A liner hanger with enhanced locking device and method of operation thereof

Abstract

The application discloses a tailpipe hanger with enhanced locking device and an operating method thereof. The tailpipe hanger comprises a hanger body, a locking assembly, a floating cone locking assembly, a driving assembly, a fixed slip assembly and a hanger slip assembly which are sequentially sleeved outside the hanger body, and a pressure holding mechanism arranged inside the hanger body. When the pressure holding mechanism is not holding pressure, the locking assembly, the floating cone locking assembly, the driving assembly, the fixed slip assembly and the hanger slip assembly are all locked. When the pressure holding mechanism is holding pressure at a first level, the locking assembly is unlocked, and then the floating cone locking assembly moves upward to be unlocked. When the pressure holding mechanism is holding pressure at a second level, the driving assembly is activated to unlock and hang the hanger slip assembly. Then the fixed slip assembly can be unlocked and fixedly hung. The tailpipe hanger provided by the application prevents all components from being started before the tailpipe hanger is unlocked and achieves smooth driving and hanging after the tailpipe hanger reaches a depth.

Description

A tailpipe hanger with an enhanced locking device and its operating method Technical Field

[0001] This invention belongs to the field of oil and gas cementing tools, and particularly relates to a tailpipe hanger with an enhanced locking device and its operating method. Background Technology

[0002] The tailpipe string is the string of tubing installed at the bottom of the casing inside an oil well. It is typically suspended above the oil layer using a hanger for oil production.

[0003] In recent years, with the rapid development of drilling technology, drilling depths have been continuously increasing, and well temperatures have been rising, resulting in situations where high temperature, high pressure, and multiple pressure systems coexist. This places higher demands on the safety of the tailpipe hanger during well entry, its setting reliability, sealing capability, and temperature resistance. Currently, conventional tailpipe hangers are insufficient to meet the increasingly complex field requirements and exhibit several problems in use. These problems mainly manifest as follows: in applications in highly deviated and deep wells, the hanger's setting and release reliability is low; the tailpipe and hanger are difficult to lower smoothly to the designed position, and repeated lifting and lowering can easily dislodge exposed components such as slips, causing more serious accidents; the pressure transmission holes between the hanger's connecting pipe and the hydraulic cylinder are exposed, meaning that any pressure generated inside the pipe could trigger the hydraulic cylinder, leading to premature setting of the hanger and causing significant operational difficulties.

[0004] To address this issue, a tailpipe suspension with an enhanced locking mechanism is needed, featuring one or more enhanced locking components that prevent all components from engaging before the tailpipe suspension is unlocked and enable smooth drive seating after the tailpipe suspension reaches its depth. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a tailpipe hanger with an enhanced locking device.

[0006] The technical solution adopted in this invention is as follows:

[0007] According to a first aspect of the present invention, a tailpipe hanger with an enhanced locking device is provided, comprising: a hanger body, wherein the hanger body is provided with a first pressure-transmitting hole and a second pressure-transmitting hole; a locking assembly, a floating cone locking assembly, a drive assembly, a fixed slip assembly, and a suspension slip assembly sequentially sleeved outside the hanger body from top to bottom, wherein a portion of the floating cone locking assembly is located between the locking assembly and the hanger body, a first pressure-blocking cavity fluidly communicating with the first pressure-transmitting hole is formed between the portion of the floating cone locking assembly and the locking assembly, and a second pressure-blocking cavity fluidly communicating with the second pressure-transmitting hole is formed between the drive assembly and the hanger body; and a pressure-blocking mechanism disposed inside the hanger body. When the pressure-holding mechanism is not pressurized, the locking assembly, the floating cone locking assembly, the drive component, the fixed slip assembly, and the suspension slip assembly are all locked to the suspension body, wherein the locking assembly is connected to the floating cone locking assembly. When the pressure-holding mechanism presses in the first stage, the first pressure-holding chamber presses, the locking assembly is disconnected from the floating cone locking assembly, the locking assembly is unlocked, and the locking assembly moves upward relative to the suspension body. After the locking assembly moves upward a certain distance, the locking assembly and the floating cone locking assembly are linked, and the locking assembly drives the floating cone locking assembly to move upward relative to the suspension body. When the pressure-holding mechanism presses in the second stage, the second pressure-holding chamber presses, activating the drive component to unlock the suspension slip assembly and realize the seated suspension slip assembly. The fixed slip assembly can be unlocked and fixed seated by the downward movement of the locking assembly, the floating cone locking assembly, and the drive component.

[0008] According to one embodiment of the present invention, the locking assembly includes a push sleeve sleeved outside the suspension body and a clamping device located between the suspension body and the push sleeve, the clamping device being connected to the push sleeve; the floating cone locking assembly includes a cone-shaped member, the upper end of the cone-shaped member being located between the push sleeve and the suspension body; when the pressure-locking mechanism is not pressure-locked, the clamping device is connected to the upper end of the cone-shaped member and locks the cone-shaped member onto the suspension body; when the pressure-locking mechanism is pressure-locked, the clamping device is disconnected from the upper end of the cone-shaped member.

[0009] According to one embodiment of the present invention, the clamping device is connected to the upper end of the tapered member via a first shear pin, which is sheared during the first stage of the compression mechanism.

[0010] According to one embodiment of the present invention, the tapered member is provided with a convex block, and the suspension body is provided with a groove that matches the convex block; when the pressing mechanism is not pressed, the convex block engages in the groove to lock the locking assembly and the floating cone locking assembly; when the locking assembly is unlocked, the convex block disengages from the groove.

[0011] According to one embodiment of the present invention, the tapered member is provided with a third pressure transmission hole; when the pressure-holding mechanism is not pressure-holding, the first pressure transmission hole and the first pressure-holding chamber are in fluid communication through the third pressure transmission hole; when the pressure-holding mechanism causes the floating cone locking assembly to unlock and move upward due to first-stage pressure-holding, the tapered member closes the fluid communication path between the first pressure transmission hole and the first pressure-holding chamber.

[0012] According to one embodiment of the present invention, a first sealing member and a second sealing member are longitudinally spaced between the push sleeve and the tapered member, and the first sealing member and the second sealing member form the first pressure-blocking cavity between the push sleeve and the tapered member.

[0013] According to one embodiment of the present invention, the locking assembly is provided with a first linkage member, and the floating cone locking assembly is provided with a second linkage member. After the locking assembly is unlocked and moves a certain distance relative to the suspension body, the first linkage member abuts against the second linkage member to drive the floating cone locking assembly to move upward relative to the suspension body via the locking assembly.

[0014] According to one embodiment of the present invention, the clamping device is connected to the push sleeve via a second shear pin.

[0015] According to one embodiment of the present invention, a sealing assembly is provided between the lower end of the push sleeve and the tapered member, and the sealing assembly is fixedly connected to the lower end of the push sleeve; when the second shear pin is sheared, the push sleeve can move downward relative to the tapered member to push the sealing assembly to sit between the tapered member and the upper sleeve.

[0016] According to one embodiment of the present invention, the clamping device includes a plurality of flexible clamping arms distributed along the circumferential direction, the ends of the flexible clamping arms being connected to the convex block of the tapered member via the first shear pin on the push sleeve.

[0017] According to one embodiment of the present invention, the floating cone locking assembly further includes a clamping member connected to the lower end of the cone member. The clamping member includes a plurality of clamping arms located between the suspension body and the drive assembly. The plurality of clamping arms achieve a locking connection between the floating cone locking assembly and the suspension body under the limiting action of the drive assembly.

[0018] According to one embodiment of the present invention, the drive assembly includes a spacer assembly, a pull ring connected to the spacer assembly, a plurality of pull rods connected to the pull ring, and a piston sleeve; wherein the pull ring is connected to the radially inner surface of the lower end of the spacer assembly, thereby forming a space between the suspension body, the pull ring, and the spacer assembly for accommodating movement of the piston sleeve, the lower end of the piston sleeve is fixedly connected to the pull ring and forms a second pressure chamber between the piston sleeve, the pull ring, and the suspension body; wherein the plurality of pull rods extend downward along the suspension body until they are located below a portion of the suspension slip assembly, and when the second pressure chamber is pressured, the piston sleeve moves upward, causing the pull ring and the plurality of pull rods connected to the pull ring to move upward, thereby unlocking the suspension slip assembly.

[0019] According to one embodiment of the present invention, the suspension slip assembly includes a sleeve clamp, a suspension slip, and a movable locking ring, wherein the upper end of the sleeve clamp is fixedly connected to the suspension slip, and the sleeve clamp is disposed between the suspension slip and the suspension body; when the suspension slip assembly is locked, the movable locking ring is located between the lower end of the sleeve clamp and the suspension slip to lock the sleeve clamp onto the suspension body; when the suspension slip assembly is unlocked, the movable locking ring moves away from the lower end of the sleeve clamp, and the sleeve clamp separates from the suspension body.

[0020] According to one embodiment of the present invention, the sleeve clamp is provided with a plurality of flexible claws evenly distributed along the circumference; when the suspension slip assembly is locked, the movable locking ring fixes the flexible claws in the concave groove of the suspension body; when the suspension slip assembly is unlocked, the flexible claws are released from the concave groove.

[0021] According to one embodiment of the present invention, when the drive assembly is activated, the pull rod moves upward to abut against the movable locking ring to drive the movable locking ring upward, thereby releasing the flexible pawl from the concave groove and unlocking the suspension slip assembly.

[0022] According to one embodiment of the present invention, a first conical surface and a second conical surface are respectively provided at the positions where the suspension slip assembly and the fixed slip assembly are fitted onto the suspension body, wherein the contact surface between the first conical surface and the slip arm of the suspension slip assembly is provided with interlocking teeth, and the contact surface between the second conical surface and the slip arm of the fixed slip assembly is provided with interlocking teeth.

[0023] According to one embodiment of the present invention, the slip arm of the suspension slip assembly and the slip arm of the fixed slip assembly are provided with engagement teeth that can engage with the inner wall of the sleeve, away from the outer surface of the suspension body.

[0024] According to one embodiment of the present invention, the suspension slip assembly and the fixed slip assembly each include a guide rail for receiving their slip arms; the slip arms are received in the guide rails before being seated; and the slip arms disengage from the guide rails during seating.

[0025] According to one embodiment of the present invention, the guide rails of the suspension slip assembly and the fixed slip assembly are aligned longitudinally, and an axial groove is formed between adjacent guide rails to accommodate a portion of the extension of the drive assembly.

[0026] According to a second aspect of the present invention, a method for operating the above-mentioned tailpipe hanger with an enhanced locking device is provided, comprising the following steps: sequentially fitting the suspension slip assembly, the fixed slip assembly, the drive assembly, the floating cone locking assembly, and the locking assembly onto the outer wall of the hanger body; connecting and locking the insertion tool to the hanger body; connecting the tailpipe or tailpipe string to the hanger body and inserting the connected tailpipe hanger and the tailpipe or tailpipe string into the well; and setting the tailpipe hanger, including: disconnecting the connection between the floating cone locking assembly and the locking assembly by a primary pressure test, and unlocking the locking assembly. The locking assembly moves upward relative to the suspension body. After the locking assembly moves upward a certain distance, the linkage between the floating cone locking assembly and the locking assembly is realized. The drive assembly is activated by a two-stage pressure to unlock the suspension slip assembly and realize the mounting of the suspension slip assembly. The tailpipe suspension is lowered, and an appropriate downward weight is applied to the locking assembly, which is then sequentially transferred downward to the floating cone locking assembly, the drive assembly, and the fixed slip assembly, thereby realizing the mounting of the fixed slip assembly. After the construction work is completed, the connection between the feeding tool and the suspension body is released, and the feeding tool is removed.

[0027] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0028] The tailpipe hanger with enhanced locking device provided by the present invention can prevent all components from starting before the tailpipe hanger is unlocked by setting a locking assembly; by setting multi-level locking, it can effectively prevent other components of the tailpipe hanger from starting prematurely, and effectively prevent premature mounting; through the cooperation of the locking assembly, floating cone locking assembly, drive assembly, fixed slip assembly and suspension slip assembly, smooth drive mounting is achieved. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 is a schematic diagram of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of a tailpipe hanger with an enhanced locking device provided in another embodiment of the present invention;

[0032] Figure 3 is a magnified view of the area within the dashed box in Figure 2;

[0033] Figure 4 is a partial external view of the locking assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0034] Figure 5 is a partial cross-sectional schematic diagram of the locking assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention in one state;

[0035] Figure 6 is a partial cross-sectional schematic diagram of the locking assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in another state;

[0036] Figure 7 is a partial cross-sectional schematic diagram of the locking assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in another state;

[0037] Figure 8 is a partial cross-sectional schematic diagram of the locking assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in another state;

[0038] Figure 9 is a partial external view of the clamping component of the floating cone locking assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0039] Figure 10 is a partial cross-sectional schematic diagram of the floating cone locking assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0040] Figure 11 is a partial view of the pull ring portion of the drive assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0041] Figure 12 is a partial cross-sectional schematic diagram of the drive assembly of the tailpipe hanger with an enhanced locking device provided in an embodiment of the present invention;

[0042] Figure 13 is a partial external view of the suspension slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention;

[0043] Figure 14 is another partial external view of the suspension slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention.

[0044] Figure 15 is a partial cross-sectional schematic diagram of the sliding lock portion of the suspension slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in one state;

[0045] Figure 16 is a partial cross-sectional schematic diagram of the sliding lock portion of the suspension slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in another state;

[0046] Figure 17 is a partial cross-sectional schematic diagram of the sliding lock portion of the suspension slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention in another state;

[0047] Figure 18 is a partial external view of the fixing slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention;

[0048] Figure 19 is another partial view of the fixed slip assembly of the tailpipe hanger with enhanced locking device provided in an embodiment of the present invention.

[0049] List of reference numerals

[0050] 1: Suspension body; 101: Upper end; 102: Lower end; 103: Groove; 104: First pressure transmission hole; 105: Concave groove; 106: First conical surface; 107: Second conical surface; 108: Second pressure transmission hole

[0051] 2: Locking assembly; 201: First shearing pin; 202: First sealing component; 203: Push sleeve; 204: Clamping device; 205: Second shearing pin; 206: Flexible clamping arm; 207: First linkage component

[0052] 3: Floating cone locking assembly; 301: Convex block; 302: Third pressure transmission hole; 303: Second sealing component (second linkage component); 304: Conical component; 305: Clamping component; 306: Clamping arm; 307: Concave groove

[0053] 4: Drive assembly; 401: Spacer assembly; 402: Pull ring; 403: Pull rod; 404: Piston sleeve; 406: Circulation hole; 407: Connector

[0054] 5: Fixed clamp assembly; 501: Fixed clamp; 502: Clamp arm; 503: Guide rail

[0055] 6: Suspension slip assembly; 601: Sleeve clamp; 602: Suspension slip; 603: Moving locking ring; 604: Flexible pawl; 605: Slip arm; 606: Guide rail

[0056] 7: Sealing assembly; 701: Connector; 702: Seal

[0057] A: First pressure chamber; B: Second pressure chamber Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0059] First, it should be noted that the specific structure, features, and advantages of the present invention will be described in detail below by way of examples. However, all descriptions are for illustrative purposes only and should not be construed as limiting the present invention in any way. Furthermore, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the accompanying drawings, can still be arbitrarily combined or deleted among these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein. Additionally, for the sake of simplifying the drawings, the same or similar technical features may be indicated only in one place in the same drawing.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0061] The embodiments of the present invention will now be described in detail with reference to Figures 1-19.

[0062] Figures 1 and 2 respectively illustrate embodiments of the tailpipe hanger with an enhanced locking device provided by the present invention, wherein Figure 1 is an external view and Figure 2 is a semi-external, semi-sectional view. As shown, the tailpipe hanger includes: a hanger body 1; a locking assembly 2, a floating cone locking assembly 3, a drive assembly 4, a fixed slip assembly 5, and a suspension slip assembly 6, which are sequentially sleeved on the outside of the hanger body 1 from top to bottom; and a pressure-retaining mechanism (not shown) disposed inside the hanger body 1. The hanger body 1 is provided with a first pressure-transmitting hole 104 (see Figures 2 and 3) and a second pressure-transmitting hole 108 (see Figures 2 and 12). A portion of the floating cone locking assembly 3 is located between the locking assembly 2 and the hanger body 1, and a first pressure-retaining cavity A, which is in fluid communication with the first pressure-transmitting hole 104, is formed between this portion of the floating cone locking assembly 3 and the locking assembly 2. A second pressure-retaining cavity B, which is in fluid communication with the second pressure-transmitting hole 108, is formed between the drive assembly 4 and the hanger body 1. When the pressure-locking mechanism is not engaged, the locking assembly 2, the floating cone locking assembly 3, the drive assembly 4, the fixed slip assembly 5, and the suspension slip assembly 6 are all locked onto the suspension body 1, with the locking assembly 2 connected to the floating cone locking assembly 3. When the pressure-locking mechanism engages at the first stage, the first pressure-locking chamber A engages, the locking assembly 2 is disconnected from the floating cone locking assembly 3, the locking assembly 2 is unlocked, and the locking assembly 2 moves upward relative to the suspension body 1. After the locking assembly 2 moves upward a certain distance, the locking assembly 2 and the floating cone locking assembly 3 are linked, and the locking assembly 2 drives the floating cone locking assembly 3 to move upward relative to the suspension body 1. When the pressure-locking mechanism engages at the second stage, the second pressure-locking chamber B engages, activating the drive assembly 4 to unlock the suspension slip assembly 5 and achieve the seat and hang of the suspension slip assembly 6. The fixed slip assembly 5 can be unlocked and fixed seat and hang by moving the locking assembly 2, the floating cone locking assembly 3, and the drive assembly 4 downward. In this invention, the locking assembly 2 serves as the main lock of the entire tailpipe suspension. When the locking assembly 2 is locked, all other components of the tailpipe suspension cannot be activated. When the locking assembly 2 is unlocked, all other components of the tailpipe suspension can be activated.

[0063] The suspension body 1 is a tubular component, the structure of which is well known in the art and will not be described in detail here. The suspension body is a multi-piece structure interconnected (as shown in Figure 2), and the present invention does not limit this. As shown in Figure 1, the suspension body 1 includes an upper end 101 and a lower end 102. The upper end 101 can be releasably connected to a delivery tool (not shown), and the lower end 102 can be connected to a tailpipe or tailpipe string. Before downhole operations, the delivery tool is connected to the suspension body 1 to deliver the suspension body 1 and the various components fitted thereon into the well; after the downhole operations are completed, the delivery tool is separated from the suspension body 1, the suspension body 1 and the various components fitted thereon remain in the well, suspended on the inner wall of the casing, and the delivery tool is pulled out of the wellhead. In the present invention, the delivery tool and its connection with the suspension body 1 adopt conventional methods in the art, and the present invention does not limit this.

[0064] Pressure-holding mechanisms are well known in the art, but are not shown in the accompanying drawings of this invention. The specific structure of the pressure-holding mechanism is described briefly below: The pressure-holding mechanism includes a central tube relatively fixedly disposed within the hanger body 1. This central tube can be fixed relative to the hanger body 1 by a feeding tool. The pressure-holding mechanism also includes a sealing element, preferably a rubber plug, fixedly disposed on the outer wall of the central tube to seal the annular space formed between the central tube and the hanger body 1. To achieve pressure-holding inside the central tube, the pressure-holding mechanism also includes a receiving seat fixedly disposed on the inner wall of the central tube and a pressure-holding component that can be sealed and received by the receiving seat. This pressure-holding component is preferably a pressure-holding ball. When the pressure-holding component is thrown into the interior of the feeding tool, it falls onto the receiving seat located inside the central tube, thereby causing pressure to begin inside the central tube. The term "first-level pressure-holding" mentioned in this invention refers to the internal pressure of the central tube reaching a first threshold; the term "second-level pressure-holding" mentioned in this invention refers to the internal pressure of the central tube reaching a second threshold greater than the first threshold. It should be understood that the first threshold is the pressure sufficient to disconnect the connection between the locking assembly and the floating cone locking assembly, while the second threshold is the pressure sufficient to activate the drive component.

[0065] In the context of this invention, unless otherwise specified, “locking” of a component means that the component is locked relative to the suspension body and cannot move relative to the suspension body; similarly, unless otherwise specified, “unlocking” of a component means that the component is unlocked relative to the suspension body and is allowed to move relative to the suspension body.

[0066] When the clamping mechanism is not clamped, the locking assembly 2 and the floating cone locking assembly 3 are connected by the first shear pin 201, and the locking assembly 2 is in a locked state. When the clamping mechanism clamps and causes the first shear pin 201 to be sheared, the locking assembly 2 and the floating cone locking assembly 3 are disconnected, and the locking assembly 2 is in an unlocked state. The floating cone locking assembly 3 is provided with a protruding block 301, and the suspension body 1 is provided with a groove 103 that matches the protruding block 301. When the locking assembly 2 is in a locked state, the protruding block 301 engages in the groove 301 to lock the locking assembly 2 and the floating cone locking assembly 3. When the locking assembly 2 is unlocked, the protruding block 301 can disengage from the groove 103.

[0067] To unlock the locking assembly 2 (i.e., to shear the first shear pin 201 when the pressure-holding mechanism is pressurized), a third pressure-transmitting hole 302 is provided radially on the floating cone locking assembly 3, as shown in the partial enlarged view of Figure 3. In the unpressurized state, the first pressure-transmitting hole 104 and the third pressure-transmitting hole 302 are aligned and aligned with the first pressure-holding chamber A, thereby enabling fluid communication between the first pressure-transmitting hole 104, the third pressure-transmitting hole 302, and the first pressure-holding chamber A. When the pressure-holding mechanism pressurizes at the first stage, the fluid located in the suspension body 1 can sequentially enter the first pressure-holding chamber A through the first pressure-transmitting hole 104 on the suspension body 1 and the third pressure-transmitting hole 302 on the floating cone locking assembly 3, thereby applying pressure to the locking assembly 2, pushing the locking assembly 2 upward, and thus shearing the first shear pin 201. Specifically, a first sealing member 202 and a second sealing member 303 are longitudinally spaced between the locking assembly 2 and the floating cone locking assembly 3. The first sealing member 202 and the second sealing member 303 form a sealed first pressure-blocking chamber A between the floating cone locking assembly 3 and the locking assembly 2. When the pressure-blocking mechanism causes the floating cone locking assembly 3 to unlock and move upwards, the third pressure-transmitting hole 302 also moves upwards, no longer aligning with the first pressure-transmitting hole 104 and the first pressure-blocking chamber A. Therefore, the first pressure-transmitting hole 104 and the first pressure-blocking chamber A cannot communicate fluidly.

[0068] To achieve linkage between the locking assembly 2 and the floating cone locking assembly 3 after the locking assembly 2 moves upward a certain distance, the locking assembly 2 is provided with a first linkage member 207 (e.g., in the form of a pin), and the floating cone locking assembly 3 is provided with a second linkage member. After the locking assembly 2 is unlocked and moves a certain distance relative to the hanger body 1, the first linkage member 207 contacts and abuts against the second linkage member, thereby causing the floating cone locking assembly 3 to move upward relative to the hanger body 1. In the embodiment shown in the accompanying drawings, the second linkage member is integrated with the second sealing member, that is, the second linkage member is also the second sealing member, which helps to reduce the number of parts and reduce the complexity of the structure. Of course, the second linkage member can also be a separate component from the second sealing member.

[0069] Figures 4-8 show the specific structure of the locking assembly 2. Figure 4 is an external view of the locking assembly 2, and Figures 5-8 are cross-sectional views of the locking assembly 2 in different states. Figure 5 corresponds to the uncompressed state of the pressure-locking mechanism, Figure 6 corresponds to the state where the first stage of pressure-locking mechanism unlocks the locking assembly 2, Figure 7 corresponds to the state where the pressure-locking mechanism continues to pressurize for one more stage, unlocking the floating cone locking assembly 3, and Figure 8 corresponds to the state where the fixed slip assembly 5 is set. As shown in Figure 5, the locking assembly 2 includes a push sleeve 203 sleeved on the outside of the suspension body 1 and a clamping device 204 located between the suspension body 1 and the push sleeve 203. The clamping device 204 is fixed to the push sleeve 203 by a second shear pin 205. In the view of Figure 4, the push sleeve 203 is omitted, thus clearly showing the structure of the clamping device 204. It can be seen that the clamping device 204 includes multiple flexible clamping arms 206 distributed along the circumferential direction. When the pressure-holding mechanism is not engaged, i.e., when the locking assembly 2 is in the locked state, as shown in Figure 5, the lower end of the flexible clamping arm 205 and the protruding block 301 of the floating cone locking assembly 3 are fixed to the push sleeve 203 by the first shear pin 201. When the pressure-holding mechanism engages for the first stage, causing the locking assembly 2 to unlock, as shown in Figure 6, the first shear pin 201 is sheared, thereby breaking the connection between the push sleeve 203 and the clamping device 204 and the protruding block 301 of the floating cone locking assembly 3. The push sleeve 203 and the clamping device 204 move upward under pressure. After the pressure-holding mechanism engages for the first stage, causing the locking assembly 2 to move upward a certain distance, as shown in Figure 7, the floating cone locking assembly 3 unlocks, the protruding block 301 disengages from the groove 103, and the push sleeve 203 and the clamping device 204 move the floating cone locking assembly 3 upward relative to the suspension body 1 under pressure. When setting the fixed slip assembly, as shown in Figure 8, the push sleeve 203 and the clamping device 204 are pressed down, so that the lower end of the flexible clamping arm 206 of the clamping device 204 abuts against the floating cone locking assembly 3, pushing the floating cone locking assembly 3 to move down, thereby realizing the mounting of the fixed slip assembly.

[0070] Figures 9-10 show the specific structure of the floating cone locking assembly 3, where Figure 9 is a partial external view of the floating cone locking assembly 3 and Figure 10 is a cross-sectional view of the floating cone locking assembly 3. As shown, the floating cone locking assembly 3 includes a cone-shaped member 304. The upper end of the cone-shaped member 304 is tapered with an outer diameter that gradually increases from top to bottom. The tapered upper end of the cone-shaped member 304 extends into the space between the locking assembly 2 and the hanger body 1. A third pressure-transmitting hole 302 is provided at the upper end of the cone-shaped member 304. When the pressure-holding mechanism is not engaged, the clamping device 204 is connected to the tapered upper end of the cone-shaped member 304 through a first shear pin 201 and locks the cone-shaped member 304 onto the hanger body 1. When the pressure-holding mechanism engages, the first shear pin 201 is sheared, and the clamping device 204 is disconnected from the upper end of the cone-shaped member 304. When the pressure-holding mechanism continues to hold pressure for the first stage, the first linkage 207 on the push sleeve 203 abuts against the second linkage on the conical member 304, causing the push sleeve 203 to move the conical member 304 upward. This causes the third pressure-transmitting hole 302 on the conical member 304 to deviate from the first pressure-transmitting hole 104 and the first pressure-holding cavity A, sealing the fluid communication path between the first pressure-transmitting hole 104 and the first pressure-holding cavity A, preventing fluid communication between them. The convex block 301 is disposed at the upper end of the conical member 304. The floating cone locking assembly 3 also includes a clamping member 305 threadedly connected to the lower end of the conical member 304. The clamping member 305 includes multiple clamping arms 306 located between the drive assembly 4 and the suspension body 1. Figure 9 shows a schematic diagram of the external structure of the clamping member 305, from which it can be seen that the multiple clamping arms 306 are evenly distributed along the circumferential direction. When the floating cone locking assembly 3 is in the locked state, the clamping arm 306 clamps the suspension body 1. Under the limiting action of the drive assembly (specifically the spacer assembly 401 mentioned below), the floating cone locking assembly 3 is kept locked and fixed in the initial position of the suspension body 1. When the clamping arm 306 moves down into the concave groove 307, the clamping arm 306 lacks the radial limiting force of the spacer assembly 401, thus unlocking the cone member 304. As shown in Figure 10, the clamping arm 306 is firmly connected to the suspension body 1 under the pressure of the external spacer assembly 401. When the locking assembly is in the state shown in Figure 8, the floating cone locking assembly 3 moves down, the cone member 304 moves down, pushing the clamping member 305 down, and the clamping arm 306 enters the concave groove 307, realizing the unlocking of the floating cone locking assembly (here, the unlocking is a downward movement). The clamping arm 306 can move freely axially within the concave groove 307. In addition, it should be mentioned that the lower end of the clamping arm 306 includes a radially enlarged protrusion. When the protrusion of the clamping arm 306 is located in the concave groove 307, the clamping arm 306 does not have a locking effect on the tapered member 304. When the protrusion of the clamping arm 306 is not located in the concave groove 307, the clamping arm 306 has a locking effect on the tapered member 304.

[0071] The drive assembly 4 abuts against the floating cone locking assembly 3, thereby unlocking the drive assembly 4 when the floating cone locking assembly 3 moves downward relative to the suspension body 1. Figures 11 and 12 show an external view and a cross-sectional view of the drive assembly 4, respectively. As shown, the drive assembly 4 includes a spacer assembly 401 abutting against the floating cone locking assembly 3 (specifically, the clamping member 305), a pull ring 402 connected to the spacer assembly 401, a plurality of pull rods 403 connected to the pull ring 402, and a piston sleeve 404 connected to the pull ring 402. The pull ring 402 is connected to the radially inner surface of the spacer assembly 401 via a connector 407 (e.g., a pin), thereby forming a space between the suspension body 1, the pull ring 402, and the spacer assembly 401 to accommodate the movement of the piston sleeve 404, which can move up and down in this space. A second pressure chamber B is formed between the piston sleeve 404, the suspension body 1, and the pull ring 402 under the action of a seal. The piston sleeve 404 is connected to the pull ring 402 by threads. In the embodiment shown in Figure 12, the upper ends of multiple pull rods 403 are connected to pull rings 402. Multiple pull rods 403 extend downwards along the suspension body 1 until they are located below a portion of the suspension slip assembly 6. As shown in Figure 11, the pull ring 402 is an annular element, and multiple pull rods 403 are evenly connected around its circumference. The upper annular sleeve of the spacer assembly 401 contacts the step of the clamping member 305, and its lower end contacts the fixed slip assembly (specifically, the circular sleeve of the fixed slip 501, described below). After the first pressure-blocking stage causes the first pressure transmission hole 104 to be blocked, a second pressure-blocking stage continues. Pressure enters the second pressure-blocking chamber B from the second pressure transmission hole 108, pushing the piston sleeve 404 upwards, causing the pull ring 402 to move upwards, thus moving the pull rods 403 upwards, ultimately achieving the mounting of the suspension slip 6. The spacer assembly 401 is designed with a circulation hole 406 to reduce the pressure difference during the upward movement of the piston sleeve 404 in the second pressure-blocking chamber B.

[0072] Figures 13-17 show the specific structure of the suspension slip assembly 6. Figures 13 and 14 are external views of the suspension slip assembly 6, and Figures 15-17 are cross-sectional views of the suspension slip assembly 6 in different states. Figure 15 corresponds to the locked state of the suspension slip assembly 6, Figure 16 corresponds to the unlocked state of the suspension slip assembly 6, and Figure 17 corresponds to the seated state of the suspension slip assembly 6. As shown, the suspension slip assembly 6 includes a sleeve clamp 601, a suspension slip 602, and a movable locking ring 603. The sleeve clamp 601 and the suspension slip 602 are fixedly connected (e.g., threaded connection), and the sleeve clamp 601 is disposed between the suspension slip 602 and the hanger body 1. When the suspension slip assembly 6 is in the locked state, as shown in Figure 15, the movable locking ring 603 is located between the lower end of the sleeve clamp 601 and the suspension slip 601 to lock the sleeve clamp 601 onto the hanger body 1. Specifically, the sleeve clamp 601 has multiple flexible claws 604 evenly distributed along its circumference. The flexible claws 604 are radially bent outwards by the sleeve clamp 601. The sleeve clamp 601 is constrained radially by an annular movable locking ring 603 radially mounted on the flexible claws 604, locking it in a concave groove 105 in the suspension body 1. In this state, the pull rod 403 and the movable locking ring 603 are longitudinally spaced apart. When the drive assembly is activated, the pull rod 403 moves upwards to abut against the movable locking ring 603, causing the movable locking ring 603 to move upwards, releasing the flexible claws 604 from the concave groove 105, thereby unlocking the suspension slip assembly 6. The unlocked state of the suspension slip assembly 6 is shown in Figure 16. By setting the movable locking ring 603, premature movement of the suspension slip 602 and premature engagement can be prevented. After the suspension slip assembly 6 is unlocked, when the movable locking ring 603 moves upward and abuts against the upper part of the sleeve clamp 601, the continued upward movement of the pull ring 403 will drive the movable locking ring 603, the sleeve clamp 601 abutting against it, and the suspension slip 602 abutting against the sleeve clamp 601 to move upward together. The suspension slip 602 moves upward and opens along the conical surface on the suspension body 1, thereby realizing the sitting and hanging inside the sleeve. The sitting and hanging state of the suspension slip assembly 6 is shown in Figure 17. As shown in Figure 13, multiple slip arms 605 are evenly arranged along the circumferential direction at the upper end of the suspension slip 602. During the sitting and hanging process, the multiple slip arms 605 sit and hang on the inner wall of the sleeve.

[0073] In some cases, a first conical surface 106 (visible in Figures 1 and 14) is provided near the position where the suspension slip assembly 6 is mounted on the suspension body 1. The contact surface between the first conical surface 106 and the slip arm 605 of the suspension slip 602 of the suspension slip assembly 6 is provided with interlocking teeth to restrict the axial movement (e.g., downward movement) of the suspension slip assembly 6 after the suspension is mounted, thus ensuring the mounting effect. The slip arm 605 of the suspension slip 602 of the suspension slip assembly 6 is provided with interlocking teeth (visible in Figure 13) on the outer surface of the suspension body 1, which can engage with the inner wall of the sleeve. This restricts the axial movement (e.g., downward movement) of the suspension slip assembly 6 relative to the inner wall of the sleeve after the suspension is mounted, thus ensuring the mounting effect.

[0074] As shown in Figures 13 and 14, the suspension slip assembly 6 also includes guide rails 606 to prevent the slip arms 605 of the suspension slip 602 from radially wedging outward during the lowering of the tailpipe hanger. Each slip arm 605 is equipped with a corresponding guide rail 606. The guide rail 603 includes a first side and a second side, which are symmetrically arranged and have opposing openings. Before mounting, the two sides of the slip arms 605 of the suspension slip 602 are respectively accommodated in the first and second sides of the guide rails 606, restricting the radial outward movement of the slip arms 605. During mounting, the two sides of the slip arms 605 of the suspension slip 602 disengage from the guide rails 606 for mounting. The guide rails 606 can be connected to the hanger body 1 or can be an integral part of the hanger body. An axial groove formed between adjacent guide rails 606 on the tailpipe hanger body 1 allows the tie rod 403 to pass through. By setting the guide rail 606, the suspension slip 602 will not move radially outward during the lowering process due to tool movement or the slip arm being squeezed by accumulated debris, which can effectively prevent premature sitting and hanging.

[0075] Figures 18-19 show the specific structure of the fixed slip assembly 5. The fixed slip assembly 5 includes a fixed slip 501, the upper end of which abuts against the spacer assembly 401 of the drive assembly 4 (see Figure 12), and a plurality of slip arms 502 are evenly arranged along the circumferential direction at the lower end of the fixed slip 501. The plurality of slip arms 502 sit on the inner wall of the sleeve during the mounting process. In some cases, a second conical surface 107 (visible in Figures 1 and 19) is provided near the position where the hanger body 1 is fitted with the fixed slip assembly 5, wherein the contact surface between the second conical surface 107 and the slip arms 502 of the fixed slip 5 of the fixed slip assembly 5 is provided with interlocking teeth, which are used to limit the axial movement (e.g., upward movement) of the fixed slip assembly 5 after the hanger is mounted, thus ensuring the mounting effect. The locking arm 502 of the locking slip 501 of the locking slip assembly 5 is provided with engagement teeth (visible in Figures 18 and 19) on the outer surface of the hanger body 1, which can engage with the inner wall of the sleeve. This is used to limit the axial movement (e.g., upward movement) of the locking slip assembly 5 relative to the inner wall of the sleeve after the hanger is seated, thus ensuring the seating effect.

[0076] As shown in Figures 18 and 19, the fixed slip assembly 5 also includes a guide rail 503 to prevent the slip arm 502 of the fixed slip 501 from radially wedging outward during the lowering of the tailpipe hanger. The structure of the guide rail 503 is similar to that of the guide rail 606 mentioned above. The guide rail 503 includes a first side and a second side, which are symmetrically arranged and have opposing openings. Before mounting, the two sides of the slip arm 502 of the fixed slip 501 are respectively accommodated in the first and second sides of the guide rail 503, restricting the radial outward movement of the slip arm 503. During mounting, the two sides of the slip arm 502 of the fixed slip 501 disengage from the guide rail 503 for mounting. The guide rail 503 can be connected to the hanger body 1 or can be an integral part of the hanger body. An axial groove formed between adjacent guide rails 503 on the tailpipe hanger body 1 allows the tie rod 403 to pass through it. To facilitate the passage of the pull rod 403 through both the fixed slip assembly 5 and the suspension slip assembly 6 to unlock the suspension slip assembly 6, the guide rail 503 and the guide rail 606 are aligned in the longitudinal direction. By setting the guide rail 503, the fixed slip 501 will not move radially outward during the lowering process due to tool movement or the slip arm being squeezed by accumulated debris, which can effectively prevent premature buckling.

[0077] As shown in Figures 1, 2, and 10, a sealing assembly 7 is provided between the lower end of the push sleeve 203 and the conical member 304. As shown in Figure 10, the sealing assembly 7 includes a connector 701 and a seal 702 disposed on the connector 701. The connector 701 is fitted onto the outer surface of the conical member 304 and is fixedly connected to the lower end of the push sleeve 203 (e.g., by a threaded connection). After the mounting is completed, when a larger weight is lowered onto the tailpipe hanger using a lowering tool, the downward force acting on the push sleeve 203 shears off the second shear pin 205 connecting the push sleeve 203 and the clamping device 204, allowing the push sleeve 203 to move downward relative to the conical member 304. Since the sealing assembly 7 is fixedly connected to the push sleeve 203, the push sleeve 203 drives the sealing assembly 7 to move downward along the conical surface of the conical member 304 until the sealing assembly 7 engages with the inner wall of the upper sleeve. It should be understood that the aforementioned sealing assembly 7 is not essential and can be selectively provided as needed. For example, the need to add this function can be determined based on the downhole conditions. The sealing component 7 functions similarly to the packer function of an existing packer suspension. Here, the operation of the sealing component 7 only requires the application of a certain weight to achieve the packer function, which is much simpler than the existing packer suspension that requires adjusting the pressure to achieve operation.

[0078] The working principle and operation process of the tailpipe hanger with enhanced locking device provided in this invention are as follows:

[0079] First, assemble the tailpipe suspension. Specifically, sequentially mount the suspension slip assembly 6, the fixed slip assembly 5, the drive assembly 4, the floating cone locking assembly 3, and the locking assembly 2 onto the outer wall of the suspension body 1; connect and lock the feed tool to the upper end 101 of the suspension body 1.

[0080] Next, the tailpipe hanger is fed in. Specifically, the tailpipe or tailpipe string is connected to the lower end of the hanger body 1, and the lowering tool (e.g., a drill pipe) is connected to the lowering tool to feed in the tailpipe.

[0081] Next, the tailpipe suspension is mounted. This includes: disconnecting the connection between the floating cone locking assembly 3 and the locking assembly 2 by primary pressure, unlocking the locking assembly 2, and moving the locking assembly 2 upward relative to the suspension body 1. After the locking assembly 2 moves upward a certain distance, the upward linkage between the floating cone locking assembly 3 and the locking assembly 2 is achieved; activating the drive component 4 by secondary pressure to unlock the suspension slip assembly 6 and mount the suspension slip assembly 6; lowering the tailpipe suspension, applying an appropriate downward weight to the locking assembly 2, and then sequentially transferring it downward to the floating cone locking assembly 3, the drive component 4, and finally the fixed slip assembly, thus mounting the fixed slip assembly. Specifically, after the tailpipe hanger is lowered to the designed depth inside the sleeve, a ball is thrown, and pressure is applied from the first stage of the lowering tool. Fluid enters the first pressure chamber A through the first pressure transmission hole 104, cutting the first shear pin 201. The push sleeve 203 moves upward relative to the hanger body 1. After the push sleeve 203 moves upward a certain distance, the first linkage 207 on the push sleeve 203 abuts against the second linkage 303 on the conical part 304. The push sleeve 203 drives the conical part 304 to move upward, and the conical part 304 moves upward to block the first pressure transmission hole 104. Then, pressure is applied from the second stage of the lowering tool, and fluid enters the second pressure chamber B through the second pressure transmission hole 108. The piston sleeve 404 moves upward under pressure, and the pull rod 403 pulls the movable locking ring 603 upward to unlock the suspension slip assembly 6. After the movable locking ring 603 abuts against the sleeve clamp 601, the pull rod 403... Continue pulling upwards, causing the suspension slip 602 to move upwards, thus achieving the seating of the suspension slip 602; lower the insertion tool to apply a certain weight, and the additional weight applied to the tailpipe hanger pushes the push sleeve 203 downwards (this can be achieved by inserting the tool). The applied weight is transferred to the conical member 304 through the push sleeve 203, pushing the spacer assembly 401 downwards, and then pushing the fixed slip assembly 5 downwards to open along the conical direction, thus achieving the seating of the fixed slip assembly 5. During this process, the clamping arm 306 of the clamping member 305 moves downwards into the concave groove 307, achieving axial freedom of the conical member 304 relative to the hanger body 1; when the additional weight is further applied, the push sleeve 203 shears the second shear pin 205, and finally the sealing assembly 7 seals the annular space between itself and the upper sleeve under the action of the conical member 304. At this point, the tailpipe hanger is completely seated. During the above process, after the suspension slips are seated, the suspension slips 602 can be lowered and lowered to bear the full weight of the tailpipe hanger, its lower tailpipe, and the tailpipe string to check whether the tailpipe hanger is seated in place in the wellbore.

[0082] Subsequently, the tailpipe hanger can be reversed and cementing can be carried out as usual.

[0083] After the operation is completed, the connection between the delivery tool and the suspension body 1 is disconnected, and the delivery tool is removed. After the delivery tool is removed, what remains in the well is a complete whole structure without any risk of pressure leakage, thus ensuring the integrity of the wellbore.

[0084] If attempts to pressurize the downrun tool fail, the tailpipe hanger can be seated at the bottom of the well. Pressure is then applied to move the clamping device 204 and pusher sleeve 203 downwards until the clamping device 204 passes the convex block 301, thereby unlocking the locking assembly 2. The greater travel distance required to unlock the locking assembly 2 by moving the pusher sleeve 203 downwards prevents accidental unlocking of the locking assembly 2 during an emergency disconnection operation of the downrun tool.

[0085] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0086] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A tailpipe hanger with an enhanced locking device, characterized in that, include: The suspension body is provided with a first pressure transmission hole and a second pressure transmission hole. The following components are sequentially fitted onto the outside of the suspension body from top to bottom: a locking assembly, a floating cone locking assembly, a drive assembly, a fixed slip assembly, and a suspension slip assembly. A portion of the floating cone locking assembly is located between the locking assembly and the suspension body. A first pressure-retaining cavity, fluidly communicating with the first pressure-transmitting hole, is formed between the portion of the floating cone locking assembly and the locking assembly. A second pressure-retaining cavity, fluidly communicating with the second pressure-transmitting hole, is formed between the drive assembly and the suspension body. A pressure-retaining mechanism is disposed inside the suspension body. When the pressure-retaining mechanism is not in use, the locking assembly, the floating cone locking assembly, the drive assembly, the fixed slip assembly, and the suspension slip assembly are all locked to the suspension body. The locking assembly is connected to the floating cone locking assembly. When the pressure-holding mechanism presses down in the first stage, the first pressure-holding chamber is pressurized, the locking assembly is disconnected from the floating cone locking assembly, the locking assembly is unlocked, and the locking assembly moves upward relative to the suspension body. After the locking assembly moves upward a certain distance, the locking assembly and the floating cone locking assembly are linked, and the locking assembly drives the floating cone locking assembly to move upward relative to the suspension body. When the pressure-holding mechanism presses down in the second stage, the second pressure-holding chamber is pressurized, activating the drive assembly to unlock the suspension slip assembly and achieve the seat and hang of the suspension slip assembly. The fixed slip assembly can be unlocked and fixed seat and hang by the downward movement of the locking assembly, the floating cone locking assembly, and the drive assembly.

2. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that: The locking assembly includes a push sleeve sleeved outside the suspension body and a clamping device located between the suspension body and the push sleeve, the clamping device being connected to the push sleeve; the floating cone locking assembly includes a cone-shaped member, the upper end of the cone-shaped member being located between the push sleeve and the suspension body; when the pressure-locking mechanism is not pressure-locked, the clamping device is connected to the upper end of the cone-shaped member and locks the cone-shaped member onto the suspension body; when the pressure-locking mechanism is pressure-locked, the clamping device is disconnected from the upper end of the cone-shaped member.

3. The tailpipe hanger with an enhanced locking device according to claim 2, characterized in that, The clamping device is connected to the upper end of the tapered member via a first shearing pin, which is sheared off during the first stage of the compression mechanism.

4. The tailpipe hanger with an enhanced locking device according to claim 3, characterized in that, The conical member is provided with a convex block, and the suspension body is provided with a groove that matches the convex block; when the clamping mechanism is not clamped, the convex block engages in the groove to lock the locking assembly and the floating cone locking assembly; when the locking assembly is unlocked, the convex block disengages from the groove.

5. The tailpipe hanger with an enhanced locking device according to claim 2, characterized in that, The tapered component is provided with a third pressure transmission hole; when the pressure-holding mechanism is not pressurized, the first pressure transmission hole and the first pressure-holding chamber are in fluid communication through the third pressure transmission hole; when the pressure-holding mechanism pressurizes at the first stage, causing the floating cone locking assembly to unlock and move upward, the tapered component closes the fluid communication path between the first pressure transmission hole and the first pressure-holding chamber.

6. The tailpipe hanger with an enhanced locking device according to claim 2, characterized in that, A first sealing member and a second sealing member are longitudinally spaced between the push sleeve and the tapered member, and the first sealing member and the second sealing member form the first pressure-retaining cavity between the push sleeve and the tapered member.

7. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that, The locking assembly is provided with a first linkage member, and the floating cone locking assembly is provided with a second linkage member. After the locking assembly is unlocked and moves a certain distance relative to the suspension body, the first linkage member abuts against the second linkage member so as to drive the floating cone locking assembly to move upward relative to the suspension body via the locking assembly.

8. The tailpipe hanger with an enhanced locking device according to claim 2, characterized in that, The clamping device is connected to the push sleeve via a second shear pin.

9. The tailpipe hanger with an enhanced locking device according to claim 8, characterized in that, A sealing assembly is provided between the lower end of the push sleeve and the tapered member, and the sealing assembly is fixedly connected to the lower end of the push sleeve; when the second shear pin is cut off, the push sleeve can move downward relative to the tapered member to push the sealing assembly to sit between the tapered member and the upper sleeve.

10. The tailpipe hanger with an enhanced locking device according to claim 4, characterized in that, The clamping device includes a plurality of flexible clamping arms distributed along the circumferential direction, and the ends of the flexible clamping arms are connected to the convex block of the tapered member and the push sleeve through the first shear pin.

11. The tailpipe hanger with an enhanced locking device according to claim 2, characterized in that, The floating cone locking assembly further includes a clamping member connected to the lower end of the cone member. The clamping member includes multiple clamping arms located between the suspension body and the drive assembly. The multiple clamping arms achieve a locking connection between the floating cone locking assembly and the suspension body under the limiting action of the drive assembly.

12. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that, The drive assembly includes a spacer assembly, a pull ring connected to the spacer assembly, a plurality of pull rods connected to the pull ring, and a piston sleeve; wherein the pull ring is connected to the radially inner surface of the lower end of the spacer assembly, thereby forming a space between the suspension body, the pull ring, and the spacer assembly for accommodating the movement of the piston sleeve, the lower end of the piston sleeve is fixedly connected to the pull ring and forms a second pressure chamber between the piston sleeve, the pull ring, and the suspension body; wherein the plurality of pull rods extend downward along the suspension body until they are located below a portion of the suspension slip assembly, and when the second pressure chamber is pressured, the piston sleeve moves upward, causing the pull ring and the plurality of pull rods connected to the pull ring to move upward, thereby unlocking the suspension slip assembly.

13. The tailpipe hanger with an enhanced locking device according to claim 12, characterized in that, The suspension slip assembly includes a sleeve clamp, a suspension slip, and a movable locking ring. The upper end of the sleeve clamp is fixedly connected to the suspension slip, and the sleeve clamp is disposed between the suspension slip and the suspension body. When the suspension slip assembly is locked, the movable locking ring is located between the lower end of the sleeve clamp and the suspension slip to lock the sleeve clamp onto the suspension body. When the suspension slip assembly is unlocked, the movable locking ring moves away from the lower end of the sleeve clamp, and the sleeve clamp separates from the suspension body.

14. The tailpipe hanger with an enhanced locking device according to claim 13, characterized in that, The sleeve clamp is provided with a plurality of flexible claws evenly distributed along the circumference; when the suspension slip assembly is locked, the movable locking ring fixes the flexible claws in the concave groove of the suspension body; when the suspension slip assembly is unlocked, the flexible claws are released from the concave groove.

15. The tailpipe hanger with an enhanced locking device according to claim 14, characterized in that, When the drive assembly is activated, the pull rod moves upward to abut against the movable locking ring, thereby causing the movable locking ring to move upward and release the flexible pawl from the concave groove, thereby unlocking the suspension slip assembly.

16. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that, The suspension body is provided with a first conical surface and a second conical surface at the positions where it is fitted onto the suspension slip assembly and the fixed slip assembly. The contact surface between the first conical surface and the slip arm of the suspension slip assembly is provided with interlocking teeth, and the contact surface between the second conical surface and the slip arm of the fixed slip assembly is provided with interlocking teeth.

17. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that, The slip arm of the suspension slip assembly and the slip arm of the fixed slip assembly are provided with engagement teeth that can engage with the inner wall of the sleeve, away from the outer surface of the suspension body.

18. The tailpipe hanger with an enhanced locking device according to claim 1, characterized in that, The suspension slip assembly and the fixed slip assembly each include a guide rail for receiving their slip arms; before being seated, the slip arms are received in the guide rails; during seating, the slip arms disengage from the guide rails.

19. The tailpipe hanger with an enhanced locking device according to claim 17, characterized in that, The guide rails of the suspension slip assembly and the fixed slip assembly are aligned longitudinally, and an axial groove is formed between adjacent guide rails to accommodate a portion of the drive assembly.

20. A method of operating a tailpipe hanger with an enhanced locking device according to any one of claims 1-19, comprising the following steps: The suspension slip assembly, fixed slip assembly, drive assembly, floating cone locking assembly, and locking assembly are sequentially fitted onto the outer wall of the hanger body. The insertion tool is connected to and locked to the hanger body. The tailpipe or tailpipe string is connected to the hanger body and the connected tailpipe hanger and tailpipe or tailpipe string are inserted into the well. The mounting of the tailpipe suspension includes: disconnecting the connection between the floating cone locking assembly and the locking assembly through a first-stage pressure release, unlocking the locking assembly, moving the locking assembly upward relative to the suspension body, and after the locking assembly moves upward a certain distance, realizing the linkage between the floating cone locking assembly and the locking assembly; activating the drive component through a second-stage pressure release to unlock the suspension slip assembly and realize the mounting of the suspension slip assembly; Lower the tailpipe hanger, apply appropriate downward weight to the locking assembly, and then sequentially transfer it downward to the floating cone locking assembly, the drive assembly, and the fixed slip assembly, thereby achieving the mounting of the fixed slip assembly; after the construction work is completed, disconnect the connection between the feeding tool and the hanger body, and remove the feeding tool.

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