Drive cover; 7. Transmission joint; 8. Limiting strip; 9. Connecting plate; 10. Drive screw; 11. Threaded plate; 12. Baffle; 13. Connecting shaft; 14. Support cover; 15. Pressure plate; 16. Putty; 17. Push plate; 18. Transmission groove; 19. Transmission shaft; 20. Spiral groove; 21. Transmission ring; 22. Stop block; 23. Rubber ring; 24. Limiting ring; 25. Moving rod; 26. Compression spring. Detailed Implementation

[0040] The present invention will be further explained below with reference to specific embodiments.

[0041] Example

[0042] refer to Figure 1-6 In this embodiment, a cement retainer is proposed, including a fixed pipe 1, a soft rubber tube 2 and a connecting cover 3. The fixed pipe 1 and the connecting cover 3 are fixedly connected to the left and right sides of the soft rubber tube 2, respectively. A fixing component is installed on the right side of the connecting cover 3. A baffle 12 is fixedly installed inside the fixed pipe 1, and a connecting component is connected to the right side of the baffle 12. The right side of the connecting component extends into the connecting cover 3 and is connected to the inner wall of the connecting cover 3. A pressure plate 15 is connected to the right side of the connecting component. Multiple rubber rings 23 are fixedly installed at equal intervals inside the soft rubber tube 2.

[0043] A transmission component is connected inside the fixed tube 1, and the left side of the transmission component extends to the left side of the fixed tube 1. The right side of the baffle 12 and the left side of the pressure plate 15 are provided with putty 16, and the right end of the transmission component extends into the connecting cover 3 and is connected to the inner wall of the connecting cover 3. The left end of the fixed component extends into the connecting cover 3 and is connected to the transmission component.

[0044] With the above structure, the fixed component can be driven to operate by the drive transmission component, so that the fixed component can be stably connected with the setting tool. When the transmission component moves, it can drive the pressure plate 15 to move, so as to squeeze the putty 16 and move it into the soft rubber tube 2, which can expand the soft rubber tube 2 and facilitate the squeezing of the inner wall of the sleeve, thereby sealing the sleeve and effectively preventing leakage.

[0045] In this embodiment, the fixing component includes a support ring 4, a connecting screw 5, and a driving component;

[0046] The support ring 4 is fixedly installed on the left side of the connecting cover 3, and the left end of the connecting screw 5 extends into the support ring 4 and is rotatably connected to the inner wall of the support ring 4. The left end of the connecting screw 5 is provided with a transmission groove 18, and the driving component is installed in the transmission groove 18. The left end of the transmission component extends into the connecting cover 3 and is connected to the right side of the transmission assembly.

[0047] After the driving component receives power from the transmission component, it can drive the connecting screw 5 to rotate, which facilitates a stable connection between the connecting screw 5 and the setting tool.

[0048] In this embodiment, the driving component includes a drive shaft 19, a drive ring 21, and a stop block 22;

[0049] The drive shaft 19 is connected to the right side of the transmission assembly, and the transmission ring 21 is fixedly installed in the transmission groove 18. The right end of the drive shaft 19 passes through the transmission ring 21 and extends into the transmission groove 18. The stop block 22 is fixedly installed on the inner wall of the transmission ring 21, and a spiral groove 20 is provided on the drive shaft 19. One side of the stop block 22 extends into the spiral groove 20 and is connected to the inner wall of the spiral groove 20.

[0050] After the drive shaft 19 receives power from the transmission component, it can move. At this time, under the transmission cooperation of the spiral groove 20 and the stop block 22, the transmission ring 21 can rotate, thereby enabling the connecting screw 5 to rotate.

[0051] In this embodiment, the connecting assembly includes two telescopic members and a limiting ring 24;

[0052] Two telescopic components are symmetrically fixedly installed on the right side of the baffle 12, and the limiting ring 24 is fixedly installed inside the connecting cover 3. The telescopic components pass through the limiting ring 24 and are connected to the limiting ring 24. The right ends of the two telescopic components are connected to the left side of the pressure plate 15.

[0053] By using two telescopic components and a limiting ring 24 for connection, a stable connection between the fixed pipe 1 and the connecting cover 3 can be achieved.

[0054] In this embodiment, the telescopic component includes a support cover 14, a moving rod 25, and a compression spring 26;

[0055] The support cover 14 is fixedly installed on the right side of the baffle 12, and the moving rod 25 is slidably connected inside the support cover 14. The right end of the moving rod 25 passes through the limiting ring 24 and is fixedly connected to the left side of the pressure plate 15. The moving rod 25 is slidably connected to the limiting ring 24, and the compression spring 26 is fixedly installed on the left inner wall of the support cover 14. The right end of the compression spring 26 is fixedly connected to the left end of the moving rod 25.

[0056] By utilizing the sliding connection between the movable rod 25 and the support cover 14, the connecting cover 3 can be slidably limited, thereby achieving a stable connection between the connecting cover 3 and the fixed tube 1.

[0057] In this embodiment, the transmission assembly includes a drive cover 6, a sliding member, a transmission joint 7, a threaded member, a connecting shaft 13, and a push plate 17.

[0058] The drive cover 6 is rotatably connected inside the fixed tube 1, and the left side of the drive cover 6 extends to the left side of the fixed tube 1 and is fixedly connected to the transmission joint 7. The sliding component is installed inside the drive cover 6, and the threaded component is installed inside the fixed tube 1. The left end of the threaded component extends into the drive cover 6 and is connected to the sliding component. The right end of the threaded component is connected to the connecting shaft 13, and the right end of the connecting shaft 13 passes through the baffle 12 and the pressure plate 15 respectively and extends to the right side of the pressure plate 15. The right end of the connecting shaft 13 is fixedly connected to the push plate 17, and the push plate 17 is slidably connected to the inner wall of the connecting cover 3. The push plate 17 is fixedly connected to the left end of the transmission shaft 19, and the connecting shaft 13 is slidably connected to the baffle 12 and the pressure plate 15 respectively.

[0059] By rotating the drive cover 6, the sliding component can drive the threaded component to operate. At this time, the push plate 17 can be moved through the connecting shaft 13, thereby enabling the transmission shaft 19 to move. After the push plate 17 contacts the pressure plate 15, it can push the pressure plate 15 to move so as to squeeze the putty 16.

[0060] In this embodiment, the sliding component includes two limiting strips 8 and a connecting plate 9;

[0061] Two limiting strips 8 are fixedly installed on the top inner wall and bottom inner wall of the drive cover 6, respectively, and the connecting plate 9 is slidably connected to the two limiting strips 8. The connecting plate 9 is connected to the right end of the threaded component.

[0062] When the connecting plate 9 is slidably connected to the two limiting strips 8, a driving force can be continuously applied to the threaded component when the drive cover 6 is rotated.

[0063] In this embodiment, the threaded component includes a threaded plate 11 and a drive screw 10;

[0064] The threaded plate 11 is fixedly installed inside the fixed tube 1, and the drive screw 10 passes through the threaded plate 11 and is threadedly connected to the threaded plate 11. The left end of the drive screw 10 extends into the drive cover 6 and is fixedly connected to the right side of the connecting plate 9. The right end of the drive screw 10 is fixedly connected to the left end of the connecting shaft 13.

[0065] When the drive screw 10 rotates with the connecting plate 9, it can move under the thread transmission of the threaded plate 11, thereby driving the connecting shaft 13 to move.

[0066] In this embodiment, when the device is lowered to the position inside the sleeve where sealing is required, an external starting tool can be connected to the transmission joint 7 to drive the drive cover 6 to rotate. When the drive cover 6 rotates, it drives the connecting plate 9 to rotate, which in turn causes the drive screw 10 to rotate. Under the threaded transmission of the threaded plate 11, the drive screw 10 moves to the left, which in turn drives the push plate 17 to move to the left via the connecting shaft 13. This, in turn, drives the transmission shaft 19 to move within the spiral groove. With the transmission cooperation of 20 and stop 22, the connecting screw 5 can be driven to rotate, so that the connecting screw 5 is connected to the setting tool. When the push plate 17 moves to the left along the connecting cover 3 and contacts the pressure plate 15, the pressure plate 15 can be driven to move to the left, which can squeeze the putty 16, so that the putty 16 moves into the soft rubber tube 2, causing the soft rubber tube 2 to expand until the soft rubber tube 2 is tightly attached to the inner wall of the sleeve, thereby achieving the sealing of the sleeve, so it has good practicality.

[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A cement retainer, comprising a fixed pipe (1), a flexible rubber tube (2), and a connecting cover (3), wherein the fixed pipe (1) and the connecting cover (3) are fixedly connected to the left and right sides of the flexible rubber tube (2), respectively, characterized in that, A fixing component is installed on the right side of the connecting cover (3), a baffle (12) is fixedly installed inside the fixing tube (1), and a connecting component is connected to the right side of the baffle (12). The right side of the connecting component extends into the connecting cover (3) and is connected to the inner wall of the connecting cover (3). A pressure plate (15) is connected to the right side of the connecting component. Multiple rubber rings (23) are fixedly installed at equal intervals inside the soft rubber tube (2). A transmission component is connected inside the fixed tube (1), and the left side of the transmission component extends to the left side of the fixed tube (1). The right side of the baffle (12) and the left side of the pressure plate (15) are provided with putty (16), and the right end of the transmission component extends into the connecting cover (3) and is connected to the inner wall of the connecting cover (3). The left end of the fixed component extends into the connecting cover (3) and is connected to the transmission component. The fixed component includes a support ring (4), a connecting screw (5) and a driving component. The support ring (4) is fixedly installed on the left side of the connecting cover (3), and the left end of the connecting screw (5) extends into the support ring (4) and is rotatably connected to the inner wall of the support ring (4). The left end of the connecting screw (5) is provided with a transmission groove (18), and the driving component is installed in the transmission groove (18). The left end of the transmission component extends into the connecting cover (3) and is connected to the right side of the transmission assembly. The transmission assembly includes a driving cover (6), a sliding component, a transmission joint (7), a threaded component, a connecting shaft (13), and a push plate (17). The drive cover (6) is rotatably connected inside the fixed tube (1), and the left side of the drive cover (6) extends to the left side of the fixed tube (1) and is fixedly connected to the transmission joint (7). The sliding component is installed inside the drive cover (6), the threaded component is installed inside the fixed tube (1), and the left end of the threaded component extends to the drive cover (6) and is connected to the sliding component. The right end of the threaded component is connected to the connecting shaft (13), and the right end of the connecting shaft (13) passes through the baffle (12) and the pressure plate (15) respectively and extends to the right side of the pressure plate (15). The right end of the connecting shaft (13) is fixedly connected to the push plate (17), and the push plate (17) is slidably connected to the inner wall of the connecting cover (3). The push plate (17) is fixedly connected to the left end of the transmission shaft (19), and the connecting shaft (13) is sealed and slidably connected to the baffle (12) and the pressure plate (15) respectively.

2. The cement retainer according to claim 1, characterized in that, The driving component includes a drive shaft (19), a drive ring (21), and a stop (22). The drive shaft (19) is connected to the right side of the transmission assembly, and the transmission ring (21) is fixedly installed in the transmission groove (18). The right end of the drive shaft (19) passes through the transmission ring (21) and extends into the transmission groove (18). The stop block (22) is fixedly installed on the inner wall of the transmission ring (21), and a spiral groove (20) is provided on the drive shaft (19). One side of the stop block (22) extends into the spiral groove (20) and is connected to the inner wall of the spiral groove (20) in a transmission connection.

3. The cement retainer according to claim 1, characterized in that, The connecting assembly includes two telescopic members and a limiting ring (24). Two telescopic components are symmetrically fixedly installed on the right side of the baffle (12), and the limiting ring (24) is fixedly installed inside the connecting cover (3). The telescopic components pass through the limiting ring (24) and are connected to the limiting ring (24). The right ends of the two telescopic components are connected to the left side of the pressure plate (15).

4. The cement retainer according to claim 3, characterized in that, The telescopic component includes a support cover (14), a moving rod (25), and a compression spring (26). The support cover (14) is fixedly installed on the right side of the baffle (12), and the moving rod (25) is slidably connected inside the support cover (14). The right end of the moving rod (25) passes through the limiting ring (24) and is fixedly connected to the left side of the pressure plate (15). The moving rod (25) is slidably connected to the limiting ring (24), and the compression spring (26) is fixedly installed on the left inner wall of the support cover (14). The right end of the compression spring (26) is fixedly connected to the left end of the moving rod (25).

5. The cement retainer according to claim 1, characterized in that, The sliding component includes two limiting strips (8) and a connecting plate (9); Two limiting strips (8) are fixedly installed on the top inner wall and bottom inner wall of the drive cover (6), and the connecting plate (9) is slidably connected to the two limiting strips (8), and the connecting plate (9) is connected to the right end of the threaded component.

6. The cement retainer according to claim 1, characterized in that, The threaded component includes a threaded plate (11) and a drive screw (10). The threaded plate (11) is fixedly installed inside the fixed tube (1), and the drive screw (10) passes through the threaded plate (11) and is threadedly connected to the threaded plate (11). The left end of the drive screw (10) extends into the drive cover (6) and is fixedly connected to the right side of the connecting plate (9). The right end of the drive screw (10) is fixedly connected to the left end of the connecting shaft (13).

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