Variable diameter expandable liner hanger

Abstract

The application discloses a variable-diameter expandable tailpipe hanger, which comprises a central pipe, a peripheral cylinder, and an upper variable-diameter unit and a lower variable-diameter unit movably arranged on the outer wall of the central pipe; the peripheral cylinder comprises an expansion pipe and a tail pipe which are sequentially and axially connected and are both sleeved outside the central pipe; the expansion pipe comprises a pipe body and a reduced-diameter section which is reduced in diameter relative to the pipe body and is axially connected with the pipe body; in the process of stretching out of the upper variable-diameter unit and the lower variable-diameter unit, the upper variable-diameter unit and the lower variable-diameter unit stretch out in the direction away from the central pipe and form a variable-diameter cone which surrounds the central pipe, the variable-diameter cone is used for passing through the reduced-diameter section and expanding the reduced-diameter section to be fastened on the inner wall of the peripheral sleeve in the process of ascending along the central pipe; in the process of retracting of the upper variable-diameter unit and the lower variable-diameter unit, the upper variable-diameter unit and the lower variable-diameter unit retract in the direction close to the central pipe, and the central pipe can drive the upper variable-diameter unit and the lower variable-diameter unit to pass through the pipe body and the reduced-diameter section in the process of ascending.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tailpipe hanger design, and particularly relates to a variable-diameter expandable tailpipe hanger. BACKGROUND

[0002] The tailpipe hanger is an important tool in cementing technology. There are many types of tailpipe hangers. The conventional tailpipe hanger suspends the tailpipe on the adjacent upper casing through the cooperation of the cone and the slip. However, this suspension method has the problem of poor fixing quality of the tailpipe overlap section. At the same time, with the increasing number of special wells such as deep wells, ultra-deep wells and horizontal wells, the well conditions are more complex. In these complex well conditions, the conventional tailpipe hanger often fails to be seated and cemented, which seriously affects the completion quality.

[0003] With the development of expandable pipe technology, the expandable tailpipe hanger appears in the related technology to overcome the shortcomings of the conventional tailpipe hanger. The expandable tailpipe hanger is a tool that is seated through the expansion of the solid pipe (i.e. the expansion pipe) and the combination of multiple seals. The expandable tailpipe hanger can integrate the sealing functions of the traditional tailpipe and the tailpipe packer, thereby reducing the packer and ultimately reducing the cost. In the specific suspension process, the expandable tailpipe hanger is tightly attached to the inner wall of the upper casing, thereby avoiding the leakage that may occur in the annular space between the tailpipe and the casing during installation and production. At the same time, the sealing ring on the expansion pipe can effectively seal the annular gap, thereby avoiding the gas channeling problem caused by poor cementing quality in subsequent work.

[0004] Due to the advantages of the expandable tailpipe hanger, the application of the expandable tailpipe hanger is becoming more and more popular. In the specific working process, the expandable tailpipe hanger is connected to the tailpipe and sent into the well through the drill pipe. After the expandable tailpipe hanger is sent into the well, cementing operation is performed. When the cementing operation is completed, the drill pipe plug and the casing plug are combined to perform the replacement operation. At the same time, the ground continues to perform the pressure operation. Under the action of the hydraulic pressure, the expansion cone descends and drives the expansion pipe to expand radially. After the expansion operation is completed, the ground performs the annular gap pressure test to verify the sealing ability of the sealing ring on the expansion pipe to the annular gap and to test the expansion effect. At present, the expansion mode of the expandable tailpipe hanger generally adopts the top-down expansion mode. The working principle is that the ground performs the ball dropping operation, and the ground performs the pump pressure operation. Under the action of the hydraulic pressure, the expansion cone ascends, thereby driving the expansion pipe to expand radially.

[0005] The expandable tail pipe hanger uses an expansion cone of a solid body, the outer diameter of the expansion cone is fixed, and in the process of expanding from bottom to top, once an accident occurs downhole, the expansion cone cannot normally expand upward, and due to the fixed outer diameter of the expansion cone, the expansion cone will be stuck downhole and cannot be normally pulled out, thereby bringing great difficulty to subsequent accident handling. SUMMARY

[0006] Embodiments of the present application disclose a variable-diameter expandable tail pipe hanger to solve the problem that the expandable tail pipe hanger uses an expansion cone of a solid body, which cannot go up in the process of not needing expansion.

[0007] To solve the above technical problems, embodiments of the present application disclose the following technical solutions:

[0008] A variable-diameter expandable tail pipe hanger, comprising a central pipe, a peripheral cylinder, and an upper diameter-changing unit and a lower diameter-changing unit movably arranged on the outer wall of the central pipe;

[0009] The peripheral cylinder comprises an expansion pipe and a tail pipe which are sequentially axially connected and both sleeved outside the central pipe; the expansion pipe comprises a pipe body and a reduced-diameter section which is reduced in diameter relative to the pipe body and axially connected with the pipe body;

[0010] In the process of extending the upper diameter-changing unit and the lower diameter-changing unit, the upper diameter-changing unit and the lower diameter-changing unit extend away from the central pipe and form a diameter-changing cone around the central pipe, the diameter-changing cone is used to pass through the reduced-diameter section and expand the reduced-diameter section to be tightened on the inner wall of the peripheral sleeve in the process of going up along the central pipe;

[0011] In the process of retracting the upper diameter-changing unit and the lower diameter-changing unit, the upper diameter-changing unit and the lower diameter-changing unit retract towards the central pipe, and the central pipe can drive the upper diameter-changing unit and the lower diameter-changing unit to pass through the pipe body and the reduced-diameter section in the process of going up.

[0012] Optionally, the variable-diameter expandable tail pipe hanger further comprises an upper cone seat and a lower cone seat; the upper cone seat is sleeved outside the central pipe and fixedly connected with the central pipe; the lower cone seat is slidably sleeved outside the central pipe;

[0013] The upper diameter-changing unit and the lower diameter-changing unit are both multiple and staggered in the circumferential direction of the central pipe; the upper diameter-changing unit is slidably arranged on the upper cone seat, and the lower diameter-changing unit is slidably arranged on the lower cone seat;

[0014] when the lower cone seat moves towards the upper cone seat, the upper variable-diameter units and the lower variable-diameter units move towards each other and extend away from the central pipe to form the variable-diameter cone;

[0015] when the lower cone seat moves away from the upper cone seat, the upper variable-diameter units and the lower variable-diameter units move away from each other and retract towards the central pipe.

[0016] Optionally, the upper cone seat is provided with a plurality of first inclined guide grooves, and the lower cone seat is provided with a plurality of second inclined guide grooves, the plurality of upper variable-diameter units are guided and matched with the plurality of first inclined guide grooves respectively, and the plurality of lower variable-diameter units are guided and matched with the plurality of second inclined guide grooves respectively.

[0017] Optionally, the variable-diameter expansion type liner hanger further comprises a cone sleeve sealing member, the cone sleeve sealing member is sleeved outside the upper cone seat and fixedly connected with the upper cone seat, the cone sleeve sealing member is in sealing contact with the inner wall of the pipe body, a first annular gap is formed between the central pipe and the peripheral cylinder, the upper variable-diameter units and the lower variable-diameter units are located in the first annular gap, when the upper variable-diameter units and the lower variable-diameter units form the variable-diameter cone and the variable-diameter expansion type liner hanger is in a pressure holding state, drilling fluid entering the first annular gap from the lumen of the central pipe will drive the cone sleeve sealing member to drive the central pipe and the variable-diameter cone to move upwards.

[0018] Optionally, the variable-diameter expansion type liner hanger further comprises a sealing sleeve, a piston and a claw sleeve;

[0019] The outer wall of the central pipe is provided with a plurality of strip-shaped protrusions distributed circumferentially along the central pipe, and a guide gap extending in the axial direction of the central pipe is formed between adjacent two strip-shaped protrusions;

[0020] The piston is slidably sleeved on the central pipe and located on a first side of the plurality of strip-shaped protrusions, the claw sleeve comprises a cylindrical sleeve body slidably sleeved on the central pipe and located on a second side of the plurality of strip-shaped protrusions, and a plurality of connecting claws connected to one end of the cylindrical sleeve body and connected with the piston through corresponding guide gaps respectively;

[0021] The sealing sleeve is sleeved outside the piston and the upper cone seat and fixed with the upper cone seat, the upper cone seat is sleeved on the plurality of strip-shaped protrusions and fixedly connected with the plurality of strip-shaped protrusions, and the sealing sleeve is located on a side of the cone sleeve sealing member away from the upper variable-diameter units and the lower variable-diameter units;

[0022] The sealing sleeve, the piston, the central pipe and the upper cone seat surround a first driving cavity, and the first driving cavity is in communication with the first annular gap through the gap between the strip-shaped protrusions and the connecting claws.

[0023] Optionally, the claw sleeve further comprises a locking ring sleeved outside the plurality of connecting claws, the piston is provided with a threaded hole, the plurality of connecting claws each comprise a connecting protrusion, the locking ring is threadedly matched with the threaded hole, and the connecting protrusion is clamped and fixed in the threaded hole of the piston.

[0024] Optionally, the claw sleeve further comprises a supporting ring, the plurality of connecting claws, the piston and the central pipe surround a ring space, and the supporting ring is arranged in the ring space.

[0025] Optionally, the second ring gap and the first ring gap are located on two sides of the taper sleeve sealing element respectively and are isolated from each other by the taper sleeve sealing element; a first end of the elastic member is connected to the central pipe, a second end of the elastic member is connected to the piston, and when the variable-diameter expandable liner hanger is in a pressure relief state, the elastic member is used to drive the lower taper seat to move away from the upper taper seat through the piston and the claw sleeve.

[0026] Optionally, the central pipe comprises a plurality of pipe segments distributed along an axial direction of the central pipe, two adjacent pipe segments are connected through a threaded sleeve sleeved outside the pipe segments, and the first end of the elastic member abuts against an end face of the threaded sleeve.

[0027] Optionally, the peripheral cylinder further comprises a bumping seat; the variable-diameter hanger further comprises a tail pipe rubber plug and a drill pipe rubber plug, the tail pipe rubber plug is connected to a lower end of the central pipe through a shear screw and blocks the first ring gap; when the drill pipe rubber plug is put into a lumen of the central pipe, the drill pipe rubber plug can flow along the lumen of the central pipe to the tail pipe rubber plug, and under the driving of the drilling fluid, the tail pipe rubber plug is driven to cut the shear screw and move to the bumping seat to block the bumping seat and make the central pipe communicate with the first ring gap.

[0028] The technical scheme disclosed by the embodiment of the present application has the following technical effects:

[0029] The variable-diameter expansion type tail pipe hanger disclosed by the embodiment of the present application is structurally improved. Compared with the traditional one whole and radially unadjustable variable-diameter cone, the upper variable-diameter unit and the lower variable-diameter unit are designed to be radially movable relative to the central pipe. When the upper variable-diameter unit and the lower variable-diameter unit are extended, a variable-diameter cone with a larger radial size is formed, which can expand the reduced diameter section and finally expand the reduced diameter section on the inner wall of the peripheral sleeve, thereby realizing the connection between the tail pipe and the peripheral sleeve adjacent thereto and achieving the purpose of suspending the tail pipe. When the abnormal state occurs in the well and the reduced diameter section does not need to be expanded, and the variable-diameter structure needs to be pulled out of the wellbore at the same time, the upper variable-diameter unit and the lower variable-diameter unit can be retracted, thereby reducing the radial size, and the central pipe can drive the upper variable-diameter unit and the lower variable-diameter unit to pass through the reduced diameter section and be pulled out of the wellbore. In this process, the user can realize the extraction of the upper variable-diameter unit and the lower variable-diameter unit when the expansion is not needed in the event of a failure, thereby avoiding the problem that the variable-diameter cone in the related art cannot be pulled up when the hanger fails and needs to be pulled up, which can also avoid further triggering more complex downhole accidents. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic diagram of the variable-diameter expansion type tail pipe hanger disclosed by the embodiment of the present application in a state;

[0031] Figure 2 is Figure 1 is an enlarged schematic diagram of part I in

[0032] Figure 3 is a part of the structural schematic diagram of the variable-diameter expansion type tail pipe hanger disclosed by the embodiment of the present application in another state;

[0033] Figure 4 is another part of the structural schematic diagram of the variable-diameter expansion type tail pipe hanger disclosed by the embodiment of the present application in another state.

[0034] The components in the figure are marked as follows:

[0035] 10 - central pipe, 11 - strip-shaped protrusion, 12 - pipe section, 13 - threaded sleeve, 131 - annular protrusion, 14 - upper joint,

[0036] 20 - peripheral cylinder, 21 - expansion pipe, 211 - pipe body, 212 - reduced diameter section, 213 - sealing rubber cylinder, 22 - tail pipe, 23 - pressure seat, 24 - float shoe, 25 - casing sub, 26 - connecting sleeve, 27 - positioning sleeve,

[0037] 31 - sealing sleeve, 32 - cone sleeve sealing element,

[0038] 40-elastic member, 50-piston,

[0039] 60-claw sleeve, 61-cylindrical sleeve body, 62-connection claw, 621-connection protrusion, 63-locking ring, 64-support ring,

[0040] 71-upper cone seat, 711-first inclined guide groove, 72-upper reducing unit, 73-lower cone seat, 731-second inclined guide groove, 74-lower reducing unit, 75-reducing cone,

[0041] 81-tailpipe rubber plug, 82-drill pipe rubber plug, 83-shear screw,

[0042] A-first annular gap, B-first driving cavity, C-second annular gap. DETAILED DESCRIPTION

[0043] To make the objects, technical solutions and advantages of the present application clearer, the following will clearly and completely describe the technical solutions of the present application with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0044] The following will describe the technical solutions disclosed by various embodiments of the present application in detail in combination with the drawings. Please refer to Figures 1 to 4 The present application discloses a variable-diameter expandable tailpipe hanger. The variable-diameter expandable tailpipe hanger can include a central pipe 10, a peripheral sleeve 20, an upper reducing unit 72 and a lower reducing unit 74.

[0045] The peripheral sleeve 20 is the peripheral structure of the variable-diameter expandable tailpipe hanger. Specifically, the peripheral sleeve 20 can be a cylindrical structure. In the embodiments of the present application, the peripheral sleeve 20 is sleeved outside the central pipe 10 and can be coaxially distributed with the central pipe 10. The peripheral sleeve 20 can include an expansion pipe 21 and a tailpipe 22. The expansion pipe 21 and the tailpipe 22 can be sequentially connected in the axial direction of the peripheral sleeve 20 and are both sleeved outside the central pipe 10.

[0046] The expansion pipe 21 and the tail pipe 22 can be directly connected or indirectly connected through other intermediate structural members, and the embodiments of the present application are not limited. For example, the expansion pipe 21 and the tail pipe 22 can be directly connected through threaded cooperation. For another example, the peripheral cylinder 20 can further include a connecting sleeve 26, a sleeve short section 25 and a positioning sleeve 27. The positioning sleeve 27, the connecting sleeve 26 and the sleeve short section 25 can be sequentially connected on the expansion pipe 21 through threaded cooperation between adjacent two, and finally the tail pipe 22 can be connected on the sleeve short section 25 through threaded cooperation. The connection is implemented through threaded cooperation, so that the detachable assembly of the corresponding members can be realized, and then the local members can be conveniently disassembled for replacement or maintenance.

[0047] The embodiments of the present application do not limit the specific structure of the peripheral cylinder 20, but the disclosed peripheral cylinder 20 at least includes the expansion pipe 21 and the tail pipe 22. In other embodiments, the members included in the peripheral cylinder 20 (such as the expansion pipe 21, the tail pipe 22, the sleeve short section 25, the connecting sleeve 26, the positioning sleeve 27, etc.) can also be assembled through connecting members, interference fit and other ways, and the embodiments of the present application do not limit the connection relationship between the constituent members included in the peripheral cylinder 20.

[0048] In the embodiments of the present application, the expansion pipe 21 is used for the structure to be expanded, and specifically, the expansion pipe 21 can include a pipe body 211 and a reduced diameter section 212, which can be coaxially distributed and connected in the axial direction of the expansion pipe 21. In the embodiments of the present application, the expansion pipe 21 is a one-piece pipe. The reduced diameter section 212 is reduced in diameter relative to the pipe body 211, that is, the diameter of the reduced diameter section 212 is smaller than the diameter of the pipe body 211, and the reduced diameter section 212 is the part to be expanded of the expansion pipe 21 and can be expanded under the action of the expansion force, so as to be expanded and fixed on the inner wall of the peripheral casing.

[0049] It should be noted that the variable-diameter expansion-type tail pipe hanger disclosed in the embodiments of the present application is used to connect the tail pipe 22 to the end of the peripheral casing. Since the expansion pipe 21 is connected to the tail pipe 22, the connection between the tail pipe 22 and the peripheral casing is naturally realized after the expansion pipe 21 is expanded and fixed on the inner wall of the peripheral casing. It should be noted that the peripheral casing has multiple sections and is connected to the downhole along the depth direction of the wellbore, and the tail pipe is essentially the last section of the casing. The peripheral casing connected to the tail pipe is essentially another section of the casing connected to the last section of the casing.

[0050] The upper and lower diameter changing units 72 and 74 are movably arranged on the outer wall of the central pipe 10, so that at least part of the upper diameter changing unit 72 and at least part of the lower diameter changing unit 74 can be extended away from the central pipe 10 or retracted towards the central pipe 10 in the radial direction of the central pipe 10. The upper and lower diameter changing units 72 and 74 are used to form a diameter changing cone 75, which has a radial dimension greater than the diameter reducing section 212, so that when the diameter changing cone 75 passes through the diameter reducing section 212, the diameter reducing section 212 can be expanded to be tightly fixed on the inner wall of the peripheral sleeve.

[0051] The upper diameter changing unit 72 is located above the lower diameter changing unit 74. During the extension of the upper and lower diameter changing units 72 and 74, the upper and lower diameter changing units 72 and 74 are extended away from the central pipe 10 and can form a diameter changing cone 75 around the central pipe 10. During the extension, the diameter changing cone 75 with a larger radial dimension is formed, which is used to pass through the diameter reducing section 212 and expand the diameter reducing section 212 to be tightly fixed on the inner wall of the peripheral sleeve during the upward movement of the central pipe 10.

[0052] During the retraction of the upper and lower diameter changing units 72 and 74, the upper and lower diameter changing units 72 and 74 are retracted towards the central pipe 10, and the central pipe 10 can drive the upper and lower diameter changing units 72 and 74 to pass through the pipe body 211 and the diameter reducing section 212 during the upward movement. It should be noted that since the upper and lower diameter changing units 72 and 74 are retracted towards the central pipe 10, the radial dimension of the upper and lower diameter changing units 72 and 74 is smaller, so that during the upward movement, the upper and lower diameter changing units 72 and 74 will not be tightly interfered with the diameter reducing section 212 and the pipe body 211, and will not expand the diameter reducing section 212, and at this time, the diameter reducing section 212 will not be expanded to be tightly fixed on the inner wall of the peripheral sleeve.

[0053] Compared with the traditional one whole and radially unadjustable variable-diameter cone, the variable-diameter expandable tailpipe hanger is designed to have the upper variable-diameter unit 72 and the lower variable-diameter unit 74 radially movable relative to the central pipe 10, and when the upper variable-diameter unit 72 and the lower variable-diameter unit 74 are extended, a variable-diameter cone 75 with a larger radial size is formed, thereby expanding the reduced-diameter section 212 during the upward movement of the central pipe 10 and expanding the reduced-diameter section 212, and finally expanding the reduced-diameter section 212 on the inner wall of the peripheral casing, thereby realizing the connection between the tailpipe 22 and the peripheral casing adjacent thereto and achieving the purpose of suspending the tailpipe 22. When an abnormal state occurs in the well and the reduced-diameter section 212 does not need to be expanded, and at the same time the variable-diameter structure needs to be pulled out of the wellbore, the upper variable-diameter unit 72 and the lower variable-diameter unit 74 can be retracted, thereby reducing the radial size, and then the central pipe 10 can drive the upper variable-diameter unit 72 and the lower variable-diameter unit 74 to pass through the reduced-diameter section 212 and be pulled out of the wellbore. In this process, the user can realize the extraction of the upper variable-diameter unit 72 and the lower variable-diameter unit 74 when the expansion is not needed due to a failure, thereby avoiding the problem that the variable-diameter cone in the related art cannot be pulled up when the hanger fails and needs to be pulled up, which can also avoid further triggering more complex downhole accidents.

[0054] As described above, the upper variable-diameter unit 72 and the lower variable-diameter unit 74 are movably arranged on the outer wall of the central pipe 10 to realize extension and retraction. There are various ways to realize this structure, and in one embodiment, the upper variable-diameter unit 72 and the lower variable-diameter unit 74 can both be multiple and staggered. The first end of the upper variable-diameter unit 72 and the first end of the lower variable-diameter unit 74 are rotatably connected to the outer wall of the central pipe 10, and the second end of the upper variable-diameter unit 72 and the second end of the lower variable-diameter unit 74 are both free ends. The first end of the upper variable-diameter unit 72 and the second end of the upper variable-diameter unit 72 are opposite ends of the upper variable-diameter unit 72. The first end of the lower variable-diameter unit 74 and the second end of the lower variable-diameter unit 74 are opposite ends of the lower variable-diameter unit 74. In the specific extension and retraction process, the pressure generated by the drilling fluid input by the variable-diameter expandable tailpipe hanger can be used to drive the upper variable-diameter unit 72 and the lower variable-diameter unit 74 to rotate away from the central pipe 10, and finally the second end of the upper variable-diameter unit 72 and the second end of the lower variable-diameter unit 74 are extended, thereby expanding the radial size of the variable-diameter cone 75 formed by the upper variable-diameter unit 72 and the lower variable-diameter unit 74. After controlling the pressure relief of the drilling fluid, the second end of the upper variable-diameter unit 72 and the second end of the lower variable-diameter unit 74 rotate towards the central pipe 10, thereby realizing retraction.

[0055] To ensure the retracting of the up-diameter unit 72 and the down-diameter unit 74 is more stable, a second end of the up-diameter unit 72 and the central pipe 10 and a second end of the down-diameter unit 74 and the central pipe 10 can be provided with elastic members, and to distinguish the latter, the elastic member here can be considered as a second elastic member. The second elastic member can be a spring, an elastic band, etc., and the embodiments of the present application do not limit the specific type of the second elastic member.

[0056] In other embodiments, the variable-diameter expandable liner hanger disclosed by the embodiments of the present application can further include an upper cone seat 71 and a lower cone seat 73. The upper cone seat 71 is sleeved outside the central pipe 10 and fixedly connected with the central pipe 10. Specifically, the upper cone seat 71 can be sleeved outside the central pipe 10 in an interference fit manner. The up-diameter unit 72 and the down-diameter unit 74 are both multiple and staggered in the circumferential direction of the central pipe 10. The up-diameter unit 72 is slidably arranged on the upper cone seat 71, and the down-diameter unit 74 is slidably arranged on the lower cone seat 73.

[0057] When the lower cone seat 73 moves towards the direction of the upper cone seat 71, the up-diameter unit 72 and the down-diameter unit 74 approach each other and simultaneously extend away from the central pipe 10 to form the variable-diameter cone 75 described above. When the lower cone seat 73 moves away from the upper cone seat 71, the up-diameter unit 72 and the down-diameter unit 74 move away from each other and simultaneously retract towards the central pipe 10. Specifically, one of the adjacent up-diameter unit 72 and down-diameter unit 74 is provided with an inclined guide groove, and the other is provided with a guide protrusion, and the guide protrusion and the inclined guide groove are in guiding cooperation. In the process of the up-diameter unit 72 and the down-diameter unit 74 approaching each other, under the cooperation of the inclined guide groove and the guide protrusion, the up-diameter unit 72 and the down-diameter unit 74 will simultaneously move away from the central pipe 10 while approaching each other to achieve the purpose of extension. Conversely, in the process of the up-diameter unit 72 and the down-diameter unit 74 moving away from each other, under the cooperation of the inclined guide groove and the guide protrusion, the up-diameter unit 72 and the down-diameter unit 74 will simultaneously move towards the central pipe 10 while moving away from each other to achieve the purpose of retraction.

[0058] As described above, the upper reducing units 72 are slidingly arranged on the upper cone seat 71, and the lower reducing units 74 are slidingly arranged on the lower cone seat 73. In order to improve the stability of sliding, in an embodiment, the upper cone seat 71 can be provided with a plurality of first inclined guide grooves 711, the lower cone seat 73 is provided with a plurality of second inclined guide grooves 731, the plurality of upper reducing units 72 are respectively guided and matched with the plurality of first inclined guide grooves 711, and the plurality of lower reducing units 74 are respectively guided and matched with the plurality of second inclined guide grooves 731. Since the movement of the upper reducing units 72 and the lower reducing units 74 is a compound movement, that is, the upper reducing units 72 and the lower reducing units 74 not only move linearly along the axis of the central pipe 10 to relatively approach or move away from each other, but also move linearly along the radial direction of the central pipe 10 to approach or move away from the central pipe 10, therefore, the first inclined guide grooves 711 and the second inclined guide grooves 731 are opposite in inclined direction and have an included angle with the radial direction of the central pipe 10.

[0059] There are various ways to drive the movement of the lower cone seat 73, and the embodiments of the present application are not limited. In an embodiment, the variable-diameter expandable liner hanger disclosed by the embodiments of the present application can further comprise a cone sleeve sealing member 32. The cone sleeve sealing member 32 can be sleeved outside the upper cone seat 71 and fixedly connected with the upper cone seat 71. Since the upper cone seat 71 is fixedly connected with the central pipe 10, the cone sleeve sealing member 32 is also fixed relative to the central pipe 10.

[0060] The cone sleeve sealing member 32 is a ring-shaped structure, and the cone sleeve sealing member 32 is in sealing contact with the inside of the pipe body 211, thereby avoiding the penetration of drilling fluid from the contact position of the cone sleeve sealing member 32 and the pipe body 211. Specifically, the cone sleeve sealing member 32 is arranged around the central pipe 10. The central pipe 10 and the peripheral cylinder 20 form a first annular gap A, and the upper reducing units 72 and the lower reducing units 74 are located in the first annular gap A, and at the same time, at least the cone sleeve sealing member 32 and the upper cone seat 71 can be used to block the first annular gap A. When the upper reducing units 72 and the lower reducing units 74 form the reducing cone 75 and the variable-diameter expandable liner hanger is in a pressure holding state, the drilling fluid entering the first annular gap A from the lumen of the central pipe 10 can drive the cone sleeve sealing member 32 to drive the central pipe 10 and the reducing cone 75 to move upward. During the upward movement of the reducing cone 75, the expansion of the reduced section 212 can be achieved. This structure can achieve the blocking of the variable-diameter expandable liner hanger by ball dropping (or the drill pipe rubber plug 82 described below can also be dropped) during work, so that the drilling fluid enters to generate a pressure holding phenomenon, and then the drilling fluid in the pressure holding state drives the reducing cone 75 and the central pipe 10 to move upward, so as to achieve the purpose of expansion.

[0061] In a further optional scheme, the variable-diameter expandable liner hanger disclosed by the embodiments of the present application can further comprise a sealing sleeve 31, a piston 50 and a claw sleeve 60.

[0062] The outer wall of the center tube 10 can be provided with a plurality of strip-shaped protrusions 11 distributed along the circumference thereof, and a guide gap extending along the axial direction of the center tube 10 can be formed between two adjacent strip-shaped protrusions 11. In this case, the center tube 10 and the plurality of strip-shaped protrusions 11 form a structure similar to a spline shaft. Specifically, the plurality of strip-shaped protrusions 11 can be fixed to the outer wall of the center tube 10 by welding, connecting members, or the like. In other embodiments, the plurality of strip-shaped protrusions 11 and the center tube 10 are of an integral structure.

[0063] The piston 50 is slidably sleeved on the center tube 10 and located at a first side of the plurality of strip-shaped protrusions 11. The claw sleeve 60 includes a cylindrical sleeve body 61 and a plurality of connecting claws 62. The cylindrical sleeve body 61 is located at a second side of the plurality of strip-shaped protrusions 11, and the first side of the strip-shaped protrusions 11 and the second side of the strip-shaped protrusions 11 are opposite sides of the strip-shaped protrusions 11. The cylindrical sleeve body 61 is slidably sleeved on the center tube 10 and can slide along the axial direction of the center tube 10 relative to the center tube 10. The plurality of connecting claws 62 are connected to one end of the cylindrical sleeve body 61 and respectively pass through the corresponding guide gaps. The plurality of connecting claws 62 can drive the cylindrical sleeve body 61 to slide along the axial direction of the center tube 10, and the plurality of connecting claws 62 and the corresponding guide gaps are in guided sliding fit during the axial sliding. In one embodiment, the plurality of connecting claws 62 can be in one-to-one sliding fit with the plurality of guide gaps.

[0064] The lower cone seat 73 is sleeved outside the cylindrical sleeve body 61 and fixedly connected with the cylindrical sleeve body 61, so as to indirectly realize the movement relative to the center tube 10 through the cylindrical sleeve body 61. In a specific working process, the cylindrical sleeve body 61 moves along the axial direction of the center tube 10, thereby driving the lower cone seat 73 to move following.

[0065] The sealing sleeve 31 is sleeved outside the piston 50 and the upper cone seat 71 and fixed with the upper cone seat 71. Since the upper cone seat 71 is relatively fixed with the center tube 10, the sealing sleeve 31 realizes the fixation relative to the center tube 10 through the fixation between the sealing sleeve 31 and the upper cone seat 71. The upper cone seat 71 is sleeved on the plurality of strip-shaped protrusions 11 and fixedly connected with the plurality of strip-shaped protrusions 11, so as to realize the fixation with the center tube 10. Specifically, the upper cone seat 71 can be fixed on the annular structure formed by the plurality of strip-shaped protrusions 11 by interference fit, or the upper cone seat 71 can be fixed on the annular structure formed by the plurality of strip-shaped protrusions 11 by threaded fit, in which case the plurality of strip-shaped protrusions 11 are provided with threaded structures.

[0066] The sealing sleeve 31 is located on the side of the cone sleeve seal 32 away from the upper variable-diameter unit 72 and the lower variable-diameter unit 74. The sealing sleeve 31, the piston 50, the central pipe 10 and the upper cone seat 71 can enclose a first driving cavity B, which is in communication with the first annular gap A through the analysis between the strip-shaped protrusion 11 and the connecting claws 62. In the specific working process, when the variable-diameter expandable liner hanger is in the pressure-accumulating state, the drilling fluid entering the first annular gap A will enter the first driving cavity B along the gap between the connecting claws 62 and the strip-shaped protrusion 11, and then push the piston 50 to move away from the strip-shaped protrusion 11. The movement of the piston 50 will be followed by the movement of the plurality of connecting claws 62 connected to the cylindrical sleeve body 61, and then the cylindrical sleeve body 61 will be followed. The movement of the cylindrical sleeve body 61 will drive the lower cone seat 73 and the lower variable-diameter unit 74 to move towards the upper variable-diameter unit 72 and the upper cone seat 71, until the upper variable-diameter unit 72 and the lower variable-diameter unit 74 form a variable-diameter cone 75. As the pressure continues to accumulate, drilling fluid with greater pressure will continue to collect in the first annular gap A, so that the drilling fluid with greater pressure will push the cone sleeve seal 32 and the sealing sleeve 31 between the central pipe 10 and the peripheral barrel 20, so that the cone sleeve seal 32, the sealing sleeve 31, the central pipe 10, the upper cone seat 71, the lower cone seat 73 and the variable-diameter cone 75 are all upward, so that the variable-diameter cone 75 can play the role of expansion and expansion when passing through the reduced diameter section 212, so as to realize the expansion of the variable-diameter cone 75 with a larger diameter on the reduced diameter section 212, so that the reduced diameter section 212 is finally attached to the inner wall of the peripheral casing by expansion.

[0067] In a more specific embodiment, the variable-diameter expandable liner hanger disclosed in the embodiments of the present application can further comprise an elastic member 40. In order to distinguish the elastic member above, the elastic member 40 here can be considered as the first elastic member. The central pipe 10 and the peripheral barrel 20 can enclose a second annular gap C, which is located on the side opposite to the first annular gap A and is separated from the first annular gap A by the cone sleeve seal 32. Specifically, the second annular gap C is located above the first annular gap A. The first end of the elastic member 40 is connected to the central pipe 10, and the second end of the elastic member 40 is connected to the piston 50. The elastic member 40 is used to drive the lower cone seat 73 to move away from the upper cone seat 71 through the piston 50 and the claw sleeve 60 when the variable-diameter expandable liner hanger is in the pressure-relief state, and then the lower variable-diameter unit 74 moves away from the upper variable-diameter unit 72 and the upper cone seat 71. At the same time, the upper variable-diameter unit 72 and the lower variable-diameter unit 74 can at least partially separate and retract towards the central pipe 10, and finally the variable-diameter cone 75 with a larger diameter becomes a split structure with a smaller diameter. The elastic member 40 realizes the reset function through the deformation recovery. Similarly, in the embodiments of the present application, the elastic member 40 can be a spring, a rubber cylinder, etc., and the embodiments of the present application do not limit the specific type of the elastic member 40.

[0068] In order to improve the stability of installation and the balance of elastic driving, in an embodiment, the elastic member 40 can be a hollow structure and can be sleeved outside the central pipe 10.

[0069] As described above, the first end of the elastic member 40 is connected to the central pipe 10. In an example, the first end of the elastic member 40 can be welded on the outer wall of the central pipe 10, so as to be fixedly connected to the central pipe 10. In another example, the outer wall of the central pipe 10 can be provided with a first annular protrusion, the elastic member 40 can be sleeved outside the central pipe 10, and the first end of the elastic member 40 can be in abutment with the first annular protrusion. The first annular protrusion can be a rib which is integrally formed with other parts of the central pipe 10.

[0070] In the embodiment of the present application, the central pipe 10 is relatively long, and in order to facilitate manufacturing, assembly and transportation, in an embodiment, the central pipe 10 can include a plurality of pipe segments 12 which are distributed along the axial direction of the central pipe 10, and two adjacent pipe segments 12 can be connected by a threaded sleeve 13. Such a structure can form a split central pipe 10, and the plurality of pipe segments 12 can be detachably connected by the threaded sleeve 13, which also facilitates the maintenance or replacement of part of the pipe segments 12.

[0071] More specifically, the threaded sleeve 13 can be sleeved outside the pipe segment 12, and the first end of the elastic member 40 can be in abutment with the end face of the threaded sleeve 13. The threaded sleeve 13 is sleeved outside the pipe segment 12, and one end face of the threaded sleeve 13 faces the piston 50, and the end face of the threaded sleeve 13 facing the piston 50 can be in abutment with the first end of the elastic member 40, so as to achieve the purpose of positioning the elastic member 40. In this embodiment, the threaded sleeve 13 not only plays the role of connecting two adjacent pipe segments 12, but also can serve as a part of the central pipe 10 to position the elastic member 40, so that the threaded sleeve 13 can play multiple roles and achieve the purpose of one thing serving multiple purposes.

[0072] The threaded sleeve 13 can include an annular protrusion 131, and the inner side of the threaded sleeve 13 located on the opposite sides of the annular protrusion 131 is fixedly connected to the corresponding pipe segment 12 by threaded cooperation. Two adjacent pipe segments 12 can be in abutment on the annular protrusion 131, so as to avoid excessive rotation of the pipe segments 12.

[0073] As described above, the claw sleeve 60 comprises a plurality of connecting claws 62, which are similar to a structure that is connected to the cylindrical sleeve 61 at one end and cantilevered at the other end. The connecting claws 62 can be connected to the piston 50 in various ways, for example, the two can be directly connected through a connecting member (such as a threaded connecting member). In other embodiments, the claw sleeve 60 can further comprise a locking ring 63, which is sleeved outside the plurality of connecting claws 62. The piston 50 is provided with a threaded hole, and the plurality of connecting claws 62 each comprise a connecting protrusion 621, the locking ring 63 is threadedly connected with the threaded hole, and the connecting protrusion 621 is clamped and fixed in the threaded hole of the piston 50, and the threaded hole is a blind hole. Specifically, the plurality of connecting claws 62 are distributed around the central pipe 10, the hole wall of the threaded hole of the piston 50 surrounds the central pipe 10, and an annular gap is formed between the hole wall and the central pipe 10, the locking ring 63 is sleeved on the central pipe 10 and extends into the annular gap to be threadedly connected with the threaded hole. During operation, the operator can rotate the locking ring 63 to move the locking ring 63 in the axial direction of the central pipe 10. The movement of the locking ring 63 can clamp or loosen the connecting protrusion 621. When the locking ring 63 clamps the connecting protrusion 621, the connection between the connecting claw 62 and the piston 50 is essentially achieved.

[0074] Such a structure can have the advantages of simple structure and convenient operation, and at the same time, the plurality of connecting claws 62 can be more evenly fixed by the locking ring 63.

[0075] In further embodiments, the variable-diameter expandable liner hanger disclosed in the embodiments of the present application can further comprise a support ring 64, and the plurality of connecting claws 62, the piston 50 and the central pipe 10 surround an annular space, and the support ring 64 is arranged in the annular space. In such a structure, the support ring 64 can limit the plurality of dispersed connecting claws 62 on the inside, ensuring that the plurality of connecting claws 62 are accurately on the same circumference, thereby facilitating the synchronous fixing of the plurality of connecting claws 62.

[0076] As described above, in the specific working process, when the variable-diameter expandable liner hanger generates a pressure build-up phenomenon, it will cause the drilling fluid to collect and the pressure to gradually increase to drive the piston 50 to move and the cone sleeve sealing element 32 to move. The structure for achieving the pressure build-up of the variable-diameter expandable liner hanger can be various, and the embodiments of the present application do not make any limitation.

[0077] In one embodiment, the peripheral cylinder 20 can further comprise a pressure seat 23, which can be arranged downstream of the tail pipe 22. In embodiments in which the peripheral cylinder 20 further comprises a positioning sleeve 27, a connecting sleeve 26 and a casing spool 25, the pressure seat 23 is fixed to the side of the tail pipe 22 away from the casing spool 25. Specifically, the pressure seat 23 can be connected to the tail pipe 22 through threaded connection.

[0078] The variable-diameter expandable liner hanger disclosed in the embodiments of the present application can further comprise a liner plug 81 and a drill pipe plug 82. The liner plug 81 can be connected to the lower end of the central pipe 10 by a shear screw 83 and block the first annular gap A. When the drill pipe plug 82 is dropped into the lumen of the central pipe 10, the drill pipe plug 82 can flow along the lumen of the central pipe 10 to the liner plug 81 and drive the liner plug 81 to cut the shear screw 83 and move to the pressure seat 23 under the driving of the drilling fluid, so as to block the pressure seat 23 and make the central pipe 10 communicate with the first annular gap A.

[0079] The working process of the variable-diameter expandable liner hanger disclosed in the embodiments of the present application will be described below with reference to the specific structure of the embodiments shown in the drawings. Figure 1 The working process of the variable-diameter expandable liner hanger disclosed in the embodiments of the present application will be described below with reference to the specific structure of the embodiments shown in the drawings.

[0080] The drill pipe plug 82 is dropped into the drill pipe, and the drill pipe plug 82 will flow to the bottom of the well under the action of the drilling fluid and gravity. When the drill pipe plug 82 flows to the liner plug 81, the liner plug 81 will be limited with the drill pipe plug 82, so as to prevent the drill pipe plug 82 from continuing to descend. At the same time, the drill pipe plug 82 will block the liner plug 81, so that the drilling fluid cannot continue to descend through the liner plug 81. In this case, as the drilling fluid is blocked and collected, the variable-diameter expandable liner hanger will appear a pressure build-up phenomenon. As the pressure continues to increase, the pressure of the drilling fluid will drive the liner plug 81 to cut the shear screw 83, so that the liner plug 81 is separated from the central pipe 10, and at the same time, the seal between the liner plug 81 and the peripheral cylinder 20 is released to communicate the lumen of the central pipe 10 with the first annular gap A. At the same time, the liner plug 81 and the drill pipe plug 82 will continue to descend together under the action of the drilling fluid until they move to the pressure seat 23. At the pressure seat 23, the liner plug 81 is limited with the pressure seat 23, so as to prevent the liner plug 81 and the drill pipe plug 82 from continuing to descend, which also achieves the blocking of the pressure seat 23.

[0081] When the pressure seat 23 is blocked, the drilling fluid will gather in the variable-diameter expandable tailpipe hanger to continue to generate pressure, and the drilling fluid with larger pressure will enter the first annular gap A from the lumen of the center pipe 10, and then enter the first driving cavity B through the gap between the strip-shaped protrusion 11 and the connecting claw 62 to drive the piston 50 to move away from the strip-shaped protrusion 11, and at the same time, the piston 50 will drive the lower cone seat 73 and the lower variable-diameter unit 74 to move towards the upper cone seat 71 and the upper variable-diameter unit 72 to form the variable-diameter cone 75 with the lower variable-diameter unit 74 and the upper variable-diameter unit 72. With the further increase of the pressure of the drilling fluid, the drilling fluid with larger pressure will enter the first annular gap A to drive the cone sleeve sealing element 32 and the sealing sleeve 31, and then the cone sleeve sealing element 32 and the sealing sleeve 31 drive the center pipe 10, the variable-diameter cone 75, the upper cone seat 71 and the lower cone seat 73 to move upwards, so that the variable-diameter cone 75 expands the reduced diameter section 212 when passing through the reduced diameter section 212, and finally realizes the expansion of the expansion pipe 21 to be expanded on the inner wall of the surrounding casing.

[0082] Of course, once the center pipe string formed by the center pipe 10, the upper cone seat 71, the lower cone seat 73, the upper variable-diameter unit 72, the lower variable-diameter unit 74, the cone sleeve sealing element 32 and the sealing sleeve 31 needs to be pulled out of the wellbore due to downhole failure, the operator can control the pressure relief on the ground to avoid the upper variable-diameter unit 72 and the lower variable-diameter unit 74 from extending away from the center pipe 10, so that the upper variable-diameter unit 72 and the lower variable-diameter unit 74 will not form a variable-diameter cone with a larger diameter, and will pass through the reduced diameter section 212 without expanding the reduced diameter section 212 during the upward movement. Of course, the cone sleeve sealing element 32 is in sealing contact with the inner wall of the pipe body 211, and during the upward movement of the cone sleeve sealing element 32, the cone sleeve sealing element 32 is an elastic member, which can pass through the reduced diameter section 212 by elastic deformation, and this process will not expand the reduced diameter section 212.

[0083] It should be noted that in the embodiment of the present application, the upper variable-diameter unit 72 and the lower variable-diameter unit 74 are both rigid members with high hardness and strength, and after the two form the variable-diameter cone 75, the variable-diameter cone 75 is a rigid member with high rigidity, which can expand the reduced diameter section 212 to realize the expansion of the reduced diameter section 212 when forcibly passing through the reduced diameter section 212. The cone sleeve sealing element 32 is an elastic structural member, which realizes sealing fit through elastic deformation, and will deform under the interference of the reduced diameter section 212 when forcibly passing through the reduced diameter section 212, so as not to cause the reduced diameter section 212 to be expanded.

[0084] As described above, the expansion pipe 21 comprises the pipe body 211 and the reduced diameter section 212, in order to improve the suspension effect, the expansion pipe 21 disclosed by the embodiment of the present application can further comprise a sealing rubber sleeve 213, the sealing rubber sleeve 213 is sleeved outside the reduced diameter section 212 and is fixedly connected with the reduced diameter section 212. When the reduced diameter section 212 is expanded by tensioning, the sealing rubber sleeve 213 is compressed and fixed between the reduced diameter section 212 and the outer sleeve, so as to realize better expansion connection, and meanwhile, the sealing property of the connection can be ensured. In an example, the sealing rubber sleeve 213 can be a vulcanizate, which is formed on the outer wall of the reduced diameter section 212 through a vulcanization process. Of course, the embodiment of the present application does not limit the more specific material and setting process of the sealing rubber sleeve 213.

[0085] In the embodiment of the present application, the upper end of the center pipe 10 is used to be connected with the drill pipe, in order to facilitate the connection, the variable diameter expansion type liner hanger disclosed by the embodiment of the present application can further comprise an upper joint 14, the upper joint 14 is a threaded sleeve, the upper joint 14 can be detachably connected with the center pipe 10 through threaded cooperation, and the upper joint 14 is used to realize the connection between the center pipe 10 and the drill pipe. In order to facilitate the downward running of the variable diameter expansion type liner hanger in the wellbore, in the variable diameter expansion type liner hanger disclosed by the embodiment of the present application, the outer sleeve 20 can further comprise a float shoe 24, the float shoe 24 is installed at the lowermost end of the outer sleeve 20, so as to play a guiding role. In the embodiment in which the outer sleeve 20 comprises the pressure seat 23, the float shoe 24 can be installed on the side of the pressure seat 23 which is away from the liner 22. Specifically, the float shoe 24 can be detachably connected with the liner 22 through threaded cooperation.

[0086] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-mentioned specific embodiments, the above-mentioned specific embodiments are only illustrative, but not restrictive, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection of the present application.

Claims

1. A variable diameter expansion tailpipe hanger, characterized in that, It includes a central tube (10), an outer cylindrical component (20), and an upper diameter reducing unit (72) and a lower diameter reducing unit (74) movably disposed on the outer wall of the central tube (10). The outer cylindrical component (20) includes an expansion tube (21) and a tail tube (22) that are axially connected in sequence and are both sleeved outside the central tube (10); the expansion tube (21) includes a tube body (211) and a reduced diameter section (212) that is axially connected to the tube body (211) and reduced diameter relative to the tube body (211). During the extension of the upper diameter-changing unit (72) and the lower diameter-changing unit (74), the upper diameter-changing unit (72) and the lower diameter-changing unit (74) extend away from the central tube (10) and form a diameter-changing cone (75) around the central tube (10). The diameter-changing cone (75) is used to pass through the reduced diameter section (212) and expand the diameter of the reduced diameter section (212) to tighten it on the inner wall of the outer sleeve during the upward movement with the central tube (10). During the retraction of the upper diameter reducing unit (72) and the lower diameter reducing unit (74), the upper diameter reducing unit (72) and the lower diameter reducing unit (74) retract toward the central tube (10). During the upward movement of the central tube (10), the upper diameter reducing unit (72) and the lower diameter reducing unit (74) can drive the upper diameter reducing unit (72) and the lower diameter reducing unit (74) through the tube body (211) and the reduced diameter section (212). It also includes an upper cone seat (71) and a lower cone seat (73). The upper cone seat (71) is sleeved outside the central tube (10) and is fixedly connected to the central tube (10). The lower cone seat (73) is slidably sleeved outside the central tube (10). There are multiple upper diameter changing units (72) and lower diameter changing units (74), which are staggered in the circumferential direction of the central tube (10); the upper diameter changing unit (72) is slidably disposed on the upper cone seat (71), and the lower diameter changing unit (74) is slidably disposed on the lower cone seat (73); When the lower cone (73) moves toward the upper cone (71), the upper variable diameter unit (72) and the lower variable diameter unit (74) move toward each other and extend toward the direction away from the central tube (10) to form the variable diameter cone (75). When the lower cone (73) moves away from the upper cone (71), the upper variable diameter unit (72) and the lower variable diameter unit (74) move away from each other and retract towards the center tube (10) at the same time; It also includes a conical sleeve seal (32), which is sleeved outside the upper conical seat (71) and fixedly connected to the upper conical seat (71). The conical sleeve seal (32) is in sealing contact with the inner wall of the tube body (211), and a first annular gap (A) is formed between the central tube (10) and the peripheral cylinder (20). It also includes a sealing sleeve (31), a piston (50), and a claw sleeve (60); The outer wall of the central tube (10) is provided with a plurality of strip-shaped protrusions (11) distributed along its circumference, and a guide gap is formed between two adjacent strip-shaped protrusions (11) extending axially along the central tube (10). The sealing sleeve (31), the piston (50), the central tube (10) and the upper cone seat (71) form a first driving cavity (B), which is connected to the first annular gap (A).

2. The variable diameter expansion tailpipe hanger according to claim 1, characterized in that, The upper cone seat (71) is provided with a plurality of first inclined guide grooves (711), the lower cone seat (73) is provided with a plurality of second inclined guide grooves (731), the plurality of upper variable diameter units (72) are respectively guided and cooperated with the plurality of first inclined guide grooves (711), and the plurality of lower variable diameter units (74) are respectively guided and cooperated with the plurality of second inclined guide grooves (731).

3. The variable diameter expansion tailpipe hanger according to claim 1, characterized in that, The upper diameter-changing unit (72) and the lower diameter-changing unit (74) are both located in the first annular gap (A). The upper diameter-changing unit (72) and the lower diameter-changing unit (74) form the diameter-changing cone (75). When the variable diameter expansion tailpipe hanger is in a pressurized state, the drilling fluid entering the first annular gap (A) from the lumen of the central tube (10) will drive the cone sleeve seal (32) to drive the central tube (10) and the diameter-changing cone (75) upward.

4. The variable diameter expansion tailpipe hanger according to claim 3, characterized in that, The piston (50) is slidably sleeved on the central tube (10) and located on the first side of the plurality of strip-shaped protrusions (11). The claw sleeve (60) includes a cylindrical sleeve (61) located on the second side of the plurality of strip-shaped protrusions (11) and slidably sleeved on the central tube (10), and a plurality of connecting claws (62) connected to one end of the cylindrical sleeve (61) and respectively passing through the corresponding guide gaps and connected to the piston (50). The lower cone seat (73) is sleeved outside the cylindrical sleeve (61) and fixedly connected to the cylindrical sleeve (61). The sealing sleeve (31) is fitted outside the piston (50) and the upper cone seat (71) and fixed to the upper cone seat (71). The upper cone seat (71) is fitted on the plurality of strip protrusions (11) and fixedly connected to the plurality of strip protrusions (11). The sealing sleeve (31) is located on the side of the cone sleeve seal (32) facing away from the upper diameter unit (72) and the lower diameter unit (74). The first drive cavity (B) communicates with the first annular gap (A) through the gap between the strip protrusion (11) and the connecting claw (62).

5. The variable diameter expansion tailpipe hanger according to claim 4, characterized in that, The claw sleeve (60) also includes a locking ring (63), which is sleeved outside the plurality of connecting claws (62). The piston (50) is provided with a threaded hole, and the plurality of connecting claws (62) all include a connecting protrusion (621). The locking ring (63) is threadedly engaged with the threaded hole and clamps and fixes the connecting protrusion (621) in the threaded hole of the piston (50).

6. The variable diameter expansion tailpipe hanger according to claim 4, characterized in that, The claw sleeve (60) also includes a support ring (64). The plurality of connecting claws (62), the piston (50) and the central tube (10) form an annular space, and the support ring (64) is disposed in the annular space.

7. The variable diameter expansion tailpipe hanger according to claim 4, characterized in that, It also includes an elastic element (40), the central tube (10) and the outer cylindrical member (20) form a second annular gap (C), the second annular gap (C) and the first annular gap (A) are located on opposite sides of the cone sleeve seal (32) and are isolated from each other by the cone sleeve seal (32); the first end of the elastic element (40) is connected to the central tube (10), the second end of the elastic element (40) is connected to the piston (50), and when the variable diameter expansion tailpipe hanger is in the depressurization state, it is used to drive the lower cone seat (73) to move away from the upper cone seat (71) by the piston (50) and the claw sleeve (60).

8. The variable diameter expansion tailpipe hanger according to claim 7, characterized in that, The central tube (10) includes a plurality of tube segments (12) distributed along its axial direction. Two adjacent tube segments (12) are connected by a threaded sleeve (13). The threaded sleeve (13) is fitted outside the tube segment (12), and the first end of the elastic element (40) abuts against the end face of the threaded sleeve (13).

9. The variable diameter expansion tailpipe hanger according to claim 3, characterized in that, The peripheral cylinder (20) also includes a pressure seat (23); the variable diameter expansion tailpipe hanger also includes a tailpipe plug (81) and a drill pipe plug (82). The tailpipe plug (81) is connected to the lower end of the central tube (10) by a shear screw (83) and seals the first annular gap (A). When the drill pipe plug (82) is placed into the cavity of the central tube (10), the drill pipe plug (82) can flow along the cavity of the central tube (10) to the tailpipe plug (81), and under the drive of the drilling fluid, the tailpipe plug (81) cuts the shear screw (83) and moves to the pressure seat (23) to seal the pressure seat (23) and make the central tube (10) communicate with the first annular gap (A).

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