A soft release tool

Abstract

This invention belongs to the field of cable well testing operations, specifically a soft release tool. Addressing the problem that existing conventional wireline / cable working tools typically require the use of a shock absorber during well deployment, which can cause the tool to slip out of the hand due to the shock effect, this invention proposes the following solution. It mainly includes a mandrel assembly, a sleeve assembly, hydraulic oil, and a locking block. A sealed space is formed between the mandrel assembly and the sleeve assembly, filled with hydraulic oil. The upper end of the upper connector is connected to the tool string; the lower end of the upper connector is connected to the upper mandrel via a threaded connection and an elastic cylindrical pin. The pressure difference generated by the relative movement of the two independent components within the sealed space of the soft release tool slows down the release action, thus ensuring a smooth release of the deployed instrument or tool. This avoids damage to the instrument or tool caused by the shock absorber's release action, protecting the deployed instrument or tool and extending its service life.

Description

Technical Field

[0001] This invention relates to the field of cable well testing technology, and more particularly to a soft release tool. Background Technology

[0002] When well-testing instruments or tools need to be placed downhole, a deployment tool is required to safely and stably place them. Ordinary wireline / cable work tools typically require a shock absorber when lowered into the well to release them. However, when placing well-testing instruments or tools, to prevent damage from shock, a deployment tool that can release them smoothly without shock is necessary. To solve this downhole operation problem, this invention proposes a soft-release tool. Summary of the Invention

[0003] To address the above problems, this invention provides a soft release tool with a simple and reasonable structural design, convenient operation, stable and reliable performance, and the ability to smoothly release well testing instruments or tools that can be grabbed and released. This soft release tool utilizes the pressure difference of hydraulic oil to achieve smooth release of the instrument or tool. The sealed space between the mandrel assembly and the sleeve assembly is filled with hydraulic oil. When the components move relative to each other, the hydraulic oil experiences a pressure difference change, which slows down the release action of the soft release tool, thereby achieving the effect of smoothly releasing the deployed instrument or tool.

[0004] This invention provides the following technical solution:

[0005] A soft-release tool includes a spindle assembly, a sleeve assembly, hydraulic oil, a locking block, and seals and fasteners; a sealed space is formed between the spindle assembly and the sleeve assembly, and the sealed space is filled with hydraulic oil;

[0006] The spindle assembly includes an upper spindle, a valve core, a spring, a lower spindle, a sliding joint, and a lower sleeve;

[0007] The sleeve assembly includes: an inner sleeve, an intermediate spindle, a body, a piston, a connector, a stop connector, and a lower skirt.

[0008] The seals and fasteners include: a first O-ring, a second O-ring, a third O-ring, a fourth O-ring, a fifth O-ring, a sixth O-ring, a seventh O-ring, a first sealing support, a second sealing support, a third sealing support, a socket head cap screw, a socket head cap screw, and a resilient cylindrical pin.

[0009] The upper end of the upper connector is connected to the tool string; the lower end of the upper connector is connected to the upper spindle via a threaded connection and a flexible cylindrical pin.

[0010] The upper mandrel is fitted with an inner sleeve and sealed by a second O-ring and a first sealing support. An intermediate mandrel is also fitted on the outside of the upper mandrel.

[0011] The lower external thread of the inner sleeve is connected to the intermediate spindle and sealed by the first O-ring;

[0012] The lower external thread of the intermediate spindle is connected to the body and is also equipped with a first O-ring for sealing; the plug is installed on the intermediate spindle and sealed by a third O-ring;

[0013] The valve core conical surface is mated with the lower conical surface of the upper spindle and sealed by a fourth O-ring; the spring is disposed in the lower hole of the valve core, the valve core is connected to the lower spindle, and the spring is located between the valve core and the lower spindle;

[0014] The upper end of the body is connected to the intermediate spindle by an internal thread and sealed by a first O-ring; the lower end of the body is connected to the connector by an internal thread; the body contains a spindle assembly and a piston; the body and the piston are sealed by a fifth O-ring and a second sealing support.

[0015] The piston is fitted outside the lower spindle and sealed by the sixth O-ring and the third sealing support;

[0016] The lower end of the connector is connected to the stop connector by an external thread and is locked by a hexagonal socket head cap screw. The lower end of the connector has a locking ring on its internal conical surface. The lower end of the connector is connected to the lower skirt by an internal thread. The connector is fitted onto the lower spindle.

[0017] The locking ring is fitted onto the lower part of the lower spindle; the locking ring is installed in the conical surface between the connector and the lower skirt, and this gap restricts the up-and-down movement of the locking ring; the locking ring serves as a limiting element.

[0018] The upper external thread of the movable joint is connected to the lower spindle; the movable joint is installed in the lower skirt; a pair of keys are installed in the groove of the movable joint and are locked by hexagonal head screws.

[0019] The key is installed in the grooves of the movable joint, the lower sleeve, and the lower skirt; the key is linked with the movable joint, the lower sleeve, and the lower skirt.

[0020] The lower sleeve is fitted onto the lower skirt; the upper end of the lower sleeve abuts against the stop joint, and a groove is provided inside the lower sleeve, which is used in conjunction with the locking block;

[0021] The locking block is installed in the groove of the lower skirt sleeve and is simultaneously locked inside the lower sleeve.

[0022] The upper end of the lower skirt sleeve is connected to the connector via an external thread; the lower spindle, connector, and key are fitted inside the lower skirt sleeve and locked with hexagonal head screws; the lower skirt sleeve and lower sleeve enclose the locking block.

[0023] In one possible design, the lower part of the upper spindle is designed with several annular grooves to form an annular channel with the body for controlling the flow rate of hydraulic oil. The lower end of the upper spindle is connected to the valve core, and the lower part of the lower spindle is provided with a cross-shaped through hole. The valve core is a one-way valve structure.

[0024] In one possible design, the upper part of the lower spindle has a cross-shaped through hole, and the middle part of the lower spindle is sealed to the piston by a sixth O-ring and a third sealing support; the lower spindle is fitted into the connector and the lower skirt; the lower end of the lower spindle is equipped with a movable connector, which moves together within the lower skirt.

[0025] In one possible design, the lower end of the piston is mounted inside the connector, and its lower end is blocked by the internal shoulder of the connector, thus restricting the displacement of the piston.

[0026] In one possible design, the upper part of the inner sleeve has a mounting hole.

[0027] In one possible design, a threaded hole for use with a plug is provided at the center of the intermediate mandrel.

[0028] In one possible design, the body and the lower mandrel form a lower sealed space, in which hydraulic oil is mainly concentrated. The hydraulic oil fills the sealed space between the mandrel assembly and the sleeve assembly. This sealed space is a large part of the sealed space formed between the mandrel assembly and the sleeve assembly. When the soft release tool is in the illustrated installation position, the hydraulic oil is mainly concentrated in this space.

[0029] In one possible design, the movable joint is linked to the lower sleeve.

[0030] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the invention.

[0031] In this invention, the pressure difference generated by the relative movement of the two independent components in the hydraulic oil inside the sealed space of the soft release tool can slow down the release action of the soft release tool, so as to release the deployed instrument or tool smoothly.

[0032] This invention avoids damage to instruments or tools caused by the release action of a shocker, effectively protecting the released instruments or tools and extending their service life; moreover, the soft release tool has a reasonable and reliable structural design and is easy to operate.

[0033] In this invention, the upper connector is connected to the tool string and can be lowered into the well. The upper end of the mandrel assembly is connected to the upper connector. By pushing the upper connector, the mandrel assembly is moved downward, causing relative displacement between the mandrel assembly and the sleeve assembly, thereby controlling the release of the tool. The sleeve assembly is fitted outside the mandrel assembly and forms a sealed space with the mandrel assembly through an O-ring. This sealed space consists of a narrower annular channel at the top and a larger sealed space at the bottom. The hydraulic oil in the sealed space flows from the lower sealed space to the narrower upper space and then back to the lower sealed space (flowing only in one direction). The pressure difference generated by the movement of the mandrel assembly can slow down the release action of the soft release tool. The assembly relationship of the stop connector, moving connector, key, lower sleeve, and lower skirt allows the moving connector to be linked with the lower sleeve to provide space for the locking block to open. If the locking block is obstructed, it will open, and the deployed instrument or tool can be released.

[0034] The soft release tool described in this invention has the following advantages over the prior art: the pressure difference generated by the relative movement of the two independent components in the hydraulic oil within the sealed space of the soft release tool can slow down the release action of the soft release tool, thus smoothly releasing the deployed instrument or tool; it avoids damage to the instrument or tool caused by the release action of a shocker, effectively protecting the deployed instrument or tool and extending its service life; moreover, the soft release tool has a reasonable and reliable structural design and is easy to operate. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the soft release tool of the present invention.

[0036] Figure label:

[0037] 1. Upper connector; 2. Upper spindle; 3. Inner sleeve; 4. Intermediate spindle; 5. Plug; 6. Valve core; 7. Body; 8. Lower spindle; 9. Piston; 10. Connector; 11. Locking ring; 12. Stop connector; 13. Moving connector; 14. Key; 15. Lower sleeve; 16. Locking block; 17. Lower skirt; 18. Elastic cylindrical pin; 19. First O-ring; 20. Second O-ring; 21. First sealing support; 22. Third O-ring; 23. Fourth O-ring; 24. Spring; 25. Fifth O-ring; 26. Second sealing support; 27. Sixth O-ring; 28. Third sealing support; 29. ​​Seventh O-ring; 30. Socket head cap screw; 31. Socket head cap screw. Detailed Implementation

[0038] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0039] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "installation" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, "connection" can be a direct connection or an indirect connection through an intermediate medium. "Fixed" means that the devices are connected to each other and their relative positional relationship remains unchanged after the connection. The directional terms mentioned in the embodiments of the present invention, such as "inner," "outer," "top," and "bottom," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present invention, and are not intended to 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 the embodiments of the present invention.

[0040] In this embodiment of the invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0041] In this embodiment of the invention, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0042] References to "one embodiment" or "some embodiments" as used in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the invention. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless otherwise specifically emphasized. Example

[0043] Reference Figure 1 A soft-release tool includes a spindle assembly, a sleeve assembly, hydraulic oil, a locking block, and seals and fasteners; a sealed space is formed between the spindle assembly and the sleeve assembly, and the sealed space is filled with hydraulic oil;

[0044] The spindle assembly includes an upper spindle 2, a valve core 6, a spring 24, a lower spindle 8, a movable joint 13, and a lower sleeve 15;

[0045] The sleeve assembly includes: an inner sleeve 3, an intermediate spindle 4, a body 7, a piston 9, a connector 10, a stop connector 12, and a lower skirt 17;

[0046] The seals and fasteners include a first O-ring 19, a second O-ring 20, a third O-ring 22, a fourth O-ring 23, a fifth O-ring 25, a sixth O-ring 27, a seventh O-ring 29, a first sealing support 21, a second sealing support 26, a third sealing support 28, a socket head cap screw 30, a socket head cap screw 31, and a resilient cylindrical pin 18;

[0047] The upper connector 1 has a boss-type structure. The upper end of the upper connector 1 is connected to the tool string going down into the well; the lower end is connected to the upper spindle 2 by a threaded connection with an elastic cylindrical pin 18.

[0048] The upper spindle 2 is a one-piece structure. Its upper end is threaded to the upper connector 1 and secured by a flexible cylindrical pin 18. The middle section is fitted inside the inner sleeve 3 and the intermediate spindle 4 and sealed by a second O-ring 20 and a first sealing support 21. The lower structure of the upper spindle 2 consists of several annular grooves, which are fitted inside the body 7, forming a narrow annular channel to control the speed of hydraulic oil flow. Its lower end has a conical surface that mates with the valve core 6 and is sealed by a fourth O-ring 23. The lower part of the upper spindle 2 has a cross-shaped through-hole, allowing hydraulic oil to flow to the valve core 6 and push it open. The inner sleeve 3 is an integral structure. It is fitted onto the upper spindle 2 and sealed by the second O-ring 20 and the first sealing support 21. The lower external thread of the inner sleeve 3 is connected to the intermediate spindle 4 and sealed by the first O-ring 19. The intermediate spindle 4 is an integral structure. The upper internal thread of the intermediate spindle 4 is connected to the inner sleeve 3 and sealed by the first O-ring 19. Its lower external thread is connected to the body 7 and sealed by the first O-ring 19. The intermediate spindle 4 is fitted onto the upper spindle 2. The small threaded hole in the middle is used to install the plug 5 and is also sealed by the third O-ring 22.

[0049] The plug 5 is an integral structure. After all other parts are assembled, hydraulic oil is injected into the internal sealed space of the soft release tool through the hole of the intermediate spindle 4. After the hydraulic oil is filled, the plug 5 with the third O-ring 22 is tightened on the intermediate spindle 4 in time to seal the hydraulic oil in the internal sealed space of the tool. The plug 5 is the outlet for draining the hydraulic oil in the sealed space before disassembling the soft release tool (place the soft release tool horizontally with the plug 5 facing upwards, remove it first, then rotate it 180° so that the hole where the plug 5 is installed faces downwards, and hydraulic oil will flow out from the air. Then fix the sleeve assembly and gently pull the spindle assembly to drain the hydraulic oil completely).

[0050] The valve core 6 has a boss-type structure. The conical surface faces the upper spindle 2 and is installed in its hole, sealed by the fourth O-ring 23. The lower hole of the valve core 6 is fitted with a spring 24, which then connects to the lower spindle 8. The valve core 6 only allows hydraulic oil to flow from its upper end through the hydraulic oil in the cross hole of the upper spindle 2 into the through hole of the lower spindle 8, but it cannot flow back from the cross hole of the lower spindle 8 through the valve core 6 (which is a one-way valve structure) to the cross hole of the upper spindle 2. The body 7 is an integral structure. Its upper end is internally threaded and connected to the middle spindle 4 and sealed by the first O-ring 19. Its lower end is internally threaded and connected to the connector 10. The body 7 contains the spindle assembly and piston 9. A narrow annular channel is formed between the upper spindle 2 and the body 7 to control the passage of hydraulic oil. The body 7 and the lower spindle 8 form a large closed space, in which the hydraulic oil is mainly concentrated. The lower end of the body 7 is sealed to the piston 9 by the fifth O-ring 25 and the second sealing support 26.

[0051] The lower spindle 8 is an integral structure. The upper part of the lower spindle 8 is connected to the upper spindle 2 by threads. The middle part of the lower spindle 8 is sealed to the piston 9 and the connector 10 by the sixth O-ring 27 and the third sealing support 28. A locking ring 11 is installed between the lower spindle 8 and the connector 10 and the lower skirt 17 to limit the relative displacement between the spindle assembly and the sleeve assembly. The lower end of the lower spindle 8 is equipped with a movable connector 13. When the spindle assembly moves up and down, the movable connector 13 is linked with the lower sleeve 15 to provide space for the locking block 16 to open.

[0052] The piston 9 is an integral structure, mounted on the outside of the lower spindle 8 and sealed by the sixth O-ring 27 and the third sealing support 28. The body 7 and the connector 10 are mounted on the outside, and are also sealed by the fifth O-ring 25 and the second sealing support 26. The lower end of the piston 9 is mounted inside the connector 10, and its lower end is blocked by the internal shoulder of the connector 10, which restricts the displacement of the piston 9. The seal formed by the O-ring can protect the hydraulic oil from leakage. The connector 10 is a boss structure, and the upper end of the connector 10 is connected to the body 7 by external thread, and is sealed to the piston 9 by the fifth O-ring 25 and the second sealing support 26. The lower end of connector 10 is externally threaded to the stop connector 12 and locked by a socket head cap screw 30. A locking ring 11 is mounted on the inner conical surface of the lower end. The internal thread of connector 10 is connected to the lower skirt 17 and fitted onto the lower spindle 8. The locking ring 11 is an integral structure, fitted onto the lower spindle 8 and located within the conical surface between connector 10 and the lower skirt 17. This gap restricts the vertical movement of the locking ring 11. The locking ring 11 has a limiting function; when the lower groove of the lower spindle 8 moves downwards to the position of the locking ring 11, the locking ring 11 falls into the groove, locking the lower spindle 8 and preventing it from moving. The mandrel assembly and sleeve assembly no longer move relative to each other when the mandrel assembly moves up and down. The stop joint 12 is an integral structure, mounted on the joint 10, connected by threads and locked with a hexagonal socket head cap screw 30. The stop joint 12 can restrict the lower sleeve 15 from continuing to move upward after the moving joint 13 is reset, ensuring that the locking block 16 does not detach from the lower skirt 17 and fall off. The moving joint 13 is a boss structure, with its upper external thread connected to the lower mandrel 8 and mounted inside the lower skirt 17. A pair of keys 14 are installed in the groove of the moving joint 13 and locked with hexagonal socket head cap screws 31. Under the action of key 14, key 14 can be linked with movable joint 13, lower sleeve 15 and lower skirt 17. When the spindle assembly moves to the lower limit, lower sleeve 15 provides space for locking block 16 to open. Key 14 is an integral sleeve structure. Key 14 is installed in the groove of movable joint 13, lower sleeve 15 and lower skirt 17 and locked in movable joint 13 by internal hexagonal head screw 31. Key 14 moves with movable joint 13. At the same time, because it is also in the waist-shaped groove of lower sleeve 15, it can drive lower sleeve 15 to move, thus realizing the linkage between movable joint 13 and lower sleeve 15.

[0053] The lower sleeve 15 is an integral structure. The lower sleeve 15 is fitted onto the lower skirt sleeve 17. Its upper end is blocked by the stop joint 12, so that it cannot continue to move upward after the moving joint 13 is reset, thus ensuring that the locking block 16 does not detach from the lower skirt sleeve 17 and fall off. The lower sleeve 15 has a groove inside. After the lower sleeve 15 moves down to the moving position, the groove can provide a certain space for the locking block 16, so that the locking block 16 can open after being blocked.

[0054] The locking block 16 is an integral structure. It is installed in the groove of the lower skirt sleeve 17 and is simultaneously locked in the lower part of the lower sleeve 15. The locking block 16 is opened by pushing the mandrel assembly downward, which causes relative displacement between the mandrel assembly and the sleeve assembly. When the mandrel assembly moves to the lower limit, the lower sleeve 15 provides space for the locking block 16 to open. After the locking block 16 is blocked, it can open, and the deployed instrument or tool can be released. The lower skirt sleeve 17 has a boss-type structure. The upper end of the lower skirt sleeve 17 is connected to the connector 10 by an external thread and moves together with the sleeve assembly. Inside, it houses the movable lower spindle 8, the movable connector 13, and the key 14, which are locked with hexagonal head screws 31. The lower skirt sleeve 17 is fitted with a lower sleeve 15. The key 14 enables the movable connector 13 and the lower sleeve 15 to move together. The lower part of the lower skirt sleeve 17 is equipped with a locking block 16. The lower skirt sleeve 17 and the lower sleeve 15 enclose the locking block 16, restricting the opening of the locking block 16.

[0055] The hydraulic oil in this tool fills the sealed space between the spindle assembly and the sleeve assembly. When the spindle assembly is pushed downward, the hydraulic oil in the lower sealed space is pressurized and enters the upper sealed space through the narrow annular channel of the upper spindle 2 (at this time, the spindle assembly and the sleeve assembly can move relative to each other). When the spindle assembly moves to the lower limit, the pressure difference of the hydraulic oil can prevent the spindle assembly from hitting the piston 9 due to inertia, which can make the movement between the components smoother.

[0056] The tool contains various O-rings and sealing supports to seal the hydraulic oil in the enclosed space between the internal spindle assembly and sleeve assembly of the soft release tool, preventing leakage; the tool also contains various screws and pins to connect and fasten the various components.

[0057] The working principle and usage process of this technical solution are as follows:

[0058] I. Tool Assembly: First, clamp the lower part of the lower skirt sleeve 17 in a suitable vise. Connect and tighten the lower end internal thread of the lower mandrel 8 to the movable joint 13. Then, insert the movable joint 13 into the lower skirt sleeve 17 from the lower end, so that the movable joint 13 fits against the inner end face of the lower skirt sleeve 17. Then, turn around and install from the upper part of the lower skirt sleeve 17. First, assemble the three locking rings 11 into a ring shape using the seventh O-ring 29 and then fit them onto the lower mandrel 8 (the joint 10 can be used to assist in the installation, pushing it to the end of the lower skirt sleeve 17 and fitting it against the mandrel). Then, tighten the internal thread of the joint 10 onto the external thread of the lower skirt sleeve 17. Finally, tighten the stop joint 12 onto the joint 10 and use the internal hexagonal socket set screw. Lock it with nail 30; at this point, the clamping position can be changed to the stop joint 12 before proceeding to the next installation step; install the two fifth O-rings 25 and the matching second sealing support 26 on the outside of the piston 9, and install the other sixth O-ring 27 and the matching third sealing support 28 on the inside of the piston 9, then insert the lower end of the piston 9 into the upper end of the joint 10, so that the lower end of the piston 9 fits against the upper shoulder of the joint 10; first install the fourth O-ring 23 on the conical surface of the valve core 6, then assemble it with the conical surface of the lower part of the upper spindle 2, then place the spring 24 in the lower hole of the valve core 6, and finally tighten the upper spindle 2 onto the external thread of the lower spindle 8 (Note: during installation, make sure the spring 24 is installed on the lower thread of the lower spindle 8). (At the center of the upper spindle 2 and lower spindle 8, ensure the spring 24 is not twisted or missing.) First, tighten the lower thread of the body 7 onto the upper part of the connector 10 (the lower part of the body 7 has a small hole to distinguish the upper and lower ends). Then, install the first O-ring 19 into the groove outside the inner sleeve 3, and install the second O-ring 20 and the matching first sealing support 21 into the groove inside it. Tighten the external thread of the inner sleeve 3 onto the intermediate spindle 4, then install the first O-ring 19 onto the intermediate spindle 4. Finally, install them together onto the internal thread on the upper part of the body 7 and tighten them. Tighten the internal thread of the upper connector 1 onto the upper external thread of the upper spindle 2. After firmly clamping the assembled parts... Drill a pin hole at the threaded connection between the upper connector 1 and the upper spindle 2 (the hole should be as close as possible to the end of the upper spindle 2). Then, insert the elastic cylindrical pin 18 into the drilled hole, ensuring that the elastic cylindrical pin 18 does not protrude from the outer circle of the upper connector 1. At this point, turn the assembled parts around, place the body 7 on a vise, and clamp it securely. First, insert the locking blocks 16 (2 pieces) into the groove of the lower skirt sleeve 17, then install the lower sleeve 15 on the lower skirt sleeve 17. Adjust the position of the spindle assembly and the lower sleeve 15 so that the grooves between the three are aligned. Then, insert the key 14 (2 pieces) into the groove, and then insert the internal hexagonal head screw 31 (2 pieces) into the key 14 and tighten it. At this point, select a suitable position for the installer to inject hydraulic oil, keep the parts horizontal, and ensure that the threaded hole of the middle spindle 4 faces directly upward. Then, clamp the parts securely on a vise.Inject the prepared hydraulic oil into the sealed space inside the soft release tool through the threaded hole of the intermediate mandrel 4. After the sealed space is filled with hydraulic oil, tighten the plug 5, which contains the third O-ring 22, into the threaded hole of the intermediate mandrel 4 (no hydraulic oil should overflow after tightening the plug 5). The installation is now complete. Wipe the outer surface of the installed soft release tool clean and check for any hydraulic oil leaks. If there are no leaks, proceed to the next step. If there are leaks, check the installation of the parts and analyze the cause of the leak.

[0059] II. Tool Disassembly: Since this soft release tool is recyclable, we can disassemble it into parts and reuse the intact parts. First, clamp the soft release tool horizontally in a vise, place an oil catcher below the plug 5, then rotate the tool so that the plug 5 faces upwards and remove the plug 5. Then rotate the tool so that the drain hole faces downwards to drain the hydraulic oil from the confined space. Clamp the soft release tool in a vise, first remove the hex socket head cap screw 31 and key 14, then remove the lower sleeve 15 and remove the locking block 16. Clamp the stop connector 12 in a vise, remove the elastic cylindrical pin 18 between the upper connector 1 and the upper spindle 2, remove the upper connector 1, then remove the body 7 from the connector 10, and remove the inner sleeve 3 and the intermediate spindle. Remove the first O-ring 19, the second O-ring 20, and the third O-ring 22 from the plug 5 respectively; continue to remove the upper spindle 2 from the lower spindle 8, remove the valve core 6, the fourth O-ring 23, and the spring 24, then remove the piston 9 from the lower spindle 8 and remove the fifth O-ring 25, the sixth O-ring 27, the second sealing support 26, and the third sealing support 28; clamp the lower skirt 17 in a vise, first remove the internal hex socket set screw 30, remove the stop connector 12 from the connector 10, then remove the connector 10, the locking ring 11, and the seventh O-ring 29, then push the lower spindle 8 to remove it from the lower end of the lower skirt 17, loosen the moving connector 13 and remove it, then remove the lower skirt 17 from the vise, and the soft release tool is disassembled.

[0060] The above are merely specific embodiments 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. In the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A soft release tool, characterized in that: It includes a spindle assembly, a sleeve assembly, hydraulic oil, a locking block, and seals and fasteners; a sealed space is formed between the spindle assembly and the sleeve assembly, and this sealed space is filled with hydraulic oil; The spindle assembly includes an upper spindle (2), a valve core (6), a spring (24), a lower spindle (8), a movable joint (13), and a lower sleeve (15). The sleeve assembly includes: an inner sleeve (3), an intermediate spindle (4), a body (7), a piston (9), a connector (10), a stop connector (12), and a lower skirt (17). The seals and fasteners include a first O-ring (19), a second O-ring (20), a third O-ring (22), a fourth O-ring (23), a fifth O-ring (25), a sixth O-ring (27), a seventh O-ring (29), a first sealing support (21), a second sealing support (26), a third sealing support (28), a socket head cap screw (30), a socket head cap screw (31), and a resilient cylindrical pin (18). The upper end of the upper connector (1) is connected to the tool string; the lower end of the upper connector (1) is connected to the upper spindle (2) by a threaded connection with an elastic cylindrical pin (18); The upper spindle (2) is fitted with an inner sleeve (3) and sealed by a second O-ring (20) and a first sealing support (21). The upper spindle (2) is also fitted with an intermediate spindle (4). The lower external thread of the inner sleeve (3) is connected to the intermediate spindle (4) and sealed by the first O-ring (19); The lower external thread of the intermediate spindle (4) is connected to the body (7) and is also equipped with a first O-ring (19) for sealing; the plug (5) is installed on the intermediate spindle (4) and sealed by a third O-ring (22); The conical surface of the valve core (6) is mated with the lower conical surface of the upper spindle (2) and sealed by the fourth O-ring (23); the spring (24) is set in the lower hole of the valve core (6), the valve core (6) is connected to the lower spindle (8), and the spring (24) is located between the valve core (6) and the lower spindle (8); The upper end of the body (7) is connected to the intermediate spindle (4) by the internal thread and sealed by the first O-ring (19); the lower end of the body (7) is connected to the connector (10) by the internal thread; the body (7) is equipped with a spindle assembly and a piston (9); the body (7) and the piston (9) are sealed by the fifth O-ring (25) and the second sealing support (26). The piston (9) is fitted onto the outside of the lower spindle (8) and sealed by the sixth O-ring (27) and the third sealing support (28); The lower end of the connector (10) is connected to the stop connector (12) by the external thread and locked by the internal hexagonal recessed set screw (30). The lower end of the connector (10) is equipped with a locking ring (11) on the inner conical surface. The lower end of the connector (10) is connected to the lower skirt sleeve (17) by the internal thread. The connector (10) is fully fitted on the lower spindle (8). The locking ring (11) is fitted onto the lower part of the lower spindle (8); the locking ring (11) is installed in the conical surface between the connector (10) and the lower skirt (17), and this gap restricts the up-and-down movement of the locking ring (11); the locking ring (11) serves as a limiter. The upper external thread of the movable joint (13) is connected to the lower spindle (8); the movable joint (13) is installed in the lower skirt (17); a pair of keys (14) are installed in the groove of the movable joint (13) and locked by the internal hexagonal head screw (31); The key (14) is installed in the groove of the movable joint (13), the lower sleeve (15) and the lower skirt (17); the key (14) is linked with the movable joint (13), the lower sleeve (15) and the lower skirt (17); The lower sleeve (15) is fitted onto the lower skirt sleeve (17); the upper end of the lower sleeve (15) abuts against the stop joint (12); a groove is provided inside the lower sleeve (15), which is used in conjunction with the locking block (16); The locking block (16) is installed in the groove of the lower skirt sleeve (17) and is simultaneously locked inside the lower sleeve (15); The upper end of the lower skirt sleeve (17) is connected to the connector (10) by an external thread; the lower spindle (8), the movable connector (13) and the key (14) are fitted inside the lower skirt sleeve (17) and locked with an internal hexagonal head screw (31); the lower skirt sleeve (17) and the lower sleeve (15) enclose the locking block (16).

2. The soft release tool as described in claim 1, characterized in that: The lower part of the upper spindle (2) is designed with several annular grooves, which form an annular channel with the body (7) to control the flow rate of hydraulic oil. The lower end of the upper spindle (2) is connected to the valve core (6). The lower part of the upper spindle (2) is provided with a cross through hole. The valve core (6) is a one-way valve structure.

3. A soft release tool as described in claim 1, characterized in that: The lower spindle (8) has a cross-shaped through hole at its upper part. The middle part of the lower spindle (8) is sealed to the piston (9) by the sixth O-ring (27) and the third sealing support (28). The lower spindle (8) is fitted into the connector (10) and the lower skirt (17). The lower end of the lower spindle (8) is equipped with a movable connector (13) which moves together in the lower skirt (17).

4. A soft release tool as described in claim 1, characterized in that: The lower end of the piston (9) is installed inside the joint (10), and its lower end is blocked by the internal shoulder of the joint (10), which restricts the displacement of the piston (9).

5. A soft release tool as described in claim 1, characterized in that: The inner sleeve (3) has an installation hole at the top.

6. A soft release tool as described in claim 1, characterized in that: The intermediate spindle (4) has a threaded hole at the middle position that is used in conjunction with the plug (5).

7. A soft release tool as described in claim 1, characterized in that: The main body (7) and the lower spindle (8) form a lower enclosed space.

8. A soft release tool as described in claim 1, characterized in that: The movable joint (13) is linked with the lower sleeve (15).

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