Recoverable hanger capable of automatically unlocking locking mechanism

Abstract

The invention relates to the technical field of well drilling and well completion operation equipment, in particular to a recoverable hanger capable of automatically unlocking a locking mechanism, which comprises a setting tool string and a hanger main body, the setting tool string comprises a central pipe, and a piston driving mechanism, a positioning connecting mechanism and a pitching pressure building mechanism which are mounted on the central pipe; the hanger main body comprises a mandrel, and a setting transmission mechanism, a slip anchoring mechanism and a locking mechanism which are mounted on the mandrel; the piston drive mechanism is configured to sequentially drive in response to different levels of hydraulic pressure. According to the recoverable hanger capable of achieving automatic unlocking of the locking mechanism, during setting, locking can be completed through a simple pressing action, and operation is easy, convenient and reliable; in the unlocking process, primary releasing of the anchor fluke is completed through ball throwing and pressure building, then the ball seat is knocked down to recycle the setting tool, then the recycling tool is lifted to trigger the locking mechanism to automatically bounce, and complete unlocking is achieved.

Description

Technical Field

[0001] This invention relates to the field of drilling and completion equipment technology, and more specifically, to a retrievable suspension with an automatically unlocking locking mechanism. Background Technology

[0002] In oil and gas drilling and completion engineering, the casing hanger, as a key piece of equipment connecting the casing string and wellhead equipment, bears the core functions of suspending the weight of the casing and maintaining the wellhead seal. Currently widely used traditional hangers employ a permanent setting design, forming a permanent connection with the casing head after initial setting. This design meets basic requirements under conventional drilling conditions, but it reveals significant limitations when dealing with later operations such as well workovers, in-casing operations, or final well abandonment. Because it cannot be directly removed, the work team must use a complex milling process to break it up and remove it. This process not only takes several weeks and significantly increases operating costs, but also carries multiple risks such as casing damage, metal debris accumulation, and seal damage. In complex conditions such as deep wells and high-pressure wells, the risks of such operations are even more pronounced.

[0003] While existing retrievable hangers have partially solved the problem of non-retrievability of traditional permanent hangers, their unlocking mechanisms often rely on complex mechanical operation sequences or precise control of operating parameters. In practical applications, these designs are often affected by factors such as well condition complexity, tool positioning accuracy, or operator experience, leading to unlocking failures or partial unlocking, thus limiting their widespread application in critical well conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a retrievable hanger with an automatically unlocking locking mechanism, which can effectively solve the problems in the prior art.

[0005] The objective of this invention is achieved through the following technical solution: A retrievable suspension device with an automatically unlocking locking mechanism includes: a setting tool string and a suspension body; the setting tool string includes: a central tube and a piston drive mechanism, a positioning connection mechanism, and a ball-throwing pressure mechanism mounted on the central tube; the suspension body includes: a spindle and a setting transmission mechanism, a slip anchoring mechanism, and a locking mechanism mounted on the spindle; the piston drive mechanism is configured to sequentially drive in response to different levels of hydraulic pressure: under a first preset pressure, it drives the positioning connection mechanism to lock and fix with the spindle to establish a setting reaction force fulcrum; under a second preset pressure, it drives the setting transmission mechanism to push the slip anchoring mechanism to complete the setting, and simultaneously drives the locking mechanism to achieve unidirectional locking to maintain the setting force; under a third preset pressure, it drives the positioning connection mechanism to unlock and triggers the ball seat in the ball-throwing pressure mechanism to fall, so that the setting tool string is in a retrievable state.

[0006] Furthermore, the setting tool string also includes: an upper connector, which is connected between the piston sleeve and the central tube, and a key block is provided between the upper connector and the central tube to limit their relative rotation; an outer cylinder pressure cap is fitted on the upper connector, and the outer cylinder pressure cap is coaxially fixed to the outer wall of the piston sleeve; a semi-ring is provided in the outer ring groove of the outer cylinder pressure cap and the upper connector.

[0007] Furthermore, the piston drive mechanism includes: a piston sleeve coaxially sleeved outside the central tube, and a piston and piston extension cylinder disposed in the annular pressure chamber formed by the two; the central tube is provided with a pressure transmission hole; one end of the piston and piston extension cylinder is fixed and can slide in a sealed manner in the pressure chamber, and the other end of the piston extension cylinder is fixed to the piston sleeve by a shear pin.

[0008] Furthermore, a setting sleeve is coaxially sleeved on the piston extension cylinder, and the setting sleeve is releasably connected to the piston extension cylinder by a shear pin; a setting joint is sleeved and fixedly connected to the outer periphery of the setting sleeve, and its end is axially limited by a sleeve pressure cap, which is fixedly connected to the setting sleeve by a set screw.

[0009] Furthermore, an inner push sleeve is coaxially sleeved on the central tube, and the inner push sleeve is releasably connected to the central tube through a shear pin three; an outer push sleeve is fixed on the outside of the inner push sleeve, and the outer push sleeve abuts axially against the end of the piston extension cylinder; the inner push sleeve is configured to act on one end of the release pawl, the release pawl slides on the central tube, and a shear pawl is engaged on the release pawl.

[0010] Furthermore, the positioning connection mechanism includes: a slip support ring, a slip spring, and a positioning short connector; the slip support ring is installed on the central tube, and its outer wall is provided with a slip spring; the positioning short connector is coaxially sleeved outside the slip support ring and the slip spring, and its inner wall abuts against the slip spring; the positioning anchor claw on the outer side of the positioning short connector is opposite to the anchor claw engagement groove on the inner side of the positioning joint, and the positioning joint is fixed to the mandrel by a set screw; wherein, the slip support ring is configured to generate axial displacement under the drive of the inner push sleeve and the release pawl, and through the interaction between its conical surface and the slip spring, drive the slip spring to expand radially, thereby pushing the positioning short connector so that its positioning anchor claw engages in the anchor claw engagement groove of the positioning joint.

[0011] Furthermore, the two ends of the positioning short joint are fixedly connected to the central tube and the ball seat short joint respectively to form a pressure flow channel; a shear ring is fixedly installed at the axial end of the ball seat short joint, the shear ring is installed inside the guide shoe, and the guide shoe is connected to the bottom of the ball seat short joint; a ball seat is connected inside the shear ring through a shear pin, and the ball seat is used to receive the thrown ball.

[0012] Furthermore, the setting transmission mechanism includes: a setting sleeve and a release sleeve; one end of the setting sleeve can axially abut against the setting joint, and the other end is fixed to the release sleeve by a set screw four; the release sleeve, which is slidably fitted to the mandrel, is connected to the limiting ring sleeved on the mandrel by a shear pin four, and the limiting ring is connected to the upper cone by a set screw five.

[0013] Furthermore, the locking mechanism is coaxially housed within an annular cavity formed by the spindle, the release sleeve, and the limiting ring; the two ends of the locking mechanism axially abut against the inner end face of the release sleeve and the limiting ring, respectively.

[0014] Furthermore, the locking mechanism includes: a release seat, a release ring, and a locking ring; the first one-way tooth on the inner side of the release ring meshes with the second one-way tooth on the outer side of the locking ring to form a first one-way transmission pair, so that when the release ring is subjected to a downward sealing force, it can drive the locking ring to move downward in one direction; the locking ring is slidably sleeved on the spindle, and the third one-way tooth on its inner side meshes with the fourth one-way tooth on the outer side of the spindle to form a second one-way locking pair; In the set-sealed state, the locking ring is locked to the spindle by the second one-way locking pair under the drive of the first one-way transmission pair. When the release sleeve is lifted by the recovery tool and shears the shear pin four and moves upward, the release seat and release ring are released from constraint and move upward, thereby releasing the drive on the locking ring and unlocking the second one-way locking pair between the locking ring and the spindle.

[0015] Furthermore, the slip anchoring mechanism includes an upper cone, a slip sleeve, slips, and a lower cone; a limiting ring is connected to the upper cone via a set screw five; the upper cone is connected to the inside of the slip sleeve via a set screw six; the slip sleeve is fitted onto a guide joint, and the guide pin on the guide joint slides within the guide groove of the slip sleeve; the guide joint is installed on a mandrel, on which the lower cone is mounted, and the guide joint is positioned below the lower cone; there are multiple slips, evenly distributed on the slip sleeve, and located between the upper and lower cones; the middle part of the slip is connected to the inner wall of the slip sleeve via a spring, and the slip teeth of the slip slide within the slip groove of the slip sleeve.

[0016] Furthermore, a limiting connector is fixedly connected to one end of the release sleeve near the upper cone. When the release sleeve is lifted by the recovery tool and shears the shear pin and moves upward, the release sleeve drives the limiting connector to slide on the limiting ring towards the positioning connector, so that the limiting connector can be engaged in the slot of the limiting ring, thereby driving the limiting ring to be lifted.

[0017] Furthermore, a lower connector is coaxially mounted on the mandrel, and a guide ring is mounted on the outer side of the lower connector. The guide ring and the lower connector are fixedly connected to the mandrel by a set screw. The guide ring and the lower connector are engaged on the side of the guide connector away from the lower cone.

[0018] The beneficial effects of this invention are as follows: This invention provides a compact, easy-to-operate, and reliable retrievable suspension device, effectively solving the problems of non-retrievability of traditional permanent suspension devices and the difficulty in unlocking existing retrievable suspension devices, which rely on complex operation sequences. The suspension device of this invention adopts a modular design, with the setting tool string and the main suspension device having clear and independent functions. The piston drive mechanism, responding to different levels of hydraulic pressure, sequentially drives the positioning connection, setting transmission, slip anchoring, and locking mechanism, achieving full automation of setting reaction force fulcrum establishment, unidirectional locking of setting force, and automatic unlocking after setting, significantly reducing the risk of human error. Specifically, the locking mechanism, through the unidirectional tooth meshing design between the release ring and the locking ring, automatically locks during setting to reliably maintain the setting force. During retrieval, simply lifting the retrieval tool triggers the release sleeve to move upward, causing the locking ring to automatically spring up and unlock, achieving a simple operation of downward locking and upward automatic unlocking, greatly improving the success rate and efficiency of retrieval. Furthermore, the coordinated design of the ball-throwing and pressure-pressing mechanism and the positioning and connecting mechanism ensures that after setting, the anchor claws can be released and the ball seat knocked down through ball-throwing and pressure-pressing, allowing the setting tool string to smoothly enter a retrievable state. The entire process is controllable in stages, preserving the safety of hydraulic operation while ensuring the reliability of final retrieval through an automatic mechanical unlocking mechanism.

[0019] This invention discloses a retrievable suspension device with an automatically unlocking locking mechanism. During setting, locking can be completed with a simple downward pressing action, making operation simple and reliable. During unlocking, the anchor claw is first released by throwing a ball to press down, then the ball seat knocks down and retrieves the setting tool, and finally the locking mechanism is automatically lifted by lifting the retrieved tool to achieve complete unlocking. The phased unlocking mechanism retains the controllability advantage of throwing and pressing down, and ensures the reliability of the final release through automatic mechanical unlocking, greatly improving the safety and success rate of the entire retrieval process.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the retrievable suspension device of the present invention in its lowering state; Figure 2 for Figure 1 Schematic diagram of local structure Figure 1; Figure 3 for Figure 1 Schematic diagram of local structure Figure 2 ; Figure 4 for Figure 1 Schematic diagram of local structure Figure 3 ; Figure 5 for Figure 1 Schematic diagram of local structure Figure 4 ; Figure 6 This is a schematic diagram of the anchoring state of the recyclable hanger of the present invention; Figure 7 for Figure 6 A schematic diagram of a partial structure; Figure 8 This is a schematic diagram showing the state in which the setting joint and setting sleeve are fitted together in preparation for pushing the slip in the recyclable suspension device of the present invention. Figure 9 for Figure 8 A schematic diagram of a partial structure; Figure 10 This is a schematic diagram showing the state of the collet in the recyclable suspension device of the present invention after it is fully seated. Figure 11 for Figure 10 A schematic diagram of a partial structure; Figure 12 This is a schematic diagram showing the state of the anchor claws unhooking when the recyclable hanger of the present invention is lost. Figure 13 for Figure 12 A schematic diagram of a partial structure; Figure 14 This is a schematic diagram showing the state of the ball seat after it is knocked down in the retrievable suspension device of the present invention; Figure 15 for Figure 14 A schematic diagram of a partial structure; Figure 16 This is a schematic diagram showing the state of the recyclable hanger of the present invention after lifting the seated sealing tool string; Figure 17 for Figure 16 A schematic diagram of a partial structure; Figure 18 This is a schematic diagram showing the connection between the main body of the suspension device and the recovery tool in this invention; Figure 19 This is a schematic diagram showing the state of the main body of the suspension device when it is lifted and retrieved by the retrieval tool in this invention; Figure 20 This is a detailed view of the tooth profiles of the release ring, locking ring, and mandrel in this invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0025] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0026] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0027] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of this application, should still fall within the scope of the technical content disclosed in this application. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of this application. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this application.

[0028] The following is in conjunction with the appendix Figure 1-20 The present invention will be described in further detail below.

[0029] Example 1 like Figure 1-20 As shown, a retrievable suspension device with an automatically unlocking locking mechanism includes: a setting tool string and a suspension body; the setting tool string includes: a central tube 5 and a piston drive mechanism, a positioning connection mechanism, and a ball-throwing pressure mechanism mounted on the central tube 5; the suspension body includes: a spindle 27 and a setting transmission mechanism, a slip anchoring mechanism, and a locking mechanism mounted on the spindle 27; the piston drive mechanism is configured to sequentially drive in response to different levels of hydraulic pressure: under a first preset pressure, it drives the positioning connection mechanism to lock and fix with the spindle 27 to establish a setting reaction force fulcrum; under a second preset pressure, it drives the setting transmission mechanism to push the slip anchoring mechanism to complete the setting, and simultaneously drives the locking mechanism to achieve unidirectional locking to maintain the setting force; under a third preset pressure, it drives the positioning connection mechanism to unlock and triggers the ball seat 50 in the ball-throwing pressure mechanism to fall, so that the setting tool string is in a retrievable state. The setting tool string also includes: an upper connector 2, which is connected between the piston sleeve 6 and the central tube 5, and a key block 7 is provided between the upper connector 2 and the central tube 5 to limit their relative rotation; an outer cylinder pressure cap 3 is fitted on the upper connector 2 and is coaxially fixed to the outer wall of the piston sleeve 6; a semi-ring 4 is provided in the outer ring groove of the outer cylinder pressure cap 3 and the upper connector 2.

[0030] The retrievable suspension device of this invention mainly consists of two parts: a setting tool string and a suspension device body. These parts cooperate to complete the setting and retrieval operations. The specific working principle is as follows: The upper connector 2 is connected between the piston sleeve 6 and the central tube 5. A key block 7 is set between the upper connector 2 and the central tube 5 to restrict their relative rotation, ensuring the stability and reliability of the setting tool string during operation. The outer cylinder pressure cap 3 is sleeved on the upper connector 2 and coaxially fixed to the outer wall of the piston sleeve 6. A semi-ring 4 is set in the outer ring groove of the outer cylinder pressure cap 3 and the upper connector 2, forming the connection and support system for the setting tool string. The piston drive mechanism's graded drive includes multiple pressure stages. In the first preset pressure stage: when the hydraulic pressure reaches the first preset pressure, the piston drive mechanism drives the positioning connection mechanism to lock and fix with the mandrel 27, establishing a setting reaction force fulcrum and providing a stable foundation for subsequent setting operations. In the second preset pressure stage: when the hydraulic pressure rises to the second preset pressure, the piston drive mechanism drives the setting transmission mechanism to push the slip anchoring mechanism to complete the setting. The slip anchoring mechanism secures the hanger body to the wellbore, achieving positioning and fixation. Simultaneously, the piston drive mechanism synchronously drives the locking mechanism to achieve one-way locking, maintaining the setting force and ensuring stable operation of the hanger after setting. In the third preset pressure stage: when the hydraulic pressure reaches the third preset pressure, the piston drive mechanism drives the positioning connection mechanism to release the lock and triggers the ball seat 50 in the ball-throwing and pressure-retaining mechanism to fall. The falling of the ball seat 50 changes the internal channels of the setting tool string, placing it in a retrievable state, preparing for subsequent retrieval operations. In this invention, the spindle 27 of the hanger body is equipped with a setting transmission mechanism, a slip anchoring mechanism, and a locking mechanism. The setting transmission mechanism, under the action of the piston drive mechanism, transmits driving force to the slip anchoring mechanism, enabling the slip anchoring mechanism to complete the setting action. The locking mechanism achieves one-way locking during the setting process, ensuring the continuous action of the setting force and ensuring the stability of the hanger in harsh environments.

[0031] This invention adopts a modular and functional separation design concept. The various functional units of the setting tool string and the main body of the hanger, such as load-bearing, sealing, and locking, work collaboratively without interfering with each other. For example, the piston drive mechanism, positioning connection mechanism, setting transmission mechanism, slip anchoring mechanism, and locking mechanism each independently complete specific functions, while cooperating to achieve the overall function of the hanger. This makes the hanger structure more compact and improves space utilization. The independent design of each functional unit fundamentally improves the working stability of the hanger under complex well conditions. In harsh environments with high temperature and high pressure, each functional unit can independently cope with different working conditions, ensuring that the hanger can still reliably set. Furthermore, the modular design allows each component of the hanger to be processed and assembled independently, simplifying the processing and assembly process. Different functional units can be produced and tested separately before overall assembly, improving production efficiency and reducing production costs. This invention establishes an unlocking mechanism centered on "downward locking and upward automatic release unlocking," changing the reliance of traditional recovery methods on complex operation sequences or precise pressure control. This unlocking mechanism simplifies the recovery process to a single, intuitive action, reducing the complexity of human operation and minimizing the risk of human error. The streamlined recovery process ensures rapid and accurate unlocking and retrieval whenever needed, significantly reducing non-productive time. For example, when the hanger needs to be replaced or repaired, the setting tool string can be quickly retrieved, reducing well site downtime and thus lowering operational risks and overall costs.

[0032] Example 2 like Figure 1-20As shown, the piston drive mechanism includes: a piston sleeve 6 coaxially sleeved outside the central tube 5, and a piston 8 and a piston extension cylinder 9 disposed within the annular pressure chamber formed by the two; the central tube 5 is provided with a pressure transmission hole; one end of the piston 8 and the piston extension cylinder 9 is fixed and can slide in a sealed manner within the pressure chamber, and the other end of the piston extension cylinder 9 is fixed to the piston sleeve 6 by a shear pin 14. A setting sleeve 12 is coaxially sleeved on the piston extension cylinder 9, and the setting sleeve 12 is releasably connected to the piston extension cylinder 9 by a shear pin 13; a setting joint 16 is sleeved on the outer periphery of the setting sleeve 12 and fixedly connected by a set screw 15, and its end is axially limited by a sleeve cap 10, which is fixedly connected to the setting sleeve 12 by a set screw 11. An inner push sleeve 18 is coaxially sleeved on the central tube 5. The inner push sleeve 18 is releasably connected to the central tube 5 via a shear pin 20. An outer push sleeve 17 is fixed to the outside of the inner push sleeve 18, and the outer push sleeve 17 axially abuts against the end of the piston extension cylinder 9. The inner push sleeve 18 is configured to act on one end of the release pawl 22, which slides on the central tube 5. A shear pawl 21 is fitted on the release pawl 22. The two ends of the positioning short joint 24 are fixedly connected to the central tube 5 and the ball seat short joint 53, respectively, to form a pressure flow channel. A shear ring 51 is fixedly installed at the axial end of the ball seat short joint 53. The shear ring 51 is installed inside the guide shoe 42, and the guide shoe 42 is connected to the bottom of the ball seat short joint 53. A ball seat 50 is connected inside the shear ring 51 via a shear pin 49. The ball seat 50 is used to receive the thrown ball 52.

[0033] In this invention, a retrievable hanger with an automatically unlocking locking mechanism is lowered into the well to a predetermined position along with the tubing. A ball 52 is then inserted from the tubing inlet into the ball seat 50 at the bottom of the hanger. After the ball 52 settles into the ball seat 50, hydraulic pressure is pumped into the tubing. This hydraulic pressure enters the annular pressure chamber formed by the central tube 5 and the piston sleeve 6 through a pressure transmission hole on the central tube 5, acting on the piston 8. The piston 8 is fixedly connected to the piston extension cylinder 9, forming a main power output unit. Under initial pressure, the unit is under overall stress, but because the piston extension cylinder 9 is fixed to the piston sleeve 6 by shear pin 14, the mechanism remains stationary, and pressure continues to accumulate. When the hydraulic pressure reaches a first preset value (i.e., the shearing force of shear pin 14), shear pin 14 is sheared. The piston 8 and piston extension cylinder 9, as a whole, begin to slide downstream in a sealed manner. The end of the piston extension cylinder 9 directly abuts against the outer push sleeve 17, which is fixed to the inner push sleeve 18. The inner push sleeve 18 is connected to the central tube 5 via shear pin 20. At this time, since the strength of shear pin 20 is higher than the system's motion resistance, the power is transmitted through the inner push sleeve 18 to the release pawl 22 acting at its end. The release pawl 22 transmits the force to the slip support ring 26 of the positioning connection mechanism, thereby completing the establishment of the setting reaction fulcrum and fixing the slip spring 25 anchor claw. At this stage, the shear pin 13 connected to the setting sleeve 12 remains intact, so the setting transmission mechanism has not yet been activated. After the positioning connection mechanism is locked, the system resistance increases. When the pressure continues to rise to the second preset value, the shear pin 20 between the inner push sleeve 18 and the central tube 5 is sheared. At this time, as the piston extension cylinder 9 continues to move, the piston extension cylinder 9 drives the setting sleeve 12 to move through the shear pin 13. The setting sleeve 12 drives the setting joint 16 to move through the set screw 15. When the setting joint 16 is in contact with the setting transmission mechanism, the setting transmission mechanism controls the slip anchoring mechanism to perform setting. Under the second preset pressure, the piston drive mechanism drives the setting transmission mechanism to push the slip anchoring mechanism to complete the setting, and simultaneously drives the locking mechanism to achieve one-way locking to maintain the setting force.

[0034] Example 3 like Figure 1-20As shown, the positioning connection mechanism includes: a slip support ring 26, a slip spring 25, and a positioning short connector 24; the slip support ring 26 is installed on the central tube 5, and the slip spring 25 is provided on its outer wall; the positioning short connector 24 is coaxially sleeved outside the slip support ring 26 and the slip spring 25, and its inner wall abuts against the slip spring 25; the positioning anchor claw on the outer side of the positioning short connector 24 is arranged opposite to the anchor claw bite groove on the inner side of the positioning joint 23, and the positioning joint 23 is fixed to the spindle 27 by a set screw 28; wherein, the slip support ring 26 is configured to generate axial displacement under the drive of the inner push sleeve 18 and the release pawl 22, and through the interaction between its conical surface and the slip spring 25, drive the slip spring 25 to expand radially, thereby pushing the positioning short connector 24 so that its positioning anchor claw is engaged in the anchor claw bite groove of the positioning joint 23.

[0035] In a retrievable suspension device with an automatically unlocking locking mechanism according to the present invention, under a first preset pressure, the inner push sleeve 18 generates axial displacement under hydraulic drive, pushing the release pawl 22, and then applying axial force to the slip support ring 26; after being subjected to a downward axial force, the slip support ring 26 generates axial displacement, and the conical surface of its outer wall interacts with the inner inclined surface of the slip spring 25. Due to the conical effect, the axial movement of the slip support ring 26 is converted into the radial outward expansion of the slip spring 25. The radially expanding slip spring 25 tightly abuts against and pushes the inner wall of the positioning short 24, thereby applying a radial outward force to the positioning short 24, forcing the positioning anchor claw on the outer side of the positioning short 24 to forcefully embed into the anchor claw biting groove on the inner side of the positioning joint 23; at this point, the setting tool string and the suspension device body are mechanically rigidly connected, and this connection point provides the necessary and stable setting reaction force fulcrum for the setting transmission mechanism to push the slip anchoring mechanism downward in the subsequent setting process.

[0036] Example 4 like Figure 1-20As shown, the slip anchoring mechanism includes an upper cone 37, a slip sleeve 38, slips 40, and a lower cone 43; a limiting ring 1 is connected to the upper cone 37 via a set screw 36; the upper cone 37 is connected to the inside of the slip sleeve 38 via a set screw 39; the slip sleeve 38 is fitted onto a guide joint 44, and a guide pin 45 on the guide joint 44 is slidably engaged in the guide groove of the slip sleeve 38; the guide joint 44 is installed on a spindle 27, and the lower cone 43 is installed on the spindle 27, with the guide joint 44 positioned below the lower cone 43; multiple slips 40 are evenly distributed on the slip sleeve 38 and located between the upper cone 37 and the lower cone 43; the middle part of the slip 40 is connected to the inner wall of the slip sleeve 38 via a spring 41, and the slip teeth of the slip 40 are slidably engaged in the slip groove of the slip sleeve 38. A lower connector 48 is coaxially mounted on the mandrel 27, and a guide ring 47 is mounted on the outer side of the lower connector 48. The guide ring 47 and the lower connector 48 are fixedly connected to the mandrel 27 by a set screw 46. The guide ring 47 and the lower connector 48 are engaged on the side of the guide connector 44 away from the lower cone 43. The setting transmission mechanism includes a setting sleeve 19 and a release sleeve 29. One end of the setting sleeve 19 can axially abut against the setting connector 16, and the other end is fixed to the release sleeve 29 by a set screw 33. The release sleeve 29, which is slidably fitted to the mandrel 27, is connected to the limiting ring 1, which is sleeved on the mandrel 27, by a shear pin 34. The limiting ring 1 is connected to the upper cone 37 by a set screw 36. One end of the release sleeve 29 near the upper cone 37 is fixedly connected to the limiting connector 35. When the release sleeve 29 is lifted by the recovery tool 54 and shears the shear pin 34 and moves upward, the release sleeve 29 drives the limiting connector 35 to slide on the limiting ring 1 towards the positioning connector 23, so that the limiting connector 35 can be engaged in the slot of the limiting ring 1, thereby driving the limiting ring 1 to lift. There is a gap between the limiting ring 1 and the spindle 27 to make room for the movement of the locking ring. The locking ring 32 in this invention is a C-shaped structure with a relatively large outer diameter. The outer diameter is reduced by compression. After installation and fixing, the outer diameter is in a compressed state. When the space above it is cleared, it can automatically spring back to its original shape.

[0037] Under the second preset pressure, the piston drive mechanism drives the seat seal joint 16 downward, with its end axially abutting against the seat seal sleeve 19. The seat seal sleeve 19 transmits force to the release sleeve 29 through the set screw 33. The release sleeve 29 transmits force to the limiting ring 1 through the uncut shear pin 34. The limiting ring 1 transmits the axial thrust to the upper cone 37 through the set screw 36. The upper cone 37 and the slip sleeve 38 are fixedly connected by the set screw 39. The slip sleeve 38 is restricted to moving only along a preset path through the sliding engagement of its guide groove with the guide pin 45 on the guide joint 44. The lower cone 43 is fixedly installed on the spindle 27. When the upper cone 37 moves downward under the thrust, it and the fixed lower cone 43 work together to squeeze the multiple slips 40 located between them. Due to the effect of the conical surface, when subjected to axial compression, the slip 40 is forced to slide radially outward along the slip groove on the slip sleeve 38; during this process, the spring 41 in the middle of the slip 40 is compressed and stores energy, providing a guarantee for the slip to reset during subsequent recovery; the radially extending slip 40 has slip teeth on its surface that embed into the inner wall of the sleeve, thereby firmly anchoring the entire suspension body to the sleeve. In this invention, the outer push sleeve 17 and the inner push sleeve 18 are connected by shear pins.

[0038] When recovery is required, the hydraulic pressure in the piston drive mechanism continuously increases. When the pressure reaches the third preset value, the drive positioning connection mechanism is unlocked, and the ball seat 50 in the ball-throwing and pressure-pressing mechanism is knocked down, putting the setting tool string into a retrievable state. Specifically, the pressure further increases to the third preset value, cutting off the shear pin between the outer push sleeve 17 and the inner push sleeve 18. At this time, the inner push sleeve 18 drives the release pawl 22 to continue moving. The release pawl 22 pushes the slip support ring 26 to move inward on the inclined surface until the slip support ring 26 presses against the positioning short circuit 24. At this time, the slip support... The conical surface of ring 26 disengages from the slip spring 25, causing the slip spring 25 to lose support and retract radially. This causes the positioning anchor claw of positioning short connector 24 to disengage from the anchor claw engagement groove of positioning connector 23, thus releasing the anchor claw. After release, hydraulic pressure acts on ball seat 50, shearing pin 49. Ball seat 50 and ball 52 fall off. After the ball seat falls, the flow channel at the bottom of the central tube 5 is opened, eliminating the piston effect when the tool string is lifted, putting it in a safe retraction state. The retraction of slip spring 25 releases the radial thrust on positioning short connector 24. Subsequently, when the setting tool string is lifted, the positioning anchor claw on positioning short connector 24 can easily disengage from the anchor claw engagement groove of positioning connector 23, clearing the way for the retraction of the setting tool string. This invention provides a clear mechanical force transmission path and achieves a rigid connection through the structural design of a conical push spring, a short-circuited spring top, and a positioning anchor biting into the anchor biting groove of the positioning joint 23. This connection method can withstand huge setting reaction forces, ensuring the stability of the entire system during the setting process and avoiding the risk of slippage or failure. The positioning joint 23 is fixed to the mandrel 27 by the set screw 28, ensuring that the reaction force is reliably transmitted to the wellhead device. By driving the slip support ring 26 past its working position, this invention can actively remove the support on the slip spring 25, thereby achieving passive retraction and uncoupling. Compared with passive unlocking that relies on complex springs or well conditions, this unlocking method is more certain and reliable, effectively avoiding the common industry problem of slip failure.

[0039] During retrieval, since the anchor claws have been unhooked and the release operation has been completed, the setting tool string can be directly lifted to complete the retrieval of the setting tool string; During the retrieval of the suspension body, the lowering retrieval tool 54 connects to the seat sleeve 19 and is lifted. The lifting force is transmitted to the release sleeve 29 through the seat sleeve 19 and the set screw 33. When this lifting force exceeds the shearing force of the shear pin 34, the shear pin 34 is sheared. The release sleeve 29 can then move upward relative to the limiting ring 1 and the spindle 27. As the release sleeve 29 moves upward, it also drives the limiting joint 35 fixed thereon to move upward together. The limiting connector 35 slides on the limiting ring 1 until it is engaged in the slot of the limiting ring 1. As the release sleeve 29 moves upward, the release sleeve 29 releases the pressure on the locking mechanism. The locking mechanism can then reset to release the pressure on the limiting ring 1, thereby releasing the pressure on the upper cone 37. Under the elastic force of the spring 41, the slip 40 drives the slip teeth to reset and disengage from the inner wall of the sleeve, and the upper cone 37 also resets simultaneously. At this point, the recovery tool 54 continues to be lifted. The force travels through the path of the release sleeve 29, the limiting connector 35, the limiting ring 1, the set screw 36, the upper cone 37, the set screw 39, and the slip sleeve 38, ultimately causing the entire slip anchoring mechanism to move upward.

[0040] Example 5 like Figure 1-20 As shown, the locking mechanism is coaxially housed in an annular cavity formed by the spindle 27, the release sleeve 29, and the limiting ring 1; the two ends of the locking mechanism axially abut against the inner end face of the release sleeve 29 and the limiting ring 1, respectively. The locking mechanism includes a release seat 30, a release ring 31, and a locking ring 32. The first one-way tooth on the inner side of the release ring 31 meshes with the second one-way tooth on the outer side of the locking ring 32, forming a first one-way transmission pair, so that when the release ring 31 is subjected to a downward setting force, it can drive the locking ring 32 to move downward in one direction. The locking ring 32 is slidably sleeved on the spindle 27, and its inner third one-way tooth meshes with the fourth one-way tooth on the outer side of the spindle 27, forming a second one-way locking pair. In the setting state, the locking ring 32 is locked to the spindle 27 by the second one-way locking pair under the drive of the first one-way transmission pair. When the release sleeve 29 is lifted by the recovery tool 54 and shears the shear pin 34 and moves upward, the release seat 30 and the release ring 31 are released from constraint and move upward, thereby releasing the drive on the locking ring 32, so that the second one-way locking pair between the locking ring 32 and the spindle 27 is unlocked. In this invention, the release sleeve 29 and the limiting connector 35 are fixedly connected. When the seat sleeve 19 is lifted, the shear pin 34 is cut off, and the seat sleeve 19 drives the limiting connector 35 to move upward, which in turn drives the limiting ring 1 to move upward, causing the slip to lose support and release the seal. At the same time, under the upward pressure of the limiting ring 1, the release ring 31 enters the groove of the release sleeve 29, making room for the outer diameter of the locking ring 32. The locking ring 32 naturally expands its inner diameter, thereby releasing the lock of the spindle 27.

[0041] The locking mechanism in this invention utilizes two sets of unidirectional toothed pairs to convert the unidirectional linear motion during setting into an irreversible mechanical lock, and automatically unlocks by releasing the constraint during recovery. Its operation can be divided into two states: locking and unlocking.

[0042] 1. Locked state (maintaining setting force during and after setting): During the setting process, the release sleeve 29 moves downward under the setting force, and its inner end face axially abuts against and pushes the release seat 30, thereby transmitting the downward setting force to the release ring 31.

[0043] First-stage one-way transmission: The first one-way tooth on the inner side of the release ring 31 meshes with the second one-way tooth on the outer side of the locking ring 32, forming the first one-way transmission pair. The characteristic of the first one-way transmission pair is that when the release ring 31 is subjected to a downward force, its tooth surface will mesh and drive the locking ring 32 to move downward synchronously; however, if the release ring 31 has an upward movement tendency, its tooth surface will slip and will not drive the locking ring 32 upward.

[0044] Second-level one-way locking: The third one-way tooth on the inner side of the driven downward moving locking ring 32 meshes with the fourth one-way tooth on the outer side of the spindle 27, forming a second one-way locking pair. The characteristic of the second one-way locking pair is that it allows the locking ring 32 to slide downward (the tooth surface slides over), but it will resolutely prevent it from moving upward (the tooth surface jams).

[0045] Therefore, under the continuous setting force, the locking ring 32 is driven downward step by step in one direction by the release ring 31, and locked in the current position in one direction by meshing with the spindle 27. This process is like a one-way ratchet or reverse gear, which makes the entire setting transmission mechanism unable to retract, thereby firmly locking the setting force in the system and ensuring that the anchoring effect of the slip 40 and the compression state of the sealing element are maintained for a long time.

[0046] 2. Unlocked state (during recycling): Triggering condition: The recovery tool 54 is lowered and then lifted. When the lifting force cuts the shear pin 34, the release sleeve 29, release seat 30, and release ring 31 move upward relative to the spindle 27 and the locked ring 32 as a whole.

[0047] Constraint release: The upward movement of the release ring 31 disengages the first one-way transmission pair between it and the locking ring 32, or more precisely, it releases the downward drive and constraint on the locking ring 32.

[0048] Automatic unlocking: Once the release ring 31 stops pushing downwards and constraining the locking ring 32, the second one-way locking pair between the locking ring 32 and the spindle 27 loses the axial pressure that maintains its locked state. At this time, the locking ring 32 itself has a certain elastic restoring ability due to its structure. In the subsequent slight displacement of the overall lifting, its tooth tip can slide out from the tooth groove of the spindle 27, thereby realizing automatic pop-up unlocking and releasing the circumferential and axial constraints of the locking ring 32 on the spindle 27.

[0049] Unlocking the second one-way locking pair means that the holding state is released. At this time, by engaging the limiting connector 35 connected to the release sleeve 29 with the slot of the limiting ring 1, the entire anchoring mechanism can be moved upward to complete the retrieval.

[0050] The locking mechanism in this invention is purely mechanical and self-locking. Once setting is complete, the locking state does not depend on continuous hydraulic pressure or any external energy input; it is solely guaranteed by the mechanical interlock between the locking ring 32 and the second unidirectional locking pair of the mandrel 27. This effectively copes with downhole pressure fluctuations, vibrations, and temperature changes, ensuring the long-term stability of the setting force and fundamentally preventing setting loosening accidents caused by locking failure. The unlocking action does not rely on complex reverse operations or precise pressure control, but is triggered by a simple, inevitable mechanical action. The upward movement of the release ring 31 directly releases the driving constraint on the locking ring 32, making the automatic release of the locking ring 32 a certainty. This lift-up-and-unlock design greatly simplifies the recovery operation, minimizes the risk of human error, and improves the success rate of recovery operations.

[0051] In this invention, the first unidirectional transmission pair ensures that the setting force can be efficiently and unidirectionally transmitted to the locking ring, while also disengaging promptly during lifting and retraction without causing interference. The second unidirectional locking pair bears the responsibility of final locking, and its strength directly determines the locking capability. The coordinated work of the two unidirectional pairs perfectly solves the contradictory requirements of both smooth downward locking and easy upward unlocking. The entire locking mechanism is cleverly housed within an annular cavity formed by the spindle 27, the release sleeve 29, and the limiting ring 1, making full use of the tool's internal space without increasing the axial length of the structure, thus conforming to the design trend of compact and modular downhole tools.

[0052] This locking mechanism not only ensures unparalleled reliability during the setting phase, but also achieves unprecedented simplicity and certainty during the recycling phase, successfully solving the core technical bottleneck faced by existing recyclable suspension devices in the locking and unlocking process.

[0053] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

[0054] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A retrievable suspender with automatic unlocking of a locking mechanism, characterized in that The application relates to a setting tool string and a hanger body. The setting tool string comprises a central pipe (5) and a piston driving mechanism, a positioning connecting mechanism and a ball-throwing pressure-holding mechanism which are arranged on the central pipe (5), and the hanger body comprises a mandrel (27) and a setting transmission mechanism, a slip anchoring mechanism and a locking mechanism which are arranged on the mandrel (27); the piston driving mechanism is configured to sequentially drive the positioning connecting mechanism and the mandrel (27) to be locked and fixed to establish a setting counterforce fulcrum under a first preset pressure, drive the setting transmission mechanism to push the slip anchoring mechanism to complete setting and synchronously drive the locking mechanism to realize one-way locking to keep the setting force under a second preset pressure, and drive the positioning connecting mechanism to be unlocked and trigger the ball seat (50) in the ball-throwing pressure-holding mechanism to fall off so that the setting tool string is in a recyclable state under a third preset pressure. The piston driving mechanism comprises a piston sleeve (6) which is coaxially sleeved outside the central pipe (5), and a piston (8) and a piston extension cylinder (9) which are arranged in an annular pressure cavity formed by the piston sleeve (6) and the central pipe (5); the central pipe (5) is provided with a pressure transmission hole; one end of the piston (8) and the piston extension cylinder (9) is fixed and can be sealingly slid in the pressure cavity, and the other end of the piston extension cylinder (9) is fixed to the piston sleeve (6) through a shear pin two (14).

2. The recyclable hanger of claim 1, wherein, A setting sliding sleeve (12) is coaxially sleeved on the piston extension cylinder (9), the setting sliding sleeve (12) is releasably connected with the piston extension cylinder (9) through a shear pin one (13), the setting sliding sleeve (12) is sleeved with a setting connector (16) on the outer periphery and is fixedly connected with the setting sliding sleeve (12) through a locking screw two (15), and the end portion is axially limited through a sliding sleeve pressing cap (10), and the sliding sleeve pressing cap (10) is fixedly connected with the setting sliding sleeve (12) through a locking screw one (11).

3. The recyclable hanger of claim 2, wherein, An inner pushing sleeve (18) is coaxially sleeved on the central pipe (5), the inner pushing sleeve (18) is releasably connected with the central pipe (5) through a shear pin three (20), the outer side of the inner pushing sleeve (18) is fixed with an outer pushing sleeve (17) through a shear pin, the outer pushing sleeve (17) is axially abutted with the end portion of the piston extension cylinder (9), the inner pushing sleeve (18) is arranged to act on one end of a release pawl (22) which is slid on the central pipe (5), and the release pawl (22) is matched with a shear pawl (21), the release pawl (22) and the shear pawl (21) are connected through staggered disc mouth structures which are mutually engaged to realize torque transmission and axial relative movement between the two.

4. The recyclable hanger of claim 3, wherein, ​ 5. The recyclable hanger of claim 4, wherein, The positioning connecting mechanism comprises a slip base ring (26), a slip spring piece (25) and a positioning short circuit (24); the slip base ring (26) is installed on the central pipe (5), and an outer wall of the slip base ring (26) is provided with the slip spring piece (25); the positioning short circuit (24) is coaxially sleeved outside the slip base ring (26) and the slip spring piece (25), and an inner wall of the positioning short circuit (24) is in abutment with the slip spring piece (25); a positioning anchor claw on an outer side of the positioning short circuit (24) is arranged opposite to an anchor claw biting groove on an inner side of the positioning connector (23), and the positioning connector (23) is fixed on the mandrel (27) through a locking screw three (28); wherein the slip base ring (26) is configured to generate axial displacement under the driving of the inner push sleeve (18) and the release pawl (22), and drive the slip spring piece (25) to radially expand through the interaction of a conical surface of the slip base ring (26) and the slip spring piece (25), and then push the positioning short circuit (24) to make the positioning anchor claw of the positioning short circuit (24) embedded in the anchor claw biting groove of the positioning connector (23).

6. The recyclable hanger of claim 5, wherein, Both ends of the positioning short circuit (24) are fixedly connected with the central pipe (5) and the ball seat short circuit (53) to form a pressure flow channel; a shear ring (51) is fixedly arranged at an axial end of the ball seat short circuit (53), the shear ring (51) is arranged inside a guide shoe (42), and the guide shoe (42) is connected to a bottom of the ball seat short circuit (53); a ball seat (50) is connected to the shear ring (51) through a shear pin five (49), and the ball seat (50) is used for receiving a dropped ball (52).

7. The recyclable hanger of claim 5, wherein, The setting transmission mechanism comprises a setting sleeve (19) and a release sleeve (29); one end of the setting sleeve (19) is axially abutted against a setting connector (16), and the other end is fixed to the release sleeve (29) through a locking screw four (33); the release sleeve (29) is slidingly fitted on the mandrel (27), and the release sleeve (29) is connected to a limiting ring (1) sleeved on the mandrel (27) through a shear pin four (34); the limiting ring (1) is connected to an upper cone (37) through a locking screw five (36); one end of the release sleeve (29) close to the upper cone (37) is fixedly connected to a limiting connector (35); when the release sleeve (29) is cut off the shear pin four (34) and moves upward under the lifting of the recovery tool (54), the release sleeve (29) drives the limiting connector (35) to slide on the limiting ring (1) in the direction of the positioning connector (23), so that the limiting connector (35) is clamped in a clamping groove of the limiting ring (1) to drive the limiting ring (1) to lift.

8. The recyclable hanger of claim 7, wherein, The locking mechanism is coaxially arranged in a ring-shaped cavity formed by the mandrel (27), the release sleeve (29) and the limiting ring (1); both ends of the locking mechanism are axially abutted against an inner end surface of the release sleeve (29) and the limiting ring (1).

9. The recyclable hanger of claim 8, wherein, The locking mechanism comprises a release seat (30), a release ring (31) and a locking ring (32); the first one-way teeth on the inner side of the release ring (31) are engaged with the second one-way teeth on the outer side of the locking ring (32) to form a first one-way transmission pair, so that the release ring (31) can drive the locking ring (32) to move downward in one direction when it bears a downward setting force; the locking ring (32) is slidably sleeved on the mandrel (27), and the third one-way teeth on the inner side of the locking ring (32) are engaged with the fourth one-way teeth on the outer side of the mandrel (27) to form a second one-way locking pair; in the setting state, the locking ring (32) is locked with the mandrel (27) through the second one-way locking pair under the drive of the first one-way transmission pair; when the release sleeve (29) is lifted by the recovery tool to shear the shear pin four (34) and move upward, the release seat (30) and the release ring (31) are released from the constraint and move upward, thereby releasing the drive to the locking ring (32), so that the second one-way locking pair between the locking ring (32) and the mandrel (27) is unlocked.

10. The recyclable hanger of claim 9, wherein, The slip anchoring mechanism comprises an upper cone (37), a slip sleeve (38), slips (40) and a lower cone (43); the limiting ring (1) is connected with the upper cone (37) through the set screw five (36); the upper cone (37) is connected to the inner side of the slip sleeve (38) through the set screw six (39); the slip sleeve (38) is sleeved on the guide joint (44), the guide pin (45) on the guide joint (44) is slidably fitted in the guide groove of the slip sleeve (38); the guide joint (44) is installed on the mandrel (27), the lower cone (43) is installed on the mandrel (27), and the guide joint (44) is clamped below the lower cone (43); the slips (40) are evenly distributed on the slip sleeve (38) and located between the upper cone (37) and the lower cone (43); the middle part of the slip (40) is connected to the inner wall of the slip sleeve (38) through the spring (41), and the slip teeth of the slip (40) are slidably fitted in the slip groove of the slip sleeve (38).

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