High-pressure-resistant drilling liner hanger

Abstract

The invention belongs to the technical field of downhole tools, and particularly relates to a high-pressure-resistant drilling liner hanger. The high-pressure-resistant drilling liner hanger comprises an external device which comprises a hanging mechanism provided with a slip and a tie-back cylinder capable of pushing the hanging mechanism to open the slip; the internal device comprises a sitting and hanging driving mechanism, and the sitting and hanging driving mechanism can be connected with the tie-back barrel through a plug cap; the external device is constructed to be left in a well after underground construction operation, and the internal device is constructed to be capable of being lifted out of a well mouth after underground construction operation; the hanging mechanism comprises a hanging mechanism body arranged below the sitting hanging driving mechanism, a taper sleeve, a slip and a slip supporting sleeve are sequentially arranged on the outer side of the hanging mechanism body, a limiting fixing cylinder is arranged on the inner side of the slip and the inner side of the slip supporting sleeve, and the upper end of the limiting fixing cylinder abuts against the taper sleeve. And the lower end part is connected with the slip supporting sleeve through a setting starting pin.

Description

Technical Field

[0001] This invention belongs to the field of downhole tool technology, specifically, it relates to a high-pressure resistant tailpipe hanger. Background Technology

[0002] Tailtub hangers are commonly used downhole tools in oil exploration and development. They can be classified into three types based on their mounting method: mechanical, hydraulic, and hydraulic-mechanical dual-acting. Hydraulic tailtub hangers are the most widely used. Hydraulic tailtub hangers activate their hydraulic cylinders by pressurizing the tubing. Currently, to address the challenges of tailtub cementing in complex well conditions such as deep wells, small-gap wells, and wells with extended reach, various types of hydraulic tailtub hangers have been developed in China, featuring high load-bearing capacity and high reliability during installation.

[0003] However, the traditional hydraulic tailpipe hanger's mounting drive mechanism is designed outside the hanger body and will remain in the well for a long time after cementing. Since the mounting drive mechanism inevitably requires the use of rubber seals, these rubber seals are prone to aging under the high temperature and high pressure environment in the well for a long time, leading to seal failure at the mounting drive mechanism and thus affecting the long-term sealing of the entire wellbore.

[0004] Chinese patent document CN112227993A discloses a liner hanger with a retrievable drive mechanism, which transfers the seat drive mechanism to the delivery tool and is retrieved along with the delivery tool after cementing, thereby effectively eliminating potential leakage risks of the liner hanger and improving the tool's pressure resistance and sealing durability. However, this liner hanger still has the following problems.

[0005] The suspension mechanism has low reliability. In existing tailpipe suspensions, the slips are fixed to the body via a slip support sleeve, ensuring they are initially retracted within the cone sleeve and preventing premature expansion. After the ball is thrown and compressed, the cone sleeve moves downwards relative to the body and slips, causing the slips to expand and form the initial suspension. For fully reliable suspension, relative movement between the cone sleeve and slips is necessary when lowering the body (tailpipe weight). However, in this structure, the slips and slip support sleeve are fixed to the body, and the cone sleeve is also unidirectionally fixed to the body via a retaining spring. This means that after initial suspension, the slips and cone sleeve cannot move freely relative to each other. When lowering the body, the body may pull the slips downwards along with it, potentially causing the tailpipe suspension to fail to suspend. In other words, while directly fixing the slips and slip cone sleeve to the body effectively prevents premature suspension, it can lead to tailpipe suspension failure.

[0006] The construction safety is insufficient, lacking an emergency release function. This tailpipe hanger uses a mechanism to prevent premature engagement of the plug cap, locking the return sleeve and the feeding tool. This prevents the hanger from engaging prematurely due to external forces during tailpipe lowering. Only after the ball is thrown and pressure is applied can the drive mechanism lock the return sleeve and feeding tool, ensuring continued engagement of the tailpipe hanger. However, in actual construction, pressure may not be applied after the ball is thrown, meaning the engagement drive mechanism may fail to activate. This would prevent the tailpipe hanger from releasing from the lower pipe string, potentially leading to a more serious construction accident.

[0007] Therefore, a new type of tailpipe suspension is needed. Summary of the Invention

[0008] In view of the technical problems mentioned above, the present invention aims to provide a high-pressure resistant tailpipe hanger that can solve at least one of the above technical problems.

[0009] According to the present invention, a high-pressure resistant tailpipe hanger is provided, comprising:

[0010] An external device, comprising a suspension mechanism with a conical sleeve and a slip, and a return sleeve capable of pushing the suspension mechanism to open the slip;

[0011] The internal device includes a seat-hanging drive mechanism that can connect to the return tube via a plug. The plug is locked before the seat-hanging drive mechanism is started and fixes the return tube. After the seat-hanging drive mechanism is started, it is unlocked and drives the return tube to move.

[0012] The external device is configured to remain in the well after the downhole operation, while the internal device is configured to be retrieved from the wellhead after the downhole operation.

[0013] The suspension mechanism includes a suspension mechanism body disposed below the seat drive mechanism. A cone sleeve, a slip, and a slip support sleeve are sequentially disposed on the outside of the suspension mechanism body. A limit fixing cylinder is disposed on the inside of the slip and the slip support sleeve. The upper end of the limit fixing cylinder abuts against the cone sleeve, and the lower end is connected to the slip support sleeve through a seat start pin.

[0014] In one specific embodiment, the suspension mechanism further includes a shear pin sleeve disposed on the outside of the suspension mechanism body via an unlocking shear pin, the upper end face of the shear pin sleeve contacting the lower end face of the slip support sleeve, and there is an axial gap between the lower end of the limiting fixing cylinder and the shear pin sleeve.

[0015] In one specific embodiment, the cone sleeve is connected to the return cylinder via a snap ring sleeve and a suspension mechanism connecting cylinder, and the snap ring sleeve and the suspension mechanism body are engaged by an anti-reverse snap ring.

[0016] In one specific embodiment, the seat drive mechanism includes a spindle, a hydraulic cylinder is disposed outside the spindle, a piston is disposed inside the hydraulic cylinder, and the end of the piston extends into and is connected to the plug cap.

[0017] The piston divides the internal space of the hydraulic cylinder into an upper space and a lower space. A pressure transmission hole is provided radially on the spindle, and the pressure transmission hole is connected to the upper space. A pressure relief hole is provided on the outer wall of the lower end of the hydraulic cylinder, and the pressure relief hole is connected to the lower space.

[0018] Before being seated, the piston is in the upstream first position and is connected to the spindle via the first shear pin. When seated, the first shear pin is cut off, the piston moves downward, and pushes the return cylinder downward through the plug cap, so that the slips of the suspension mechanism are opened.

[0019] In one specific embodiment, at least one secondary hydraulic cylinder is further provided outside the mandrel. The secondary hydraulic cylinder is located between the hydraulic cylinder and the plug cap. A secondary piston is provided inside the secondary hydraulic cylinder and is connected to the piston.

[0020] The secondary piston divides the internal space of the secondary hydraulic cylinder into an upper space and a lower space. The spindle is provided with a secondary pressure transmission hole that connects to the upper space in a radial direction. The outer wall of the lower end of the secondary hydraulic cylinder is provided with a pressure relief hole that connects to the lower space.

[0021] In one specific embodiment, the end of the piston is provided with a piston connecting cylinder via an extension cylinder, and a seat sleeve that can push the cap downward is fixed on the piston connecting cylinder.

[0022] In one specific embodiment, the plug includes:

[0023] A mounting and pushing device connecting the return tube;

[0024] A support cylinder is disposed inside the seat-hanging push device, and the support cylinder is configured to push the seat-hanging push device axially downward under the action of the seat-hanging drive mechanism.

[0025] The seat-mounted pushing device is provided with a locking block assembly that moves radially. A return tube slot is provided on the inner side of the return tube. The support tube supports the inner side of the locking block assembly, so that the outer end of the locking block assembly is engaged in the return tube slot.

[0026] When the support cylinder moves upward relative to the seat-mounting push device, it can release the support of the locking block assembly, thereby releasing the locking block assembly from the locking slot of the return cylinder.

[0027] In one specific embodiment, the locking block component includes:

[0028] A locking block that is radially movable on the seat-mounting push device;

[0029] A locking pin is fixedly installed inside the locking block, and the locking pin is used to engage with the return tube slot.

[0030] In one specific embodiment, the plug cap further includes a fixed sleeve connected to the spindle of the seat-hanging drive mechanism. The fixed sleeve is connected to the seat-hanging push device through a connecting body. A stop block is axially movable inside the outer wall of the fixed sleeve. A slot is provided on the inner wall of the connecting body. The piston connecting cylinder of the seat-hanging drive mechanism extends into the fixed sleeve and supports the stop block, so that the outer end of the stop block is engaged in the slot.

[0031] In one specific embodiment, a central tube is connected below the seat-hanging drive mechanism via a release mechanism, and a sealing core is provided between the central tube and the suspension mechanism.

[0032] Compared with the prior art, the advantages of this application are as follows.

[0033] The tailpipe hanger of this invention, after setting and engaging, has its setting and engaging drive mechanism pulled out of the wellhead after cementing operations. This eliminates the potential risk and weakness of the setting and engaging drive mechanism remaining in the well for an extended period, significantly improving the pressure resistance of the tailpipe hanger and the durability of the tubing string seal. Furthermore, the plug effectively prevents premature setting and engaging of the hanger mechanism during tailpipe running, enhancing the safety and reliability of the operation.

[0034] This invention incorporates a fixed limiting cylinder within the slip, which is connected to the slip support sleeve via a shear pin. The upper end of the fixed limiting cylinder axially abuts against the conical sleeve, thus achieving both initial positioning of the slip and the conical sleeve while ensuring a direct, unfixed connection between the slip and the main body. This allows for initial engagement of the suspension mechanism after the conical sleeve descends relative to the slip, further downward pressure on the suspension mechanism body can drive the conical sleeve to move further downward relative to the slip, enhancing the radial expansion of the slip and improving engagement reliability. Furthermore, when disengaging, lifting the suspension mechanism body causes the shear pin sleeve to move upward relative to the fixed limiting cylinder and abut against it. This contact cuts the unlocking shear pin, preventing the shear pin sleeve from exerting an upward axial force on the slip and avoiding disengagement failure.

[0035] The seat-mounted drive mechanism adopts a multi-stage hydraulic cylinder structure, which can provide sufficient downward pressure to the downlink components such as the return cylinder and cone sleeve, thereby ensuring that the tailpipe suspension mechanism completes the seat-mounted action.

[0036] The locking block assembly of this invention includes a locking block body and a locking shear pin. It can lock the return cylinder and the feed tool, and also, when the seat-mounted drive mechanism fails to operate, lift the shear pin to release the tailpipe hanger in an emergency, thereby reducing the possibility of major accidents. Furthermore, the strength of the locking shear pin can be adjusted according to the actual site conditions, making operation convenient. Attached Figure Description

[0037] The present invention will now be described with reference to the accompanying drawings.

[0038] Figure 1 A schematic diagram of one embodiment of the high-pressure resistant tailpipe hanger according to the present invention is shown;

[0039] Figure 2 A schematic diagram of the plug cap and seat drive mechanism of the high-pressure resistant tailpipe hanger according to the present invention is shown;

[0040] Figure 3 This shows a schematic diagram of the connection between the plug cap and the return sleeve of the high-pressure tailpipe hanger according to the present invention;

[0041] Figure 4 A schematic diagram showing the contact connection between the plug cap and the return sleeve of the high-pressure tailpipe hanger according to the present invention is shown;

[0042] Figure 5 A schematic diagram of the suspension mechanism body of the high-pressure resistant tailpipe hanger according to the present invention is shown;

[0043] Figure 6 This shows a schematic diagram of the suspension mechanism body of the high-pressure tailpipe hanger according to the present invention.

[0044] Figure 7 This shows a schematic diagram of the structure of the suspension mechanism body of the high-pressure tailpipe hanger according to the present invention, which is released from the seat.

[0045] Figure 8 A schematic diagram showing the locking block assembly of the high-pressure tailpipe hanger according to the present invention is shown in contact with and locked to the return cylinder;

[0046] Figure 9 The high-pressure resistant tailpipe hanger according to the present invention is shown in Figure 8 A schematic diagram showing the separation of the reconnector and the plug cap;

[0047] Figure 10 , Figure 11 and Figure 12A schematic diagram of the locking block assembly of the high-pressure resistant tailpipe hanger according to the present invention is shown;

[0048] Figure 13 A schematic diagram of the emergency release mechanism of the high-pressure resistant tailpipe hanger according to the present invention is shown.

[0049] The reference numerals in the figure are as follows:

[0050] 1. Lifting connector; 2. Variable buckle connector; 3. Plug cap; 4. Return sleeve; 5. Seat-hanging drive mechanism; 6. Release mechanism; 7. Sealing core; 8. Suspension mechanism; 9. Center tube; 10. Rubber plug connector; 100. High-pressure resistant tailpipe hanger; 301. Fixing sleeve; 302. Connector; 303. Seat-hanging push device; 311. First opening; 312. Stop block; 313. Annular groove; 321. Cavity; 322. Slot; 331. Stop block sleeve; 332. Second opening; 333. Support sleeve; 334. Second shear pin; 335. Locking block assembly; 341. Locking shear pin; 342. Locking block body; 343. Fixing shoulder; 401. Return sleeve slot; 501. Core Shaft; 502, Piston; 503, Hydraulic Cylinder; 504, First Shear Pin; 505, Piston Connecting Cylinder; 506, Seat Sleeve; 507, Lower Connector; 508, Pressure Transmission Hole; 509, Pressure Relief Hole; 510, Extension Cylinder; 511, Secondary Hydraulic Cylinder; 512, Secondary Piston; 513, Secondary Pressure Transmission Hole; 514, Secondary Pressure Relief Hole; 601, Drop Hand Connector; 801, Suspension Mechanism Body; 802, Slip; 803, Suspension Mechanism Connecting Cylinder; 804, Anti-reverse Snap Ring; 805, Snap Ring Sleeve; 806, Cone Sleeve; 807, Shear Pin Sleeve; 808, Unlocking Shear Pin; 809, Slip Support Sleeve; 810, Limit Fixing Cylinder; 811, Sealing and Starting Pin; 812, Straightening Ring.

[0051] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0052] The invention will now be described with reference to the accompanying drawings.

[0053] It should be noted that in this embodiment, the directions such as "up" and "down" are determined according to the state of the high-pressure resistant tailpipe hanger in the downhole working state described in this embodiment. "Up" is the direction towards the wellhead, and "down" is the direction away from the wellhead.

[0054] Figure 1A high-pressure resistant tailpipe hanger 100 according to an embodiment of the present invention is schematically shown. It includes an external device comprising a suspension mechanism 8, on which a slip 802 is disposed. The external device also includes a return tube 4, which is disposed above and connected to the suspension mechanism 8. The return tube 4 is movable in the axial direction (moving vertically in the working state). When the return tube 4 moves downward, it can apply a thrust to the suspension mechanism 8, thereby causing the slip 802 to expand radially. The high-pressure resistant tailpipe hanger 100 also includes an internal device comprising a mounting drive mechanism 5 and a cap 3. The mounting drive mechanism 5, under hydraulic pressure, pushes the return tube 4 to move via the cap 3. When the tailpipe hanger of this embodiment is lowered to the appropriate position, the mounting drive mechanism 5 increases pressure after being pressurized, thereby driving the cap 3 to push the return tube 4 to move, and further pushing the slip 802 of the suspension mechanism 8 to expand radially to complete the mounting. The plug 3 is designed to prevent premature mounting. Before mounting, the plug 3 is locked to fix the return tube 4, and is unlocked after the mounting drive mechanism 5 is started, thereby driving the return tube 4 to move.

[0055] In this embodiment, the external device remains in the well after the downhole construction operation, while the internal device is pulled out of the wellhead after the downhole construction operation. In this embodiment, the downhole construction operation is cementing construction, but other situations such as well completion construction are also within the scope of this invention.

[0056] When using the high-pressure resistant tailpipe hanger 100 according to this embodiment, during the wellhead insertion process, the return cylinder 4 cannot descend relative to the liner due to the action of the plug cap 3, thus preventing the suspension mechanism 8 from prematurely engaging. After the tailpipe is lowered into place, pressure is applied to the plug cap 3 by ball-throwing and pressure buildup. First, the plug cap 3 is unlocked, and then the return cylinder 4 is driven downward. The return cylinder 4 pushes the slips of the suspension mechanism 8 open, thereby enabling the suspension mechanism 8 to engage. After the final construction is completed, all internal components are removed. Compared with existing tailpipe hangers, the tailpipe hanger of this embodiment has its engagement drive mechanism 5 located inside the internal device. After construction is completed, it is lifted out of the wellhead along with the internal device and will not remain inside the well. This avoids the problem of the rubber sealing device of the engagement drive mechanism 5 aging and failing under the high temperature and high pressure environment downhole, affecting the long-term sealing of the entire wellbore.

[0057] In one embodiment, such as Figure 2As shown, the seat-mounted drive mechanism 5 has a spindle 501, which is a tubular structure. A hydraulic cylinder 503 is installed outside the spindle 501. The hydraulic cylinder 503 has an upward opening, and a piston 502 is installed inside it, extending upward from the opening. The upper end of the piston 502 is connected to a cap 3. In this embodiment, the piston 502 is in an upward-extended state before seat-mounting. The position of the piston 502 inside the hydraulic cylinder 503 at this time is taken as the first position. During seat-mounting, the piston 502 moves downward, causing the cap 3 to push the return cylinder 4 downward, thereby opening the slip 802 of the suspension mechanism 8.

[0058] In the high-pressure tailpipe hanger 100 according to this embodiment, in the first position, the bottom end of the piston 502 is located above the hydraulic cylinder 503. A pressure-transmitting hole 508 is provided on the side wall of the spindle 501 corresponding to the upper part of the hydraulic cylinder 503, and a pressure-relief hole 509 is provided at the lower end of the side wall of the hydraulic cylinder 503. The pressure-relief hole 509 is located below the bottom end of the piston 502. When the ball is thrown and pressurized, the liquid inside the spindle 501 enters the hydraulic cylinder 503 through the pressure-transmitting hole 508. At this time, the pressure of the liquid forces the piston 502 to move downwards, unlocking the cap 3 and driving the return cylinder 4 to move downwards, completing the mounting. Of course, the pressure source of the hydraulic cylinder 503 in this embodiment can also be other methods.

[0059] In a preferred embodiment, a secondary hydraulic cylinder 511 is further provided outside the mandrel 501. Both the upper and lower ends of the secondary hydraulic cylinder 511 have openings, with the port of the secondary hydraulic cylinder 511 connected to the upper port of the hydraulic cylinder 503. A secondary piston 512 is provided inside the secondary hydraulic cylinder 511, connected to the piston 502, allowing the secondary piston 512 to push the piston 502 axially downwards. Specifically, in this embodiment, the inner surface of the secondary piston 512 is connected to the outer surface of the piston 502 via a stepped surface, enabling the secondary piston 512 to push the piston 502 axially downwards. A secondary pressure transmission hole 513 is provided on the side wall of the mandrel 501 at a position corresponding to the upper part of the secondary hydraulic cylinder 511, located above the secondary piston 512. A secondary pressure relief hole 514 is provided at the lower end of the side wall of the secondary hydraulic cylinder 511, located below the secondary piston 512. After the ball is thrown and pressurized, the fluid inside the spindle 501 enters the hydraulic cylinder 503 through the secondary pressure relief hole 514. At this time, the pressure of the fluid forces the secondary piston 512 to move downward, pushing the piston 502. Of course, the pressure source of the hydraulic cylinder 503 in this embodiment can also be other methods.

[0060] In one embodiment, such as Figure 1As shown, the upper end of the mandrel 501 is connected to the lifting joint 1 via a variable thread connector 2, and the lifting joint 1 is connected to the upper feed drill string. The lower end of the mandrel 501 is connected to the central tube 9, and the lower end of the central tube 9 is connected to the tailpipe string via a rubber plug connector 10. A tailpipe cementing connector is provided at the upper end of the tailpipe string for connecting the rubber plug connector 10.

[0061] In a preferred embodiment, such as Figure 2 As shown, a piston connecting cylinder 505 is provided at the end of the piston 502, and a seat sleeve 506 is provided on the piston connecting cylinder 505. The seat sleeve 506 is provided on the outer wall of the piston connecting cylinder 505 and cooperates with the plug cap 3. Before seating, the piston 502 is connected to the spindle 501 by a first shear pin 504, which ensures that the piston 502 is in an extended state before seating.

[0062] By setting the first shear pin 504, the piston 502 and the spindle 501 are further secured before the seat is engaged, preventing the piston 502 from retracting prematurely and causing the cap 3 to unlock, thus preventing the return tube 4 from moving down and engaging prematurely.

[0063] In a preferred embodiment, piston 502 divides the internal space of hydraulic cylinder 503 into an upper space and a lower space. A pressure transmission hole 508 is radially provided on spindle 501, connecting the upper space and the inner cavity of spindle 501. A pressure relief hole 509 is provided on the outer wall of the lower end of hydraulic cylinder 503, connecting the lower space and the external space of hydraulic cylinder 503. A flow channel is provided at the center of spindle 501 for the flow of drilling fluid or other liquids. During setup, a pressure-blocking ball is inserted into the flow channel, which locks onto the upper end of the tailpipe, increasing the pressure inside spindle 501. Under pressure, the liquid inside spindle 501 enters the upper space through the pressure transmission hole 508, pushing piston 502 downwards.

[0064] The structure of the secondary hydraulic cylinder 511 is similar to that of the hydraulic cylinder 503. When the cylinder is seated, a pressure ball is inserted into the flow channel. The pressure ball will be stuck at the upper end of the tail pipe, which will increase the pressure in the spindle 501. Under the action of pressure, the liquid in the spindle 501 enters the upper space of the secondary hydraulic cylinder 511 through the secondary pressure transmission hole 513, and pushes the piston 502 downward through the secondary piston 512.

[0065] In one embodiment, such as Figure 2As shown, the plug 3 includes a fixing sleeve 301, which is connected to the mandrel 501. In this embodiment, a stepped structure is provided between the fixing sleeve 301 and the mandrel 501, with the stepped structure being tapered at the top and thicker at the bottom. This prevents the fixing sleeve 301 from sliding downwards relative to the mandrel 501. Of course, other fixing methods can also be used between the fixing sleeve 301 and the mandrel 501; the stepped structure facilitates processing and assembly. In this embodiment, a seat-hanging pushing device 303 is provided below the fixing sleeve 301, and the seat-hanging pushing device 303 is connected to the return sleeve 4. The fixing sleeve 301 and the seat-hanging pushing device 303 are connected by a connecting body 302, which is attached to the outside of both the fixing sleeve 301 and the seat-hanging pushing device 303.

[0066] Preferably, there is a certain distance between the fixed sleeve 301 and the seat-hanging pushing device 303, so that a cavity 321 is formed between the fixed sleeve 301 and the seat-hanging pushing device 303, and between the connecting body 302 and the spindle 501. The piston connecting sleeve 505 at the end of the piston 502 extends into the cavity 321, while the seat-hanging sleeve 506 is confined within the cavity 321 and can slide up and down within the cavity 321 as the piston 502 moves. Preferably, in this embodiment, the fixed sleeve 301 and the connecting body 302 are detachably connected, and the seat-hanging pushing device 303 and the return sleeve 4 are also detachably connected.

[0067] In one embodiment, an annular groove 313 is provided on the inner side of the lower part of the fixed sleeve 301, and the end of the piston connecting cylinder 505 can extend axially into the annular groove 313. A plurality of first openings 311 are provided on the sidewall of the annular groove 313 in the circumferential direction of the fixed sleeve 301, and the first openings 311 penetrate the fixed sleeve 301 radially. A stop block 312 is provided in the first opening 311, and the stop block 312 can move radially within the first opening 311. A slot 322 is provided on the connecting body 302 corresponding to the first opening 311, and the stop block 312 can extend into the slot 322. Before mounting, when the piston 502 is in the extended first position, the end of the piston connecting cylinder 505 is fixed in the annular groove 313 and supports the inner side of the stop block 312, and the outer end of the stop block 312 is engaged in the slot of the connecting body 302.

[0068] In the high-pressure resistant tailpipe hanger 100 according to this embodiment, when the piston 502 is in the extended state, such as Figure 2 and Figure 3As shown, the piston connecting cylinder 505 supports the stop block 312, which extends into the slot 322 of the connecting body 302, connecting the fixed sleeve 301 to the connecting body 302. Since the fixed sleeve 301 and the spindle 501 are relatively fixed, the fixed sleeve 301 cannot move downwards relative to the spindle 501, thus limiting the downward movement of the connecting body 302. Consequently, the sitting and pushing device 303 and the return cylinder 4, connected to the connecting body 302, also cannot move downwards, ensuring that the suspension mechanism 8 of this embodiment will not prematurely engage. When the piston 502 moves downwards, as... Figure 4 As shown, the piston connecting cylinder 505 moves downward, causing the inner side of the stop block 312 to lose support. The stop block 312 slides inward, separating the connecting body 302 from the fixing sleeve 301. Preferably, the outer edge of the stop block 312 is rounded, chamfered, or beveled, so that it is smoothly connected with the groove 322 of the connecting body 302. When the connecting body 302 moves downward, it provides an inward force to the stop block 312, causing the stop block 312 to disengage from the connecting body 302.

[0069] In a preferred embodiment, such as Figure 2 As shown, the seat-mounting pushing device 303 includes a stop sleeve 331, which is a cylindrical structure. The upper part of the stop sleeve 331 is connected to the connecting body 302, and the lower outer side is provided with a conical or annular groove. The inner side of the upper end of the return sleeve 4 is engaged in the conical or annular groove. In this embodiment, the stop sleeve 331 is provided with a plurality of second openings 332. The second openings 332 are arranged circumferentially around the stop sleeve 331, and the opening direction of the second openings 332 is arranged radially along the stop sleeve 331. A locking block assembly 335 is provided within the second opening 332, and the locking block assembly 335 can move radially within the second opening 332 along the stop sleeve 331. Figure 8 As shown, a return tube groove 401 is provided at the position corresponding to the second opening 332 of the return tube 4, and the outer end of the locking block assembly 335 can extend into the return tube groove 401. In this embodiment, a support tube 333 is provided on the inner side of the stop sleeve 331, and the support tube 333 supports the inner side of the locking block assembly 335, so that the outer end of the locking block assembly 335 is engaged in the return tube groove 401. Figure 9 As shown, when the support of the support cylinder 333 is lost, the locking block assembly 335 will slide out from the return cylinder slot 401.

[0070] When using the high-pressure tailpipe hanger 100 according to this embodiment, when the mounting push device 303 pushes the return cylinder 4 downward, the locking block assembly 335 and the return cylinder slot 401 ensure a stable connection between the mounting push device 303 and the return cylinder 4. When the drill string is lifted, such as Figure 9As shown, the locking block assembly 335 slides out of the slot of the return cylinder 4, thereby separating the seated push device 303 and the return cylinder 4, so that the return cylinder 4 remains downhole while the plug cap 3 is raised to the wellhead.

[0071] In a preferred embodiment, such as Figures 10-12 As shown, the locking block assembly 335 includes a locking block 342 and a locking shear pin 341. The locking block 342 is radially movable within the second opening 332, allowing it to move radially on the mounting drive device 303 without engaging the return tube slot 401. The locking shear pin 341 is radially fixed within the locking block 342 and engages with the return tube slot 401. In this configuration, if the mounting drive mechanism 5 fails to operate and the return tube 4 is stuck in the well, the locking shear pin 341 can be cut off by lifting the high-pressure resistant tailpipe hanger 100, thus allowing the high-pressure resistant tailpipe hanger 100 to be released in an emergency, reducing the likelihood of a major accident.

[0072] Furthermore, a fixing shoulder 343 is provided on the side of the locking block 342. The radially outer side of the fixing shoulder 343 of the locking block 342 contacts the radially inner side of the stop sleeve 331, thereby preventing the locking block 342 from disengaging from the radially outer side of the stop sleeve 331.

[0073] In a preferred embodiment, the upper part of the support cylinder 333 is connected to the stop sleeve 331 via a second shear pin 334, and the lower part is provided with a stepped structure, which is thicker at the top and thinner at the bottom. The stepped structure divides the support cylinder 333 into a first part and a second part, with the first part being thicker than the second part. The upper end of the support cylinder 333 is flush with the upper end of the stop sleeve 331, and the lower part of the second part of the support cylinder 333 extends below the stop sleeve 331, so that the support cylinder 333 can support the locking block assembly 335 (e.g., Figure 2 As shown). When the drill bit is lifted, the hydraulic cylinder 503 moves upward with the mandrel 501, contacts the lower end of the support cylinder 333, and pushes the support cylinder 333 upward, thereby shearing the second shear pin 334 (as shown). Figure 8 As shown). When the stepped structure moves above the second opening 332, the locking block assembly 335 loses the support of the first part of the support cylinder 333 and slides out of the return cylinder slot 401 (as shown). Figure 8 Hydraulic cylinder 503 continues to push support cylinder 333 until seated drive device 303 is completely disengaged from return cylinder 4 (e.g., Figure 9 (As shown).

[0074] Preferably, the locking block assembly 335 has a similar structure to the stop block 312. The outer edge of the locking block assembly 335 is rounded, chamfered or beveled, so that it is smoothly connected with the return tube slot 401. When the stop sleeve 331 moves upward, it will provide an inward force to the locking block assembly 335, causing the locking block assembly 335 to slide out of the return tube slot 401, thereby causing the seat push device 303 to disengage from the return tube 4.

[0075] In one embodiment, such as Figure 5 As shown, the suspension mechanism 8 includes a suspension mechanism body 801, which is a tubular connector and is located inside the return cylinder 4.

[0076] A conical sleeve 806, a slip 802, and a slip support sleeve 809 are sequentially arranged on the outside of the suspension mechanism body 801. These components are all movably fitted onto the outside of the suspension mechanism body 801. A limiting fixing cylinder 810 is provided on the inner side of the slip 802 and the slip support sleeve 809. That is, the inner side of the limiting fixing cylinder 810 contacts the outer wall of the suspension mechanism body 801, and its inner and outer sides contact the slip 802 and the slip support sleeve 809. The upper end of the limiting fixing cylinder 810 abuts against the conical sleeve 806, and the lower end is connected to the slip support sleeve 809 via a setting start pin 811. The slip support sleeve 809, the limiting fixing cylinder 810, and the conical sleeve 806 together limit the movement of the slip 802.

[0077] The suspension mechanism 8 also includes a shear pin sleeve 807 disposed on the outside of the suspension mechanism body 801 by means of an unlocking shear pin 808. The upper end face of the shear pin sleeve 807 contacts the lower end face of the slip support sleeve 809, and there is an axial gap between the lower end of the limiting fixing cylinder 810 and the shear pin sleeve 807.

[0078] Furthermore, the cone sleeve 806 is connected to the return sleeve 4 via the snap ring sleeve 805 and the suspension mechanism connecting sleeve 803. The snap ring sleeve 805 and the suspension mechanism body 801 are engaged by an anti-reverse snap ring 804. The anti-reverse snap ring 804 ensures that the snap ring sleeve 805 can only move downwards and cannot move upwards.

[0079] When using the high-pressure tailpipe hanger 100 according to this embodiment, the return sleeve 4 moves downward under the action of the mounting drive mechanism 5 and the plug cap 3. The return sleeve 4 provides a downward thrust to the suspension mechanism connecting sleeve 803 and the snap ring sleeve 805, driving the cone sleeve 806 to move downward. The cone sleeve 806 pushes the limiting fixing sleeve 810 to move downward relative to the slip support sleeve 809, shearing the setting start pin 811. The cone sleeve 806 continues to move downward, and the slip 802 remains relatively stationary under the action of the slip support sleeve 809. The cone sleeve 806 moves relative to the slip 802, thereby radially expanding the slip 802 and completing the mounting. After the outer wall of the slip 802 is mounted with the wellbore, the suspension mechanism body 801 can be moved downward by pressing down the drill string, thereby driving the cone sleeve 806 to move downward relative to the slip 802 through the anti-reverse snap ring 804, further radially expanding the slip 802.

[0080] When using the high-pressure resistant tailpipe hanger 100 according to this embodiment, if the suspension mechanism 8 gets stuck prematurely during the tailpipe lowering process, the tubing string can be lifted to a certain tonnage, the unlocking shear pin 808 can be cut off, the slip 802 can move downwards, thereby unlocking the suspension mechanism 8, and the entire tubing string can be pulled out of the wellhead.

[0081] Preferably, a straightening ring 812 is coaxially disposed on the outer side of the suspension mechanism body 801, and the straightening ring 812 is located below the shear pin sleeve 807. In this embodiment, the straightening ring 812 is a spiral straightening ring.

[0082] In a preferred embodiment, such as Figure 2 As shown, a release mechanism 6 is provided below the seat-hanging drive mechanism 5. A lower connector 507 is provided below the seat-hanging drive mechanism 5, and the release mechanism 6 is connected to the lower part of the lower connector 507. The lower part of the release mechanism 6 is connected to the suspension mechanism body 801 by a thread.

[0083] During use, after successful mounting, rotating the drill bit drives the mounting drive mechanism 5 and the release mechanism 6 to rotate relative to the suspension mechanism body 801, thus releasing the handle and disengaging the release mechanism 6 from the suspension mechanism body 801. Raising the drill bit causes the mounting drive mechanism 5 to move upwards, bringing the upper end face of the secondary hydraulic cylinder 511 into contact with the lower end face of the support cylinder 333. Figure 8 As shown.

[0084] A sealing core 7 is provided between the central tube 9 and the suspension mechanism body 801.

[0085] In using the high-pressure resistant tailpipe hanger 100 according to this embodiment, the high-pressure resistant tailpipe hanger 100 is first lowered to a suitable position downhole. Then, a ball is dropped to pressurize the shaft. The seat-hanging drive mechanism 5, under pressure, actuates, and the piston 502 experiences a downward force, breaking the first shear pin 504. The piston 502 then moves downward, and the piston connecting cylinder 505 at the upper end of the piston 502 is pulled out of the annular groove 313. When the end of the piston connecting cylinder 505 is pulled out to a position below the first opening 311, the stop block 312 loses support, its inner side slides into the annular groove 313, and its outer end slides out of the slot 322, separating the fixing sleeve 301 and the connecting body 302. The piston connecting cylinder 505 continues to move downward, and the seat-hanging sleeve 506 contacts the seat-hanging push device 303. At this time, the seat-hanging push device 303 connects to the return cylinder 4, driving the return cylinder 4 to move downward. As the return sleeve 4 moves downward, it drives the retaining ring sleeve 805 and the cone sleeve 806 in the suspension mechanism 8 to move downward. The cone sleeve 806 pushes the slip 802 to open, completing the seat hanging.

[0086] After the suspension is completed, the release mechanism 6 is disconnected from the suspension mechanism body 801 by rotating the drill bit.

[0087] As the drill string is lifted, the mounting drive mechanism 5 moves upward. During the upward movement of the hydraulic cylinder 503, it contacts the support cylinder 333, and then the second shear pin is pulled off. The support cylinder 333 moves upward with the hydraulic cylinder 503. When the stepped structure of the support cylinder 333 moves above the second opening 332, the locking block assembly 335 slides out from the return cylinder slot 401. At this time, the stop sleeve 331 and the return cylinder 4 separate. After the hydraulic cylinder 503 contacts the stop sleeve 331, it drives the stop sleeve 331 to move upward, thereby lifting the entire plug 3 and the mounting drive mechanism 5 out of the wellhead.

[0088] In the description of this invention, it should be understood that 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 as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0089] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0090] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure resistant tailpipe hanger, characterized in that, include: The external device includes a suspension mechanism (8) with a cone sleeve (806) and a slip (802), and a return sleeve (4) capable of pushing the suspension mechanism (8) to open the slip (802); The internal device includes a seat-hanging drive mechanism (5), which can be connected to the return tube (4) via a plug (3). The plug (3) is in a locked state before the seat-hanging drive mechanism (5) is started and fixes the return tube (4). After the seat-hanging drive mechanism (5) is started, it is in an unlocked state and drives the return tube (4) to move. The external device is configured to remain in the well after the downhole operation, while the internal device is configured to be retrieved from the wellhead after the downhole operation. The suspension mechanism (8) includes a suspension mechanism body (801) disposed below the seat drive mechanism (5). A cone sleeve (806), a slip (802), and a slip support sleeve (809) are sequentially disposed on the outside of the suspension mechanism body (801). A limiting fixing cylinder (810) is disposed on the inside of the slip (802) and the slip support sleeve (809). The upper end of the limiting fixing cylinder (810) abuts against the cone sleeve (806), and the lower end is connected to the slip support sleeve (809) through a seat start pin (811).

2. The high-pressure resistant tailpipe hanger according to claim 1, characterized in that, The suspension mechanism (8) also includes a shear pin sleeve (807) disposed on the outside of the suspension mechanism body (801) by means of an unlocking shear pin (808). The upper end face of the shear pin sleeve (807) contacts the lower end face of the slip support sleeve (809), and there is an axial gap between the lower end of the limiting fixing cylinder (810) and the shear pin sleeve (807).

3. The high-pressure resistant tailpipe hanger according to claim 2, characterized in that, The cone sleeve (806) is connected to the return sleeve (4) through the snap ring sleeve (805) and the suspension mechanism connecting sleeve (803). The snap ring sleeve (805) and the suspension mechanism body (801) are engaged by the anti-reverse snap ring (804).

4. The high-pressure resistant tailpipe hanger according to any one of claims 1 to 3, characterized in that, The seat drive mechanism (5) includes a spindle (501), a hydraulic cylinder (503) is provided outside the spindle (501), a piston (502) is provided inside the hydraulic cylinder (503), and the end of the piston (502) extends into and is connected to the plug cap (3); The piston (502) divides the internal space of the hydraulic cylinder (503) into an upper space and a lower space. A pressure transmission hole (508) is provided radially on the spindle (501), and the pressure transmission hole (508) is connected to the upper space. A pressure relief hole (509) is provided on the outer wall of the lower end of the hydraulic cylinder (503), and the pressure relief hole (509) is connected to the lower space. The piston (502) is in the first position upstream before being seated and is connected to the spindle (501) via the first shear pin (504). When seated, the first shear pin (504) cuts off, the piston (502) moves downward, and pushes the return cylinder (4) downward via the plug cap (3) so that the slip (802) of the suspension mechanism (8) is opened.

5. The high-pressure resistant tailpipe hanger according to claim 4, characterized in that, At least one secondary hydraulic cylinder (511) is also provided outside the mandrel (501). The secondary hydraulic cylinder (511) is located between the hydraulic cylinder (503) and the plug (3). A secondary piston (512) is provided inside the secondary hydraulic cylinder (511). The secondary piston (512) is connected to the piston (502). The secondary piston (512) divides the internal space of the secondary hydraulic cylinder (511) into an upper space and a lower space. The spindle (501) is provided with a secondary pressure transmission hole (513) that communicates with the upper space in a radial direction. The outer wall of the lower end of the secondary hydraulic cylinder (511) is provided with a pressure relief hole (509) that communicates with the lower space.

6. The high-pressure resistant tailpipe hanger according to claim 4, characterized in that, The piston (502) has a piston connecting sleeve (505) provided at its end via an extension sleeve (510), and a seat sleeve (506) that can push the cap (3) downward is fixed on the piston connecting sleeve (505).

7. The high-pressure resistant tailpipe hanger according to any one of claims 1 to 6, characterized in that, The stopper (3) includes: A seat-mounted pusher (303) is connected to the return tube (4); A support cylinder (333) is provided inside the seat-hanging push device (303). The support cylinder (333) is configured to push the seat-hanging push device (303) axially downward under the action of the seat-hanging drive mechanism (5). The seat-mounted push device (303) is provided with a locking block assembly (335) that moves radially. A return tube slot (401) is provided on the inner side of the return tube (4). The support tube (333) supports the inner side of the locking block assembly (335) so that the outer end of the locking block assembly (335) is engaged in the return tube slot (401). When the support cylinder (333) moves upward relative to the seat-mounted push device (303), it can release the support of the locking block assembly (355), thereby releasing the locking block assembly (355) from the locking slot (401).

8. The high-pressure resistant tailpipe hanger according to claim 7, characterized in that, The locking block assembly (355) includes: A locking block (342) is radially movable on the seat-mounting push device (303); A locking pin (341) is fixedly installed inside the locking block (342), and the locking pin (341) is used to engage with the return tube slot (401).

9. The high-pressure resistant tailpipe hanger according to claim 7, characterized in that, The cap (3) also includes a fixed sleeve (301) connected to the spindle (501) of the seat drive mechanism (5). The fixed sleeve (301) is connected to the seat push device (303) through a connecting body (302). A stop (312) is axially movable inside the outer wall of the fixed sleeve (301). A slot (322) is provided on the inner wall of the connecting body (302). The piston connecting cylinder (505) of the seat drive mechanism (5) extends into the fixed sleeve (301) and supports the stop (312), so that the outer end of the stop (312) is engaged in the slot (322).

10. The high-pressure resistant tailpipe hanger according to any one of claims 1 to 9, characterized in that, The seat drive mechanism (5) is connected to a central tube (9) via a release mechanism (6) below it, and a sealing core (7) is provided between the central tube (9) and the suspension mechanism (8).

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