A retrievable bridge plug

Abstract

The utility model discloses a kind of retrievable bridge plug, including center tube assembly, setting sealing mechanism, anchoring locking mechanism and fishing release mechanism.The center tube assembly is connected by upper mandrel, lower mandrel and center tube in proper order;Setting sealing mechanism is sleeved in the outside of center tube assembly, containing sealing tube, liner, rubber cylinder assembly and balance valve;Anchoring locking mechanism is located below setting sealing mechanism, and anchoring is realized by track pin, upper wedge body, slip shoe, slip and lower wedge body cooperation;Fishing release mechanism is connected on the upper end of center tube assembly, containing fishing head, upper joint and release bolt, and fishing head is connected with upper mandrel by shear pin.The bridge plug can dismantle design to realize core component recycling reuse to reduce cost, anchoring mechanism ensures anchoring firm and unlocking smooth, setting mechanism guarantees high-pressure sealing and pressure fluctuation adaptability, improves operation reliability.

Description

Technical Field

[0001] This utility model belongs to the technical field of oil extraction equipment, specifically a removable bridge plug. Background Technology

[0002] In downhole operations such as oil and gas field development and water well testing, bridge plugs are widely used as important sealing tools to temporarily or permanently seal a section of the wellbore to achieve stratified extraction, testing, fracturing, and other operational objectives. As oil and gas resource development progresses towards deeper wells and more complex well sections, the performance requirements for bridge plugs are becoming increasingly stringent. They must not only possess reliable sealing and anchoring capabilities to cope with complex conditions such as high pressure and high corrosion, but also balance operational efficiency and cost control. Their technical level directly affects the safety and economy of downhole operations, making them one of the indispensable key pieces of equipment in the oil and gas extraction field.

[0003] Current bridge plug technology faces several technical challenges. First, traditional bridge plugs are mostly single-use, making it difficult to recover core components after operation, leading to material waste and high construction costs. Second, the functional mechanisms of some recyclable bridge plugs are poorly designed, causing numerous problems in practical applications. For example, the anchoring mechanisms of some recyclable bridge plugs are poorly designed, easily resulting in insecure anchoring under complex downhole conditions such as high pressure and temperature, leading to bridge plug displacement or difficulty in unsealing, affecting operational effectiveness. Furthermore, the sealing structures of some bridge plugs exhibit unstable sealing performance under pressure fluctuations, failing to effectively prevent fluid leakage and reducing the reliability of the plug's sealing. In addition, the retrieval process for some recyclable bridge plugs is complex, requiring specialized tools and operating skills, increasing operation time and costs.

[0004] For example, patent application number CN202022135006.3 discloses a detachable bridge plug, including a rubber bushing, bushing, anti-fouling cover, sealing ring, retaining ring, threaded groove, upper slip assembly, bolt rod, lower slip assembly, central shaft, and variable diameter support ring. Although this bridge plug achieves a detachable function, its anchoring and sealing reliability still needs improvement. Its anchoring mechanism lacks stability under complex well conditions, and the sealing components are prone to aging and failure under long-term high-pressure environments. Utility Model Content

[0005] The purpose of this invention is to provide a removable bridge plug to solve the following technical problems mentioned in the background art:

[0006] Existing technologies make it difficult to achieve convenient recycling and reuse of the core components of the bridge plug while ensuring reliable setting, firm anchoring, and good sealing.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A removable bridge plug includes a central tube assembly, a setting and sealing mechanism, an anchoring and locking mechanism, and a retrieval and release mechanism. The setting and sealing mechanism is sleeved on the outside of the central tube assembly. The anchoring and locking mechanism is sleeved on the outside of the central tube assembly and located below the setting and sealing mechanism. The retrieval and release mechanism is connected to the upper end of the central tube assembly. The central tube assembly includes an upper mandrel, a lower mandrel, and a central tube connected sequentially from top to bottom. The setting and sealing mechanism includes a sealing tube, a liner, a rubber sleeve assembly, and a balance valve. One end of the sealing tube is sleeved on the upper mandrel, and the other end is sleeved on the central tube. The liner is sleeved on the outside of the central tube. The rubber sleeve assembly is sleeved on the liner. The outer side of the pipe; the balance valve is located on the outer side of the sealing pipe; the anchoring and locking mechanism includes an upper wedge, a slip, a slip, and a lower wedge; the upper wedge is connected to the liner and the central pipe by a track pin, the track pin extending into a groove on the liner and the central pipe; the slip is sleeved on the outer side of the liner and located below the upper wedge; the slip is installed on the slip; the lower wedge is sleeved on the outer side of the central pipe, and its conical surface matches the inner conical surface of the slip; the retrieval and release mechanism includes a retrieval head, an upper connector, and a release bolt; the upper connector is connected to the upper mandrel; the retrieval head is connected to the outer side of the upper mandrel by a shear pin; the release bolt is connected to the upper end of the upper connector.

[0009] Furthermore, it also includes a bottom connecting mechanism, which includes an adjusting ring, a support ring, and a lower connector; the adjusting ring is connected to the end of the central tube; the support ring is connected to the adjusting ring; and the lower connector is connected to the support ring.

[0010] Furthermore, the adjusting ring is used to adjust the relative position of the bottom connecting mechanism and the central tube assembly to pre-tighten the entire bridge plug.

[0011] Furthermore, the setting and sealing mechanism also includes a locking ring sleeve, a first pressure cap, and a second pressure cap; the two ends of the locking ring sleeve are respectively connected to the sealing tube and the liner; the first pressure cap is located below the locking ring sleeve; and the second pressure cap is located on the upper wedge.

[0012] Furthermore, the tube assembly includes two rubber tubes and a spacer ring disposed between the two rubber tubes.

[0013] Furthermore, the salvage and release mechanism also includes a safety helmet located on the outside of the upper connector.

[0014] Furthermore, the upper wedge is fitted onto the outside of the liner and is located between the second pressure cap and the camo.

[0015] Furthermore, the retrieval head is connected to the upper mandrel via shear pins. When the applied tension exceeds the shear strength of the shear pins, the retrieval head can be separated from the upper mandrel.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The bridge plug of this utility model adopts a detachable design, and the core components of the bridge plug can be recycled and reused through the retrieval and release mechanism, which greatly reduces the construction cost. The structure of the track pin and the conical surface in the anchoring and locking mechanism ensures that the anchoring is firm and the unlocking is smooth, which improves the reliability of the operation. The combination of the rubber sleeve assembly and the balance valve in the setting and sealing mechanism not only ensures the high-pressure sealing effect, but also adapts to pressure fluctuations and enhances the sealing stability. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional view of the bridge plug of this utility model;

[0019] Figure 2 This is a partial cross-sectional view of the upper mandrel of this utility model;

[0020] Figure 3 This is a partial cross-sectional view of the sealing tube of this utility model;

[0021] Figure 4 This is a partial cross-sectional view of the locking ring sleeve of this utility model;

[0022] Figure 5 This is a partial cross-sectional view of the central tube of this utility model;

[0023] Figure 6 This is a partial cross-sectional schematic diagram of the upper wedge of this utility model;

[0024] Figure 7 This is a partial cross-sectional view of the lower wedge of this utility model;

[0025] Figure 8 This is a partial cross-sectional view of the liner of this utility model.

[0026] The markings in the diagram are: 1-Release bolt, 2-Upper connector, 3-Safety cap, 4-Retrieval head, 5-Upper mandrel, 6-Shear pin, 7-Balance valve, 8-Sealing tube, 9-Lower mandrel, 10-Locking ring sleeve, 11-Central tube, 12-Locking ring, 13-Bearing ring, 14-First pressure cap, 15-Rubber sleeve, 16-Spacer ring, 17-Second pressure cap, 18-Rail pin, 19-Upper wedge, 20-Liner, 21-Vacuum plate, 22-Vacuum plate, 23-Lower wedge, 24-Adjusting ring, 25-Supporting ring, 26-Lower connector. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Example:

[0029] A removable bridge plug includes a central tube assembly, a setting and sealing mechanism, an anchoring and locking mechanism, and a retrieval and release mechanism. The setting and sealing mechanism is sleeved on the outside of the central tube assembly. The anchoring and locking mechanism is sleeved on the outside of the central tube assembly and located below the setting and sealing mechanism. The retrieval and release mechanism is connected to the upper end of the central tube assembly. The central tube assembly includes an upper mandrel 5, a lower mandrel 9, and a central tube 11 connected sequentially from top to bottom. The setting and sealing mechanism includes a sealing tube 8, a liner 20, a rubber sleeve assembly, and a balance valve 7. One end of the sealing tube 8 is sleeved on the upper mandrel 5, and the other end is sleeved on the central tube 11. The liner 20 is sleeved on the outside of the central tube 11. The rubber sleeve assembly is sleeved on the outside of the liner 20. The balance valve 7 is disposed on the sealing tube 8. The outer side; the anchoring and locking mechanism includes an upper wedge 19, a chuck 21, a slip 22, and a lower wedge 23; the upper wedge 19 is connected to the liner 20 and the central tube 11 via a track pin 18, the track pin 18 extending into a groove provided on the liner 20 and the central tube 11; the chuck 21 is sleeved on the outside of the liner 20 and located below the upper wedge 19; the slip 22 is installed on the chuck 21; the lower wedge 23 is sleeved on the outside of the central tube 11, and its conical surface mates with the inner conical surface of the slip 22; the retrieval and release mechanism includes a retrieval head 4, an upper connector 2, and a release bolt 1; the upper connector 2 is connected to the upper spindle 5; the retrieval head 4 is connected to the outside of the upper spindle 5 via a shear pin 6; the release bolt 1 is connected to the upper end of the upper connector 2.

[0030] Specifically, during setting, an axial setting force is applied through the retrieval and release mechanism. This force is transmitted to the upper mandrel 5 via the upper connector 2, causing the upper wedge 19 to move downwards relative to the track pin 18 within the grooves of the liner 20 and the center tube 11. The upper wedge 19 pushes the slipper 21, causing the slipper 22 to open outwards under the action of the tapered surface of the lower wedge 23, anchoring itself to the inner wall of the sleeve for locking. Simultaneously, the relative movement of the liner 20 and the sealing tube 8 compresses the rubber sleeve assembly, causing it to expand radially to form a seal. The balance valve 7 balances the pressure above and below the bridge plug, assisting in stable setting. During retrieval and release, the retrieval head 4 is grabbed by the retrieval tool and a pulling force is applied. After shearing the shear pin 6, the action of the release bolt 1 separates the upper connector 2 from the upper mandrel 5, thereby recovering the core components such as the center tube assembly and completing the bridge plug disassembly.

[0031] The bridge plug of this utility model adopts a detachable design, and the core components of the bridge plug can be recycled and reused through the retrieval and release mechanism, which greatly reduces the construction cost. The structure of the track pin 18 and the conical surface in the anchoring and locking mechanism ensures firm anchoring and smooth unlocking, improving the reliability of operation. The combination of the rubber sleeve assembly and the balance valve 7 in the setting and sealing mechanism not only ensures the high-pressure sealing effect, but also adapts to pressure fluctuations and enhances the sealing stability.

[0032] In a preferred embodiment, a bottom connection mechanism is also included, comprising an adjusting ring 24, a support ring 25, and a lower connector 26. The adjusting ring 24 is connected to the end of the central tube 11; the support ring 25 is connected to the adjusting ring 24; and the lower connector 26 is connected to the support ring 25. In the bottom connection mechanism, the adjusting ring 24 can adjust the bottom length of the bridge plug to adapt to different working conditions, the support ring 25 provides support and positioning for the lower structure, enhancing overall stability, and the lower connector 26 is used to connect other downhole tools, such as setting tools, to achieve convenient docking between the bridge plug and subsequent equipment, improving structural adaptability and connection reliability.

[0033] In a preferred embodiment, the adjusting ring 24 is used to adjust the relative position of the bottom connecting mechanism and the central tube assembly to pre-tighten the entire bridge plug. By adjusting the relative position of the bottom connecting mechanism and the central tube assembly, the adjusting ring 24 achieves pre-tightening of the entire bridge plug, enhancing the tightness of the structural assembly.

[0034] In a preferred embodiment, the setting and sealing mechanism further includes a locking ring sleeve 10, a first pressure cap 14, and a second pressure cap 17. The two ends of the locking ring sleeve 10 are respectively connected to the sealing tube 8 and the liner 20. The first pressure cap 14 is located below the locking ring sleeve 10; the second pressure cap 17 is located on the upper wedge 19. The locking ring sleeve 10 connects the sealing tube 8 and the liner 20, fixing their relative positions. The first pressure cap 14 acts as a clamping force below the locking ring sleeve 10, preventing it from loosening. The second pressure cap 17 is located on the upper wedge 19, assisting in fixing related components and ensuring the overall stability of the setting and sealing mechanism.

[0035] In a preferred embodiment, the rubber sleeve assembly includes two rubber sleeves 15 and a spacer ring 16 disposed between the two rubber sleeves 15. The two rubber sleeves 15 enhance sealing reliability, and the spacer ring 16 separates the rubber sleeves 15 to prevent them from compressing each other, thus ensuring their respective sealing performance.

[0036] In a preferred embodiment, the retrieval and release mechanism further includes a safety helmet 3 disposed on the outside of the upper connector 2. The safety helmet 3 can protect the outside of the upper connector 2 from damage caused by external impacts, ensuring the normal use and structural integrity of the retrieval and release mechanism.

[0037] In a preferred embodiment, the upper wedge 19 is fitted onto the outside of the liner 20 and is located between the second pressure cap 17 and the vault 21. The upper wedge 19 is positioned in this way to receive the force from above during setting, accurately push the vault 21, and allow the vault 22 to open smoothly for anchoring. At the same time, it can cooperate with other components to ensure the orderly execution of the entire setting and anchoring action.

[0038] In a preferred embodiment, the retrieval head 4 is connected to the upper mandrel 5 via a shear pin 6. When the applied tension exceeds the shear strength of the shear pin 6, the retrieval head 4 can separate from the upper mandrel 5. By setting the shear strength of the shear pin 6, the retrieval head 4 can separate from the upper mandrel 5 when a suitable tension is applied, thereby enabling the retrieval release mechanism to operate in a predetermined manner and complete the retrieval and disassembly operation of the bridge plug.

[0039] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A removable bridge plug, characterized in that: It includes a central tube assembly, a setting and sealing mechanism, an anchoring and locking mechanism, and a retrieval and release mechanism; the setting and sealing mechanism is sleeved on the outside of the central tube assembly; the anchoring and locking mechanism is sleeved on the outside of the central tube assembly and located below the setting and sealing mechanism; the retrieval and release mechanism is connected to the upper end of the central tube assembly; The central tube assembly includes an upper mandrel (5), a lower mandrel (9), and a central tube (11) connected sequentially from top to bottom; the setting and sealing mechanism includes a sealing tube (8), a liner (20), a rubber sleeve assembly, and a balance valve (7); one end of the sealing tube (8) is sleeved on the upper mandrel (5), and the other end is sleeved on the central tube (11); the liner (20) is sleeved on the outside of the central tube (11); the rubber sleeve assembly is sleeved on the outside of the liner (20); and the balance valve (7) is located on the outside of the sealing tube (8). The anchoring and locking mechanism includes an upper wedge (19), a chuck (21), a slip (22), and a lower wedge (23); the upper wedge (19) is connected to the liner (20) and the center tube (11) via a track pin (18), the track pin (18) extending into a groove provided on the liner (20) and the center tube (11); the chuck (21) is sleeved on the outside of the liner (20) and located below the upper wedge (19); the slip (22) The lower wedge (23) is fitted on the outside of the central tube (11), and its conical surface matches the inner conical surface of the slip (22). The retrieval and release mechanism includes a retrieval head (4), an upper connector (2) and a release bolt (1). The upper connector (2) is connected to the upper spindle (5). The retrieval head (4) is connected to the outside of the upper spindle (5) by a shear pin (6). The release bolt (1) is connected to the upper end of the upper connector (2).

2. The removable bridge plug according to claim 1, characterized in that: It also includes a bottom connection mechanism, which includes an adjusting ring (24), a support ring (25) and a lower connector (26); the adjusting ring (24) is connected to the end of the central tube (11); the support ring (25) is connected to the adjusting ring (24); and the lower connector (26) is connected to the support ring (25).

3. A removable bridge plug according to claim 1, characterized in that: The adjusting ring (24) is used to adjust the relative position of the bottom connecting mechanism and the central tube assembly to pre-tighten the entire bridge plug.

4. A removable bridge plug according to claim 1, characterized in that: The sealing mechanism also includes a locking ring sleeve (10), a first pressure cap (14), and a second pressure cap (17); the two ends of the locking ring sleeve (10) are connected to the sealing tube (8) and the liner (20) respectively; the first pressure cap (14) is located below the locking ring sleeve (10); the second pressure cap (17) is located on the upper wedge (19).

5. A removable bridge plug according to claim 4, characterized in that: The glue cartridge assembly includes two glue cartridges (15) and a spacer ring (16) disposed between the two glue cartridges (15).

6. A removable bridge plug according to claim 1, characterized in that: The salvage release mechanism also includes a safety helmet (3) located on the outside of the upper connector (2).

7. A removable bridge plug according to claim 1, characterized in that: The upper wedge (19) is fitted on the outside of the liner (20) and is located between the second pressure cap (17) and the camo (21).

8. A removable bridge plug according to claim 1, characterized in that: The retrieval head (4) is connected to the upper mandrel (5) via a shear pin (6). When the applied tension exceeds the shear strength of the shear pin (6), the retrieval head (4) can be separated from the upper mandrel (5).

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