Casing head assembly

Abstract

The application provides a casing head assembly, and belongs to the field of petroleum equipment. The casing head assembly comprises a lower casing head unit, an upper casing head unit, a lower positioning assembly and an upper positioning assembly. The upper casing head unit is adapted to butt joint with the lower casing head unit, has a second slip hanger, and the second slip hanger has a movable gap with the inner wall of the upper casing head unit; the lower positioning assembly is arranged at the lower end of the upper casing head unit and is provided with a driving block for controlling the up-down movement of the upper slip; the upper slip of the upper positioning assembly is arranged at the lower positioning assembly and moves along the radial direction of the casing head with the lower positioning assembly, and the upper slip can slide along the axial direction of the casing head relative to the lower positioning assembly. The second slip hanger is directly positioned with the first slip hanger through the lower positioning assembly and the upper positioning assembly, so as to ensure the concentricity of the casing and reduce the butt joint precision requirement of the upper casing head unit and the lower casing head unit, and the limiting of the slips of the first slip hanger is realized.

Description

Technical Field

[0001] This application belongs to the field of petroleum equipment technology, and more specifically, relates to a casing head assembly. Background Technology

[0002] A casing head is a device used to suspend casing in oil and gas wells. Typically, multiple layers of casing are installed in each well, so multiple casing heads need to be connected in series at the wellhead. Each casing head uses a hanger to suspend the layers of casing inside.

[0003] Since each layer of bushing is suspended from a different bushing head, accurate alignment of the bushing heads is required during installation to ensure high concentricity. However, due to the significant weight of the bushing heads and the fact that they are typically lifted using hoisting equipment, controlling their position is difficult. Achieving the required alignment precision is extremely challenging and time-consuming. Summary of the Invention

[0004] In view of this, the present application provides a sleeve head assembly to solve the technical problem in the prior art that it is difficult and time-consuming to ensure the concentricity of the sleeve by controlling the docking accuracy of the sleeve head.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] On the one hand, a casing head assembly is provided, comprising:

[0007] The lower-level casing head unit has a first slip hanger, and the upper end of the slip of the first slip hanger has a first outer bevel.

[0008] The upper-level sleeve head unit is adapted to dock with the lower-level sleeve head unit and has a second slip hanger. There is a movable gap between the second slip hanger and the inner wall of the upper-level sleeve head unit, and the lower end of the slip seat of the slip hanger has a second outer bevel. The width of the movable gap is greater than the maximum offset distance between the central axes of the upper-level sleeve head unit and the lower-level sleeve head unit when they dock.

[0009] The lower positioning component is located at the lower end of the upper sleeve head unit and can move radially along the sleeve head. The lower positioning component is provided with a lower clamping head, and the lower end of the lower clamping head is provided with a first inner inclined surface that is adapted to the first outer inclined surface.

[0010] The upper positioning component includes a drive block and an upper clamping head; the upper clamping head is disposed on the lower positioning component and moves radially along the sleeve head with the lower positioning component, and the upper clamping head can slide axially relative to the lower positioning component along the sleeve head; the upper end of the upper clamping head is provided with a second inner inclined surface adapted to the second outer inclined surface; the lower positioning component is provided with an inner sliding hole along the radial direction of the sleeve head, the drive block is slidably installed in the inner sliding hole, and the drive block cooperates with the lower inclined surface of the upper clamping head to control the up and down movement of the upper clamping head;

[0011] During assembly, the lower positioning component moves radially inward along the sleeve head to make the first inner inclined surface fit with the first outer inclined surface, limiting the slip of the first slip hanger and positioning the upper clamp head and the first slip hanger radially in the sleeve head; then, when the second slip hanger is installed into the upper sleeve head unit, the second slip hanger fits with the second inner inclined surface through the second outer inclined surface, supporting the upper clamp head to achieve radial positioning in the sleeve head; the driving block moves radially outward along the sleeve head, controlling the upper clamp head to move axially downward along the sleeve head, so that the second slip hanger is installed downward into place.

[0012] In some embodiments, the lower end of the upper sleeve head unit is provided with a plurality of lower positioning components distributed circumferentially, and each lower positioning component is provided with a corresponding upper positioning component.

[0013] In some embodiments, the lower positioning component includes:

[0014] A radial slider is located at the lower end of the upper-level sleeve head unit and slides radially along the sleeve head;

[0015] The main screw is radially threaded to the lower end of the upper sleeve head unit and drives the radial slider.

[0016] The lower clamp is fixed to the bottom of the radial slider, and its lower end is adapted to the first outer inclined surface.

[0017] In some embodiments, the top of the radial slider is provided with a mounting hole along the axial direction of the sleeve head, and the lower end of the upper clamp is slidably inserted into the mounting hole;

[0018] The inner sliding hole is provided on the radial slider and communicates with the mounting hole; the driving block is slidably arranged in the inner sliding hole, and the driving block cooperates with the lower end inclined surface of the upper clamping head to control the up and down movement of the upper clamping head;

[0019] The main screw is internally threaded with an internal screw rod, which extends into the internal sliding hole and drives the drive block.

[0020] In some embodiments, the slip seat of the second slip hanger includes:

[0021] The second bottom ring has the second outer bevel at its lower end;

[0022] The second upper seat is located above the second bottom ring;

[0023] The second sealing assembly is disposed between the second bottom ring and the second upper seat body, and includes a second inner sealing ring and a second outer sealing ring.

[0024] The second inner sealing ring is axially compressed by the second upper seat and the second bottom ring, and deforms inward to seal with the inner wall of the upper sleeve head unit; the second outer sealing ring is axially compressed by the second upper seat and the second bottom ring, and deforms outward to seal with the oil sleeve.

[0025] In some embodiments, a plurality of second guide posts are distributed circumferentially on the top of the second bottom ring, and a plurality of second guide holes are provided correspondingly on the bottom of the second upper body. The second guide posts are inserted into the second guide holes to guide the second bottom ring and the second upper body axially along the sleeve head.

[0026] The second inner sealing ring is located inside the annulus formed by each of the second guide posts, and the outer periphery of the second inner sealing ring is constrained by each of the second guide posts; the second outer sealing ring surrounds the outer periphery of the annulus formed by each of the second guide posts, and the inner periphery of the second inner sealing ring is constrained by each of the second guide posts; the cross-section of the second outer sealing ring is an outwardly convex C-shape.

[0027] In some embodiments, the slip seat of the first slip hanger includes:

[0028] The first bottom ring has the first outer inclined surface at its lower end;

[0029] The first upper body is located above the first bottom ring;

[0030] The first sealing assembly is disposed between the first bottom ring and the first upper seat body, and includes a first inner sealing ring and a first outer sealing ring.

[0031] The first inner sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming inward to seal with the inner wall of the lower sleeve head unit; the first outer sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming outward to seal with the oil sleeve.

[0032] The beneficial effects of the sleeve head assembly provided in this application embodiment are as follows: Compared with the prior art, the sleeve head assembly in this application embodiment breaks away from the traditional installation method of ensuring sleeve concentricity by improving the docking accuracy. By setting an movable gap between the second slip hanger and the inner wall of the upper sleeve head unit, the second slip hanger no longer relies on the upper sleeve head unit for radial positioning, thereby reducing the docking accuracy requirements between the upper and lower sleeve head units and facilitating construction.

[0033] The lower positioning component is positioned radially on the casing head by fitting the first inner inclined surface and the first outer inclined surface together with the first slip hanger, thus positioning the upper clamp of the upper positioning component and the first slip hanger radially on the casing head; the second slip hanger is positioned radially on the casing head by fitting the second outer inclined surface and the second inner inclined surface together with the upper clamp; thus positioning the second slip hanger and the first slip hanger radially on the casing head ensures the concentricity of the casing.

[0034] Furthermore, the lower clamping head of the lower positioning component can also limit the clamping of the first clamping device by fitting the first inner inclined surface with the first outer inclined surface at the upper end of the clamping surface of the first clamping device through the first inner inclined surface, thus ensuring that the clamping surface of the first clamping device tightly grips the sleeve.

[0035] After the casing heads of each level are connected, the upper clamp of the upper positioning component can be pressed against the second inner inclined surface of the second slip hanger through the second outer inclined surface. This allows the slip hangers of the upper and lower casing heads to be connected into a whole under the action of the upper and lower clamps, ensuring both concentricity and locking of the casing head hangers of each level. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the internal structure of the sleeve head assembly provided in the embodiments of this application;

[0038] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0039] Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0040] Figure 4 for Figure 1 Bottom view of the upper-middle level casing head unit;

[0041] Figure 5 for Figure 1 Top view of the upper-middle bushing head unit;

[0042] The following are the labeling elements in the figure:

[0043] 1-Lower-level sleeve head unit; 11-First slip hanger; 111-First bottom ring; 112-First upper seat body; 113-First inner sealing ring; 114-First outer sealing ring; 12-First outer bevel; 2-Upper-level sleeve head unit; 21-Second slip hanger; 211-Second bottom ring; 212-Second upper seat body; 213-Second inner sealing ring; 214-Second outer sealing ring; 215-Second guide post; 22-Second outer bevel; 23-Movement clearance; 3-Radial slider; 31-Lower chuck; 32-First inner bevel; 33-Main screw; 34-Inner screw; 4-Upper chuck; 41-Drive block; 42-Second inner bevel; 5-Sleeve. Detailed Implementation

[0044] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0045] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0046] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and 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 this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0048] Please refer to the following: Figures 1 to 5 The following describes the sleeve head assembly provided in the embodiments of this application. A sleeve head assembly includes: a lower sleeve head unit, an upper sleeve head unit, a lower positioning component, and an upper positioning component.

[0049] The lower-level casing head unit has a first slip hanger, and the upper end of the slip of the first slip hanger has a first outer bevel. The first slip hanger inside the lower-level casing head unit can refer to the structure of slip hangers on the market, which mainly consists of slips and slip seats, and will not be described in detail here.

[0050] An upper-level casing head unit, suitable for docking with a lower-level casing head unit, has a second slip hanger. There is a movable gap between the second slip hanger and the inner wall of the upper-level casing head unit, and the lower end of the slip seat of the slip hanger has a second outer bevel. The width of the movable gap is greater than the maximum offset distance between the central axes of the upper-level and lower-level casing head units when they dock. The second slip hanger inside the upper-level casing head unit can refer to commercially available slip hanger structures, mainly composed of slips and slip seats, which will not be elaborated here. Compared to traditional slip hangers that only have a small gap inside the casing head (to facilitate positioning of the slip hanger within the casing head by positioning the casing head, see background art), in this application, the inner diameter of the upper-level casing head unit is increased, increasing the width of the movable gap between the second slip hanger and the inner wall of the upper-level casing head unit. The width of the movable gap is equal to the inner radius of the upper-level casing head unit minus the outer radius of the second slip hanger. The width of the movable gap is greater than the maximum offset distance between the central axes of the upper and lower casing head units when they are docked. This ensures that even if the central axes of the upper and lower casing head units reach the maximum offset distance when they are docked, the second slip hanger in the upper casing head unit can still move to a suitable position to align with the first slip hanger in the lower casing head unit, thereby ensuring the concentricity of the casing.

[0051] The lower positioning component is located at the lower end of the upper-level sleeve head unit and can move radially along the sleeve head. The lower positioning component has a lower clamp, and the lower end of the lower clamp has a first inner bevel that matches the first outer bevel. The lower positioning component is mounted at the lower end of the upper-level sleeve head unit via a sliding structure to adjust the radial position of the lower positioning component on the sleeve head, thereby positioning the positioning component mounted on the lower positioning component radially on the sleeve head. The lower end of the lower clamp uses a first inner bevel that matches the first outer bevel of the first slip hanger, which allows the lower positioning component to be positioned radially on the sleeve head via the first slip hanger, and also allows the slip of the first slip hanger to be limited and locked by the lower clamp.

[0052] The upper positioning component includes a drive block and an upper clamping head; the upper clamping head is located on the lower positioning component and moves radially along the sleeve head with the lower positioning component, and the upper clamping head can slide axially relative to the lower positioning component along the sleeve head. The upper end of the upper clamping head is provided with a second inner inclined surface that matches the second outer inclined surface; the lower positioning component is provided with an inner sliding hole along the radial direction of the sleeve head, and the drive block is slidably installed in the inner sliding hole. The drive block cooperates with the lower inclined surface of the upper clamping head to control the up and down movement of the upper clamping head.

[0053] The upper clamp is mounted on the lower positioning assembly and moves radially along the sleeve head with the lower positioning assembly. After the lower positioning assembly and the first slip hanger are positioned radially along the sleeve head, the upper clamp can also be positioned radially along the sleeve head with the first slip hanger. The upper clamp can slide axially along the sleeve head relative to the lower positioning assembly, allowing the upper clamp to rise under the action of the drive block. The second slip hanger is supported by the second inner inclined surface at the upper end, causing the second slip hanger to automatically align with the first slip hanger under the action of the second inner inclined surface. Once the second slip hanger is aligned, the drive block can be controlled to lower the upper clamp, causing the second slip hanger to descend onto the step on the inner wall of the upper sleeve head unit, completing the installation of the second slip hanger.

[0054] During assembly, after the upper-level sleeve head unit and the lower-level sleeve head unit are docked and fixed, the following operations are performed: First, the lower positioning component is moved radially inward along the sleeve head so that the first inner inclined surface and the first outer inclined surface are in contact, thereby limiting the slip of the first slip hanger and positioning the upper clamp and the first slip hanger radially on the sleeve head; then, when the second slip hanger is installed into the upper-level sleeve head unit, the drive block is pushed inward to raise the upper clamp, so that the installed second slip hanger is in contact with the second outer inclined surface and the second inner inclined surface, supported on the upper clamp to achieve radial positioning on the sleeve head; finally, the drive block is moved radially outward along the sleeve head, controlling the upper clamp to move axially downward along the sleeve head so that the second slip hanger is installed downward into place.

[0055] Compared with the prior art, the casing head assembly of this application embodiment, by setting an movable gap between the second slip hanger and the inner wall of the upper casing head unit, makes the second slip hanger no longer rely on the upper casing head unit for radial positioning, thereby reducing the docking accuracy requirements between the upper and lower casing head units and facilitating construction.

[0056] The lower positioning component, through its first inner bevel and first outer bevel, positions itself radially with the first slip hanger at the casing head, thus positioning the upper clamp of the upper positioning component and the first slip hanger radially at the casing head. Similarly, the second slip hanger, through its second outer bevel and second inner bevel, positions itself radially with the upper clamp at the casing head. This radial positioning of the second and first slip hangers ensures the concentricity of the casing. Furthermore, the lower clamp of the lower positioning component, through its first inner bevel, engages with the first outer bevel at the upper end of the slip of the first slip hanger, also limiting the movement of the slip of the first slip hanger and ensuring its tight grip on the casing.

[0057] After the various levels of the casing heads are connected, the upper clamp of the upper positioning component can be pressed against the second inner inclined surface of the second slip hanger via the second outer inclined surface. This allows the slip hangers of the upper and lower casing heads to connect into a single unit under the action of the upper and lower clamps, ensuring both concentricity and locking of the various levels of casing head hangers. In practice, three or more levels of casing heads can be used for connection. The casing head combination structure of this application embodiment is used between adjacent casing heads, allowing the slip hangers in each level of the casing head to connect into a single unit under the action of the upper and lower clamps, thus improving overall stability.

[0058] Please see Figure 4 and Figure 5 As a specific embodiment of the sleeve head assembly provided in this application, the lower end of the upper sleeve head unit has multiple lower positioning components distributed circumferentially, and each lower positioning component is provided with a corresponding upper positioning component.

[0059] In this embodiment, the number of lower positioning components can be three or more, preferably four or more.

[0060] In a practical implementation, the outer side of the upper end of the first slip hanger can be machined into a conical surface to form a first outer inclined surface. Each lower positioning component simultaneously engages with the first outer inclined surface of the first slip hanger through its respective first inner inclined surface, thereby achieving the positioning of each lower positioning component and also limiting the movement of the first slip hanger.

[0061] The outer side of the lower end of the slip seat of the second slip hanger can be machined into a conical surface to form a second outer bevel. The upper clamps on each lower positioning component simultaneously engage with the second outer bevel of the second slip hanger through their respective second inner bevels, thereby achieving the positioning of the second slip hanger.

[0062] Please see Figure 1 and Figure 2 As a specific embodiment of the sleeve head assembly provided in this application, the lower positioning component includes a radial slider and a main screw.

[0063] The radial slider is located at the lower end of the upper-level sleeve head unit and slides radially along the sleeve head. The main screw is threaded to the lower end of the upper-level sleeve head unit radially along the sleeve head and drives the radial slider. The lower clamp is fixed to the bottom of the radial slider, and its lower end is adapted to the first outer inclined surface.

[0064] In this embodiment, the radial slider can slide smoothly along the radial direction of the sleeve head. The main screw drives the radial slider, which can fix the position of the radial slider through self-locking. It is easy to operate and has a strong driving force.

[0065] In practical implementation, a rectangular main sliding hole along the radial direction of the sleeve head is provided on the side wall at the lower end of the upper sleeve head unit. The radial slider is rectangular and is installed in the main sliding hole, giving the radial slider a certain load-bearing capacity. The lower clamp is integrally formed at the bottom of the radial slider.

[0066] Please see Figure 1 and Figure 2 As a specific embodiment of the sleeve head assembly provided in this application, the top of the radial slider is provided with a mounting hole along the axial direction of the sleeve head, and the lower end of the upper clamp is slidably inserted into the mounting hole. An inner sliding hole is provided on the radial slider and communicates with the mounting hole; a driving block is slidably disposed within the inner sliding hole, and the driving block engages with the lower inclined surface of the upper clamp to control the up-and-down movement of the upper clamp. An inner thread is internally connected to the main screw, which extends into the inner sliding hole and drives the driving block.

[0067] In this embodiment, the drive block can slide smoothly along the radial direction of the sleeve head. The drive block is driven by an internal screw, which can fix the position of the drive block by self-locking. It is easy to operate and has a strong driving force.

[0068] In practical implementation, the inner sliding hole and the mounting hole are both rectangular holes, connected at a 90° angle. Correspondingly, the upper chuck and the drive block also have rectangular cross-sections, slidingly installed in the mounting hole and the inner sliding hole, respectively. The upper chuck and the drive block form an inclined contact at the connection point between the mounting hole and the inner sliding hole, allowing the drive block to push the upper chuck upwards when sliding radially inwards along the sleeve head, and the upper chuck to automatically descend when sliding radially outwards along the sleeve head. The internal threaded rod is threaded at the center of the main screw, with its end abutting against the drive block.

[0069] Please see Figure 1 and Figure 2 As a specific embodiment of the sleeve head assembly provided in this application, the slip seat of the second slip hanger includes: a second bottom ring, a second upper seat body, and a second sealing assembly.

[0070] The lower end of the second bottom ring is provided with a second outer bevel; specifically, the outer periphery of the lower end of the second bottom ring can be machined into a conical surface to form the second outer bevel.

[0071] The second upper seat is located above the second bottom ring. The second upper seat is mainly used to cooperate with the slips to clamp the sleeve, which can be referred to as the cooperation between the slips and the slip seat in existing slip hangers.

[0072] The second sealing assembly is located between the second bottom ring and the second upper seat body, and includes a second inner sealing ring and a second outer sealing ring. The second inner sealing ring is axially compressed by the second upper seat body and the second bottom ring, and deforms inward to seal against the inner wall of the upper casing head unit. The second outer sealing ring is axially compressed by the second upper seat body and the second bottom ring, and deforms outward to seal against the oil casing. The second sealing assembly is used to ensure the seal between the second slip hanger and the inner wall of the upper casing head unit and the outer wall of the casing.

[0073] In its implementation, the second bottom ring is annular and supported below the second upper seat. The second sealing assembly is located within the annular space between the second bottom ring and the second upper seat, with the second inner sealing ring located on the inner ring of the annular space and the second outer sealing ring on the outer ring. When the second upper seat is pressed downward by the second slip hanger, it compresses the second inner and outer sealing rings, causing the second inner sealing ring to expand inward and the second outer sealing ring to expand outward, thereby achieving a seal.

[0074] Please see Figure 1 and Figure 2 In one specific embodiment of the sleeve head assembly provided in this application, a plurality of second guide posts are distributed circumferentially on the top of the second bottom ring, and a plurality of second guide holes are correspondingly provided on the bottom of the second upper seat. The second guide posts are inserted into the second guide holes to guide the second bottom ring and the second upper seat axially along the sleeve head. The second guide posts of the second bottom ring are inserted into the second guide holes of the second upper seat for guidance, so that the second bottom ring and the second upper seat can only move relative to each other axially, compressing or releasing the second sealing assembly. Specifically, the number of second guide posts and second guide holes is greater than six and they are evenly distributed.

[0075] The second inner sealing ring is located on the inner side of the ring formed by each of the second guide posts. The outer periphery of the second inner sealing ring is constrained by each of the second guide posts, so that when the second inner sealing ring is squeezed, it deforms more inward and forms a tighter seal with the sleeve.

[0076] The second outer sealing ring surrounds the annular outer side formed by each of the second guide posts, and the inner circumference of the second inner sealing ring is constrained by each of the second guide posts, so that when the second outer sealing ring is squeezed, it deforms more outward and forms a tighter seal with the inner wall of the upper sleeve head unit.

[0077] The cross-section of the second outer sealing ring is a C-shaped protrusion, which improves the ability of the second outer sealing ring to deform outward. This allows the second outer sealing ring to form a good seal even if the width of the movable gap between the second slip hanger and the inner wall of the upper sleeve head unit is large.

[0078] In practice, the maximum extrusion amount of the second inner sealing ring and the second outer sealing ring can be controlled by controlling the difference between the length of the second guide post and the depth of the second guide hole.

[0079] Please see Figure 1 and Figure 3 As a specific embodiment of the sleeve head assembly provided in this application, the slip seat of the first slip hanger includes: a first bottom ring, a first upper seat body, and a first sealing assembly.

[0080] The lower end of the first bottom ring is provided with a first outer bevel; specifically, the outer periphery of the lower end of the first bottom ring can be machined into a conical surface to form the first outer bevel.

[0081] The first upper seat is located above the first bottom ring; the first upper seat is mainly used to cooperate with the slip to hold the sleeve, which can be referred to as the cooperation between the slip and the slip seat in the existing slip hanger.

[0082] The first sealing assembly, located between the first bottom ring and the first upper seat, includes a first inner sealing ring and a first outer sealing ring. The first inner sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming inward to seal against the inner wall of the lower-level casing head unit. The first outer sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming outward to seal against the oil casing. The first sealing assembly ensures the seal between the first slip hanger and the inner wall of the lower-level casing head unit and the outer wall of the casing.

[0083] In its implementation, the first bottom ring is annular and supported below the first upper body. The first sealing assembly is located within the annular space between the first bottom ring and the first upper body, with the first inner sealing ring located on the inner ring of the annular space and the first outer sealing ring on the outer ring. When the first upper body is pressed downwards by the first slip hanger, it compresses the first inner and first outer sealing rings, causing the inner sealing ring to expand inwards and the outer sealing ring to expand outwards, thus achieving a seal.

[0084] More specifically, a guide post can also be used to guide the first bottom ring and the first upper body. For details, refer to the second guide post structure between the second bottom ring and the second upper body.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sleeve head assembly, characterized in that, include: The lower-level casing head unit has a first slip hanger, and the upper end of the slip of the first slip hanger has a first outer bevel. The upper-level sleeve head unit is adapted to dock with the lower-level sleeve head unit and has a second slip hanger. There is a movable gap between the second slip hanger and the inner wall of the upper-level sleeve head unit, and the lower end of the slip seat of the slip hanger has a second outer bevel. The width of the movable gap is greater than the maximum offset distance between the central axes of the upper-level sleeve head unit and the lower-level sleeve head unit when they dock. The lower positioning component is located at the lower end of the upper sleeve head unit and can move radially along the sleeve head. The lower positioning component is provided with a lower clamping head, and the lower end of the lower clamping head is provided with a first inner inclined surface that is adapted to the first outer inclined surface. The upper positioning component includes a drive block and an upper clamping head; the upper clamping head is disposed on the lower positioning component and moves radially along the sleeve head with the lower positioning component, and the upper clamping head can slide axially relative to the lower positioning component along the sleeve head; the upper end of the upper clamping head is provided with a second inner inclined surface adapted to the second outer inclined surface; the lower positioning component is provided with an inner sliding hole along the radial direction of the sleeve head, the drive block is slidably installed in the inner sliding hole, and the drive block cooperates with the lower inclined surface of the upper clamping head to control the up and down movement of the upper clamping head; During assembly, the lower positioning component moves radially inward along the sleeve head to make the first inner inclined surface fit with the first outer inclined surface, limiting the slip of the first slip hanger and positioning the upper clamp head and the first slip hanger radially in the sleeve head; when the second slip hanger is installed into the upper sleeve head unit, the second slip hanger fits with the second inner inclined surface through the second outer inclined surface and is supported on the upper clamp head to achieve radial positioning in the sleeve head; the driving block moves radially outward along the sleeve head and controls the upper clamp head to move axially downward along the sleeve head to make the second slip hanger be installed downward into place.

2. The sleeve head assembly as described in claim 1, characterized in that, The lower end of the upper sleeve head unit has a plurality of lower positioning components distributed circumferentially, and each lower positioning component is provided with a corresponding upper positioning component.

3. The sleeve head assembly as described in claim 1, characterized in that, The lower positioning component includes: A radial slider is located at the lower end of the upper-level sleeve head unit and slides radially along the sleeve head. The main screw is radially threaded to the lower end of the upper sleeve head unit and drives the radial slider. The lower clamp is fixed to the bottom of the radial slider, and its lower end is adapted to the first outer inclined surface.

4. The sleeve head assembly as described in claim 3, characterized in that, The top of the radial slider is provided with a mounting hole along the axial direction of the sleeve head, and the lower end of the upper clamp is slidably inserted into the mounting hole; The inner sliding hole is provided on the radial slider and communicates with the mounting hole; the driving block is slidably arranged in the inner sliding hole, and the driving block cooperates with the lower end inclined surface of the upper clamping head to control the up and down movement of the upper clamping head; The main screw is internally threaded with an internal screw, which extends into the internal sliding hole and drives the drive block.

5. The sleeve head assembly as described in claim 1, characterized in that, The second slip hanger includes: The second bottom ring has the second outer bevel at its lower end; The second upper seat is located above the second bottom ring; The second sealing assembly is disposed between the second bottom ring and the second upper seat body, and includes a second inner sealing ring and a second outer sealing ring. The second inner sealing ring is axially compressed by the second upper seat and the second bottom ring, and deforms inward to seal with the inner wall of the upper sleeve head unit; the second outer sealing ring is axially compressed by the second upper seat and the second bottom ring, and deforms outward to seal with the oil sleeve.

6. The sleeve head assembly as described in claim 5, characterized in that, The top of the second bottom ring is provided with multiple second guide posts distributed circumferentially, and the bottom of the second upper body is provided with multiple second guide holes corresponding to each other. The second guide posts are inserted into the second guide holes to guide the second bottom ring and the second upper body along the sleeve head axial direction. The second inner sealing ring is located inside the annulus formed by each of the second guide posts, and the outer periphery of the second inner sealing ring is constrained by each of the second guide posts; the second outer sealing ring surrounds the outer periphery of the annulus formed by each of the second guide posts, and the inner periphery of the second inner sealing ring is constrained by each of the second guide posts; the cross-section of the second outer sealing ring is an outwardly convex C-shape.

7. The sleeve head assembly as described in claim 1, characterized in that, The first slip hanger includes: The first bottom ring has the first outer inclined surface at its lower end; The first upper body is located above the first bottom ring; The first sealing assembly is disposed between the first bottom ring and the first upper seat body, and includes a first inner sealing ring and a first outer sealing ring. The first inner sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming inward to seal with the inner wall of the lower sleeve head unit; the first outer sealing ring is axially compressed by the first upper seat and the first bottom ring, deforming outward to seal with the oil sleeve.

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