An active grabbing type recovery device for an inflatable bridge plug

Abstract

The application provides an active grabbing type recovery device for an inflatable bridge plug, comprising a fishing barrel, one end face of the fishing barrel is provided with an oil pressure cavity for communicating with a coiled tubing; a plurality of fishing claws are uniformly distributed around the circumference of the fishing barrel, the plurality of fishing claws are provided with clamping claw grooves for clamping a fishing head of the inflatable bridge plug; a hydraulic drive member is further included, the hydraulic drive member can make one end of the plurality of fishing claws provided with the clamping claw grooves tend to be close to each other under the action of the hydraulic pressure; a restoring element is further included, the restoring force of the restoring element can make the one end of the plurality of fishing claws provided with the clamping claw grooves tend to be far away from each other. The application overcomes the low fishing efficiency and poor fishing effect of the existing fishing tool for the through-tubing inflatable bridge plug, can be centered in the wellbore during running, and can press and grab the coiled tubing, the fault tolerance of fishing is high, and the operation efficiency and operation effect are greatly improved.

Description

An active gripping and recovery device for expanding bridge plugs Technical Field

[0001] This invention relates to the field of expansion bridge plug recycling technology, and more specifically, to an active gripping recycling device for expansion bridge plugs. Background Technology

[0002] If a malfunction occurs during oil and gas production, gas production, water injection, or gas injection, leading to a production stoppage or injection halt, manual intervention is required for well workover to eliminate the downhole fault and restore the well to normal operation. Well workover operations mainly include: retrieval, unsticking, pump inspection, casing repair, casing windowing, sand flushing, sand control, wax removal, unblocking, and perforation repair.

[0003] During well workover, blowout preventers such as gate valves at the wellhead need to be removed. After removing the blowout preventers, if the reservoir pressure is higher than the fluid column pressure in the wellbore, an uncontrolled blowout may occur, i.e., oil and gas gushing to the surface. Uncontrolled blowouts can cause significant safety hazards and serious environmental pollution accidents. Alternatively, during the construction of ash plugs, interference from the well's own conditions, such as inter-layer conflicts, well leakage, and well overflow, can lead to frequent failures in ash plug construction, increasing unnecessary workover cycles and causing significant cost waste for oilfield production. Furthermore, when dealing with misaligned casing wells and wells with severely deformed casing, to avoid complicating the construction and reduce the difficulty, a bridge plug needs to be installed at a certain distance below the misaligned or severely deformed casing area for isolation. Therefore, during gas well workover, an expansion bridge plug is often used to seal the production tubing to isolate the workover fluid from the lower reservoir, thereby achieving reservoir protection.

[0004] After well workover is completed, appropriate fishing tools need to be lowered to retrieve the tubing expansion bridge plug. The working principle of existing fishing tools is to engage the fishing cup and fishing head through impact. However, in actual application, due to factors such as well type and depth, the fishing tools are often difficult to center in the wellbore, resulting in repeated impacts and pressure that fail to engage the fishing cup and fishing head, leading to poor fishing efficiency and effect. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing tubing expansion bridge plug retrieval tools, which suffer from low retrieval efficiency and poor retrieval effect, and to provide an active gripping and recovery device for expansion bridge plugs. This invention can center itself in the wellbore during the running process and apply pressure to grip the coiled tubing, resulting in a high fault tolerance rate and significantly improving operational efficiency and effectiveness.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] An active gripping and recovery device for an expansion bridge plug includes a retrieval cylinder, one end face of which is provided with a hydraulic chamber for connecting to a continuous oil pipe; it also includes a plurality of retrieval claws evenly distributed around the circumference of the retrieval cylinder, one end of which is rotatably connected to the retrieval cylinder via a rotating shaft, and the other end of which extends out of the retrieval cylinder and is provided with a claw groove for engaging the expansion bridge plug retrieval head.

[0008] It also includes a hydraulic drive unit with one end connected to the oil pressure chamber and the other end connected to several retrieval claws. Under hydraulic action, the hydraulic drive unit can cause the ends of the several retrieval claws with claw grooves to tend to converge towards each other. It also includes a return element with one end fixedly connected to the retrieval cylinder and the other end connected to the retrieval claws. The return force of the return element can cause the ends of the several retrieval claws with claw grooves to tend to move away from each other.

[0009] It should be noted that when the coiled tubing connected to the hydraulic chamber is not pressurized, the retrieval claws are in their normal state. At this time, the restoring force of the restoring element causes the ends of the retrieval claws with the clasp grooves to tend to move away from each other, that is, the retrieval claws are in an outward-expanding state. During the lowering process, the retrieval claws being in an open state is conducive to centering the grabbing tool of the present invention in the wellbore. The device of the present invention can be lowered quickly and smoothly, and the retrieval head corresponding to the expansion bridge plug can be quickly aligned. After being lowered to the designated position, the retrieval process applies pressure by pumping liquid into the coiled tubing and controls the contraction and retraction of the retrieval claws. When the hydraulic pressure applied exceeds the restoring force of the return element, the hydraulic drive component, under hydraulic pressure, pushes the ends of several retrieval claws with clamping grooves to tend towards mutual convergence. During the retraction process, it can grasp the expansion bridge plug retrieval head within a certain range. Unlike traditional retrieval tools, it does not require impact to engage the retrieval cup and retrieval head. The actively opening and closing retrieval claws of this invention actively and effectively clamp the clamping grooves of the expansion bridge plug retrieval head during the retraction process. The error tolerance is higher than that of traditional retrieval tools, which can effectively improve the success rate of single retrieval. The operation is simple and effectively improves retrieval efficiency. After the retrieval claws grip the expansion bridge plug retrieval head, the upward action releases the rubber pressure of the expansion bridge plug in the oil pipe, thus releasing it from its sealing state and disengaging the oil pipe expansion packer.

[0010] It should also be noted that there are no strict requirements on the specific ratio between the retrieval claw and the retrieval cylinder. In order to ensure durability and practicality, the size of the retrieval claw needs to meet the following requirements: when the retrieval claw is fully open, it should be close to the size of the oil / sleeve that needs to be set; when the retrieval claw is fully retracted, it should be pressed against the groove of the expansion bridge plug retrieval head; the length of the retrieval claw should be as short as possible while still satisfying the function of gripping the expansion bridge plug retrieval head, so as to reduce energy loss.

[0011] Furthermore, the hydraulic chamber includes a pressure chamber located inside the retrieval tube, and a connecting pipe with one end connected to the pressure chamber and extending to the outside of the retrieval tube. The other end of the connecting pipe has an external thread for connecting to a continuous tubing. The extended connecting pipe facilitates the connection between the continuous tubing and the pressure chamber, resulting in a more rational design.

[0012] Furthermore, the hydraulic drive component includes a hydraulic cylinder connected to the hydraulic chamber, and a slider with one end connected to the output end of the hydraulic cylinder. The other end of the slider is connected to the retrieval claw. Driven by the output end of the hydraulic cylinder, the slider drives the retrieval claw to rotate around the rotation axis, causing the ends of the retrieval claws with clenching grooves to tend to converge towards each other. The slider and the retrieval claw are rotatably connected, and when the slider moves, it drives the retrieval claw to rotate around the rotation axis.

[0013] Furthermore, the restoring element is a spring. One end of the spring is fixedly connected to the retrieval cylinder, and the other end is connected to the retrieval claw. The restoring force of the spring pulls the retrieval claw to rotate around the rotation axis and causes the ends of the retrieval claws with clenching grooves to tend to move away from each other. In the initial state, the spring is compressed, and its restoring force is the elastic force that restores the deformation. The elastic force tends to return to the initial normal state, so it pushes the end of the retrieval claw connected to it and makes it rotate around the rotation axis, causing the ends of the retrieval claws with clenching grooves to tend to move away from each other and be in an open state.

[0014] Furthermore, the chuck groove consists of a first ratchet and a second ratchet protruding from the outer wall surface of the retrieval claw. The expansion bridge plug retrieval head has a chuck groove, which is generally a fish head. The fish head usually has a double groove design. By optimizing the size and spacing of the first and second ratchets of the retrieval claw, ideally, both grooves can be hooked at the same time. When the fish head is not centered and parallel to the wellbore, the double hook design makes it easier to hook the fish head groove and distribute the force evenly.

[0015] Furthermore, the angle α formed between the edge of the first and second ratchet teeth facing the retrieval tube and the outer wall surface of the retrieval claw is ≤90°. The barbed design makes it easier to engage the groove, improving the locking stability during retrieval.

[0016] Furthermore, the end of the retrieval claw with the chuck groove has a rounded transition end. The smooth transition end not only allows for centered lowering within the wellbore but also provides better maneuverability compared to fixed-diameter tools.

[0017] Furthermore, the number of retrieval claws is at least three. Three fixing points provide better stability, and the retrieval claws are evenly distributed on the outside of the retrieval tube at 120-degree intervals, which can meet most of the securing requirements.

[0018] Furthermore, the retrieval cylinder is a frustum-shaped retrieval cylinder, with a hydraulic chamber located on the bottom surface of the frustum-shaped retrieval cylinder. One end of several retrieval claws is rotatably connected to the outer wall of the frustum-shaped retrieval cylinder and close to the bottom surface, while the other end of several retrieval claws extends out of the top surface of the frustum-shaped retrieval cylinder.

[0019] Furthermore, the outer wall of the retrieval tube is provided with several limiting slots that match the shape and position of the retrieval claws. One end of several retrieval claws is rotatably connected to the limiting slots via a rotating shaft, and the other end of several retrieval claws can move in and out of the limiting slots when rotating.

[0020] The movement of the retrieval claws is restricted by the limiting slots, allowing them to move in and out only within the limiting slots. The frustum-shaped retrieval cylinder is larger at one end and smaller at the other. One end of each of the retrieval claws is rotatably connected to the outer wall of the frustum-shaped retrieval cylinder and close to the bottom surface. This provides a greater clamping force when the retrieval claws retract, ensuring a stable grip. At the same time, the frustum-shaped retrieval cylinder makes the device lighter and the structure more reasonable.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The device of this invention can be quickly and smoothly lowered, and the retrieval head corresponding to the expansion bridge plug is quickly aligned. After being lowered to the designated position, the retrieval process applies pressure by pumping liquid into the continuous tubing and controls the retraction action of the retrieval claws. When the injected hydraulic pressure is greater than the restoring force of the return element, the hydraulic drive component pushes the ends of several retrieval claws with the claw grooves to tend to retract towards each other under hydraulic action. During the retraction process, the retrieval head of the expansion bridge plug can be grabbed within a certain range. Unlike traditional retrieval tools, there is no need to use impact to make the retrieval cup and retrieval head engage. The actively opening and closing retrieval claws of this invention actively and effectively clamp the grooves of the expansion bridge plug retrieval head during the retraction process. The fault tolerance rate is higher than that of traditional retrieval tools, which can effectively improve the success rate of single retrieval. The operation is simple and effectively improves the retrieval efficiency. Attached Figure Description

[0023] Figure 1 is a structural schematic diagram of Embodiment 1 of the present invention;

[0024] Figure 2 is a schematic diagram of the movement of the retrieval claw in Embodiment 1 of the present invention;

[0025] Figure 3 is a schematic diagram of the snap-fit ​​structure of the retrieval claw and the expansion bridge plug retrieval head in Embodiment 2 of the present invention;

[0026] Figure 4 is a schematic diagram of the structure of the retrieval claw in Embodiment 3 of the present invention.

[0027] The markings in the diagram are explained below:

[0028] 1-Retrieval cylinder, 111-Pressure chamber, 112-Connecting pipe, 113-External thread, 12-Limiting groove, 2-Retrieval claw, 21-Claw groove, 211-First ratchet, 212-Second ratchet, 3-Rotating shaft, 4-Hydraulic drive component, 5-Returning element, 8-Expansion bridge plug retrieval head. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," 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 the present invention 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0031] Example 1

[0032] As shown in Figures 1 and 2, an active gripping and recovery device for an expansion bridge plug includes a retrieval cylinder 1, one end face of which is provided with a hydraulic chamber for connecting a continuous oil pipe; it also includes a plurality of retrieval claws 2 evenly distributed around the circumference of the retrieval cylinder 1, one end of the plurality of retrieval claws 2 being rotatably connected to the retrieval cylinder 1 via a rotating shaft 3, and the other end of the plurality of retrieval claws 2 extending out of the retrieval cylinder 1 and being provided with a claw groove 21 for engaging the expansion bridge plug retrieval head 8;

[0033] It also includes a hydraulic drive unit 4 with one end connected to the oil pressure chamber and the other end connected to a plurality of retrieval claws 2. Under hydraulic action, the hydraulic drive unit 4 can cause the ends of the plurality of retrieval claws 2 with claw grooves 21 to tend to converge towards each other. It also includes a return element 5 with one end fixedly connected to the retrieval cylinder 1 and the other end connected to the retrieval claws 2. The return force of the return element 5 can cause the ends of the plurality of retrieval claws 2 with claw grooves 21 to tend to move away from each other.

[0034] In this embodiment, the size of the retrieval claw 2 is designed to meet the following requirements for durability and practicality: when the retrieval claw 2 is fully open, it is slightly smaller than the size of the oil / sleeve that needs to be set; when the retrieval claw 2 is fully retracted, it is pressed against the groove of the expansion bridge plug retrieval head 8; the length of the retrieval claw 2 is minimized while still satisfying the function of gripping the expansion bridge plug retrieval head 8, thereby reducing energy loss.

[0035] As shown in Figure 2, the hydraulic chamber includes a pressure chamber 111 located inside the retrieval cylinder 1, and a connecting pipe 112 that connects to the pressure chamber 111 at one end and extends to the outside of the retrieval cylinder 1. The other end of the connecting pipe 112 is provided with an external thread 113 for connecting to a continuous tubing. The extended connecting pipe 112 facilitates the connection between the continuous tubing and the pressure chamber 111, making the design more reasonable.

[0036] In this embodiment, the hydraulic drive component 4 includes a hydraulic cylinder connected to the hydraulic chamber, and a slider with one end connected to the output end of the hydraulic cylinder. The other end of the slider is connected to the retrieval 2. Driven by the output end of the hydraulic cylinder, the slider drives the retrieval claws 2 to rotate around the rotation axis 3, and causes the ends of the retrieval claws 2 with the claw grooves 21 to tend to converge towards each other. The slider and the retrieval claws 2 are rotatably connected. When the slider moves, it drives the retrieval claws 2 to rotate around the rotation axis 3.

[0037] In this embodiment, the restoring element 5 is a spring. One end of the spring is fixedly connected to the retrieval cylinder 1, and the other end of the spring is connected to the retrieval claw 2. The restoring force of the spring pulls the retrieval claw 2 to rotate around the rotation axis 3, and causes the ends of the retrieval claws 2 with the claw grooves 21 to tend to move away from each other. In the initial state, the spring is in a compressed state, and its restoring force is the elastic force that restores the deformation. The elastic force tends to return to the initial normal state, so it pushes the end of the retrieval claw 2 connected to it and makes it rotate around the rotation axis 3, causing the ends of the retrieval claws 2 with the claw grooves 21 to tend to move away from each other and be in an open state.

[0038] In this embodiment, there are three retrieval claws 2. The three fixing points provide better stability, and the retrieval claws are evenly distributed on the outside of the retrieval cylinder at 120-degree intervals, which can meet most of the locking requirements.

[0039] As shown in Figures 1 and 2, the retrieval cylinder 1 is a frustum-shaped retrieval cylinder. The hydraulic chamber is located on the bottom surface of the frustum-shaped retrieval cylinder. One end of several retrieval claws 2 is rotatably connected to the outer wall of the frustum-shaped retrieval cylinder and close to the bottom surface. The other end of several retrieval claws 2 extends out of the top surface of the frustum-shaped retrieval cylinder.

[0040] As shown in Figures 1 and 2, the outer wall of the retrieval cylinder 1 is also provided with several limiting slots 12 that match the shape and position of the retrieval claws 2. One end of several retrieval claws 2 is rotatably connected to the limiting slots 12 through the rotating shaft 3, and the other end of several retrieval claws 2 can move in and out of the limiting slots 12 when rotating.

[0041] As shown in Figure 2, the movement of the retrieval claws is restricted by the limiting slot 12, and they can only move in and out of the limiting slot 12. The frustum-shaped retrieval cylinder is larger at one end and smaller at the other. One end of several retrieval claws 2 is rotatably connected to the outer wall of the frustum-shaped retrieval cylinder and close to the bottom surface. In this way, when the retrieval claws retract, they can provide a greater retraction clamping force to ensure stable clamping. At the same time, the frustum-shaped retrieval cylinder makes the device lighter and the structure more reasonable.

[0042] The operating principle of this embodiment is as follows: When the continuous tubing connected to the hydraulic chamber is not pressurized, the retrieval claws are in a normal state. At this time, the restoring force of the restoring element 5 can cause the ends of several retrieval claws 2 with the claw grooves 21 to move away from each other, that is, the retrieval claws 2 are in an outward expansion state. During the lowering process, the retrieval claws 2 are in an open state, which is conducive to centering the grabbing tool of this embodiment in the wellbore. The device can be lowered quickly and smoothly, and the retrieval head corresponding to the expansion bridge plug can be quickly aligned. After being lowered to the designated position, the retrieval process applies pressure by pumping liquid into the continuous tubing and controls the contraction action of the retrieval claws 2. When the injected hydraulic pressure exceeds the restoring force of the restoring element 5, the hydraulic drive component 4, under hydraulic action, pushes the ends of several retrieval claws 2 with claw grooves 21 to retract towards each other. During the retraction process, it can grab the expansion bridge plug retrieval head 8 within a certain range. Unlike traditional retrieval tools, it does not require impact to engage the retrieval cup and retrieval head. In this embodiment, the actively opening and closing retrieval claws 2 actively and effectively clamp the grooves of the expansion bridge plug retrieval head 8 during the retraction process. The fault tolerance rate is higher than that of traditional retrieval tools, which can effectively improve the success rate of single retrieval. The operation is simple and effectively improves the retrieval efficiency. After the retrieval claws 2 grip the expansion bridge plug retrieval head 8, the pressure of the expansion bridge plug rubber through the oil pipe is released by the lifting action, thus releasing the sealing state of the expansion packer through the oil pipe.

[0043] Example 2

[0044] This embodiment is similar to Embodiment 1, except that in this embodiment:

[0045] As shown in Figure 3, the end of the retrieval claw 2 with the claw groove 21 has a rounded transition end. The smooth transition end not only allows for centered lowering in the wellbore, but also provides better maneuverability compared to fixed-diameter tools.

[0046] As shown in Figure 3, the chuck groove 21 consists of a first ratchet 211 and a second ratchet 212 protruding from the outer wall surface of the retrieval claw 2. The expansion bridge plug retrieval head 8 has a chuck groove, which is generally fish-head shaped. The fish head is usually designed with double grooves. By optimizing the size and spacing of the first ratchet 211 and the second ratchet 212 of the retrieval claw 2, it can ideally hook the double grooves at the same time. When the fish head is not centered and parallel to the wellbore, the double hook design makes it easier to hook the fish head grooves and distribute the force evenly.

[0047] The other structures and principles of this embodiment are the same as those of Embodiment 1.

[0048] Example 3

[0049] This embodiment is similar to Embodiment 2, except that in this embodiment:

[0050] As shown in Figure 4, the angle α formed by the toothed edge of the first ratchet 211 and the second ratchet 212 facing the retrieval cylinder 1 and the outer wall surface of the retrieval claw 2 is ≤90°. The barbed design makes it easier to engage the groove, improving the locking stability during retrieval.

[0051] The other structures and principles of this embodiment are the same as those of Embodiment 2.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An active gripping and recycling device for expanding bridge plugs, characterized in that, The system includes a retrieval cylinder (1), one end of which is provided with a hydraulic chamber for connecting a continuous oil pipe; it also includes a plurality of retrieval claws (2) evenly distributed around the circumference of the retrieval cylinder (1), one end of which is rotatably connected to the retrieval cylinder (1) via a rotating shaft (3), and the other end of which extends out of the retrieval cylinder (1) and is provided with a claw groove (21) for engaging the expansion bridge plug retrieval head; it also includes a hydraulic drive component (4) with one end connected to the hydraulic chamber and the other end connected to the plurality of retrieval claws (2), the hydraulic drive component (4) Under hydraulic pressure, the ends of the several retrieval claws (2) with claw grooves (21) can tend to converge towards each other; it also includes a return element (5) with one end fixedly connected to the retrieval cylinder (1) and the other end connected to the retrieval claws (2), the return force of the return element (5) can cause the ends of the several retrieval claws (2) with claw grooves (21) to tend to move away from each other; the hydraulic chamber includes a pressure chamber (111) opened inside the retrieval cylinder (1), and a connecting pipe (112) with one end connected to the pressure chamber (111) and extending to the outside of the retrieval cylinder (1), the The other end of the connecting pipe (112) is provided with an external thread (113) for connecting to a continuous oil pipe; the hydraulic drive (4) includes a hydraulic cylinder communicating with the oil pressure chamber, and a slider with one end connected to the output end of the hydraulic cylinder, the other end of the slider being connected to the retrieval claw (2), the slider being driven by the output end of the hydraulic cylinder to drive the retrieval claw (2) to rotate around the rotating axis (3) and causing the ends of the retrieval claws (2) with the claw grooves (21) to tend to converge towards each other; the return element (5) is a spring, one end of the spring being fixedly connected to the retrieval On the cylinder (1), the other end of the spring is connected to the retrieval claw (2). The restoring force of the spring pulls the retrieval claw (2) to rotate around the rotating axis (3) and causes the ends of the retrieval claws (2) with the claw grooves (21) to tend to move away from each other. The claw grooves (21) are composed of a first ratchet (211) and a second ratchet (212) protruding from the outer wall surface of the retrieval claw (2). The angle α formed between the tooth edge of the first ratchet (211) and the outer wall surface of the retrieval claw (2) facing the retrieval cylinder (1) and the side of the retrieval claw (2) is ≤90°.

2. The active gripping and recycling device for expanding bridge plugs according to claim 1, characterized in that, The retrieval claw (2) has a claw groove (21) at one end, which is a rounded transition end.

3. The active gripping and recycling device for expanding bridge plugs according to claim 1, characterized in that, The number of the salvage claws (2) is at least three.

4. The active gripping and recycling device for expanding bridge plugs according to claim 1, characterized in that, The retrieval cylinder (1) is a frustum-shaped retrieval cylinder. The hydraulic chamber is located on the bottom surface of the frustum-shaped retrieval cylinder. One end of each of the retrieval claws (2) is rotatably connected to the outer wall of the frustum-shaped retrieval cylinder and close to the bottom surface. The other end of each of the retrieval claws (2) extends out of the top surface of the frustum-shaped retrieval cylinder.

5. The active gripping and recycling device for expansion bridge plugs according to claim 4, characterized in that, The outer wall of the retrieval cylinder (1) is also provided with several limiting slots (12) that match the shape and position of the retrieval claws (2). One end of each of the retrieval claws (2) is rotatably connected to the limiting slots (12) via a rotating shaft (3). The other end of each of the retrieval claws (2) can move in and out of the limiting slots (12) when rotating.

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