A bare hole wellbore plugging tool

Abstract

A kind of open hole wellbore plugging tool.The existing open hole well cement plug sealing construction cycle is long, and the cementing quality is poor.The characteristics are that the lower end of the delivery rod (1) is connected with the release lower short circuit (4), the release lower short circuit (4) is provided with an anchoring mechanism outside, the lower part of the release lower short circuit (4) is connected with the plugging tool upper connector (18), the plugging tool upper connector (18) is internally threaded connected with the plugging tool body (31), the plugging tool body (31) is internally connected with the compression sleeve (19) through the compression sleeve downward shear pin (27), and the compression sleeve (19) is internally threaded connected with the isolation valve body (21).The plugging tool body (31) is provided with a rubber tube (29) outside, and the rubber tube (29) is provided with a compression sleeve (26) on the upper part.The open hole wellbore plugging tool can release the tool after expanding and sealing anchoring at the predetermined position, play the role of open hole bridge plug and artificial well bottom, improve the cementing quality of cement plug, and shorten the construction time.

Description

Technical Field

[0001] This invention relates to the field of drilling engineering technology, specifically to a tool for plugging open-hole wells. Background Technology

[0002] During oilfield drilling and development, some wells, after completion logging, are found to have poorly developed lower oil layers, so only the upper oil layers are retained. To save drilling costs, the casing is only run to the bottom of the upper oil layer. During cementing, because the density of the cement slurry is greater than that of the drilling fluid, the cement slurry and drilling fluid are displaced and sink, resulting in leaks in the upper well section and substandard cementing quality at the bottom corner of the casing. This necessitates the use of cement plugs to seal and abandon the lower well section, leading to problems such as long construction periods and high costs.

[0003] Meanwhile, in deep drilling development, situations requiring open-hole sidetracking may arise. In such cases, it is necessary to install a cement plug while suspended in the borehole and then use a bent screw for sidetracking. This necessitates high-quality cement plugs. However, during cement plug installation, the density difference between the cement slurry and the drilling fluid can cause instability in the cement slurry, resulting in poor bonding quality. Furthermore, some cement slurry may mix into the drilling fluid, causing calcification and deterioration of the drilling fluid, increasing the cost and workload of drilling fluid treatment. Summary of the Invention

[0004] To overcome the problems of long construction cycles and poor cement slurry bonding quality in existing open-hole well cement plug sealing construction, this invention provides an open-hole well plugging tool. This open-hole well plugging tool can be expanded and anchored in a predetermined position and then released, serving as an open-hole bridge plug and artificial well bottom, improving the cement plug bonding quality, shortening the construction time, and can also be used for open-hole well casing when it is scrapped.

[0005] The technical solution of the present invention is as follows: a plugging tool for open-hole wells, comprising an insertion rod, the lower end of which is connected to a release short connector, an anchoring mechanism being provided on the outside of the release short connector, and an upper connector for the plugging tool being connected to the lower part of the release short connector, with an anchoring hydraulic cylinder being provided on the outside of the upper connector; the upper connector is internally threaded to the plugging tool body, and the plugging tool body is internally connected to a compression sleeve via a downward shear pin, with an isolation valve body internally threaded to the compression sleeve, and an isolation valve core being internally connected to the isolation valve body via an isolation valve shear pin; a rubber sleeve is provided on the outside of the plugging tool body, with a compression outer sleeve on the upper part of the rubber sleeve, and a positioning sleeve is connected to the lower end of the inside of the plugging tool body.

[0006] The lower end of the feed rod is located inside the lower release connector. A stop block is provided on the side wall of the lower release connector. The inside of the stop block is located in the groove on the outer wall of the feed rod. A release cylinder is provided outside the stop block and is connected to the lower release connector by a release pin.

[0007] The anchoring mechanism includes an upper connecting ring for the anchoring rod and a lower connecting ring for the anchoring rod. The upper connecting ring for the anchoring rod is connected to the lower short connector of the release arm, and the lower connecting ring for the anchoring rod is connected to the anchoring liquid cylinder. Several anchoring rods are connected between the upper connecting ring for the anchoring rod and the lower connecting ring for the anchoring rod.

[0008] The anchor rod includes an upper anchor rod and a lower anchor rod, wherein the upper anchor rod and the lower anchor rod are connected by an anchor rod pivot pin. The upper anchor rod is connected to the lower end of the upper connecting ring by an upper retaining ring connecting pin, and the lower anchor rod is connected to the upper end of the lower anchor rod connecting ring by a lower retaining ring connecting pin.

[0009] The isolation valve body has a liquid passage hole on its side wall, and the isolation valve core has a liquid passage hole on its side wall. When the isolation valve body and the isolation valve core are connected, the two liquid passage holes are connected.

[0010] The outer surface of the isolation valve core is provided with an isolation valve retaining spring, and the inner wall of the isolation valve body has a retaining groove corresponding to the isolation valve retaining spring.

[0011] The compression sleeve is provided with a compression sleeve shear pin positioning sleeve, and an expansion rubber tube shear pin is connected inside the compression sleeve. An axial groove is opened on the side wall of the sealing tool. After the expansion rubber tube shear pin passes through the groove on the side wall of the sealing tool, its end is located on the outer wall of the compression sleeve.

[0012] The inner wall of the compression jacket is provided with a rubber sleeve anti-reverse spring, and the outer wall of the sealing tool body is provided with a groove corresponding to the rubber sleeve anti-reverse spring.

[0013] The outer surface of the compression sleeve is provided with a compression sleeve anti-reverse spring, and the inner wall of the sealing tool body is provided with a corresponding groove for the compression sleeve anti-reverse spring.

[0014] The lower part of the anchoring cylinder is threadedly connected to the anchoring anti-reverse ring, and the upper connector of the sealing tool is connected to the anchoring anti-reverse ring through an anchoring opening pin.

[0015] The present invention has the following beneficial effects: Due to the above-mentioned solution, the plugging tool is lowered into the designed position of the wellbore through the drill pipe, and the tool is expanded and anchored in the predetermined position by ball injection and pressure in the drill pipe before being released. It serves as an open hole bridge plug and artificial well bottom, which can be used to abandon the lower well section. It can also improve the cement plug bonding quality, shorten the construction time, and can also be used for open hole wellbore abandonment plugging. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram after the sealing construction.

[0017] In the diagram: 1-Infeed rod, 2-Stop block, 3-Release cylinder, 4-Release lower short circuit, 5-Release pin, 6-Anchor rod upper connecting ring, 7-Upper stop ring connecting pin, 8-Upper anchor rod, 9-Lower anchor rod, 10-Anchor rod pivot pin, 11-Anchor lower connecting ring, 12-Elastic sleeve, 13-Anchor connecting ring, 14-Anchor cylinder, 15-Anchor anti-reverse ring, 16-Anchor snap ring, 17-Anchor opening pin, 18-Sealing tool upper Connector, 19-Compression sleeve, 20-Isolation valve retaining ring, 21-Isolation valve body, 22-Isolation valve shear pin, 23-Isolation valve core, 24-Compression sleeve shear pin positioning sleeve, 25-Pressure expansion rubber tube shear pin, 26-Compression sleeve, 27-Compression sleeve downward shear pin, 28-Rubber tube anti-reverse retaining ring, 29-Rubber tube, 30-Compression sleeve anti-reverse retaining ring, 31-Blocking tool body, 32-Positioning sleeve, 33-Guide shoe, 34-Lower retaining ring connecting pin. Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings: Depend on Figure 1 , Figure 2 As shown, an open-hole well plugging tool includes a feed rod 1, the upper end of which is connected to the drill string, and the lower end of which is connected to a release connector 4. The feed rod 1 and the release connector 4 are connected by a stop block 2. The lower end of the feed rod 1 is located inside the release connector 4. The outer surface of the feed rod 1 is provided with a groove. Several stop blocks 2 are provided on the side wall of the release connector 4. The inside of the stop block 2 is located in the groove on the surface of the feed rod 1, and a release hydraulic cylinder 3 is provided outside the stop block 2. The release hydraulic cylinder 3 keeps the stop block 2 in the groove, thereby connecting the feed rod 1 and the release connector 4. The lower end of the release cylinder 3 is connected to the release lower short connector 4 by the release pin 5. When the release pin 5 is cut, the release cylinder 3 can slide down along the release lower short connector 4, thereby exposing the stop block 2. The stop block 2 then comes out from the groove on the side wall of the release lower short connector 4 and the surface of the feeding rod 1, thus separating the feeding rod 1 from the release lower short connector 4.

[0019] The lower part of the release connector 4 is threadedly connected to the upper connector 18 of the sealing tool. An anchoring liquid cylinder 14 is provided on the outside of the upper connector 18. An anchoring anti-reverse ring 15 is threadedly connected to the lower part of the anchoring liquid cylinder 14, and the upper connector 18 and the anchoring anti-reverse ring 15 are connected by an anchoring release pin 17. A liquid inlet hole is opened on the side wall of the upper connector 18, communicating with the anchoring liquid cylinder 14. An anchoring mechanism is provided on the lower outside of the lower end of the release connector 4, with the lower end of the anchoring mechanism located outside the upper connector 18. The anchoring mechanism includes an upper connecting ring 6 and a lower connecting ring 11. The upper connecting ring 6 is threadedly connected to the release connector 4, and the lower connecting ring 11 is connected to the anchoring liquid cylinder 14. The lower connecting ring 11 of the anchor rod is connected to the anchoring liquid cylinder 14 via an anchoring connecting ring 13. The anchoring connecting ring 13 consists of two semi-ring structures, which are fastened together by a snap-fit ​​and then welded into a whole. An elastic sleeve 12, made of rubber, is provided between the lower end face of the lower connecting ring 11 and the upper end face of the anchoring liquid cylinder 14. The anchoring connecting ring 13 encloses the elastic sleeve 12 inside. Several anchor rods are connected between the upper connecting ring 6 and the lower connecting ring 11 of the anchor rod. The number of anchor rods is preferably three, evenly distributed along the circumference. The anchor rod includes an upper anchor rod 8 and a lower anchor rod 9, wherein the upper anchor rod 8 and the lower anchor rod 9 are connected by an anchor rod pivot pin 10, allowing them to rotate relative to each other. The upper anchor rod 8 is connected to the lower end of the upper connecting ring 6 through an upper retaining ring connecting pin 7, and the lower anchor rod 9 is connected to the upper end of the lower anchor rod connecting ring 11 through a lower retaining ring connecting pin 34. Thus, when the anchor rod is subjected to axial force, the middle parts of the upper and lower anchor rods can extend outward, thereby anchoring to the inner wall of the well barrel.

[0020] The sealing tool's upper connector 18 is internally threaded to the sealing tool body 31. The sealing tool body 31 is internally connected to the compression sleeve 19 via a downward shear pin 27. The compression sleeve 19 is internally threaded to the isolation valve body 21, which contains an isolation valve core 23. The two are connected via an isolation valve shear pin 22. The outer surface of the isolation valve core 23 has an isolation valve retaining ring 20, and the inner wall of the isolation valve body 21 has a corresponding groove for the retaining ring 20. The side wall of the isolation valve body 21 has a valve body liquid passage hole, and the side wall of the isolation valve core 23 has a valve core liquid passage hole. When the retaining ring 20 is located within the groove on the inner wall of the isolation valve body 21, the isolation valve body 21 and the isolation valve core 23 are connected, and the two liquid passage holes are interconnected.

[0021] The sealing tool body 31 is externally provided with a rubber sleeve 29, and a compression jacket 26 is provided on the upper part of the rubber sleeve 29. Several circular holes are formed on the side wall of the compression jacket 26, and a compression jacket shear pin positioning sleeve 24 is provided inside each hole. An expansion rubber sleeve shear pin 25 is connected inside the compression jacket shear pin positioning sleeve 24. An axial groove is formed on the side wall of the sealing tool 31. After the expansion rubber sleeve shear pin 25 passes through the groove on the side wall of the sealing tool 31, its end is located on the outer wall of the compression jacket 19. The expansion rubber sleeve shear pin 25 can move axially along the groove on the side wall of the sealing tool 31. A rubber sleeve anti-reverse spring 28 is provided on the inner wall of the compression jacket 26, and a corresponding groove is provided on the outer wall of the sealing tool body 31. A compression sleeve anti-reverse spring 30 is provided on the outer surface of the compression jacket 19, and a corresponding groove is provided on the inner wall of the sealing tool body 31.

[0022] The lower end of the sealing tool body 31 is connected to a positioning sleeve 32, and the compression sleeve 19 can sit on the positioning sleeve 32 when it moves downward. The lower end of the sealing tool body 31 is connected to a guide shoe 33.

[0023] When plugging the wellbore, the feed rod 1 is connected to the lower end of the drill string and lowered into the pre-set position inside the open hole. A ball is dropped, and the steel ball falls into the isolation valve core 23, sealing the inner hole of the valve core. After pressurizing to 5 MPa, the isolation valve core 23 shears the isolation valve shear pin 22 and descends, closing the fluid passage holes on the side wall of the isolation valve core 23 and the isolation valve body 21. The pressure is further increased to 10 MPa, and the compression sleeve 19 shears the compression sleeve descending shear pin 27 and descends. Through the expansion rubber sleeve shear pin 25, the compression outer sleeve 26 expands the rubber sleeve 29, thereby sealing the open hole. After completion, the compression outer sleeve 26 and the plugging tool body 31 are locked by the rubber sleeve anti-reverse spring 28. The pressure is further increased to 12 MPa, and the compression sleeve 19 shears the expansion rubber sleeve shear pin 25 and continues to descend to the positioning inner sleeve 32, where it is locked to the plugging tool body 31 by the compression sleeve anti-reverse spring 30. Continue pressurizing to 15 MPa. The anchoring cylinder 14 shears the anchoring release pin 17 and moves upward, pushing the lower anchoring rod 9 to extend and insert into the open hole wellbore. After anchoring is completed, the anchoring anti-reverse ring 15 automatically locks with the upper connector 18 of the plugging tool via the anchoring snap ring 16. Continue pressurizing to 18 MPa. The release cylinder 3 shears the release pin 5 and moves downward. The stop block 2 loses its limit, and the drill string is lifted, bringing out the feed rod 1, thus releasing the drill string. At this point, pressure is released, and the operation is complete.

Claims

1. A plugging tool for open-hole wells, comprising a feed rod (1), characterized in that: The lower end of the feeding rod (1) is connected to the release lower short connector (4). The release lower short connector (4) is provided with an anchoring mechanism. The lower part of the release lower short connector (4) is connected to the upper connector (18) of the sealing tool. The upper connector (18) of the sealing tool is provided with an anchoring liquid cylinder (14). The upper connector (18) of the sealing tool is internally threaded to the sealing tool body (31). The sealing tool body (31) is internally connected to the compression sleeve (19) through the compression sleeve downward shear pin (27). The compression sleeve (19) is internally threaded to the isolation valve body (21). The isolation valve body (21) is internally connected to the isolation valve core (23) through the isolation valve shear pin (22). The isolation valve body (21) has a valve body liquid passage hole on its side wall, and the isolation valve core (23) has a valve core liquid passage hole on its side wall. When the isolation valve body (21) and the isolation valve core (23) are connected, the two liquid passage holes are connected. After the isolation valve core (23) moves down, the valve core liquid passage hole and the valve body liquid passage hole are closed. The outer surface of the isolation valve core (23) is provided with an isolation valve retaining ring (20), and the inner wall of the isolation valve body (21) is provided with a retaining groove corresponding to the isolation valve retaining ring (20); The sealing tool body (31) is provided with a rubber tube (29) on the outside. The rubber tube (29) is provided with a compression jacket (26) on the upper part. The compression jacket (26) is provided with a compression jacket shear pin positioning sleeve (24) on the side wall. The compression jacket shear pin positioning sleeve (24) is connected to the inside of the compression jacket shear pin (25). The sealing tool body (31) has an axial groove on the side wall. After the compression jacket shear pin (25) passes through the axial groove on the side wall of the sealing tool body (31), its end is located on the outer wall of the compression sleeve (19). When the compression sleeve (19) moves down, the compression jacket (26) is driven by the compression jacket shear pin (25) to compress the rubber tube (29). The lower end of the sealing tool body (31) is connected to a positioning sleeve (32). After the compression sleeve (19) cuts the compression sleeve shear pin (25), it continues to descend and sits on the positioning sleeve (32). The anchoring mechanism includes an upper connecting ring (6) and a lower connecting ring (11) for the anchoring rod. The upper connecting ring (6) is connected to the release lower short connector (4), and the lower connecting ring (11) is connected to the anchoring liquid cylinder (14). Several anchoring rods are connected between the upper connecting ring (6) and the lower connecting ring (11). The anchor rod includes an upper anchor rod (8) and a lower anchor rod (9), wherein the upper anchor rod (8) and the lower anchor rod (9) are connected by an anchor rod pivot pin (10), the upper anchor rod (8) is connected to the lower end of the upper connecting ring (6) of the anchor rod by an upper retaining ring connecting pin (7), and the lower anchor rod (9) is connected to the upper end of the lower connecting ring (11) of the anchor rod by a lower retaining ring connecting pin (34); The lower part of the anchoring cylinder (14) is threadedly connected to the anchoring anti-reverse ring (15), and the upper connector (18) of the sealing tool is connected to the anchoring anti-reverse ring (15) through the anchoring opening pin (17).

2. The open-hole well plugging tool according to claim 1, characterized in that: The lower end of the feeding rod (1) is located inside the lower short connector (4) of the release mechanism. A stop block (2) is provided on the side wall of the lower short connector (4). The inside of the stop block (2) is located in the groove of the outer wall of the feeding rod (1). A release liquid cylinder (3) is provided outside the stop block (2), and the release liquid cylinder (3) is connected to the lower short connector (4) of the release mechanism through a release pin (5).

3. The open-hole well plugging tool according to claim 1, characterized in that: The inner wall of the compression jacket (26) is provided with a rubber sleeve anti-reverse spring (28), and the outer wall of the sealing tool body (31) is provided with a groove corresponding to the rubber sleeve anti-reverse spring (28).

4. The open-hole well plugging tool according to claim 1, characterized in that: The outer surface of the compression sleeve (19) is provided with a compression sleeve anti-reverse spring (30), and the inner wall of the sealing tool body (31) is provided with a corresponding groove for the compression sleeve anti-reverse spring (30).

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