Hydraulic reset catch release tool

Abstract

The application provides a hydraulic reset grabbing and releasing tool. The tool comprises an upper joint, an upper mandrel, a central pipe and a lower central pipe which are connected in sequence and constitute a first axial body, a first elastic mechanism, a second axial body, a second elastic mechanism and an elastic slip which are sleeved on the first axial body in sequence, a throttling assembly, a first cavity formed between the second axial body and the second axial body, a locking mechanism installed in the first cavity, the throttling assembly arranged in the central pipe, a plurality of through holes formed in the central pipe and communicated with the first cavity, and a differential pressure forming mechanism formed by the throttling assembly and the central pipe. The method is simple, and can be used to smoothly implement drag fracturing in an oil and gas well with large differences in reservoir thickness, large well inclination and complex well conditions. The hydraulic reset grabbing and releasing tool can cooperate with a butt joint cylinder, and can completely rely on the hydraulic pressure and liquid flow in the fracturing pipe column to implement the releasing or grabbing of the bottom drag packer.

Description

Technical Field

[0001] This invention relates to the field of fracturing operations in oil and gas development and extraction technology, and more specifically, to a hydraulic reset gripping and release tool. Background Technology

[0002] Multi-stage fracturing with a single tubing string is a common production enhancement method used in the development of unconventional oil and gas fields both domestically and internationally. The tubing string used in fracturing operations typically consists of "bottom drag packer + sandblaster + top packer" from bottom to top. The operation method is as follows: the fracturing string is lowered to the design depth of the first target layer, the bottom drag packer is set, the top packer is set, and then fracturing fluid and proppant are injected into the formation through the tubing and sandblaster to the design pressure, completing the fracturing of this layer; the fracturing string is then pulled up, the top packer is released, the bottom drag packer is released, and then the string is pulled up to the design depth of the second target layer, the bottom drag packer is set, the top packer is set, and then fracturing fluid and proppant are injected into the formation through the tubing and sandblaster to the design pressure, completing the fracturing of the second layer; multi-stage fracturing is carried out sequentially layer by layer.

[0003] The distance between the bottom drag packer and the sandblaster and top packer in the above-mentioned fracturing string is fixed, which is more suitable for fracturing multiple reservoirs with relatively uniform reservoir thickness. Once the reservoir thickness varies greatly, the fracturing string must be removed, the piping re-connected, and the distance between the bottom drag packer and the sandblaster and top packer adjusted before the fracturing string is lowered again to continue the fracturing operation of the next layer.

[0004] Existing technology provides a reverse pressure-resetting grabbing tool, connected between the sandblaster and the bottom drag packer, and inserted into the well along with the fracturing string. After the bottom drag packer is set, the reverse pressure-resetting grabbing tool can be separated into two parts—a grabbing tool and a docking sleeve—by positive pressure within the fracturing string. The docking sleeve, connected to the bottom drag packer, remains in its original position, while the grabbing tool, connected to the sandblaster, can be lifted to any designed position with the fracturing string after being released from the docking sleeve, thus adapting to any reservoir thickness. After fracturing of the current layer is completed, the grabbing tool is lowered to dock with the docking sleeve. By reverse pressure in the annulus, the grabbing tool catches the docking sleeve. At this point, lifting the fracturing string can drag the bottom drag packer to a designated position in another fracturing layer.

[0005] The reverse pressure-reset grabbing tool has a simple structure and is easy to maintain on site, but its application range is limited. It is more suitable for vertical wells, wellbore conditions that are good, and oil and gas wells with good packer setting conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome at least one of the aforementioned shortcomings of the prior art. For example, one objective of this invention is to enable the successful implementation of drag fracturing in oil and gas wells with large reservoir thickness differences, high well inclination, and complex well conditions.

[0007] To achieve the above objectives, the present invention provides a hydraulic reset gripping and release tool.

[0008] The tool includes: an upper connector, an upper mandrel, a central tube, and a lower central tube connected in sequence to form a first axial body; a first elastic mechanism, a second axial body, a second elastic mechanism, and an elastic collet sequentially sleeved on the body of the first axial body; and a throttling assembly; a first cavity is formed between the second axial body and the second axial body; a locking mechanism is installed in the first cavity; the throttling assembly is disposed inside the central tube, and the central tube has several through holes that communicate with the first cavity; the throttling assembly and the central tube constitute a pressure differential forming mechanism.

[0009] Furthermore, the locking mechanism includes a locking ring, a locking sleeve, and a support sleeve; wherein, the locking ring is connected to the left end of the connecting sleeve; the locking sleeve is connected to the upper spindle, and a boss is provided at the right end of the locking sleeve, and an inner cavity is formed between the locking sleeve and the central tube; the support sleeve is sleeved on the central tube and located in the inner cavity, and a boss is provided at the right end of the support sleeve.

[0010] Furthermore, the boss on the lock sleeve is of the multi-lobed elastic claw type; the internal thread of the lock ring can engage with the boss.

[0011] Furthermore, the tool also includes a third elastic mechanism, which is sleeved on the central tube and located in the inner cavity, with the third elastic element located on the right side of the support sleeve.

[0012] Furthermore, the pressure throttling assembly includes an upper bushing, a throttling seat, and a lower bushing arranged sequentially.

[0013] Furthermore, the first, second, and third elastic elements can all include springs.

[0014] Furthermore, the upper bushing is provided with a through hole, and the lower bushing is also provided with a through hole.

[0015] Furthermore, a through hole is provided at the left end of the main body of the central tube, which corresponds to the through hole on the upper bushing but the central axes of the two are separated by a certain distance; a through hole is provided at the right end of the main body of the central tube, which corresponds to the through hole on the lower bushing but the central axes of the two are separated by a certain distance.

[0016] Furthermore, the upper bushing and the central tube are fitted with a clearance fit; the lower bushing and the central tube are also fitted with a clearance fit.

[0017] Furthermore, the throttling seat and the central tube are sealed with a non-metallic seal; the inner surface of the throttling seat is a small circular hole with tapered chamfers at both ends, the chamfer angle being 30° to 45°.

[0018] Furthermore, the tool also includes a spring sleeve, the left end of which is threaded to the right end of the connecting sleeve, and a second cavity is formed between the spring sleeve and the second axial body; the second elastic mechanism is located in the second cavity, the left end of the elastic collet is located in the second cavity, and the rest is located outside the second cavity.

[0019] Furthermore, the outer surface of the lower central tube is provided with a groove and a boss; the right end of the spring sleeve is provided with an inner boss; both ends of the elastic collet are bosses; wherein, the left boss and the inner boss of the spring sleeve limit the movement, and when the right boss of the elastic collet is in the position of the boss of the lower central tube, the right boss is opened; when the right boss of the elastic collet is in the position of the groove of the lower central tube, the right boss retracts.

[0020] Furthermore, the right-side boss is divided into multiple lobe elastic claw shapes.

[0021] Furthermore, the tool is used in conjunction with the docking cylinder.

[0022] Compared with the prior art, the beneficial effects of the present invention include: the method of the present invention is simple and can be smoothly implemented in oil and gas wells with large differences in reservoir thickness, large well inclination and complex well conditions; the hydraulic reset grab release tool of the present invention, through cooperation with the docking tube, can implement the release or grab of the bottom drag packer by relying entirely on the hydraulic pressure and fluid flow rate inside the fracturing string. Attached Figure Description

[0023] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of the docking cylinder is shown;

[0025] Figure 2 A schematic diagram of a hydraulic reset gripping release tool is shown.

[0026] Figure 3 A schematic diagram of the locking mechanism is shown;

[0027] Figure 4 A schematic diagram of a differential pressure generating mechanism is shown.

[0028] Figure 5 A schematic diagram of an open-loop locking ring is shown.

[0029] Explanation of key figure labels:

[0030] 1. Fishing groove; 2. Well washing through hole; 3. Sealing cavity; 4. Check valve;

[0031] Upper connector 5, first spring 6, upper spindle 7, upper cylinder liner 8, upper bushing 9, locking sleeve 10, support sleeve 11, throttle seat 12, center tube 13, locking ring 14, internal thread 14a, external thread 14b, lower bushing 15, connecting sleeve 16, second spring 17, spring sheath 18, third spring 19, lower center tube 20, elastic slip 21, sealing ring 22. Detailed Implementation

[0032] In the following description, a hydraulic reset gripping and releasing tool of the present invention will be explained in detail with reference to exemplary embodiments.

[0033] Exemplary Example 1

[0034] This exemplary embodiment provides a hydraulically reset gripping and releasing tool.

[0035] Figure 1 A schematic diagram of the docking cylinder is shown; Figure 2 A schematic diagram of a hydraulic reset gripping release tool is shown. Figure 3 A schematic diagram of the locking mechanism is shown; Figure 4 A schematic diagram of a differential pressure generating mechanism is shown. Figure 5 A schematic diagram of an open-end locking ring is shown, where 14a is the internal thread and 14b is the external thread. The following is in conjunction with... Figures 1 to 5 The present invention describes a hydraulic reset gripping and release tool.

[0036] The hydraulic reset gripping and releasing tool of the present invention is used in conjunction with a docking cylinder. The docking cylinder has the following structural shape: Figure 1 As shown, it includes functional components such as a retrieval groove 1, a well cleaning through hole 2, a sealing cavity 3, and a one-way valve 4.

[0037] At the start of the operation, the hydraulic reset grab release tool is connected to the docking sleeve, which is then placed between the sandblaster and the bottom drag packer and inserted into the well along with the fracturing string. After the bottom drag packer is set, hydraulic pressure is applied inside the fracturing string, causing the hydraulic reset grab release tool to disengage from the docking sleeve. The docking sleeve, connected to the bottom drag packer, remains in the same position, while the hydraulic reset grab release tool, connected to the sandblaster, can be raised to any designed position along with the fracturing string after disengagement from the docking sleeve, thus adapting to any reservoir thickness. Subsequently, when high-volume pumping is performed inside the fracturing string, all components of the hydraulic reset grab release tool automatically reset.

[0038] In other words, the hydraulic reset gripping release tool of the present invention, through cooperation with the docking cylinder, can release or grip the bottom-dragging packer entirely by relying on the hydraulic pressure and fluid flow inside the fracturing string.

[0039] The technical solution of the hydraulic reset gripping and releasing tool of the present invention is as follows:

[0040] The tool consists of an upper connector 5, a first spring 6, an upper mandrel 7, an upper cylinder liner 8, an upper bushing 9, a locking sleeve 10, a support sleeve 11, a throttle seat 12, a central tube 13, a locking ring 14, a lower bushing 15, a connecting sleeve 16, a second spring 17, a spring sheath 18, a third spring 19, a lower central tube 20, an elastic slip 21, and a sealing ring 22. It should be noted that the terms "first," "second," and "third" are used only to distinguish them from each other and have no specific meaning regarding their order.

[0041] One end of the upper spindle 7 has an external thread, which connects to the upper connector 5; the other end has two threads, an internal thread, which connects to the central tube 13, and an external thread, which connects to the locking sleeve 10; there is a boss in the middle of the outer surface.

[0042] The first spring 6 and the upper cylinder liner 8 enter from the left end of the upper mandrel 7 and are loosely fitted on the outer surface of the upper mandrel 7.

[0043] The upper cylinder liner 8 has a step on the left end of its inner hole and a thread on the right end. Except for the step on the left end which is blocked by the boss in the middle of the outer surface of the upper mandrel 7, the rest of the step passes over the boss in the middle of the outer surface of the upper mandrel 7 and is loosely fitted on the outer surfaces of the upper mandrel 7 and the locking sleeve 10.

[0044] The outer surface of the connecting sleeve 16 is threaded at both ends. The threaded left end connects to the upper cylinder liner 8, and the threaded right end connects to the spring sleeve 18.

[0045] The left end of the inner cavity of the connecting sleeve 16 has a special-shaped internal thread, the right end has a smooth round hole with a larger diameter, and the middle part has a smooth round hole with a smaller diameter. These two smooth round holes with different diameters act as pistons.

[0046] The third spring 19 and the elastic slip 21 are fitted into the cavity formed by the connecting sleeve 16 and the spring sleeve 18; when the axial force on the elastic slip 21 reaches a certain value, it can overcome the elastic force of the third spring 19 and move axially.

[0047] When the connecting sleeve 16 moves, it will drive the upper cylinder liner 8, locking ring 14, spring sleeve 18, elastic slip 21 and other components to move synchronously.

[0048] The left end of the lock sleeve 10 has an internal thread that connects to the upper spindle 7; the right end has a boss, which is a multi-lobed elastic claw type, and the outer surface of the boss has a special-shaped thread; the entire lock sleeve 10 is fitted into the inner cavity of the upper cylinder liner 8.

[0049] The outer surface of the central tube 13 has an external thread on the left end that connects to the upper mandrel 7, and an internal thread on the right end that connects to the lower central tube 20. In addition to the threads, there are four cylindrical surfaces from left to right, with diameters increasing from small to large, which are the first to fourth cylindrical surfaces.

[0050] The central tube 13 has three through holes, located between the external thread and the first cylindrical surface, in the middle of the second cylindrical surface, and between the third and fourth cylindrical surfaces, respectively; the third and fourth cylindrical surfaces are non-metallic sealing surfaces, which cooperate with the two smooth round holes in the inner cavity of the connecting sleeve 16 for sealing.

[0051] The inner surface of the central tube 13 has two smooth circular holes of different diameters, with the left-end hole having a larger diameter.

[0052] The upper bushing 9, the throttle seat 12, and the lower bushing 15 are all loosely fitted inside the round hole at the left end of the central tube 13.

[0053] The upper bushing 9 has a through hole on its body, and the central axis of this through hole is a certain distance away from the central axis of the through hole at the left end of the central tube 13 body; the outer surface of the upper bushing 9 is in clearance fit with the inner cavity of the central tube 13.

[0054] The outer surface of the throttle seat 12 is a non-metallic sealing surface, which is sealed by fitting with the left end round hole of the central tube 13.

[0055] The inner surface of the throttle seat 12 is a small circular hole with tapered chamfers at both ends, with a cone angle of 30° to 45°.

[0056] The lower bushing 15 has a through hole on its body, and the central axis of this through hole is a certain distance away from the central axis of the through hole in the middle of the second cylindrical surface of the central tube 13.

[0057] The outer surface of the lower bushing 15 is fitted with the inner cavity of the central tube 13 with clearance.

[0058] The locking ring 14 is located inside the thread on the left end of the connecting sleeve 16 and is an open ring.

[0059] The inner and outer surfaces of the locking ring 14 are both special threads. The external thread engages with the left end thread of the connecting sleeve 16; the internal thread engages with the external thread of the right end boss of the locking sleeve 10.

[0060] The outer surface of the left end of the support sleeve 11 is a non-metallic sealing surface, while the outer surface of the right end is a boss.

[0061] The support sleeve 11 and the second spring 17 are loosely fitted on the first cylindrical surface of the outer surface of the central tube 13, and both are located in the inner cavity of the locking sleeve 10.

[0062] The lower central tube 20 has threaded ends, one end is connected to the central tube 13, and the other end is connected to the sealing ring 22; there is a groove and a boss in the middle of the outer surface.

[0063] Both ends of the elastic slip 21 are protrusions, and the left protrusion is limited by the protrusion inside the spring sleeve 18, while the right protrusion is divided into multiple elastic claw shapes. When the protrusion of the elastic slip 21 is in the position of the protrusion of the lower central tube 20, the protrusion of the elastic slip 21 is opened. When the protrusion of the elastic slip 21 is in the position of the groove of the lower central tube 20, the protrusion of the elastic slip 21 retracts.

[0064] The left end of the sealing ring 22 is threaded and connected to the lower central tube 20; the right end is a sealing surface that mates with the sealing cavity 3 of the docking cylinder.

[0065] The locking mechanism will be further explained below.

[0066] The locking mechanism consists of a locking ring 14, a locking sleeve 10, and a support sleeve 11. The locking ring 14 is located inside the threaded left end of the connecting sleeve 16 and is an open ring. Both the inner and outer surfaces of the locking ring 14 have special threads. The external thread engages with the threaded left end of the connecting sleeve 16, and the internal thread engages with the external thread of the right end boss of the locking sleeve 10. The left end of the locking sleeve 10 has an internal thread and connects to the upper mandrel 7; the right end has a boss, which is a multi-lobed elastic claw type with a specially shaped thread on its outer surface. The outer surface of the left end of the support sleeve 11 is a non-metallic sealing surface, and the outer surface of the right end is a boss.

[0067] Under normal circumstances, the support sleeve 11 supports the lower part of the locking sleeve 10, and the locking ring 14 is located on the right side of the locking sleeve 10. When the locking sleeve 10 is subjected to an axial force to the left, its inner diameter expands and moves to the left along the axial direction. The locking sleeve 10 and the locking ring 14 engage through a special thread, locking the position of the locking ring. When the support sleeve 11 is subjected to an axial force to the right, the support sleeve 11 moves to the right side of the locking sleeve 10, the inner diameter of the locking sleeve 10 shrinks, releasing the locking ring 14, and the locking ring 14 returns to the right side of the locking sleeve.

[0068] The pressure differential forming mechanism will be further explained below.

[0069] The differential pressure generating mechanism consists of a central tube 13, an upper bushing 9, a throttling seat 12, and a lower bushing 15. The upper bushing, throttling seat, and lower bushing are installed in the inner cavity of the central tube in a left-to-right order, with a clearance fit between the upper and lower bushings and the central tube. Both the bushings and the lower bushing have guide holes (also called through holes), and the central tube also has guide holes at corresponding positions on the upper and lower bushings, but the central axes of these guide holes are spaced a certain distance apart. Specifically:

[0070] The inner surface of the central tube 13 has two smooth circular holes of different diameters. The diameter of the circular hole at the left end is larger. The upper bushing 9, the throttle seat 12 and the lower bushing 15 are all loosely fitted inside the circular hole at the left end.

[0071] The upper bushing 9 has a through hole, and the central axis of this through hole is a certain distance away from the central axis of the through hole between the external thread of the central tube 13 and the first cylindrical surface; the outer surface of the upper bushing 9 is in clearance fit with the inner cavity of the central tube 13.

[0072] The outer surface of the throttle seat 12 is a non-metallic sealing surface, which is sealed with the left end of the central tube 13 through a circular hole; the inner surface of the throttle seat 12 is a small circular hole with tapered chamfers at both ends, with a cone angle of 30° to 45°.

[0073] The lower bushing 15 has a through hole, and the central axis of this through hole is separated from the central axis of the through hole between the third and fourth cylindrical surfaces of the central tube 13 by a certain distance. The outer surface of the lower bushing 15 is in clearance fit with the inner cavity of the central tube 13.

[0074] The tool of this invention can retrieve the docking cylinder by pressing it down; by applying hydraulic pressure to the tool's inner cavity, then depressurizing and lifting the tool, the docking cylinder can be released; by injecting a large flow of fluid (positive well washing or positive fracturing fluid) into the tool's inner cavity, the various components of the tool can be restored to their original state.

[0075] To better understand the above exemplary embodiments, the implementation process is further explained below.

[0076] Implementation Procedure 1: Connecting the drop tool to the docking tube

[0077] 1) The gripping tool presses down on the docking cylinder;

[0078] 2) The elastic slip 21 is subjected to the pressure of the docking cylinder, compresses the third spring 19, and moves to the left. When the boss of the elastic slip 21 is in the groove position of the lower central tube 20, the boss of the elastic slip 21 retracts.

[0079] 3) The docking cylinder loses its constraint on the elastic slip 21;

[0080] 4) The third spring 19 pushes the elastic slip 21 to the right, and the protrusion of the elastic slip 21 enters the docking cylinder's retrieval groove 1;

[0081] 5) The third spring 19 pushes the elastic slip 21 to continue moving to the right. When the boss of the elastic slip 21 is in the position of the boss of the lower central tube 20, the boss of the elastic slip 21 is opened. At this time, the grabbing tool catches the docking cylinder.

[0082] Implementation Procedure Two: Release the tool and docking cylinder from your hands

[0083] 1) Apply hydraulic pressure to the inner cavity of the release tool; at this time, control the injection flow rate within a certain range so that the throttle seat 12 does not generate a throttling pressure difference;

[0084] 2) The hydraulic pressure is transmitted through the through holes of the third and fourth cylindrical surfaces of the central tube 13 to the unequal diameter sealing surfaces of the inner cavity of the connecting sleeve 16, and pushes the connecting sleeve 16 to move to the left.

[0085] 3) The locking ring 14, which is connected to the connecting sleeve 16 by a thread, moves to the left in sync with the right end boss of the locking sleeve 10, and the internal and external threads of the two engage.

[0086] 4) The upper cylinder sleeve 8, which is connected to the connecting sleeve 16 by a thread, compresses the first spring 6 synchronously and moves to the left;

[0087] 5) The spring sleeve 18, which is connected to the connecting sleeve 16 by a thread, moves to the left in sync, and drives the third spring 19 and the elastic slip 21 in the cavity to move to the left in sync.

[0088] 6) When the boss of the elastic slip 21 is in the groove position of the lower central tube 20, the boss of the elastic slip 21 retracts.

[0089] 7) Stop applying hydraulic pressure to the inside of the disarm tool and depressurize it to zero;

[0090] 8) The locking ring 14 engages with the right end thread of the locking sleeve 10 and remains in its current position. The connecting sleeve 16 and the upper cylinder sleeve 8, spring sleeve 18, third spring 19, and elastic slip 21 connected to it also remain in their current positions. That is, the boss of the elastic slip 21 remains in the groove position of the lower central tube 20. At this time, lifting the release tool will release it from the docking cylinder.

[0091] Implementation Step 3: Reset all parts of the discarded tool

[0092] 1) Inject a large flow of fluid (positive well washing or positive fracturing fluid) into the cavity of the hand-dropping tool;

[0093] 2) Throttling seat 12 generates a throttling pressure difference, with the hydraulic pressure at its left end being greater than that at its right end;

[0094] 3) The hydraulic pressure at the left end of the throttle seat 12 is transmitted to the left end of the support sleeve 11 through the through hole of the upper bushing 9 body and the through hole between the external thread of the central tube 13 body and the first cylindrical surface; the hydraulic pressure at the right end of the throttle seat 12 is transmitted to the right end of the support sleeve 11 through the through hole of the lower bushing 15 and the through hole at the right end of the central tube 13 body; since the hydraulic pressure at the left end is greater than the hydraulic pressure at the right end, the pressure difference overcomes the elastic force of the second spring 17, pushing the support sleeve 11 to move to the right until the boss at the right end of the support sleeve 11 is completely disengaged from the boss at the right end of the locking sleeve 10; at this time, the locking ring 14 loses its restraining force;

[0095] 4) The elastic force of the first spring 6 pushes the upper cylinder sleeve 8 to move to the right, and drives the connecting sleeve 16, locking ring 14, spring sleeve 18, third spring 19 and elastic slip 21 to move to the right in sync, until the locking ring 14 completely disengages from the boss at the right end of the locking sleeve 10, and the boss of the elastic slip 21 is located at the boss position of the lower central tube 20.

[0096] 5) Stop injecting fluid (positive well washing or positive fracturing fluid) into the cavity of the disengagement tool at a high flow rate, and depressurize to zero;

[0097] 6) The elastic force of the second spring 17 pushes the support sleeve 11 to move to the left and return to its original position; at this time, all parts of the release tool have returned to their original positions;

[0098] 7) Repeat steps one through three to perform the work on the next level.

[0099] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A hydraulic resetting gripping and releasing tool, characterized in that, The tool includes: an upper connector, an upper mandrel, a central tube, and a lower central tube that are connected in sequence to form a first axial body; a first elastic mechanism, a second axial body, a second elastic mechanism, and an elastic slip that are sequentially sleeved on the body of the first axial body; and a throttling assembly. A first cavity is formed between the second axial body and the second axial body, and a locking mechanism is installed in the first cavity; The throttling component is disposed inside the central tube, and the central tube has several through holes that communicate with the first cavity. The throttling component and the central tube constitute a pressure differential forming mechanism.

2. The hydraulic reset gripping and releasing tool according to claim 1, characterized in that, The locking mechanism includes a locking ring, a locking sleeve, and a support sleeve; wherein... The locking ring is connected to the left end of the connecting sleeve; The locking sleeve is connected to the upper spindle, and a boss is provided at the right end of the locking sleeve. An inner cavity is formed between the locking sleeve and the central tube. The support sleeve is fitted onto the central tube and located in the inner cavity, and a boss is provided at the right end of the support sleeve.

3. The hydraulic reset gripping and releasing tool according to claim 2, characterized in that, The protrusions on the lock sleeve are of the multi-lobed elastic claw type; The internal thread of the locking ring can engage with the boss.

4. The hydraulic reset gripping and releasing tool according to claim 2, characterized in that, The tool also includes a third elastic mechanism, which is sleeved on the central tube and located in the inner cavity, with the third elastic element located on the right side of the support sleeve.

5. The hydraulic reset gripping and releasing tool according to claim 1, characterized in that, The pressure throttling assembly includes an upper bushing, a throttling seat, and a lower bushing arranged in sequence.

6. The hydraulic reset gripping and releasing tool according to claim 5, characterized in that, The upper bushing is provided with a through hole, and the lower bushing is also provided with a through hole.

7. The hydraulic reset gripping and releasing tool according to claim 6, characterized in that, A through hole is provided at the left end of the main body of the central tube. The through hole corresponds to the through hole on the upper bushing, but the central axes of the two are separated by a certain distance. The central tube has a through hole at the right end of its main body. This through hole corresponds to the through hole of the lower bushing, but their central axes are separated by a certain distance.

8. The hydraulic reset gripping and releasing tool according to claim 5, characterized in that, The upper bushing and the central tube are fitted with a clearance fit; the lower bushing and the central tube are fitted with a clearance fit.

9. The hydraulic reset gripping and releasing tool according to claim 5, characterized in that, The throttling seat and the central tube are sealed with a non-metallic seal; the inner surface of the throttling seat is a small circular hole with tapered chamfers at both ends, with a cone angle of 30° to 45°.

10. The hydraulic reset gripping and releasing tool according to claim 1, characterized in that, The tool also includes a spring sleeve, the left end of which is threaded to the right end of the connecting sleeve, and a second cavity is formed between the spring sleeve and the second axial body; The second elastic mechanism is located in the second cavity, with the left end of the elastic latch located in the second cavity and the rest located outside the second cavity.

11. The hydraulic reset gripping and releasing tool according to claim 10, characterized in that, The outer surface of the lower central tube is provided with grooves and bosses; the right end of the spring sleeve is provided with an inner boss; Both ends of the elastic collet are bosses; the left boss and the inner boss of the spring sleeve provide limiting. When the right protrusion of the elastic slip is in the position of the protrusion of the lower central tube, the right protrusion is expanded; when the right protrusion of the elastic slip is in the position of the groove of the lower central tube, the right protrusion retracts.

12. The hydraulic reset gripping and releasing tool according to claim 11, characterized in that, The right-side protrusion is divided into a multi-lobed elastic claw shape.

13. The hydraulic reset gripping and releasing tool according to claim 1, characterized in that, The tool is used in conjunction with the docking cylinder.

Images