A detachable sand control buried bridge plug and its fishing tool

Abstract

The application relates to a detachable sand-prevention buried bridge plug, which comprises a central pipe, a setting connection structure, a setting connection structure comprising a setting joint which is screwed with the end of the central pipe, the outside of the setting joint is sleeved with a fishing sleeve, the outside of the fishing sleeve is connected with a lock spring outer sleeve, a setting structure, a rubber tube structure, the rubber tube structure comprising a rubber tube core pipe which is connected with one end of the central pipe, the outside of the rubber tube core pipe is sleeved with a plurality of rubber tubes, the plurality of rubber tubes are arranged at the lower edge position of the outer sleeve, a releasing structure, the releasing structure comprising a lock jaw one which is arranged on the end of the rubber tube core pipe away from the central pipe, and further comprising a supporting sleeve which is arranged on the inner wall of the end of the rubber tube core pipe away from the central pipe, and the lock jaw one is a multi-equal-section split structure. The application has the advantages that the releasing success rate is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of bridge plugs, specifically relating to a disposable, sand-proof bridge plug and its retrieval tool. Background Technology

[0002] Bridge plugs are a common downhole tool used in oilfields. When in use, the bridge plug is lowered to a predetermined position inside the casing through the tubing string. The bridge plug is then set using a corresponding setting method. After setting, the bridge plug is anchored to the inner wall of the casing by its slips and the casing is sealed by its rubber sleeve. A bridge plug is a packer that remains at a certain depth in the well and is detached from the tubing string, hence it is also called a drop-out packer.

[0003] The existing drop-out bridge plug has a locking sleeve at the end of the central tube. The locking sleeve has an opening and a clutch is embedded in the opening. The clutch and the locking sleeve are separate structures. When retrieving the bridge plug, the clutch may enter the central tube of the bridge plug from the opening of the locking sleeve, thereby affecting the movement of the piston rod of the bridge plug retrieval tool and causing the drop-out to fail. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a dropable anti-sand-buried bridge plug and its retrieval tool, which effectively improves the success rate of dropping.

[0005] The objective of this invention is achieved through the following technical solution: a removable sand-proof bridge plug, comprising...

[0006] Central tube;

[0007] The setting connection structure includes a setting joint that is threaded to the end of the central tube, a retrieval sleeve is fitted on the outside of the setting joint, and a locking spring outer sleeve is connected to the outside of the retrieval sleeve.

[0008] The setting structure includes a cone sleeved on the outer circumference of a central tube. One end of the cone is threadedly connected to a locking spring sleeve. The outer wall of the central tube has a groove for the end of the cone away from the locking spring sleeve to be embedded. The end of the cone away from the locking spring sleeve extends toward the groove and engages with the groove. The end of the cone away from the locking spring sleeve has a slip. The cone and the slip are in conical contact. The slip is sleeved on the outer circumference of the central tube. A sandproof rubber sleeve is sleeved on the outer circumference of the cone. The sandproof rubber sleeve is placed between the locking spring sleeve and the slip. The end of the central tube away from the setting connection structure is sleeved with an outer sleeve.

[0009] The rubber tube structure includes a rubber tube core tube connected to one end of a central tube, and multiple rubber tubes are sleeved on the outside of the rubber tube core tube, with the multiple rubber tubes positioned at the lower edge of the outer sleeve.

[0010] The release mechanism includes a locking claw 1 located at the end of the rubber tube furthest from the center tube, and a support sleeve located on the inner wall of the end of the rubber tube furthest from the center tube. The locking claw 1 has a multi-segmented structure. The rubber tube and the support sleeve are connected by a release pin. The outer circumference of the support sleeve has a groove. A lower connector is fitted around the locking claw 1. There is a chamber between the lower connector and the support sleeve to accommodate the locking claw 1. The outer side of the end of the locking claw 1 has a protrusion. The inner wall of the chamber has a limiting groove that matches the protrusion.

[0011] A further improvement of the present invention is that: an O-ring 1 is provided between the lower connector and the locking claw 1, and an O-ring 2 is provided between the rubber core tube and the support sleeve.

[0012] A further improvement of the present invention is that: the multiple rubber tubes are arranged sequentially as an upper rubber tube, a middle rubber tube, and a lower rubber tube, with the upper rubber tube positioned close to the outer casing and the lower rubber tube positioned close to the release mechanism; an upper rubber tube seat is provided between the upper rubber tube and the outer casing, and an upper disc spring is provided between the upper rubber tube seat and the outer casing; the outer side of the lower rubber tube is provided with a lower rubber tube seat, a lower disc spring, and a nut in sequence; an upper wrist guard is provided between the upper rubber tube seat and the upper rubber tube, and a lower wrist guard is provided between the lower rubber tube seat and the lower rubber tube; an upper spacer is provided between the upper rubber tube and the middle rubber tube, and a lower spacer is provided between the middle rubber tube and the lower rubber tube.

[0013] A further improvement of the present invention is that: the slip has a compression spring, and the end of the slip near the sand-proof rubber sleeve has a pressure cap.

[0014] A further improvement of the present invention is that a sealing ring is provided between the core tube and the central tube.

[0015] A further improvement of the present invention is that the locking spring outer sleeve and the retrieval sleeve are connected by a setting pin, and a sand-proof ring is provided between the locking spring outer sleeve and the retrieval sleeve.

[0016] A further improvement of the present invention is that the retrieval sleeve and the central tube are connected by a release pin, and the central tube and the cone have a locking claw two, the end of the locking claw two being embedded between the retrieval sleeve and the central tube.

[0017] A further improvement of the present invention is that a locking spring is provided between the locking spring jacket and the cone.

[0018] A salvage tool for a releasable anti-sand-buried bridge plug includes an upper connector, an intermediate connector, and a salvage cylinder connected in sequence. A piston rod passes through the upper connector, the intermediate connector, and the salvage cylinder. The inner wall of the salvage cylinder has salvage claws on the outer circumference of the piston rod. The salvage claws are connected to the salvage sleeve of the releasable anti-sand-buried bridge plug. The end of the piston rod contacts the end of the support sleeve of the releasable anti-sand-buried bridge plug.

[0019] A further improvement of the present invention is that the upper connector and the piston rod are connected by a shear pin.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention adds a release mechanism, which consists of a support sleeve, a release pin, and a lower connector. The lower end of the rubber tube has a locking claw with a multi-segmented structure. The locking claw is embedded in the cavity between the lower connector and the support sleeve. The protrusion on the locking claw is embedded in the limiting groove of the cavity. When the piston rod of the retrieval tool for the releaseable sand-proof bridge plug moves down, it cuts the shearing pin. The piston rod pushes the support sleeve of the releaseable sand-proof bridge plug to move down until the locking claw separates from the support sleeve. At the same time, the central tube is lifted, and the locking claw at the lower end of the rubber tube retracts and disengages from the lower connector, thereby achieving release. This application changes the traditional clutch and locking sleeve to a separate structure, adopting a structure in which the locking claw and the rubber tube are integrated, effectively ensuring the success rate of release. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a removable sand-proof bridge plug according to the present invention.

[0023] Figure 2 for Figure 1 An enlarged schematic diagram of structure A in the middle.

[0024] Figure 3 This is a schematic diagram of the structure of a salvage tool for a removable, sand-proof bridge plug according to the present invention.

[0025] Numbering on the map:

[0026] 1-Sandproof ring, 2-Setting pin, 3-Locking spring outer sleeve, 4-Setting joint, 5-Retrieval sleeve, 6-Locking spring, 7-Unsealing pin, 8-Center tube, 9-Locking claw one, 10-Sandproof rubber sleeve, 11-Pressure cap, 12-Cone, 13-Clip, 14-Compression spring, 15-Outer sleeve, 16-Upper disc spring, 17-Upper rubber sleeve seat, 18-Sealing ring, 19-Upper wrist guard, 20-Upper rubber sleeve, 21-Upper spacer ring, 22-Middle rubber sleeve, 23-Lower spacer ring, 24- 25-Lower wrist guard, 26-Lower rubber sleeve seat, 27-Lower disc spring, 28-Matching nut, 29-Rubber sleeve core tube, 30-Release pin, 31-O-ring II, 32-O-ring I, 33-Support sleeve, 34-Lower connector, 35-Locking claw I, 36-Slot, 37-Protrusion, 38-Limiting groove, 39-Groove, 40-Upper connector, 41-Piston push rod, 42-Shearing pin, 43-Intermediate connector, 44-Retrieving claw, 45-Retrieving cylinder. Detailed Implementation

[0027] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship, such as those based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0029] In this invention, unless otherwise explicitly specified and limited, terms such as “connection,” “provided with,” and “have” should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can be described as a mechanical connection, a direct connection, or a connection through an intermediate medium. Those skilled in the art can understand the basic meaning of the above terms in this invention according to the specific circumstances.

[0030] A disposable sand-proof bridge plug, such as Figure 1 As shown, including

[0031] Central tube 8;

[0032] The setting connection structure includes a setting joint 4 that is threaded to the end of the central tube 8, a retrieval sleeve 5 is sleeved on the outside of the setting joint 4, and a locking spring sleeve 3 is connected to the outside of the retrieval sleeve 5.

[0033] The setting structure includes a cone 12 sleeved on the outer circumference of the central tube 8. One end of the cone 12 is threadedly connected to the locking spring sleeve 3. The outer wall of the central tube 8 has a groove 39 for the end of the cone 12 away from the locking spring sleeve 3 to be embedded. The end of the cone 12 away from the locking spring sleeve 3 extends toward the groove 39 and engages with the groove 39. The end of the cone 12 away from the locking spring sleeve 3 has a slip 13. The cone 12 and the slip 13 are in conical contact. The slip 13 is sleeved on the outer circumference of the central tube 8. A sandproof rubber sleeve 10 is sleeved on the outer circumference of the cone 12. The sandproof rubber sleeve 10 is placed between the locking spring sleeve 3 and the slip 13. An outer sleeve 15 is sleeved on the end of the central tube 8 away from the setting connection structure.

[0034] The rubber tube structure includes a rubber tube core tube 29 connected to one end of the central tube 8, and multiple rubber tubes are sleeved on the outside of the rubber tube core tube 29, with the multiple rubber tubes positioned at the lower edge of the outer sleeve 15.

[0035] Dropping structure, such as Figure 2As shown, the release mechanism includes a locking claw 35 located at the end of the rubber tube 29 away from the central tube 8, and a support sleeve 33 located on the inner wall of the end of the rubber tube 29 away from the central tube 8. The locking claw 35 has a multi-segmented structure. The rubber tube 29 and the support sleeve 33 are connected by a release pin 30. The outer circumference of the support sleeve 33 has a groove 36. The locking claw 35 is fitted with a lower connector 34. There is a cavity between the lower connector 34 and the support sleeve 33 to accommodate the locking claw 35. The outer side of the end of the locking claw 35 has a protrusion 37 protruding outward. The inner wall of the cavity has a limiting groove 38 that cooperates with the protrusion 37.

[0036] This invention adds a release mechanism, which consists of a support sleeve 33, a release pin 30, and a lower connector 34. The lower end of the rubber core tube 29 has a locking claw 35 with a multi-segmented structure. The locking claw 35 is embedded in the cavity between the lower connector 34 and the support sleeve 33. The protrusion 37 on the locking claw 35 is embedded in the limiting groove 38 of the cavity. When the piston rod of the retrieval tool of the releaseable sand-proof bridge plug moves down, it cuts the shearing pin. The piston rod pushes the support sleeve 33 of the releaseable sand-proof bridge plug to move down until the locking claw 35 separates from the support sleeve 33. At the same time, the central tube 8 is lifted, and the locking claw 35 at the lower end of the rubber core tube 29 retracts and disengages from the lower connector 34, thereby realizing the release. This application changes the traditional clutch and locking sleeve to a separate structure, adopting a structure in which the locking claw 35 and the rubber core tube 29 are integrated, effectively ensuring the success rate of the release.

[0037] In this application, the removable sand-proof bridge plug is threadedly connected to the lower end of the bridge plug setting tool via the setting joint 4. The upper part of the bridge plug setting tool is connected to the tubing. After the setting tool string is lowered to the designed position downhole, hydraulic pressure is applied to the tubing through the ground. When the pressure reaches a certain value, the bridge plug setting tool pushes the locking spring sleeve 3 and the cone 12 downward. The locking spring sleeve 3 compresses the sand-proof rubber sleeve 10 to expand until the sand-proof rubber sleeve 10 seals with the inner wall of the casing to prevent sand. The conical surface of the cone 12 pushes the slip 13 outward until the slip 13 is anchored to the inner wall of the casing. Hydraulic pressure continues to be applied, and the lower end of the bridge plug setting tool drives the setting joint 4, the retrieval sleeve 5, the central tube 8, the rubber sleeve core tube 29, and others to move upward, compressing the expansion of multiple rubber sleeves on the bridge plug and sealing them with the inner wall of the casing, thus achieving bridge plug setting. After setting, the setting tool and its upper tubing string are removed.

[0038] Based on this embodiment, an O-ring 32 is provided between the lower connector 34 and the locking claw 35, and an O-ring 31 is provided between the rubber core tube 29 and the support sleeve 33.

[0039] Based on this embodiment, the multiple rubber tubes are arranged sequentially as an upper rubber tube 20, a middle rubber tube 22, and a lower rubber tube 24. The upper rubber tube 20 is located near the outer casing 15, and the lower rubber tube 24 is located near the release mechanism. There is an upper rubber tube seat 17 between the upper rubber tube 20 and the outer casing 15, and an upper disc spring 16 between the upper rubber tube seat 17 and the outer casing 15. The outer side of the lower rubber tube 24 is provided with a lower rubber tube seat 26, a lower disc spring 27, and a nut 28 in sequence. There is an upper wrist guard 19 between the upper rubber tube seat 17 and the upper rubber tube 20, and a lower wrist guard 25 between the lower rubber tube seat 26 and the lower rubber tube 24. There is an upper spacer 21 between the upper rubber tube 20 and the middle rubber tube 22, and a lower spacer 23 between the middle rubber tube 22 and the lower rubber tube 24.

[0040] The upper disc spring 16, the upper rubber sleeve seat 17, the lower rubber sleeve seat 26, and the lower disc spring 27 can enhance the protection of the rubber sleeve and compensate for the compression sealing effect of the rubber sleeve.

[0041] Based on this embodiment, the slip 13 has a compression spring 14, and the end of the slip 13 near the sandproof rubber sleeve 10 has a pressure cap 11.

[0042] In this application, the cone 12 and the slip 13 are in a conical fit. During setting, the cone 12 moves downward, pushing the slip 13 outward to anchor the casing wall. During unsetting, the cone 12 moves upward, and the slip 13 loses the support of the cone 12. Under the elastic force of the compression spring 14, the slip 13 retracts inward and leaves the casing wall. The conical fit structure not only prevents foreign objects such as sand from entering or from rusting and sticking downhole over a long period of time, but also efficiently achieves setting and unsetting.

[0043] Based on this embodiment, a sealing ring 18 is provided between the rubber core tube 29 and the central tube 8.

[0044] Based on this embodiment, the locking spring sleeve 3 and the retrieval sleeve 5 are connected by a seated pin 2, and a sand-proof ring 1 is provided between the locking spring sleeve 3 and the retrieval sleeve 5.

[0045] Based on this embodiment, the retrieval sleeve 5 and the central tube 8 are connected by a release pin 7, and the central tube 8 and the cone 12 have a locking claw 9, the end of which is embedded between the retrieval sleeve 5 and the central tube 8.

[0046] Based on this embodiment, a locking spring 6 is provided between the locking spring outer sleeve 3 and the cone 12.

[0047] A disposable salvage tool for preventing sand burial of bridge plugs, such as Figure 3As shown, it includes an upper connector 40, an intermediate connector 43, and a retrieval cylinder 45 connected in sequence. A piston push rod 41 passes through the upper connector 40, the intermediate connector 43, and the retrieval cylinder 45. The inner wall of the retrieval cylinder 45 is provided with retrieval claws 44 on the outer circumference of the piston push rod 41. The retrieval claws 44 are connected to the retrieval sleeve 5 of the releasable anti-buried bridge plug. The end of the piston push rod 41 contacts the end of the support sleeve 33 of the releasable anti-buried bridge plug.

[0048] Furthermore, the upper connector 40 is connected to the piston rod 41 by a shear pin 42.

[0049] When releasing the bridge plug, connect the bridge plug retrieval tool to the lower end of the tubing. When it is 2-3m away from the top of the bridge plug, start flushing with sand. When clean water is flowing in and out, slowly lower the retrieval tool while flushing until the internal thread of the retrieval claw 44 of the retrieval tool locks the external thread of the retrieval sleeve 5 of the bridge plug. Then lift the retrieval tool to release the plug. If the lower part of the bridge plug is blocked by sand from the formation, the ground is thrown to pressurize it, pushing the piston rod 41 of the retrieval tool to move down. At the same time, it pushes the support sleeve 33 of the bridge plug to cut off the release pin 30 and move down simultaneously until the locking claw 35 separates from the support sleeve 33. At the same time, the central tube 8 is lifted, and the locking claw 35 at the lower end of the rubber core tube 29 retracts and disengages from the lower connector 34, thus releasing the plug.

[0050] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A removable sand-proof bridge plug, characterized in that: include Central tube (8); The setting connection structure includes a setting joint (4) that is threaded to the end of the central tube (8), and a retrieval sleeve (5) is sleeved on the outside of the setting joint (4), and a locking spring sleeve (3) is connected to the outside of the retrieval sleeve (5). The sealing structure includes a cone (12) sleeved on the outer circumference of the central tube (8). One end of the cone (12) is threadedly connected to the locking spring sleeve (3). The outer wall of the central tube (8) has a groove (39) for the cone (12) to be embedded at the end away from the locking spring sleeve (3). The end of the cone (12) away from the locking spring sleeve (3) extends toward the groove (39) and engages with the groove (39). The end of the cone (12) away from the locking spring sleeve (3) has a slip (13). The cone (12) and the slip (13) are in conical contact. The slip (13) is sleeved on the outer circumference of the central tube (8). A sandproof rubber sleeve (10) is sleeved on the outer circumference of the cone (12). The sandproof rubber sleeve (10) is placed between the locking spring sleeve (3) and the slip (13). The end of the central tube (8) away from the sealing connection structure is sleeved with a sleeve (15). The rubber tube structure includes a rubber tube core tube (29) connected to one end of the central tube (8), and a plurality of rubber tubes are sleeved on the outside of the rubber tube core tube (29), and the plurality of rubber tubes are positioned at the lower edge of the outer sleeve (15). The release structure includes a locking claw (35) on the end of the rubber tube (29) away from the center tube (8), and a support sleeve (33) on the inner wall of the end of the rubber tube (29) away from the center tube (8). The locking claw (35) is a multi-segmented structure. The rubber tube (29) and the support sleeve (33) are connected by a release pin (30). The outer circumference of the support sleeve (33) has a groove (36). The locking claw (35) is fitted with a lower connector (34). There is a chamber between the lower connector (34) and the support sleeve (33) for the locking claw (35) to be embedded. The outer side of the end of the locking claw (35) has a protrusion (37). The inner wall of the chamber has a limiting groove (38) that cooperates with the protrusion (37).

2. The removable sand-proof bridge plug according to claim 1, characterized in that: The lower connector (34) has an O-ring (32) between it and the locking claw (35), and the rubber core tube (29) has an O-ring (31) between it and the support sleeve (33).

3. The removable sand-proof bridge plug according to claim 2, characterized in that: The plurality of rubber tubes are an upper rubber tube (20), a middle rubber tube (22), and a lower rubber tube (24) arranged in sequence. The upper rubber tube (20) is located near the outer casing (15), and the lower rubber tube (24) is located near the release mechanism. There is an upper rubber tube seat (17) between the upper rubber tube (20) and the outer casing (15). There is an upper disc spring (16) between the upper rubber tube seat (17) and the outer casing (15). The outer side of the lower rubber tube (24) is provided with a lower rubber tube seat (26), a lower disc spring (27), and a nut (28) in sequence. There is an upper wrist guard (19) between the upper rubber tube seat (17) and the upper rubber tube (20). There is a lower wrist guard (25) between the lower rubber tube seat (26) and the lower rubber tube (24). There is an upper spacer (21) between the upper rubber tube (20) and the middle rubber tube (22). There is a lower spacer (23) between the middle rubber tube (22) and the lower rubber tube (24).

4. The removable sand-proof bridge plug according to claim 3, characterized in that: The slip (13) has a compression spring (14), and the end of the slip (13) near the sand-proof rubber sleeve (10) has a pressure cap (11).

5. The removable sand-proof bridge plug according to claim 4, characterized in that: A sealing ring (18) is provided between the core tube (29) and the center tube (8).

6. The removable sand-proof bridge plug according to claim 5, characterized in that: The locking spring sleeve (3) and the retrieval sleeve (5) are connected by a seated pin (2), and there is a sand-proof ring (1) between the locking spring sleeve (3) and the retrieval sleeve (5).

7. The removable sand-proof bridge plug according to claim 6, characterized in that: The retrieval sleeve (5) is connected to the central tube (8) by a sealing pin (7). The central tube (8) and the cone (12) have a locking claw (9), the end of which is embedded between the retrieval sleeve (5) and the central tube (8).

8. The removable sand-proof bridge plug according to claim 7, characterized in that: A locking spring (6) is provided between the locking spring jacket (3) and the cone (12).

9. A retrieval tool for the disposable sand-proof bridge plug as described in any one of claims 1 to 8, characterized in that: The device includes an upper connector (40), an intermediate connector (43), and a retrieval cylinder (45) connected in sequence. A piston rod (41) passes through the upper connector (40), the intermediate connector (43), and the retrieval cylinder (45). The inner wall of the retrieval cylinder (45) is placed on the outer circumference of the piston rod (41) and has retrieval claws (44). The retrieval claws (44) are connected to the retrieval sleeve (5) of the releasable anti-buried bridge plug. The end of the piston rod (41) contacts the end of the support sleeve (33) of the releasable anti-buried bridge plug.

10. The retrieval tool for a disposable sand-proof bridge plug according to claim 9, characterized in that: The upper connector (40) is connected to the piston rod (41) by a shear pin (42).

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