A tailpipe hanger and plug assembly

Abstract

The present application belongs to the technical field of drilling engineering, and particularly relates to a liner hanger and a rubber plug assembly used for the liner hanger. The liner hanger comprises an outer pipe assembly, an inner pipe, a locking assembly and a torque transmission assembly. The torque transmission assembly comprises a torque strip fixed on the outer wall of the inner pipe, a torque block fixed on the inner wall of the first outer pipe, a transmission nut and a back-off nut in sliding cooperation with the torque strip, and the outer ring of the transmission nut and the back-off nut is connected with the first outer pipe and the second outer pipe through threads respectively. The present application can complete the releasing before fixing, and after releasing, the quality of cementing can be improved through rotating operation.

Description

Technical Field

[0001] This invention belongs to the field of drilling engineering technology, specifically, it relates to a tailpipe hanger and a rubber plug assembly that can be used in the tailpipe hanger. Background Technology

[0002] In oil and gas well cementing operations in the petroleum engineering industry, a tailpipe hanger is often used in conjunction with a tailpipe suspension system. The tailpipe is suspended and driven to the designed position for cementing. However, with the increasing number of deep wells, ultra-deep wells, highly deviated wells, and horizontal wells, safe and efficient tailpipe installation becomes increasingly difficult. Furthermore, during cementing, the high friction between the tubing string and the fluid leads to tubing string sticking to the edges, resulting in low displacement efficiency and poor cementing quality. When using circulation de-blocking, in certain low-pressure, lost-circulation formations, the circulating pressure can easily cause leakage. Therefore, under special well conditions, conventional tailpipe hangers are often insufficient to meet the needs of field applications.

[0003] To address the aforementioned issues, hydraulic tailpipe hangers are currently widely used. These hangers utilize rotation to remove resistance during the running-in process and improve cementing quality through rotation during cementing operations. Chinese patent document CN201024940Y discloses an internally mounted rotary tailpipe hanger. This hanger can only rotate the tailpipe during tubing string running; however, once the hanger is released, it cannot perform rotational operations for cementing, thus failing to improve cementing quality through rotation during the fixing process. Chinese patent document CN201410253648.X allows for rotational operations during tailpipe running and cementing, but this structure carries the risk of premature release during lifting and lowering when encountering resistance during running-in. Chinese patent document CN200710178298.5 discloses an expandable rotary tailpipe hanger, which allows for rotary running-in and rotary cementing operations, but the release operation is only performed after cementing, posing a significant risk of failure to release and retrieve the hanger. Summary of the Invention

[0004] To address the technical problems described above, the present invention aims to provide a tailpipe hanger that can be released before cementing and can still improve cementing quality through rotation after release.

[0005] The present invention also proposes a rubber stopper assembly with strong adaptability.

[0006] According to the present invention, a tailpipe hanger is provided, comprising a hanger body, a slip, and a second hydraulic cylinder for actuating the slip, the tailpipe hanger further comprising:

[0007] An outer tube assembly, the outer tube assembly comprising a first outer tube and a second outer tube axially inserted into each other, the second outer tube being connected to the suspension body;

[0008] Inner tube, which is fitted inside the outer tube assembly;

[0009] A locking assembly for preventing the inner tube from moving downward relative to the outer tube assembly in the initial state;

[0010] And a torque transmission assembly disposed between the outer tube assembly and the inner tube, the torque transmission assembly comprising:

[0011] A torque bar is fixedly installed on the outer wall of the inner tube;

[0012] A torque block is fixedly installed on the inner wall of the first outer tube, and the torque block is axially slidably engaged with the upper part of the torque bar;

[0013] A transmission nut and a reverse nut are fitted onto the inner tube and slide in engagement with the torque bar. The outer rings of the transmission nut and the reverse nut are connected to the first outer tube and the second outer tube respectively via threads.

[0014] One end of the undercut nut abuts against the step on the outer wall of the inner tube;

[0015] And a stop portion disposed inside the first outer tube;

[0016] During the release process, the inner tube rotates relative to the outer tube assembly, causing the undercut nut to disengage from the thread of the second outer tube, thereby allowing the inner tube to move upward relative to the second outer tube and complete the release; at the same time, the transmission nut moves to abut against the stop part, so that the torque continues to be transmitted between the first outer tube and the inner tube.

[0017] In one specific embodiment, in the initial state, the lower end of the undercut nut abuts axially with the inner tube, and the smooth upper surface of the inner wall of the second outer tube provides space for the undercut nut to move away from the threads of the inner wall of the second outer tube.

[0018] In one specific embodiment, a lower connector is provided at the lower end of the inner tube. The outer diameter of the lower connector is larger than the outer diameter of the inner tube. In the initial state, the lower end of the undercut nut axially abuts against the upper end face of the lower connector.

[0019] In one specific embodiment, the locking assembly includes:

[0020] A first liquid cylinder is mounted on the outer wall of the inner tube by means of a shear pin, and the top of the first outer tube is sleeved between the first liquid cylinder and the inner tube.

[0021] A stop block is radially slidably installed on the top wall of the first outer tube. In the initial state, one end of the stop block is inserted into the outer wall of the inner tube, and the other end abuts against the first liquid cylinder.

[0022] In one specific embodiment, an inclined surface is provided at the connection between the inner tube and the stop block. When the first hydraulic cylinder no longer abuts against the stop block and the inner tube moves downward relative to the first outer tube, the inclined surface can push the stop block radially outward from the inner tube.

[0023] In one specific embodiment, the locking assembly further includes an elastic pressure-bearing module disposed inside the inner tube by a shear pin, and a flow channel communicating the first hydraulic cylinder and the inner cavity of the inner tube is provided in the tube wall of the inner tube. In the initial state, the elastic pressure-bearing module covers the flow channel.

[0024] In one specific embodiment, the elastic pressure-bearing module includes a plurality of circumferentially evenly distributed elastic claws and a plurality of pressure-bearing blocks disposed at the ends of each of the elastic claws. An accommodating cavity for accommodating the pressure-bearing blocks is provided on the inner wall of the inner tube. The elastic pressure-bearing module is configured such that after a pressure-bearing ball is placed and sealed with the pressure-bearing block, pressure is applied. The pressure-bearing block moves down to the accommodating cavity and expands radially outward under the action of the elastic claws, allowing the pressure-bearing ball to pass through.

[0025] In one specific embodiment, a rubber stopper assembly is connected and disposed below the inner tube. The pressure ball falls into the rubber stopper assembly after passing through the elastic pressure-bearing module, forming a seal.

[0026] In one specific embodiment, the circumferential dimension of the cross-section of the through hole of the first outer tube for passing through the stop is larger than that of the stop, and the circumferential dimension of the cross-section of the through hole of the torque block for sliding engagement with the torque bar is larger than that of the torque bar. This configuration allows the inner tube to drive the stop to rotate relative to the first hydraulic cylinder within a certain angular range.

[0027] An exposure hole is provided on the first hydraulic cylinder, and the inner tube can drive the stop block to rotate to the position corresponding to the exposure hole. When the first hydraulic cylinder cannot move upward due to an unexpected situation, the stop block can be rotated to the position corresponding to the exposure hole by rotating the inner tube in the opposite direction, so as to realize emergency release.

[0028] In one specific embodiment, the second hydraulic cylinder is provided with two identical pressure differential working surfaces, and a rubber plug assembly is connected to the lower end of the inner tube. The rubber plug assembly is located between the two working surfaces of the second hydraulic cylinder. After the pressure ball is sealed with the rubber plug assembly, the two working surfaces of the second hydraulic cylinder can be separated.

[0029] The present invention also provides a rubber stopper assembly, comprising:

[0030] Rubber stopper body;

[0031] A rubber stopper cup and a seal are disposed on the outer wall of the rubber stopper body, the seal being located above the rubber stopper cup, and the rubber stopper body (61) is configured to allow the rubber stopper cup (62) and the seal to be separated;

[0032] A ball seat slide is mounted inside the rubber stopper body via a pin.

[0033] In one specific embodiment, the rubber stopper body includes a first body and a second body. An elastic element is provided on the upper part of the second body. An inner sliding sleeve for accommodating the radial contraction of the elastic element is provided inside the second body by means of a shear pin. The upper part of the elastic element extends into the interior of the first body and is engaged with the first body under the radial abutment action of the inner sliding sleeve.

[0034] Compared with the prior art, the advantages of this application are as follows.

[0035] This invention enables the release of resistance during well entry through rotation, placing the release process before cementing and reducing the risk of release failure. Furthermore, even after release, torque can still be transmitted between the inner and outer tube assemblies, allowing the torque of the inner tube to be sequentially transmitted through the first outer tube, second outer tube, and hanger body to the tailpipe. This, in turn, improves cementing quality through rotation during the fixing process.

[0036] Furthermore, this invention can also utilize a high-volume circulation method for derailment. During the high-volume derailment process, neither the first nor the second hydraulic cylinder of this invention is affected by the pressure of the circulating liquid, thus preventing premature release or premature stalling.

[0037] This invention offers multiple methods for disengaging the device. One method involves the first hydraulic cylinder operating normally, allowing the stop block to detach from the inner tube, thus completing the disengagement process. Another method, when the first hydraulic cylinder malfunctions, involves reversing the rotation of the inner tube to align the stop block with the exposed hole on the first hydraulic cylinder, thereby allowing the stop block to detach from the inner tube. The simultaneous use of both methods further reduces the risk of disengagement failure.

[0038] Furthermore, the second hydraulic cylinder of the present invention for pushing the slip is provided with two identical differential pressure working surfaces, thereby preventing the second hydraulic cylinder from working prematurely and pushing the slip during the circulation of drilling fluid. Attached Figure Description

[0039] The present invention will now be described with reference to the accompanying drawings.

[0040] Figure 1 A schematic diagram of the upper half of an embodiment of a tailpipe hanger according to the present invention is shown;

[0041] Figure 2 A schematic diagram of the lower half of an embodiment of a tailpipe hanger according to the present invention is shown;

[0042] Figure 3 A schematic diagram of one embodiment of the rubber stopper assembly according to the present invention is shown;

[0043] Figure 4 The invention is shown Figure 1 A schematic diagram of the AA cross-sectional structure;

[0044] Figure 5 The invention is shown Figure 1 A schematic diagram of the BB cross-sectional structure.

[0045] In the diagram: 1. Outer tube assembly; 2. Inner tube; 3. Torque transmission assembly; 4. Locking assembly; 5. Lower connector; 6. Rubber plug assembly; 11. First outer tube; 12. Second outer tube; 31. Torque bar; 32. Torque block; 33. Transmission nut; 34. Backed nut; 35. Stop; 36. Bearing assembly; 37. Anti-rotation pin; 41. First hydraulic cylinder; 42. Stop block; 43. Elastic pressure-bearing module; 44. Locking ring; 411. Exposed hole; 431. Elastic claw; 432. Pressure-bearing block; 433. Receiving cavity; 61. Rubber plug body; 62. Rubber plug cup; 63. Ball seat sleeve; 64. Elastic element; 65. Inner sleeve; 611. First body; 612. Second body; 71. Second hydraulic cylinder; 100. Tailpipe hanger.

[0046] 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

[0047] The invention will now be described with reference to the accompanying drawings.

[0048] It should be noted that in this application, the direction near the wellhead according to the present invention is described as "upper" or a similar term, while the direction away from the wellhead is described as "lower" or a similar term. "Axial" refers to the direction of the central axis of the outer tube assembly 1, and "radial" refers to the direction perpendicular to the "axial". These terms are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0049] For clarity of illustration, this invention is divided into upper and lower parts, respectively in... Figure 1 and Figure 2 The text shows that, Figure 1 A schematic diagram of the upper half of an embodiment of the tailpipe hanger 100 according to the present invention is shown. Figure 2 A schematic diagram of the lower half of an embodiment of a tailpipe hanger 100 according to the present invention is shown.

[0050] In the prior art, the suspension device includes a slip and a hydraulic cylinder. The hydraulic cylinder pushes the slip to expand, thereby achieving seat hanging. The connection between the slip and the hydraulic cylinder is not the technical point of this invention and will not be described in detail here.

[0051] like Figure 1 As shown, the tailpipe hanger 100 of the present invention includes, in addition to the hanger body, slips (not shown) and a second hydraulic cylinder 71 for pushing the slips, an outer pipe assembly 1, an inner pipe 2, a locking assembly 4 and a torque transmission assembly 3. The inner pipe 2 is sleeved inside the outer pipe assembly 1.

[0052] The outer tube assembly 1 includes a first outer tube 11 and a second outer tube 12 that are axially inserted from top to bottom. Specifically, it is not limited to the jaw clamp connection method in this embodiment, as long as they can move relative to each other axially and transmit axial torque. The lower part of the second outer tube 12 is connected to the suspension body, and the two can transmit torque.

[0053] The upper end of the outer tube 11 is connected to the inner tube 2 via a locking assembly 4. The locking assembly 4 is fixedly connected to the inner tube 2 via a shear pin. In the initial state, i.e. Figure 1 As shown, the locking assembly 4 can prevent the inner tube 2 from moving downward relative to the outer tube assembly 1.

[0054] In one specific embodiment, the locking assembly 4 includes a first hydraulic cylinder 41 and a stop 42. For example... Figure 1 As shown, the first hydraulic cylinder 41 is sleeved on the outside of the inner tube 2 by a shear pin, located above the first outer tube 11. The step at the top of the first outer tube 11 extends into the interior of the first hydraulic cylinder 41, that is, the part where the lower end of the second outer tube 12 overlaps with the top of the first outer tube 11. Multiple stop blocks 42 are provided, evenly arranged circumferentially on the tube wall of the first outer tube 11. In this embodiment, four stop blocks 42 are provided, all of which slide radially through the first outer tube 11. The two ends of the stop block 42 contact the inner tube 2 and the first hydraulic cylinder 41 respectively, wherein the stop block 42 is inserted into the inner tube 2, thereby preventing the inner tube 2 from moving axially relative to the first outer tube 11. The stop block 42 and the first hydraulic cylinder 41 have a normal contact relationship, and the first hydraulic cylinder 41 is used to prevent the stop block 42 from sliding radially outward from the inner tube 2.

[0055] According to the present invention, an inclined surface is provided at the contact position between the stop block 42 and the inner tube 2, so that when the inner tube 2 moves downward relative to the first outer tube 11, it can push the stop block 42 to move radially outward. This inclined surface can be provided on the inner tube 2 or on the stop block 42. When the first hydraulic cylinder 41 blocks the stop block 42, the stop block 42 cannot move radially outward. At this time, when the first outer tube 11 moves downward, it will inevitably drive the first outer tube 11 to move downward as well. When the stop block 42 is no longer blocked by the first hydraulic cylinder 41, the first outer tube 11 can move downward relative to the first outer tube 11, pushing the stop block 42 radially outward, thereby disengaging the torque block 32 and the torque bar 31, and thus allowing the block to be released by rotating the first outer tube 11.

[0056] According to the present invention, the locking assembly 4 further includes an elastic pressure-bearing module 43 disposed inside the inner tube 2 by means of a shear pin. A flow channel communicating between the first hydraulic cylinder 41 and the inner cavity of the inner tube 2 is provided within the tube wall of the inner tube 2. In the initial state, the elastic pressure-bearing module 43 covers the flow channel. The elastic pressure-bearing module 43 will only move after it has sealed and pressurized with the pressure-absorbing ball. Therefore, during the unblocking process using a large-volume circulation method, even if the drilling fluid circulation volume is large, the elastic pressure-bearing module 43 will not move, and thus the first hydraulic cylinder 41 will not operate. Therefore, the present invention can adapt to large-volume drilling fluid circulation. In contrast, due to structural characteristics, existing technologies, once a large-volume drilling fluid circulation occurs, can lead to unexpected situations such as premature loss of control.

[0057] Specifically, the elastic pressure-bearing module 43 includes a plurality of circumferentially evenly distributed elastic claws 431 and a plurality of pressure-bearing blocks 432 disposed at the ends of each elastic claw 431. In the initial state, the plurality of pressure-bearing blocks 432 form a closed ring, the outer wall of which is sealed to the inner wall of the inner tube 2, and the inner wall of which can cooperate with the pressure-bearing ball to form a sealed connection structure. A receiving cavity 433 for accommodating the pressure-bearing blocks 432 is provided on the inner wall of the inner tube 2, and the receiving cavity 433 is located below the pressure-bearing blocks 432. After the pressure-bearing ball is placed and sealed with the pressure-bearing block 432, pressure is applied, and the pressure-bearing block 432 moves down to the receiving cavity 433 and expands radially outward under the action of the elastic claws 431. After the pressure-bearing block 432 moves downward, the flow channel connecting the inner cavity of the inner tube 2 and the first liquid cylinder 41 is opened, and at the same time, after the pressure-bearing block 432 expands to the receiving cavity 433, the middle channel widens, allowing the pressure-bearing ball to pass through.

[0058] In one specific embodiment, a locking ring 44 is also provided between the first hydraulic cylinder 41 and the inner tube 2. The locking ring 44 is fixedly connected to the inner tube 2, and the first hydraulic cylinder 41 is fixedly connected to the locking ring 44 by a shear pin. Sealing rings are respectively provided between the locking ring 44, the first hydraulic cylinder 41, and the inner tube 2. These two sealing rings seal the working surface of the first hydraulic cylinder 41 and the flow channel connecting the inner cavity of the inner tube 2 together, allowing the pressure inside the inner tube 2 to be transmitted to the working surface of the first hydraulic cylinder 41, thereby enabling the first hydraulic cylinder 41 to move upward.

[0059] According to the present invention, a rubber stopper assembly 6 is connected and disposed below the inner tube 2. After the pressure ball passes through the elastic pressure-bearing module 43, it falls onto the rubber stopper assembly 6 and forms a seal.

[0060] Specifically, such as Figure 3 As shown, the rubber stopper assembly 6 includes a rubber stopper body 61, a rubber stopper cup 62 disposed on the outer wall of the rubber stopper body 61, and a ball seat sleeve 63 disposed inside the rubber stopper body 61 by a pin. This arrangement allows the ball seat sleeve 63 to cooperate with the pressure-holding ball to form a seal, facilitating pressure buildup and thus driving the first hydraulic cylinder 41 to operate. Furthermore, during subsequent operations, the rubber stopper assembly 6 can move downwards, allowing the rubber stopper cup 62 to clean the pipe wall.

[0061] In one specific embodiment, the rubber plug body 61 includes a first body 611 and a second body 612. The upper end of the first body 611 is connected to the lower connector 5 via a connector or other downhole connection tool, and a sealing element, such as a sealing ring, is provided at the maximum outer diameter of the first body 611 for sealing with the hanger body. An elastic element 64 is fixedly provided on the upper part of the second body 612. When no external force is applied, the upper end of the elastic element 64 is in a radially contracted state. In this embodiment, the upper end of the elastic element 64 extends into the interior of the first body 611, and an inner sliding sleeve 65 is provided inside the elastic element 64, abutting against the upper end of the elastic element 64 to prevent radial contraction. At this time, the upper end of the elastic element 64 is fixedly connected to the first body 611 by a snap-fit ​​mechanism.

[0062] According to the present invention, the inner sliding sleeve 65 is connected to the second body 612 via a shear pin. After the inner sliding sleeve 65 cuts the shear pin, it moves downward and contacts the elastic member 64, thereby causing the elastic member to contract radially and contact the first body 611 in a fixed connection state. At this time, the second body 612 with the rubber stopper cup 62 can be separated from the first body 611 with the sealing ring. With this arrangement, after the first body 611 with the sealing ring is separated from the second body 612 with the rubber stopper cup 62, the second body 612 with the rubber stopper cup 62 moves along the tubing and scrapes and cleans the inner wall of the tubing. Since the rubber stopper cup 62 is relatively soft, it can adapt to tubing of different diameters within a certain range, thus exhibiting strong adaptability.

[0063] The torque transmission assembly 3 is disposed between the outer tube assembly 1 and the inner tube 2, and includes a torque bar 31, a torque block 32, a transmission nut 33, and a backed nut 34.

[0064] The torque strip 31 is elongated and fixedly mounted on the outer wall of the inner tube 2. Specifically, a groove matching the torque strip 31 is provided on the outer wall of the inner tube 2, and the torque strip 31 is embedded in the groove of the outer wall of the inner tube 2. The thickness of the torque strip 31 is greater than the depth of the groove.

[0065] The torque block 32 is fixedly disposed on the inner wall of the first outer tube 11. Specifically, it can be disposed on the inner wall of the first outer tube 11 with a groove matching the shape of the torque block 32, and the torque block 32 is embedded in the groove. Alternatively, it can be disposed as follows: Figure 5 As shown, the torque block 32 and the first outer tube 11 are fixedly connected by the radially arranged anti-rotation nail 37.

[0066] In the initial state, the torque block 32 and the torque bar 31 cooperate with each other through a sliding connection. Figure 1 As shown, the torque block 32 is located at the top of the torque bar 31. Specifically, in this embodiment, the upper edge of the torque block 32 is flush with the upper edge of the torque bar 31.

[0067] The inner and outer walls of the transfer nut 33 contact the inner tube 2 and the first outer tube 11, respectively. The transfer nut 33 and the torque strip 31 on the inner tube 2 are axially slidably connected. The transfer nut 33 and the first outer tube 11 are threadedly connected. When the inner tube 2 drives the transfer nut 33 to rotate, the thread between the transfer nut 33 and the first outer tube 11 causes the transfer nut 33 to move axially relative to the first outer tube 11. In this embodiment, when the transfer nut 33 moves axially downward relative to the first outer tube 11, the rotation direction of the inner tube 2 is defined as forward rotation.

[0068] A stop portion 35 is provided on the inner wall of the first outer tube 11, and the stop portion 35 is located below the transmission nut 33. When the transmission nut 33 moves downward relative to the first outer tube 11 by a certain distance, it can abut against the upper end face of the stop portion 35.

[0069] Meanwhile, a bearing assembly 36 is also provided between the first outer tube 11 and the inner tube 2. A reduced-size step is provided at the top of the first outer tube 11 to prevent the bearing assembly 36 from dislodging. The bearing assembly 36 is fitted onto the inner tube 2 and does not affect the relative axial movement of the first outer tube 11 and the inner tube 2. In this way, when the inner tube 2 rotates relative to the first outer tube 11, it can provide a supporting function to ensure that the central axes of the inner tube 2 and the first outer tube 11 always coincide.

[0070] The inner and outer walls of the undercut nut 34 contact the inner tube 2 and the second outer tube 12, respectively. The undercut nut 34 and the torque bar 31 on the inner tube 2 are axially slidably connected. The undercut nut 34 and the second outer tube 12 are threadedly connected. The thread direction between the undercut nut 34 and the second outer tube 12 is opposite to the thread direction between the transmission nut 33 and the first outer tube 11. That is, when the inner tube 2 rotates clockwise, the torque bar 31 drives the transmission nut 33 and the undercut nut 34 to rotate. The transmission nut 33 moves axially downward relative to the first outer tube 11, while the undercut nut 34 moves axially upward relative to the second outer tube 12.

[0071] In one specific embodiment, a lower connector 5 is provided at the lower end of the inner tube 2, and the outer diameter of the lower connector 5 is larger than the outer diameter of the inner tube 2. For example... Figure 1 As shown, in the initial state, the lower end face of the undercut nut 34 abuts against the upper end face of the lower connector 5. In this configuration, since the undercut nut 34 and the second outer tube 12 are connected by threads, and the lower end face of the undercut nut 34 abuts against the lower connector 5, the inner tube 2 cannot move upward relative to the second outer tube 12.

[0072] The threads on the inner wall of the second outer tube 12 that mate with the undercut nut 34 are only distributed in the lower half of the second outer tube 12, while the upper half of the second outer tube 12 is unthreaded and has a smooth wall surface. Specifically, the length of the unthreaded portion of the second outer tube 12 is greater than the thread height of the undercut nut 34. When the undercut nut 34 moves upward relative to the second outer tube 12 until it disengages from the thread, the undercut nut 34 is released from its connection with the second outer tube 12. At this time, the inner tube 2 can move upward relative to the second outer tube 12. Simultaneously, during the upward movement of the inner tube 2, the lower connector 5 abuts against the undercut nut 34, and the undercut nut abuts against the first outer tube 11, allowing the first outer tube 11 to move upward along with the inner tube 2, thus releasing the inner tube.

[0073] In a preferred embodiment of the present invention, the second hydraulic cylinder 71 is provided with two differential pressure working surfaces (not shown in the figure) of the same size but opposite directions. Figure 2 As shown, the rubber plug assembly 6, located at the lower end of the inner tube 2, is situated between the two differential pressure working surfaces of the second hydraulic cylinder 71. Specifically, the sealing ring of the rubber plug assembly 6, located at the maximum outer diameter of the first main body 611, is positioned in front of the two differential pressure working surfaces. After the pressure-locking ball and the rubber plug assembly 6 are sealed together, the two working surfaces of the second hydraulic cylinder are separated. In this configuration, as long as the rubber plug assembly 6 is not sealed, the upper and lower differential pressure working surfaces of the second hydraulic cylinder 71 will be subjected to the same pressure, thereby maintaining the balance of the second hydraulic cylinder 71 and preventing premature engagement of the hanger due to premature movement of the second hydraulic cylinder 71 during drilling fluid circulation. Only after the rubber plug assembly 6 and the pressure-locking ball form a seal, causing the forces on the two differential pressure working surfaces of the second hydraulic cylinder 71 to differ, will the second hydraulic cylinder 71 begin to move, pushing the slips to complete the engagement. Therefore, under high-volume drilling fluid circulation conditions, as long as the rubber plug assembly 6 is not sealed with the pressure-locking ball, the present invention will not engage prematurely.

[0074] The working principle of this invention is as follows.

[0075] according to Figure 1 and Figure 2 As shown, the invention is lowered into the well. During the lowering process, the inner tube 2 can be rotated to rotate clockwise. The torque bar 31 and torque block 32 work together to drive the first outer tube 11 to rotate clockwise along with the inner tube 2. Since the second outer tube 12 and the first outer tube 11 are connected by a toothed connection, the first outer tube 11 will drive the second outer tube 12 to rotate together, thereby causing the entire tailpipe hanger 100 to rotate and complete the rotational unblocking operation.

[0076] After the device is lowered to the designed depth in the well, a pressure-absorbing ball is placed inside. The pressure-absorbing ball first cooperates with the pressure-bearing block 432 to form a seal. After pressure is absorbed, the shear pins used to fix the pressure-bearing block 432 are sheared off, the pressure-bearing block 432 moves downward and expands radially into the receiving cavity 433, and the pressure-absorbing ball falls into the ball seat sliding sleeve 63 of the rubber plug body 61, forming a seal again.

[0077] 0. Continue to pressurize. Because the rubber stopper body 61 has a hole connecting its inner cavity to the upper pressure differential working surface of the second hydraulic cylinder 71, the second hydraulic cylinder 71 cuts off the shearing pin used for connection and begins to move, pushing the slip to complete the seating. Subsequently, the first hydraulic cylinder 41 cuts off the shearing pin connected to the locking ring 44 and moves upward, thus no longer abutting against the stop block 42. It is easy to understand that by designing the strength of the shearing pins of the first hydraulic cylinder 41 and the second hydraulic cylinder 71, the second hydraulic cylinder 71 moves before the first hydraulic cylinder 41, thereby allowing the seating of the present invention to be released before the user.

[0078] After the first hydraulic cylinder 41 moves upward, it no longer prevents the stop block 42 from moving radially outward. Since the mounting is complete, the second outer tube 12 connected to the main body of the suspension device and the first outer tube 11, which is connected to the second outer tube 12 in a jaw-clamped manner, are both unable to move downward. At this time, the inner tube 2 moves downward, pushing the stop block 42 radially outward. At the same time, the inner tube 2 drives the torque bar 31 to move downward, thereby causing the torque block 32 to disengage from the torque bar 31.

[0079] Then, the inner tube 2 is rotated clockwise, which drives the transmission nut 33 and the undercut nut 34 to rotate clockwise via the torque bar 31. Under the action of the threads on the inner walls of the first outer tube 11 and the second outer tube 12, the transmission nut 33 moves axially downward relative to the first outer tube 11, and the undercut nut 34 moves axially upward relative to the second outer tube 12. After the undercut nut 34 moves upward and disengages from the second outer tube 12, the inner tube 2 can move upward relative to the second outer tube 12, separating from the second outer tube 12, thus completing the release operation.

[0080] To ensure that the inner tube 2 can still drive the second outer tube 12 to rotate during cementing, while maintaining the jaw engagement between the first outer tube 11 and the second outer tube 12, the inner tube 2 is rotated clockwise until the transmission nut 33 moves to abut against the stop 35 on the inner wall of the first outer tube 11. If the inner tube 2 continues to rotate clockwise at this point, it will only drive the first outer tube 11 to rotate as well. Therefore, by maintaining the jaw engagement between the first outer tube 11 and the second outer tube 12, continuing to rotate the inner tube 2 clockwise allows the second outer tube 12 to rotate as well, facilitating rotation during the cementing process and improving cementing quality.

[0081] According to a preferred embodiment of the present invention, such as Figure 1 and Figure 4 As shown, an exposure hole 411 is provided on the first hydraulic cylinder 41, and the inner tube 2 can drive the stop block 42 to rotate to the corresponding exposure hole 411. When the first hydraulic cylinder 41 fails due to an unexpected situation and cannot move upward, the stop block 42 can be disengaged from the first hydraulic cylinder 41 by rotating it to the corresponding exposure hole 411.

[0082] Specifically, such as Figure 4 and Figure 5As shown, the circumferential dimension of the through hole of the first outer tube 11 for passing through the stop 42 is larger than that of the stop 42. Similarly, the circumferential dimensions of the through holes of the torque block 32, the transmission nut 33, and the undercut nut 34 for sliding engagement with the torque bar 31 are all larger than that of the torque bar 31. This configuration allows the inner tube 2 to drive the stop 42 to rotate relative to the first hydraulic cylinder 41 within a certain angular range. Initially, the stop 42 and the first outer tube 11 are in circumferential contact, and the torque bar 31 is also in circumferential contact with the torque block 32, the transmission nut 33, and the undercut nut 34, all on the same side. For example, when the inner tube 2 rotates clockwise, the torque bar 31 can directly drive the torque block 32, the transmission nut 33, and the undercut nut 34 to rotate. Simultaneously, the inner tube 2 directly drives the first outer tube 11 to rotate via the stop 42, without any rotational margin. When the inner tube 2 reverses, there is a rotational margin on this side. After the inner tube 2 rotates a certain angle through the stop block 42, the stop block 42 will make circumferential contact with the first outer tube 11. The relationship between the torque bar 31, the torque block 32, the transmission nut 33, and the undercut nut 34 is similar. That is, within a certain angle of reversal, the inner tube 2 can rotate the stop block 42 to the corresponding exposed hole 411 without transmitting torque to the outer tube assembly 1, so that the stop block 42 can be radially disengaged from the inner tube 2.

[0083] The subsequent process of releasing the hand is the same as the process of releasing the hand in the working principle of the present invention described above, and will not be repeated here.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 tailpipe hanger, comprising a hanger body, slips, and a second hydraulic cylinder for actuating the slips, characterized in that, The tailpipe suspension also includes: The outer tube assembly (1) includes a first outer tube (11) and a second outer tube (12) that are axially inserted into each other. The first outer tube (11) and the second outer tube (12) are connected by a toothed clamp, and the second outer tube (12) is connected to the suspension body. Inner tube (2), which is sleeved inside the outer tube assembly (1); A locking assembly (4) for preventing the inner tube (2) from moving downward relative to the outer tube assembly (1) in the initial state. and a torque transmission assembly (3) disposed between the outer tube assembly (1) and the inner tube (2), the torque transmission assembly (3) comprising: Torque bar (31) is fixedly installed on the outer wall of the inner tube (2); A torque block (32) is fixedly installed on the inner wall of the first outer tube (11), and the torque block (32) slides axially with the torque bar (31); A transmission nut (33) and a reverse nut (34) are fitted onto the inner tube (2) and slide in cooperation with the torque bar (31). The outer rings of the transmission nut (33) and the reverse nut (34) are connected to the first outer tube (11) and the second outer tube (12) respectively by threads. One end of the undercut nut (34) abuts against the step on the outer wall of the inner tube (2); And a stop (35) provided inside the first outer tube (11); During the release process, the inner tube (2) rotates relative to the outer tube assembly (1), causing the undercut nut (34) to disengage from the thread of the second outer tube (12), thereby allowing the inner tube (2) to move upward relative to the second outer tube (12) to complete the release; at the same time, the transmission nut (33) moves to abut against the stop part (35), so that the torque continues to be transmitted between the first outer tube (11) and the inner tube (2). While maintaining the toothed engagement between the first outer tube and the second outer tube, the inner tube rotates forward, causing the second outer tube to rotate together.

2. The tailpipe hanger according to claim 1, characterized in that, In the initial state, the lower end of the undercut nut (34) abuts axially with the inner tube (2), and the upper part of the inner wall of the second outer tube (12) is a smooth wall surface, which provides movement space for the undercut nut (34) to disengage from the inner wall thread of the second outer tube (12).

3. The tailpipe hanger according to claim 2, characterized in that, A lower connector (5) is provided at the lower end of the inner tube (2). The outer diameter of the lower connector (5) is larger than the outer diameter of the inner tube (2). In the initial state, the lower end of the undercut nut (34) axially abuts against the upper end face of the lower connector (5).

4. The tailpipe hanger according to any one of claims 1 to 3, characterized in that, The locking assembly (4) includes: A first liquid cylinder (41) is set on the outer wall of the inner tube (2) by a shear pin, and the top of the first outer tube (11) is sleeved between the first liquid cylinder (41) and the inner tube (2); A stop (42) is radially slidably installed on the top wall of the first outer tube (11). In the initial state, one end of the stop (42) is inserted into the outer wall of the inner tube (2), and the other end abuts against the first liquid cylinder (41).

5. The tailpipe hanger according to claim 4, characterized in that, An inclined surface is provided at the connection between the inner tube (2) and the stop (42). When the first hydraulic cylinder (41) no longer abuts against the stop (42), and the inner tube (2) moves downward relative to the first outer tube (11), the inclined surface can push the stop (42) outward radially from the inner tube (2).

6. The tailpipe hanger according to claim 5, characterized in that, The locking assembly (4) further includes an elastic pressure-bearing module (43) disposed inside the inner tube (2) by a shear pin. A flow channel is provided inside the inner tube (2) to connect the first hydraulic cylinder (41) and the inner cavity of the inner tube (2). In the initial state, the elastic pressure-bearing module (43) covers the flow channel.

7. The tailpipe hanger according to claim 6, characterized in that, The elastic pressure-bearing module (43) includes a plurality of elastic claws (431) evenly distributed in the circumference and a plurality of pressure-bearing blocks (432) disposed at the ends of each elastic claw (431). The inner wall of the inner tube (2) is provided with a receiving cavity (433) for accommodating the pressure-bearing blocks (432). The elastic pressure-bearing module (43) is configured such that after the pressure-bearing ball is placed and sealed with the pressure-bearing block (432), pressure is applied. The pressure-bearing block (432) moves down to the receiving cavity (433) and expands radially outward under the action of the elastic claws (431) so that the pressure-bearing ball can pass through.

8. The tailpipe hanger according to claim 7, characterized in that, A rubber stopper assembly (6) is connected and disposed below the inner tube (2). The pressure ball falls to the rubber stopper assembly (6) after passing through the elastic pressure-bearing module (43) and forms a seal.

9. The tailpipe hanger according to claim 4, characterized in that, The circumferential dimension of the cross-section of the through hole of the first outer tube (11) for passing through the stop (42) is larger than that of the stop (42), and the circumferential dimension of the cross-section of the through hole of the torque block (32) for sliding cooperation with the torque bar (31) is larger than that of the torque bar (31), thereby constructing the inner tube (2) to drive the stop (42) to rotate relative to the first hydraulic cylinder (41) within a certain angle range. An exposure hole (411) is provided on the first liquid cylinder (41), and the inner tube (2) can drive the stop (42) to rotate to the corresponding exposure hole (411).

10. The tailpipe hanger according to any one of claims 1 to 3, characterized in that, The second hydraulic cylinder is provided with two identical pressure differential working surfaces. A rubber plug assembly (6) is connected to the lower end of the inner tube (2). The rubber plug assembly (6) is located between the two working surfaces of the second hydraulic cylinder. After the pressure ball is sealed and fitted with the rubber plug assembly (6), the two working surfaces of the second hydraulic cylinder can be separated.

11. The tailpipe hanger according to claim 10, characterized in that, Also includes: Rubber stopper body (61); A rubber stopper cup (62) and a seal are disposed on the outer wall of the rubber stopper body (61), the seal being located above the rubber stopper cup (62), and the rubber stopper body (61) is configured to allow the rubber stopper cup (62) and the seal to be separated. The ball seat sleeve (63) is set inside the rubber stopper body (61) by a pin.

12. The tailpipe hanger according to claim 11, characterized in that, The rubber stopper body (61) includes a first body (611) and a second body (612). An elastic element (64) is provided on the upper part of the second body (612). An inner sliding sleeve (65) for accommodating the radial contraction of the elastic element (64) is provided inside the second body (612) by means of a shear pin. The upper part of the elastic element (64) extends into the interior of the first body (611) and is engaged with the first body (611) under the radial abutment action of the inner sliding sleeve (65).

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