A high temperature and high pressure resistant bushing head and a control system thereof

Abstract

The present application relates to the technical field of casing head, in particular to a high-temperature and high-pressure resistant casing head and a control system thereof, the high-temperature and high-pressure resistant casing head comprises a pipe joint with a central hole, and further comprises an annular slip, the slip is formed by connecting a plurality of arc segments in a head-to-tail manner, the end faces of both ends of each arc segment are inclined faces, the inclined faces of the opposite ends of the adjacent two arc segments are mutually attached, and the opposite ends of the adjacent two arc segments are connected in a sliding manner, the slip is movably arranged along the central hole in an axial direction, a pushing system for pushing the slip to move along the central hole in an axial direction is arranged in the pipe joint, the outer side face of the slip is a conical face, the central hole comprises a conical hole segment in extrusion fit with the outer side face of the slip, and when the slip moves along the central hole in an axial direction, each arc segment can move inward or outward along the radial direction of the slip to realize the reduction or increase of the inner diameter of the slip. The present application solves the technical problems of inconvenient slip installation and casing damage in the prior art.

Description

Technical Field

[0001] This invention relates to the field of bushing head technology, specifically to a high-temperature and high-pressure resistant bushing head and its control system. Background Technology

[0002] The casing head is used to connect the wellhead casing string, seal the annular space between each casing layer, and provide a transition connection for installing blowout preventers, tubing heads, and Christmas trees. The casing head is a crucial connecting component between the casing and the wellhead equipment. Its lower end is connected to the surface casing via threads, and its upper end is connected to the wellhead equipment or blowout preventer via flanges or clamps. Casing heads are generally made of 35 or 42CrMo high-quality alloy structural steel. A casing hanger is also installed inside the casing head to suspend the casing string of the appropriate size and seal the annular space.

[0003] Currently, casing hangers are mainly divided into two categories: mandrel type and slip type. A casing head with an internal mandrel-type hanger is called a mandrel-type casing head, and a casing head with an internal slip type hanger is called a slip type casing head. The connection between the mandrel-type casing head and the casing is a threaded connection, while the connection between the slip type casing head and the casing is a slip connection. Slip type hangers include types such as G, W, WD, and WE. The WD type hanger is used to connect the casing head and the outer casing; it uses external force to make the slip teeth grip the casing. The W type hanger uses a weight-activated seal structure, while the WE and G types are manually activated seal structures.

[0004] In existing technologies, the main structure of a slip-type casing head consists of a tubing tee, oil layer casing, flange bolts, injection-molded reducing flange, sealing gasket, slip-type hanger, casing head body, and technical casing assembly. The advantages of the slip-type casing head include flexible control of casing height during casing installation. Since the slip-type hanger can be installed after cementing operations, it greatly avoids the risk of casing jamming due to installation time constraints. Its superior features, such as free control of casing height, have led to its widespread adoption.

[0005] The installation and removal of slips in existing slip-type bushing heads is quite cumbersome. To achieve this, the bushing head is divided into upper and lower parts, significantly increasing the number of parts and installation steps. Furthermore, to allow for adjustment of the slip radius, the slip is composed of multiple arc-shaped segments with a large gap between adjacent segments. During use, the slip segments clamp the bushing tightly, resulting in uneven stress on the bushing and making it more prone to damage. When the bushing rotates, the gap between adjacent slip segments can cause irreversible damage to the outer side of the bushing. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention proposes a high-temperature and high-pressure resistant bushing head and its control system to solve the technical problems of inconvenient installation of slips and easy damage to bushings in existing technologies.

[0007] The present invention provides a high-temperature and high-pressure resistant bushing head and its control system, which adopts the following technical solution:

[0008] A high-temperature and high-pressure resistant bushing head and its control system include a pipe joint with a central hole and a slip disposed within the central hole. The slip is annular and is composed of multiple arc-shaped segments connected end to end. The end faces of each arc-shaped segment are inclined surfaces, and the inclined surfaces at both ends of each arc-shaped segment are inclined to the same side along the circumference of the slip. The inclined surfaces at opposite ends of two adjacent arc-shaped segments fit together, and the opposite ends of two adjacent arc-shaped segments are slidably connected. The slip is movably disposed along the axial direction of the central hole. The pipe joint is provided with a pushing system for pushing the slip to move axially along the central hole. The outer surface of the slip is conical. The central hole includes a conical hole segment that is pressed and fitted with the outer surface of the slip. When the slip moves axially along the central hole, each arc-shaped segment can move radially inward or outward along the slip to reduce or increase the inner diameter of the slip.

[0009] Furthermore, the hydraulic jacking system includes a jacking piston telescopically disposed within the pipe joint, and a control oil circuit opened within the pipe joint. The control oil circuit is used to drive the jacking piston to extend and retract. The extension of the jacking piston is used to push the slip to move axially along the central hole, so that each arc-shaped segment of the slip moves toward the center of the slip, thereby reducing the inner diameter of the slip.

[0010] Furthermore, a groove is provided on one end face of each arc segment, and a slider is fixed on the other end face. The slider on one arc segment is slidably installed in the groove on another arc segment. The opposite ends of two adjacent arc segments are slidably connected through the slider and the groove. A stop block is connected in the groove of each arc segment. The stop block is detachably connected in the groove by fastening screws. The stop block is located at one end of the groove and is used to prevent the slider from falling off from one end of the groove.

[0011] Furthermore, the slider and the stop are wedge-shaped blocks, and the groove is a constricting groove to prevent the slider from falling out of the groove.

[0012] Furthermore, the inclination angle of the inclined surface of each arc segment is greater than 65°, and the inclination angle is the angle between the inclined surface and the radius of the end of the chuck that passes through the inclined surface toward the center of the chuck.

[0013] Furthermore, the inclination angle of the inclined surface of each arc segment is between 65° and 90°.

[0014] Furthermore, the central hole of the pipe joint extends in the vertical direction, and the slip is movably disposed in the central hole in the vertical direction. There are two slips spaced vertically, with the upper slip on the upper side and the lower slip on the lower side. The conical hole section has two sections, which correspond to the upper slip and the lower slip respectively. The inclined surfaces at both ends of the arc-shaped sections of the upper slip are in the opposite direction to the inclined surfaces at both ends of the arc-shaped sections of the lower slip.

[0015] Furthermore, the lower side of the upper latch is provided with a plurality of upper spring pieces spaced apart along the circumference of the upper latch, and the plurality of upper spring pieces are inclined in the same direction along the circumference of the upper latch. The upper side of the lower latch is provided with a plurality of lower spring pieces spaced apart along the circumference of the lower latch, and the plurality of lower spring pieces are inclined in the same direction along the circumference of the lower latch. The upper spring pieces and the lower spring pieces are arranged in a one-to-one correspondence, and the inclination directions of the upper spring pieces and the lower spring pieces are opposite. The upper spring pieces and the lower spring pieces are interlocked with each other.

[0016] Furthermore, two push pistons are provided: an upper push piston and a lower push piston. The upper push piston is positioned above the upper slip and is used to push the upper slip downward. When the upper slip moves downward, each arc-shaped segment of the upper slip moves towards the center of the upper slip to reduce the inner diameter of the upper slip. The lower push piston is positioned on the radial side of the lower slip. The radial side of the lower slip is provided with a push inclined surface that cooperates with the push piston. The lower push piston pushes the lower slip radially, causing the lower slip to move downward. Each arc-shaped segment of the lower slip moves towards the center of the lower slip to reduce the inner diameter of the lower slip.

[0017] A control system for a high-temperature and high-pressure bushing head includes the aforementioned high-temperature and high-pressure bushing head and a controller. When the bushing extends into the pipe joint and into the slip, the controller controls the pushing system of the high-temperature and high-pressure bushing head to push the slip along the axial direction of the central hole, thereby reducing the inner diameter of the slip to grip the bushing tightly.

[0018] The beneficial effects of this invention are as follows: The high-temperature and high-pressure bushing head and its control system of this invention allow for the reduction and expansion of the inner diameter of the clamp within the bushing joint. During installation, the clamp is reduced to its minimum size and then inserted into the central hole from the lower end of the bushing joint. This allows the bushing joint to be designed as a single unit, eliminating the need for a separate structure and simplifying the clamp installation process. Simultaneously, each arc-shaped segment of the clamp fits snugly against the others. As the inner hole of the clamp expands or shrinks, the inclined surfaces of adjacent arc-shaped segments maintain contact without significant gaps. When the bushing is held tightly by the clamp, the force on the outer side of the bushing is evenly distributed, reducing the risk of damage. Furthermore, under the weight of the bushing itself, the bushing, carrying the clamp, tends to move downwards, further securing the clamp to the outer wall of the bushing.

[0019] Furthermore, the present invention is provided with two slips, which double-lock the sleeve, and the inclined directions of the inclined surfaces at both ends of each arc segment of the two slips are opposite. Once the sleeve rotates, one of the two slips will always hold the outer wall of the sleeve tightly, and the sleeve will not be loosened due to the rotation of the sleeve. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0021] Figure 1 This is a three-dimensional schematic diagram of a first embodiment of a high-temperature and high-pressure resistant bushing head according to the present invention;

[0022] Figure 2 This is a front view of a first embodiment of a high-temperature and high-pressure resistant bushing head according to the present invention;

[0023] Figure 3 for Figure 2 Sectional view along line AA;

[0024] Figure 4 for Figure 3 A magnified view of a local area X in the middle;

[0025] Figure 5 This is a three-dimensional schematic diagram of the upper and lower slips in the initial state of the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0026] Figure 6 This is a front view of the upper and lower slips in the initial state of the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0027] Figure 7 for Figure 6 Sectional view along the BB direction;

[0028] Figure 8 for Figure 7 A magnified schematic diagram of a local area Y;

[0029] Figure 9 This is a three-dimensional schematic diagram of one arc-shaped section of the upper slip in the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0030] Figure 10 This is a front view of one arc-shaped section of the upper slip in the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0031] Figure 11 This is a three-dimensional schematic diagram from another direction of one arc-shaped segment of the upper slip in the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0032] Figure 12 This is a three-dimensional schematic diagram of the upper slip in a reduced state in the first embodiment of the high-temperature and high-pressure bushing head of the present invention;

[0033] Figure 13 This is a top view of the upper slip in a reduced state in the first embodiment of the high temperature and high pressure bushing head of the present invention;

[0034] Figure 14 This is a top view of the upper slip in an enlarged state in the first embodiment of the high temperature and high pressure bushing head of the present invention;

[0035] Figure 15 This is a three-dimensional schematic diagram of the stop block in the first embodiment of a high-temperature and high-pressure bushing head according to the present invention.

[0036] In the diagram: 100, pipe fitting; 101, connecting stud; 102, connecting flange; 103, mating flange; 104, oil inlet; 105, push piston; 200, upper slip; 201, upper corrugated teeth; 202, upper spring; 203, stop block; 204, first slide groove; 205, first slider; 210, lower slip; 211, lower corrugated teeth; 212, lower spring. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The serial numbers assigned to components in this document, such as "first," "second," etc., are merely used to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] A first embodiment of the high-temperature and high-pressure resistant bushing head of the present invention, as follows: Figures 1 to 15 As shown, the high-temperature and high-pressure casing head includes a pipe joint 100 with a central hole and slips disposed within the central hole. For better description of the invention, the axis of the central hole is defined as running vertically, and the central axis of the pipe joint 100 extends vertically as well. The upper end of the pipe joint 100 is provided with a connecting stud 101, and the lower end is provided with a mating flange 103, which is used for connection with other pipelines or oil production equipment. A radially communicating hole and a connecting flange 102 are provided on one side of the pipe joint 100, which is used for connecting other pipelines. In use, the casing in the oil well extends from the lower end of the pipe joint 100 into the central hole, and the slips within the central hole grip the outer wall of the casing, thereby achieving connection between the casing and the pipe joint 100.

[0041] In this embodiment, two clamps are provided, namely an upper clamp 200 and a lower clamp 210. The upper clamp 200 and the lower clamp 210 have basically the same structure. Both the upper clamp 200 and the lower clamp 210 are annular and are composed of multiple arc-shaped segments connected end to end. The end faces of each arc-shaped segment of the upper clamp 200 and the lower clamp 210 are inclined surfaces. The inclined surfaces at both ends of each arc-shaped segment are inclined to the same side along the circumference of the clamp. The inclined surfaces at both ends of each arc-shaped segment of the upper clamp 200 are in the opposite direction to the inclined surfaces at both ends of each arc-shaped segment of the lower clamp 210. In this embodiment, the inclined surfaces at both ends of each arc-shaped segment of the upper slip 200 are inclined counterclockwise along the circumference of the upper slip 200 (counterclockwise here refers to looking down from above the pipe joint 100), and the inclined surfaces at both ends of each arc-shaped segment of the lower slip 210 are inclined clockwise along the circumference of the lower slip 210. The inclined surfaces at opposite ends of two adjacent arc-shaped segments of each slip are in contact with each other, and the opposite ends of two adjacent arc-shaped segments are slidably connected. In this invention, both slips are movably arranged along the central hole axially. At the same time, the pipe joint 100 is provided with a pushing system for pushing the two slips to move axially along the central hole respectively. The outer surfaces of both slips are conical surfaces, and the central hole includes conical hole segments that are respectively pressed and fitted with the outer surfaces of each slip. When the two slips move axially along the central hole, under the cooperation of the conical hole section and the conical surface, each arc-shaped segment can move radially inward or outward along the corresponding slip, thereby reducing or increasing the inner diameter of the two slips. The reduction in the inner diameter of the two slips causes them to grip the sleeve tightly. In this embodiment, to increase the friction between the slips and the outer wall of the sleeve, the inner side of each arc-shaped segment of the two slips is provided with corrugated teeth. The corrugated teeth on the inner side of the upper slip 200 are upper corrugated teeth 201, and the corrugated teeth on the inner side of the lower slip 210 are lower corrugated teeth 211.

[0042] In this embodiment, the hydraulic jacking system includes a jacking piston 105 telescopically disposed within the pipe joint 100, and a control oil circuit opened within the pipe joint 100. The control oil circuit is used to drive the extension and retraction of the jacking piston 105. The outer side of the pipe joint 100 has an oil inlet 104 connected to the control oil circuit. Hydraulic oil is introduced into the control oil circuit through the oil inlet 104, thereby driving the jacking piston 105 to extend. Two push pistons 105 are provided, namely an upper push piston and a lower push piston. The upper push piston is located above the upper slip 200 and is used to push the upper slip 200 downward. When the upper slip 200 moves downward, each arc segment of the upper slip 200 moves towards the center of the upper slip 200 to reduce the inner diameter of the upper slip 200. The lower push piston is located on the radial side of the lower slip 210. The radial side of the lower slip 210 is provided with a push inclined surface that cooperates with the push piston. The lower push piston pushes the lower slip 210 radially, causing the lower slip 210 to move downward. Each arc segment of the lower slip 210 moves towards the center of the lower slip 210 to reduce the inner diameter of the lower slip 210.

[0043] In this embodiment, a groove is formed on one end face of each arc segment, and a slider is fixed on the other end face. The groove on the upper clamp 200 is the first groove 204. The slider on one arc segment is slidably installed in the groove on another arc segment. The opposite ends of two adjacent arc segments are slidably connected by the slider and the groove. In this embodiment, the groove on the lower clamp 210 is the second groove, the slider on the upper clamp 200 is the first slider 205, and the slider on the lower clamp 210 is the second slider. A stop 203 is connected to the groove of each arc segment. The stop 203 in the first groove 204 is the first stop, and the stop 203 in the second groove is the second stop. In this embodiment, the stop 203 is detachably connected to the corresponding groove by fastening screws. The stop 203 is located at one end of the groove and is used to prevent the slider from falling off from one end of the groove. The slider and the stop 203 are wedge-shaped blocks, and the groove is a constricting groove to prevent the slider from falling out of the groove.

[0044] In this embodiment, the inclination angle of the inclined surface of each arc segment is greater than 65°. The inclination angle is the angle between the inclined surface and the radius of the end of the slip that passes through the inclined surface towards the center of the slip. The inclination angle of the inclined surface of each arc segment is between 65° and 90°, so that when each arc segment of each slip moves towards the center of the slip, the inclined surfaces of adjacent arc segments can always contact each other, and the contact area will change.

[0045] In this embodiment, the lower side of the upper latch 200 is provided with a plurality of upper spring pieces 202 spaced apart along the circumference of the upper latch 200. The plurality of upper spring pieces 202 are inclined in the same direction along the circumference of the upper latch 200. The upper side of the lower latch 210 is provided with a plurality of lower spring pieces 212 spaced apart along the circumference of the lower latch 210. The plurality of lower spring pieces 212 are inclined in the same direction along the circumference of the lower latch 210. The upper spring pieces 202 and the lower spring pieces 212 are arranged in a one-to-one correspondence, and the inclination directions of the upper spring pieces 202 and the lower spring pieces 212 are opposite. The upper spring pieces 202 and the lower spring pieces 212 are interlocked with each other.

[0046] This invention discloses a control system for a high-temperature and high-pressure bushing head, comprising the aforementioned high-temperature and high-pressure bushing head and a controller (not shown here). When the bushing extends into the pipe joint 100 and into the slip, the controller can control the pushing system of the high-temperature and high-pressure bushing head to move, causing the pushing piston 105 of the pushing system to push the slip along the axial direction of the central hole, thereby reducing the inner diameter of the slip to grip the bushing tightly.

[0047] This invention provides a high-temperature and high-pressure resistant sleeve head. When assembling the upper slip 200 and lower slip 210, it is only necessary to reduce the inner diameter of the upper slip 200 and lower slip 210 to their minimum. Then, the two slips are inserted into the central hole from the lower end of the pipe connector 100. After the two slips enter the conical section of the central hole, they are slightly spread apart so that they are contained within the conical section of the central hole. This allows the pipe connector 100 to be configured as a single unit, eliminating the need for a separate structure and simplifying the slip installation process. Simultaneously, each arc-shaped segment of each slip fits snugly against the others. As the inner hole of the slip expands or contracts, the inclined surfaces of adjacent arc-shaped segments maintain contact without significant gaps. When the sleeve is held tightly by the slips, the force on the outer side of the sleeve is evenly distributed, reducing the risk of damage to the outer side of the sleeve.

[0048] In operation, the casing in the oil well extends from the lower end of the pipe joint 100 into the central bore and passes through the upper and lower slips. Initially, the inner diameter of the two slips is slightly smaller than the outer wall of the casing. Simultaneously, the two jacking pistons 105 of the jacking system avoid the two slips. The upper and lower ends of the two slips are chamfered, allowing the casing to smoothly enter the two slips during insertion into the central bore. The casing then pushes the two slips outward. Once the casing's position in the pipe joint 100 is determined, the two jacking pistons 105 are activated. The upper jacking piston pushes the upper slip 200 downward, and the lower jacking piston pushes the lower slip 210 radially inward. Guided by the conical bore section and conical surface, both the upper slip 200 and lower slip 210 move downward. The arc-shaped sections of the two slips move towards the center of the slips, causing both slips to shrink and grip the outer wall of the casing. In addition, under the weight of the casing itself, the casing, along with the two slips, tends to move downwards, which makes the two slips hold the outer wall of the casing more firmly.

[0049] Furthermore, under the action of the spring clips between the upper slip 200 and the lower slip 210, the two slips can maintain a certain distance in the initial state. When the upper slip 200 and the lower slip 210 grip the outer wall of the sleeve, the upper spring clip 202 and the lower spring clip 212 interlock to connect the two slips, thus achieving double clamping of the sleeve. Moreover, the inclination directions of the inclined surfaces at both ends of each arc segment of the two slips are opposite. Once the sleeve rotates, one of the two slips will always grip the outer wall of the sleeve, and will not loosen due to the rotation of the sleeve.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature and high-pressure resistant bushing head, comprising a pipe fitting (100) having a central hole, and a slip disposed within the central hole, characterized in that: The slip is annular and is composed of multiple arc-shaped segments connected end to end. The end faces of each arc-shaped segment are inclined surfaces, and the inclined surfaces of each arc-shaped segment are inclined to the same side along the circumference of the slip. The inclined surfaces of the opposite ends of two adjacent arc-shaped segments fit together, and the opposite ends of two adjacent arc-shaped segments are slidably connected. The slip is movably arranged along the central hole. The pipe joint (100) is provided with a pushing system for pushing the slip to move along the central hole. The outer surface of the slip is a conical surface. The central hole includes a conical hole segment that is pressed and fitted with the outer surface of the slip. When the slip moves along the central hole, each arc-shaped segment can move radially inward or outward along the slip to reduce or increase the inner diameter of the slip.

2. The high-temperature and high-pressure resistant bushing head according to claim 1, characterized in that: The hydraulic jacking system includes a jacking piston (105) telescopically disposed within a pipe joint (100), and a control oil circuit opened within the pipe joint (100). The control oil circuit is used to drive the jacking piston to extend and retract, and the jacking piston (105) extends to jack the slip to move axially along the central hole.

3. The high-temperature and high-pressure resistant bushing head according to claim 2, characterized in that: Each arc segment has a groove on one end face and a slider fixed on the other end face. The slider on one arc segment is slidably installed in the groove on another arc segment. The opposite ends of two adjacent arc segments are slidably connected by the slider and the groove. Each arc segment has a stop (203) connected in the groove. The stop (203) is detachably connected in the groove by fastening screws. The stop (203) is located at one end of the groove and is used to prevent the slider from falling off from one end of the groove.

4. The high-temperature and high-pressure resistant bushing head according to claim 3, characterized in that: The slider and the stop (203) are wedge-shaped blocks, and the groove is a constricting groove to prevent the slider from falling out of the groove.

5. The high-temperature and high-pressure resistant bushing head according to claim 1, characterized in that: The inclination angle of the inclined surface of each arc segment is greater than 65°, and the inclination angle is the angle between the inclined surface and the radius of the end of the chuck that passes through the inclined surface toward the center of the chuck.

6. The high-temperature and high-pressure resistant bushing head according to claim 5, characterized in that: The inclination angle of the inclined surface of each arc segment is between 65° and 90°.

7. The high-temperature and high-pressure resistant bushing head according to claim 3, characterized in that: The central hole of the pipe joint (100) extends in the vertical direction, and the slip is movably disposed in the central hole in the vertical direction. There are two slips arranged at intervals, with the upper slip (200) on the upper side and the lower slip (210) on the lower side. The conical hole section has two sections, which correspond to the upper slip (200) and the lower slip (210) respectively. The inclined surfaces at both ends of each arc segment of the upper slip (200) are in the opposite direction to the inclined surfaces at both ends of each arc segment of the lower slip (210).

8. The high-temperature and high-pressure resistant bushing head according to claim 7, characterized in that: The lower side of the upper latch (200) is provided with a plurality of upper spring pieces (202) spaced apart along the circumference of the upper latch (200). The plurality of upper spring pieces (202) are inclined in the same direction along the circumference of the upper latch (200). The upper side of the lower latch (210) is provided with a plurality of lower spring pieces (212) spaced apart along the circumference of the lower latch (210). The plurality of lower spring pieces (212) are inclined in the same direction along the circumference of the lower latch (210). The upper spring pieces (202) and the lower spring pieces (212) are arranged in a one-to-one correspondence, and the inclination directions of the upper spring pieces (202) and the lower spring pieces (212) are opposite. The upper spring pieces (202) and the lower spring pieces (212) are interlocked.

9. The high-temperature and high-pressure resistant bushing head according to claim 8, characterized in that: Two push pistons (105) are provided, namely an upper push piston and a lower push piston. The upper push piston is located above the upper slip (200) and is used to push the upper slip (200) downward. When the upper slip (200) moves downward, each arc segment of the upper slip (200) moves toward the center of the upper slip (200) to reduce the inner diameter of the upper slip (200). The lower push piston is located on the radial side of the lower slip (210). The radial side of the lower slip (210) is provided with a push inclined surface that cooperates with the push piston. The lower push piston pushes the lower slip (210) radially, causing the lower slip (210) to move downward. Each arc segment of the lower slip (210) moves toward the center of the lower slip (210) to reduce the inner diameter of the lower slip (210).

10. A control system for a high-temperature and high-pressure resistant bushing head, characterized in that: The high-temperature and high-pressure bushing head and controller as described in any one of claims 1-9 are provided. When the bushing extends into the pipe joint (100) and into the slip, the controller controls the pushing system of the high-temperature and high-pressure bushing head to push the slip along the axial direction of the central hole, thereby reducing the inner diameter of the slip so that the slip grips the bushing tightly.

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