Downhole tool releasing structure capable of preventing secondary locking

Abstract

The invention provides a downhole tool releasing structure capable of preventing secondary locking, and relates to the technical field of downhole releasing devices.The downhole tool releasing structure comprises a male connector sleeve and a female connector sleeve which are arranged in a sleeved mode, an annular groove is formed between the male connector sleeve and the female connector sleeve, and a releasing assembly is installed in the annular groove; the releasing assembly comprises an opening reed ring and an unsealing sleeve arranged on the outer side of the male connector sleeve in a sleeving mode, the unsealing sleeve is sleeved with a spring claw sleeve, and a plurality of spring clamping claws are arranged at the bottom end of the spring claw sleeve. When the releasing structure is locked, the lower end of the deblocking sleeve is inserted into the opening reed ring, and the outer wall of the opening reed ring supports the inner wall of the spring clamping jaw so that the lower end of the spring clamping jaw can be clamped with a limiting clamping groove in the inner wall of the female connector sleeve. When the releasing structure is unlocked, the lower end of the deblocking sleeve is separated from the opening reed ring, the opening reed ring is arranged on the outer wall of the male connector sleeve in a contracting and sleeving mode, and the spring clamping jaw is contracted and separated from the limiting clamping groove. The device is used for effectively preventing secondary locking of the device.

Description

Technical Field

[0001] This invention relates to the field of downhole tool release technology, and in particular to a downhole tool release structure that prevents secondary locking. Background Technology

[0002] As oil and gas development deepens, the application of techniques such as stratified extraction and precision water injection is increasing. These techniques require multi-stage packers connected in series to form a multi-stage stratified process tubing. To improve the stability of the process tubing, complex structures such as downhole release mechanisms and secondary docking are often required. However, during tubing string tripping, repeated lock-up of the release mechanism causes difficulties in unsealing and unsticking, and excessive load leads to unsealing failure, ultimately resulting in major workovers.

[0003] To address the aforementioned issues, existing research employs pull-out safety couplings or unsealing tools to achieve the release of the tubing string. However, this method has some drawbacks, such as the safety coupling or unsealing tool easily breaking off midway during well entry; and the inability to accurately calculate the starting pull force of the safety coupling or unsealing tool due to complex conditions such as downhole scaling, sand production, and casing deformation, or the failure to achieve the purpose of release due to unreasonable design.

[0004] To address the aforementioned technical issues, Chinese Utility Model Patent CN212406646U discloses a safe release and release device. This device consists of an upper connector, an outer sleeve, a piston, a locking ring, a central tube, and a lower connector. It prevents the starting pin from shearing during the lifting or lowering of the tubing string, completely avoiding the possibility of the device breaking off midway due to excessive load on the tailpipe or unstable operation during lifting or lowering. Chinese Utility Model Patent CN205977165U discloses a wellbore release plugger, including a sealing tubing string and a plugging assembly for lowering into the sealing tubing string. The plugging assembly includes a retrieval connector and a plugging head connected to the retrieval connector. One end of the plugging head is equipped with an inner spring claw mechanism, which, after the plugging assembly is lowered into the sealing tubing string, engages with the inner liner of the spring claw, causing the inner liner of the spring claw to move away from the upper connector.

[0005] Although the above solution achieves safe and stable unlocking of the unloaded structure, the process of lowering the tubing string during tool removal after unlocking can easily lead to secondary jamming, causing well sticking and major repairs.

[0006] Therefore, there is an urgent need for a downhole tool release structure that prevents secondary locking to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a downhole tool release structure to prevent secondary locking, thereby solving the technical problem in existing release mechanisms where secondary locking can easily occur during the tool lowering process after unlocking, leading to stuck wells and major workovers. The various technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.

[0008] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a downhole tool release structure to prevent secondary locking, comprising a male connector sleeve and a female connector sleeve, wherein an annular groove is provided between the male connector sleeve and the female connector sleeve, and a release component is installed in the annular groove; The release assembly includes an open spring ring and a release sleeve fitted on the outside of the male connector sleeve. The release sleeve is fitted with a spring claw sleeve, and the bottom end of the spring claw sleeve is provided with several spring claws. When the release mechanism is locked, the lower end of the release sleeve is inserted into the open spring ring, and the outer wall of the open spring ring supports the inner wall of the spring claw so that its lower end engages with the limiting groove on the inner wall of the female connector sleeve. When the release mechanism is unlocked, the lower end of the release sleeve disengages from the open spring ring, the open spring ring retracts and fits onto the outer wall of the male connector sleeve, and the spring claw retracts and disengages from the limiting groove.

[0009] Preferably, a plurality of unsealing limiting pins are installed between the outer wall of the unsealing sleeve and the outer wall of the male connector sleeve. When the release mechanism is unlocked, the unsealing sleeve cuts off the unsealing limiting pins.

[0010] Preferably, a limiting ring is fitted on the outer wall of the male connector sleeve, and the limiting ring is fixedly connected to the male connector sleeve by a plurality of fixing pins.

[0011] Preferably, the upper end of the limiting ring has a plurality of L-shaped slots arranged in an annular array, and the lower end of the open spring ring has a plurality of L-shaped lugs arranged in an annular array, with the plurality of L-shaped lugs respectively inserted into the plurality of L-shaped slots.

[0012] Preferably, the unsealing sleeve is a stepped sleeve, a first piston chamber is provided in the annular groove at the upper end of the unsealing sleeve, and a second piston chamber is provided in the annular groove at the lower end of the unsealing sleeve.

[0013] Preferably, the first piston chamber is connected to the inner cavity of the male connector sleeve through a pressure relief hole, and the second piston chamber is connected to the outer wall of the female connector sleeve through a liquid inlet hole.

[0014] Preferably, a plurality of sealing rings are provided on the inner and outer walls of the upper end of the unsealing sleeve, and the sealing rings slide and seal with the outer wall of the male connector sleeve and the inner wall of the spring claw sleeve.

[0015] Preferably, the lower end of the spring claw is provided with a locking protrusion, which can engage with the limiting slot.

[0016] Preferably, the limiting groove is an annular groove.

[0017] The downhole tool release structure for preventing secondary locking provided by this invention uses an open spring ring. When the release structure is locked, the open spring ring supports the spring claw to achieve locking. When the release is unlocked, the end face of the open spring ring limits the end face of the release sleeve, effectively preventing secondary locking. The device has high stability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an embodiment of the downhole tool drop-off structure for preventing secondary locking according to the present invention; Figure 2 This is a schematic diagram of the unsealing sleeve in the downhole tool release structure for preventing secondary locking of the present invention; Figure 3 This is a schematic diagram of the spring claw sleeve and spring chuck in the anti-secondary locking downhole tool release structure of the present invention; Figure 4 This is a schematic diagram of the open spring ring in the downhole tool release structure for preventing secondary locking of the present invention; Figure 5 This is a schematic diagram of the limiting ring in the downhole tool release structure for preventing secondary locking according to the present invention; Figure 6 This is a schematic diagram of the structure of the open spring ring and the limiting ring when the release structure of the present invention is locked; Figure 7 This is a schematic diagram of the structure of the open spring ring and the limiting ring when the release mechanism of the present invention is unlocked.

[0020] In the diagram: 1. Male connector sleeve; 2. Female connector sleeve; 3. Annular groove; 4. Open spring ring; 5. Unsealing sleeve; 6. Spring claw sleeve; 7. Spring claw; 8. Limiting groove; 9. Unsealing limiting pin; 10. Limiting ring; 11. Fixing pin; 12. L-shaped groove; 13. L-shaped lug; 14. First piston chamber; 15. Second piston chamber; 16. Pressure relief hole; 17. Liquid inlet hole; 18. Snap-fit ​​boss; 19. Sealing ring; 20. Irregular sealing ring. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] In the description of this invention, it should be understood that the terms "center," "side," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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, they should not be construed as limitations on this invention.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] like Figure 1 , Figure 2 and Figure 3 The shown is a downhole tool release structure to prevent secondary locking, including a male connector sleeve 1 and a female connector sleeve 2. The upper end of the male connector sleeve 1 is provided with an outer ring platform, and the lower end of the female connector sleeve 2 is provided with an inner ring platform. The inner ring platform is slidably sleeved on the lower outer wall of the male connector sleeve 1.

[0025] An annular groove 3 is provided between the upper end of the male connector sleeve 1 and the lower end of the female connector sleeve 2. A release assembly is installed in the annular groove 3. The release assembly includes a spring claw sleeve 6. The inner wall of the upper end of the spring claw sleeve 6 is provided with an internal thread, and the outer annular surface is provided with an external thread. The spring claw sleeve 6 is threadedly connected to the male connector sleeve 1. Several spring claws 7 are provided in an annular shape at the lower end of the spring claw sleeve 6. A locking boss 18 is provided at the lower end of the spring claws 7. A limiting groove 8 is provided on the inner wall of the female connector sleeve 2 to engage with the locking boss 18. The limiting groove 8 is an annular groove.

[0026] like Figure 1 , Figure 2 and Figure 3As shown, a release sleeve 5 is provided between the inner wall of the spring claw sleeve 6 and the male connector sleeve 1. The release sleeve 5 is sleeved on the outer wall of the male connector sleeve 1, and several release limiting pins 9 are installed between the outer wall of the release sleeve 5 and the outer wall of the male connector sleeve 1.

[0027] like Figure 1 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the lower end of the unsealing sleeve 5 is provided with an open spring ring 4 and a limiting ring 10. The limiting ring 10 is fixedly connected to the male connector sleeve 1 by a number of fixed pins 11 arranged in a ring array. The upper end of the limiting ring 10 is provided with a number of L-shaped slots 12 in a ring array. The bottom end of the open spring ring 4 is provided with a number of L-shaped lugs 13 in a ring array. The number of L-shaped lugs 13 are respectively inserted into the number of L-shaped slots 12.

[0028] In this embodiment, there are three L-shaped slots 12 and three L-shaped lugs 13, which are arranged in a circular array rotated 120° in sequence.

[0029] like Figure 1 As shown, the unsealing sleeve 5 is a stepped sleeve. The upper step of the unsealing sleeve 5 divides the annular groove 3 into a first piston chamber 14 and a second piston chamber 15. The first piston chamber 14 is connected to the inner cavity of the male connector sleeve 1 through the pressure relief hole 16, and the second piston chamber 15 is connected to the outer wall of the female connector sleeve 2 through the liquid inlet hole 17.

[0030] In this embodiment, to improve the sealing performance of the first piston chamber 14 and the second piston chamber 15, sealing rings 19 are provided on the inner and outer end faces of the upper step of the unsealing sleeve 5 and on the outer wall of the male connector sleeve 1. The sealing rings 19 achieve sliding sealing between the unsealing sleeve 5 and the male connector sleeve 1 and the spring claw sleeve 6, as well as fixed sealing between the male connector sleeve 1 and the inner wall of the spring claw sleeve 6 and the female connector sleeve 2. In this embodiment, as shown... Figure 1 As shown, the liquid inlet 17 is located between the two spring claws 7. In this embodiment, the upper end of the female connector sleeve 2 is a stepped opening. A special-shaped sealing ring 20 is provided at the stepped opening of the female connector sleeve 2. The special-shaped sealing ring 20 is used to seal the outer wall of the spring claw sleeve 6 and the inner wall of the female connector sleeve 2, thereby achieving the sealing of the second piston chamber 15.

[0031] In this embodiment, when the release mechanism is locked, the lower end of the release sleeve 5 is inserted into the open spring ring 4. The outer wall of the open spring ring 4 supports the inner wall of the spring claw 7, causing its lower end to engage with the limiting groove 8 on the inner wall of the female connector sleeve 2. When the release mechanism is unlocked, the pressure of the drilling fluid in the outer cavity of the female connector sleeve 2 increases and enters the second piston chamber 15, pushing the release sleeve 5 to slide upward. The upward sliding of the release sleeve 5 cuts off the release limiting pin 9, and the lower end of the release sleeve 5 disengages from the open spring ring 4. The open spring ring 4 retracts and fits onto the outer wall of the male connector sleeve 1. When the male connector is lifted, the engaging boss 18 at the lower end of the spring claw 7 retracts and disengages from the limiting groove 8.

[0032] In this embodiment, by setting the L-shaped lug 13 and the L-shaped slot 12, the circumferential fixation of the open spring ring 4 is achieved, and it does not move with the movement of the unsealing sleeve 5 during the sliding process. After the unsealing sleeve 5 moves, the open spring ring 4 retracts onto the male connector sleeve 1. When the pressure of the central tube fluctuates, the unsealing sleeve 5 moves downward. At this time, the retracted open spring ring 4 will restrict the unsealing sleeve 5 from continuing to move downward, keeping the lower part of the spring claw 7 suspended and preventing the tool from locking again, thus realizing the function of preventing secondary locking.

[0033] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A downhole tool release structure to prevent secondary locking, comprising a male connector sleeve (1) and a female connector sleeve (2), wherein an annular groove (3) is provided between the male connector sleeve (1) and the female connector sleeve (2), characterized in that, A release assembly is installed inside the annular groove (3); The release assembly includes an open spring ring (4) and a release sleeve (5) sleeved on the outside of the male connector sleeve (1). The release sleeve (5) is covered with a spring claw sleeve (6), and the bottom end of the spring claw sleeve (6) is provided with several spring claws (7). When the release structure is locked, the lower end of the release sleeve (5) is inserted into the open spring ring (4), and the outer wall of the open spring ring (4) supports the inner wall of the spring claw (7) so that its lower end is engaged with the limiting groove (8) on the inner wall of the female connector sleeve (2). When the release mechanism is unlocked, the lower end of the release sleeve (5) disengages from the open spring ring (4), the open spring ring (4) retracts and is sleeved on the outer wall of the male connector sleeve (1), and the spring claw (7) retracts and disengages from the limiting groove (8).

2. The downhole tool release structure for preventing secondary locking according to claim 1, characterized in that: A plurality of unsealing limiting pins (9) are installed between the outer wall of the unsealing sleeve (5) and the outer wall of the male connector sleeve (1). When the release structure is unlocked, the unsealing sleeve (5) cuts off the unsealing limiting pins (9).

3. The downhole tool release structure for preventing secondary locking according to claim 1, characterized in that: A limiting ring (10) is fitted on the outer wall of the male connector sleeve (1), and the limiting ring (10) is fixedly connected to the male connector sleeve (1) by a number of fixing pins (11).

4. The downhole tool release structure for preventing secondary locking according to claim 3, characterized in that: The upper end of the limiting ring (10) is provided with several L-shaped slots (12) in an annular array, and the lower end of the open spring ring (4) is provided with several L-shaped ears (13) in an annular array. The several L-shaped ears (13) are respectively placed in the several L-shaped slots (12).

5. The downhole tool release structure for preventing secondary locking according to claim 1, characterized in that: The unsealing sleeve (5) is a stepped sleeve. A first piston chamber (14) is provided in the annular groove (3) at the upper end of the unsealing sleeve (5), and a second piston chamber (15) is provided in the annular groove (3) at the lower end of the unsealing sleeve (5).

6. The downhole tool release structure for preventing secondary locking according to claim 5, characterized in that: The first piston chamber (14) is connected to the inner cavity of the male connector sleeve (1) through the pressure relief hole (16), and the second piston chamber (15) is connected to the outer wall of the female connector sleeve (2) through the liquid inlet hole (17).

7. The downhole tool release structure for preventing secondary locking according to claim 5, characterized in that: The upper end of the unsealing sleeve (5) is provided with several sealing rings (19) on the inner and outer walls. The sealing rings (19) slide and seal with the outer wall of the male connector sleeve (1) and the inner wall of the spring claw sleeve (6).

8. The downhole tool release structure for preventing secondary locking according to claim 5, characterized in that: The lower end of the spring claw (7) is provided with a locking boss (18), which can engage with the limiting slot (8).

9. A downhole tool release structure for preventing secondary locking according to claim 1 or 8, characterized in that: The limiting slot (8) is an annular slot.

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