Detachable and reusable casing hanger

Abstract

The utility model discloses a detachable and reusable casing hanger, and belongs to the technical field of oil and gas drilling and production equipment. The hanger aims at solving the problem that an existing hanger cannot be disassembled without damage and reused. The C-shaped casing hanger body is made of an elastic metal material and provided with a notch, and the annular retention sleeve is arranged above the C-shaped casing hanger body. During installation, the retention sleeve is rotated to apply axial pressure to the hanger body, so that the hanger body moves downwards along the inclined surface of the inner wall of the casing head and is tightened in the radial direction, and a casing is clamped; and during disassembly, the retention sleeve is reversely rotated to relieve the pressure, and the hanger body is automatically bounced off and loosened by virtue of self elasticity. The device is simple in structure and convenient to mount and dismount, can realize complete lossless dismounting and reutilization, and remarkably reduces the operation cost and the material consumption.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas drilling and production equipment technology, and in particular to a casing hanger for suspending casing at the wellhead. Background Technology

[0002] In oil and gas drilling operations, the casing hanger is a key component of the wellhead assembly, used to suspend the weight of the casing string in the wellhead and seal the annular space between the casing layers.

[0003] Existing slip-type casing hangers typically consist of multiple separate slip blocks, resulting in a relatively complex structure and a cumbersome installation process. More importantly, these hangers are usually single-use components. When it is necessary to retrieve the casing or remove the wellhead, due to their self-locking principle and the enormous clamping force after setting, destructive methods such as cutting the casing or forcefully prying are often required to remove them, rendering the hanger completely unusable. This not only increases the difficulty and risk of the operation but also results in a huge waste of materials and costs.

[0004] Therefore, the market urgently needs a new type of sleeve hanger that is simple in structure, easy to install, and can be disassembled without damage for reuse. Utility Model Content

[0005] The purpose of this utility model is to solve the technical problems of existing sleeve hangers being complex in structure, unable to be disassembled without damage, and unable to be reused, and to provide a sleeve hanger with a simplified structure, convenient installation, and complete non-destructive disassembly and reuse.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A detachable and reusable casing hanger includes a casing hanger body and a retaining sleeve, which is installed inside the casing head for suspending the casing.

[0008] The casing hanger body is an integral ring structure made of elastic metal material (preferably spring steel). This integrated design replaces the traditional multi-piece slips, simplifying the structure. The ring structure has a C-shaped notch, which gives the body the elastic capacity for radial contraction and expansion. The inner wall of the casing hanger body has slip teeth for clamping the casing, and the outer wall has an outer bevel that mates with the conical cup (i.e., the inner wall slope) of the inner wall of the casing head.

[0009] The retaining sleeve is a ring-shaped structure located above the casing hanger body. Its upper part has a serrated structure that mates with the installation tool for applying rotational torque. By rotating, the retaining sleeve can actively apply or remove axial pressure to the casing hanger body.

[0010] The retaining sleeve is connected to the casing head via threads. During operation, when the retaining sleeve is rotated clockwise, it applies a downward axial pressure to the casing hanger body, forcing the body to slide down along the inclined inner wall of the casing head. Under the action of the tapered inclined surface, the body is forced to contract radially, narrowing its C-shaped notch, while the locking teeth on the inner wall tightly grip and lock the casing, thereby achieving reliable suspension of the entire casing string.

[0011] During disassembly, simply rotate the retaining sleeve in the opposite direction (counterclockwise) to release its downward axial pressure. After the pressure is released, the casing hanger body will automatically expand outward using the elastic potential energy of its material, restoring the notch to its initial width, and the locking teeth will then release the casing. At this point, the casing and all components of the hanger can be easily and completely removed, achieving completely non-destructive disassembly.

[0012] Furthermore, to provide basic sealing and isolation functions under low-pressure or unpressurized annular conditions, a sealing ring groove can be created on the inner bevel of the bushing head, and a sealing ring can be pre-installed. When the hanger body is set, its outer bevel will press against the sealing ring, forming an effective annular barrier to prevent external impurities from entering and internal liquid from leaking. In applications requiring high sealing, additional sealing flanges can be connected to the bushing head to enhance the seal.

[0013] Furthermore, the locking teeth on the inner wall of the sleeve hanger body are unidirectional oblique teeth, which can effectively prevent the sleeve from shifting downwards.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. Reusable and cost-saving: It completely solves the problem of traditional hangers being used only once. It can be reused multiple times through non-destructive disassembly, which greatly saves material costs and total life cycle costs.

[0016] 2. Simplified structure and convenient installation: The integrated C-shaped structure replaces the complex multi-piece clamps, reducing the number of parts and making on-site installation and disassembly simpler and faster, saving operation time.

[0017] 3. Active control, safe and reliable: Active setting and unsetting are achieved by rotating the retaining sleeve, which makes the operation highly controllable and avoids the uncertainty of traditional hangers that rely solely on gravity for setting.

[0018] 4. Strong applicability: It is particularly suitable for applications such as cementing wells, water injection wells, and exploration wells where the requirements for high-pressure sealing of the annulus are not high, but the requirements for cost and operational efficiency are high. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the overall structure of this utility model;

[0020] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0021] Figure 3 This is a cross-sectional view of the casing head.

[0022] Figure 4 yes Figure 3 A magnified view of part B in the middle;

[0023] Figure 5 This is a schematic diagram of the casing hanger body;

[0024] Figure 6 This is a schematic diagram of the retaining sleeve.

[0025] In the figure: 10, casing hanger body; 11, notch; 12, locking tooth; 13, outer bevel; 20, retaining sleeve; 21, serrated structure; 30, casing head; 31, inner wall bevel; 32, sealing ring groove; 40, sealing ring. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments.

[0027] The description of this utility model is merely a structural or even functional description of the embodiments, and the scope of this utility model is not limited by the embodiments described herein.

[0028] like Figures 1-6 As shown, this embodiment is achieved through the following technical solution:

[0029] The reusable casing hanger of this utility model includes a casing hanger body 10 and a retaining sleeve 20, which is installed inside the casing head 30 at the wellhead and is used to suspend the casing that is lowered into the wellbore.

[0030] The casing hanger body 10 is integrally machined from a highly elastic metal material such as spring steel. It is a C-shaped ring with a notch 11. The notch allows the casing hanger body 10 to radially spring open and retract. The inner surface of the casing hanger body 10 is machined with locking teeth 12 for engaging the outer wall of the casing, and its outer surface has an outer bevel 13. The taper of the outer bevel 13 matches the inner wall bevel 31 inside the casing head 30.

[0031] The retaining sleeve 20 is a metal ring with a serrated structure 21 on its upper part, which facilitates the application of rotational torque using a special tool. The retaining sleeve 20 is connected to the casing head 30 by threads, and the lower end face of the retaining sleeve 20 contacts the upper end face of the casing hanger body 10 and transmits axial pressure.

[0032] The installation process is as follows:

[0033] The first step is to install two O-rings 40 in the pre-set sealing groove 32 on the inner wall slope 31 of the sleeve head 30 as needed.

[0034] The second step is to insert the C-shaped casing hanger body 10 and the retaining sleeve 20 into the casing head 30 in sequence.

[0035] The third step is to lower the casing normally, passing it through the hanger.

[0036] Fourth, after the casing reaches the predetermined depth, use a lifting clamp to slightly lift the casing string, then use a special tool to clamp the serrated structure 21 of the retaining sleeve 20, rotate it clockwise and apply a predetermined torque. The retaining sleeve 20 presses downward against the casing hanger body 10, causing it to slide down along the inner wall slope 31. Under the action of the slope, the notch 11 of the casing hanger body 10 is forced to narrow, causing the locking teeth 12 to firmly bite into the outer wall of the casing, while its outer slope 13 presses against the sealing ring 40.

[0037] Fifth, slowly lower the casing string. Its weight will further increase the wedging force of the slips, forming a reliable suspension.

[0038] The disassembly process is as follows:

[0039] The first step is to use a lifting clamp to fully lift the weight of the casing string.

[0040] The second step is to use a special tool to hold the serrated structure 21 of the retaining sleeve 20 and rotate it counterclockwise to loosen the retaining sleeve.

[0041] Third, when the upward pressure of the retaining sleeve 20 is completely released, the sleeve hanger body 10 automatically springs open due to its own elasticity, the notch 11 opens, and the locking teeth 12 completely disengage from the sleeve.

[0042] Fourth step: Pull out the casing, retaining sleeve 20 and casing hanger body 10. All parts are intact and can be used for the next operation.

[0043] Of course, the above description is only a preferred embodiment of this utility model and should not be considered as limiting the scope of the embodiments of this utility model. This utility model is not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of this utility model should be included in the patent coverage of this utility model.

Claims

1. A detachable and reusable sleeve hanger, installed inside the sleeve head (30) for suspending the sleeve, characterized in that, include: The sleeve hanger body (10) is an integral ring structure made of elastic metal material. The ring structure has a notch (11) that makes it C-shaped. The inner wall of the sleeve hanger body (10) is provided with a locking tooth (12) for clamping the sleeve, and the outer wall is provided with an outer inclined surface (13) that matches the inclined surface (31) of the inner wall of the sleeve head (30). The retaining sleeve (20) is an annular structure and is located above the casing hanger body (10). The retaining sleeve (20) is configured to apply or remove axial pressure to the casing hanger body (10) by rotation. When the retaining sleeve (20) rotates to apply axial pressure, the sleeve hanger body (10) moves down along the inner wall slope (31) of the sleeve head (30) and is constrained by the inner wall slope (31) to narrow the notch (11), thereby driving the locking teeth (12) to tighten inward to clamp the sleeve. When the retaining sleeve (20) rotates in the opposite direction to remove the axial pressure, the sleeve hanger body (10) relies on its own elasticity to open the notch (11), thereby causing the locking tooth (12) to loosen the sleeve.

2. The reusable and detachable sleeve hanger according to claim 1, characterized in that: The retaining sleeve (20) is connected to the sleeve head (30) by threads.

3. The reusable and detachable sleeve hanger according to claim 1, characterized in that: The material of the sleeve hanger body (10) is spring steel.

4. The detachable and reusable sleeve hanger according to claim 1, characterized in that: The upper part of the retaining sleeve (20) is provided with a serrated structure (21) that cooperates with the installation tool for transmitting torque.

5. The reusable and detachable sleeve hanger according to claim 1, characterized in that: The inner wall slope (31) of the sleeve head (30) is provided with a sealing ring groove (32), and a sealing ring (40) is pre-installed in the sealing ring groove (32).

6. The reusable and detachable sleeve hanger according to claim 1, characterized in that: The locking teeth (12) on the inner wall of the sleeve hanger body (10) are unidirectional oblique teeth.

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