High pressure wellhead lifting tool

Abstract

The present application relates to a kind of high-pressure wellhead head lifting tools, comprising: mandrel, is the tubular structure of the shape of variable-diameter step of inside hollow, outside, the middle part of the mandrel is provided with outer thread, the large-diameter part of mandrel is located above the outer thread;Main body, is the stepped cylindrical structure of upper large lower small with axial inner hole in inside, the inner thread of the axial inner hole of the main body is provided with with the outer thread cooperation, it is radially provided with several installation holes, the installation hole is used to install lock block;The main body is set in the mandrel outside;Lock block, is the stepped structure, the lock block is set in the installation hole;Positive rotation mandrel, when mandrel and main body are tightened by outer thread and inner thread, the head of the lock block is used to abut with high-pressure wellhead head, its tail is used to abut with the large-diameter part of mandrel, to realize locking;Reverse rotation mandrel, when lock block tail is separated from the large-diameter part of mandrel, realize unlocking.

Description

Technical Field

[0001] This invention relates to the field of underwater wellhead equipment technology, specifically to a high-pressure wellhead lifting tool. Background Technology

[0002] In the process of offshore oil and gas exploration and development, the subsea wellhead system is a key piece of equipment, serving to fix the wellbore and support subsequent oil production equipment. Among them, the high-pressure wellhead is a key component of the subsea wellhead system. When drilling on an offshore platform, a 3-4 meter short section is welded to the lower part of the high-pressure wellhead, and the entire component weighs 5-6 tons.

[0003] During drilling, the wellhead is repeatedly changed from a horizontal to a vertical position or vice versa. Considering both ease of operation and safety, there is an urgent need to design a dedicated high-pressure wellhead lifting tool. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a high-pressure wellhead lifting tool that enables horizontal and vertical lifting of high-pressure wellheads with short sections. It is convenient and quick to operate, features a purely mechanical connection structure, is simple and reliable, has a long service life, and is reusable.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The high-pressure wellhead lifting tool of the present invention comprises: a mandrel, which is a hollow tubular structure with a stepped outer diameter, the mandrel having an external thread in the middle and a large-diameter portion above the external thread; a body, which is a stepped cylindrical structure with an axial inner hole, the inner hole of the body having an internal thread that mates with the external thread, and a plurality of mounting holes radially arranged therein for mounting locking blocks; the body is fitted over the mandrel; and a locking block, which is a stepped structure and is disposed within the mounting holes. When the mandrel is rotated in the forward direction and the body is tightened by the external and internal threads, the head of the locking block abuts against the high-pressure wellhead, and its tail abuts against the large-diameter portion of the mandrel to achieve locking; when the mandrel is rotated in the reverse direction and the tail of the locking block disengages from the large-diameter portion of the mandrel, unlocking is achieved.

[0007] Preferably, the high-pressure wellhead lifting tool further includes a positioning device; the positioning device includes a positioning body in the shape of a "7" and a fixing seat; the fixing seat is disposed at the bottom of the vertical rod of the positioning body and is fixed to the top of the body; the horizontal rod of the positioning body extends to the top of the high-pressure wellhead and is used for precise positioning of the locking block and the annular groove on the inner wall of the high-pressure wellhead.

[0008] Preferably, the high-pressure wellhead lifting tool further includes a lower filler core and a limiting ring; the lower outer wall of the mandrel is provided with an annular groove; the limiting ring is sleeved on the mandrel and located in the annular groove; the lower filler core is sleeved on the lower part of the mandrel, and its upper part is located between the main body and the mandrel, and its lower part is fixed to the limiting ring; the lower filler core is used to straighten the mandrel.

[0009] Preferably, the locking block head of the high-pressure wellhead lifting tool is provided with a toothed groove, and the high-pressure wellhead is provided with a corresponding toothed groove. In the locked state, the toothed groove of the locking block head and the toothed groove of the high-pressure wellhead engage and bite together.

[0010] Preferably, in the high-pressure wellhead lifting tool, the tail of the locking block is provided with a sealing groove, and a sealing ring is provided in the sealing groove to prevent the locking block from falling out freely.

[0011] Preferably, the high-pressure wellhead lifting tool further includes an anti-collision ring; the anti-collision ring is sleeved on the bottom of the large-diameter cylinder of the main body to avoid damaging the sealing cone surface of the high-pressure wellhead.

[0012] Preferably, the high-pressure wellhead lifting tool further includes an anti-rotation key; the anti-rotation key is installed on the main body and located between the main body and the high-pressure wellhead, and is used to prevent the lifting tool from rotating against the inner wall of the high-pressure wellhead.

[0013] Preferably, the anti-rotation key of the high-pressure wellhead lifting tool includes an anti-rotation body and a spring; an anti-rotation groove is provided on the inner wall of the high-pressure wellhead; the anti-rotation body is a stepped structure with a central protrusion; the edge of the anti-rotation body is fixed to the main body by screws, and its protrusion extends into the anti-rotation groove; the spring is located between the anti-rotation body and the main body; when the spring extends, it prevents the lifting tool from rotating against the inner wall of the high-pressure wellhead.

[0014] Preferably, the upper end of the mandrel of the high-pressure wellhead lifting tool is provided with a plurality of radial holes, which facilitate the application of torque to the mandrel.

[0015] The present invention has the following advantages due to the adoption of the above technical solutions:

[0016] (1) This invention achieves locking, lifting and unlocking of the high-pressure wellhead through the mechanical cooperation between the main body, mandrel and locking block. The weight of the high-pressure wellhead and short section is transferred to the tool body through the annular groove on the locking block, and then the load is transferred to the tool mandrel through the thread of the tool body. It is a pure mechanical connection structure with simple and reliable structure, reasonable setting, convenient use and installation, high safety and reliability, long service life and can be reused.

[0017] (2) The main body of the present invention is provided with an anti-collision ring to prevent damage to the sealing cone surface at the end of the high-pressure wellhead during use;

[0018] (3) The upper part of the main body of the present invention is provided with a positioning device to achieve precise positioning of the tool locking block and the annular groove on the inner wall of the high-pressure wellhead;

[0019] (4) The spindle of the present invention has a radial hole to facilitate the provision of torque. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of the lifting tool locking the high-pressure wellhead in this invention;

[0022] Figure 2 This is a schematic diagram of the anti-rotation state of the anti-rotation key in this invention;

[0023] Figure 3 This is a schematic diagram of the main body of the present invention;

[0024] Figure 4 This is a schematic diagram of the mandrel in this invention;

[0025] Figure 5 This is a schematic diagram of the locking block in this invention;

[0026] Figure 6 This is a schematic diagram of the limiting ring in this invention;

[0027] Figure 7 This is a schematic diagram of the lower filler core structure in this invention;

[0028] Figure 8 This is a schematic diagram of the positioning device in this invention;

[0029] Figure 9 This is a schematic diagram of the anti-rotation key structure in this invention.

[0030] The markings in the attached diagram are as follows:

[0031] 1-Mandrel; 101-Annular groove; 102-Radial hole; 2-Positioning device; 201-Positioning body; 202-Fixing seat; 3-Body; 4-Locking block; 401-Groove; 402-Sealing ring; 5-Anti-collision ring; 6-Lower core; 7-Limiting ring; 8-High-pressure wellhead; 9-Anti-rotation key; 901-Anti-rotation body; 902-Spring; 903-Screw. Detailed Implementation

[0032] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0033] This invention provides a high-pressure wellhead lifting tool. Through the mechanical cooperation between the main body, mandrel, and locking block, the high-pressure wellhead can be locked, lifted, and unlocked. The weight of the high-pressure wellhead and short section is transferred to the tool body through the annular groove on the locking block, and then the load is transferred to the tool mandrel through the thread of the tool body. It is a purely mechanical connection structure, which is simple and reliable, reasonably designed, easy to use and install, highly safe and reliable, long service life, and reusable.

[0034] like Figure 1 As shown, the high-pressure wellhead lifting tool provided by the present invention includes: a mandrel 1, which is a tubular structure with a hollow interior and a stepped outer diameter. An external thread is provided in the middle of the mandrel 1, and the large-diameter portion of the mandrel is located above the external thread. The specific structure of the mandrel 1 is as follows: Figure 4 As shown; the main body 3 is a stepped cylindrical structure with a larger upper part and a smaller lower part, having an axial inner hole. The axial inner hole of the main body 3 is provided with an internal thread that mates with the external thread, and it has several mounting holes arranged radially for mounting the locking block 4. The main body 3 is sleeved on the outside of the spindle 1; the specific structure of the main body is as follows... Figure 3 As shown; the locking block 4 has a stepped structure and is installed in the mounting hole. The specific structure of the locking block is as follows. Figure 5 As shown; when the mandrel 1 is rotated in the forward direction and the main body 3 is tightened by the external and internal threads, the head of the locking block 4 is used to abut against the high-pressure wellhead 8, and its tail is used to abut against the large diameter part of the mandrel 1 to achieve locking; when the mandrel 1 is rotated in the reverse direction and the tail of the locking block 4 is disengaged from the large diameter part of the mandrel 1, unlocking is achieved.

[0035] In the above embodiments, preferably, as follows: Figure 1 and Figure 8 As shown, the present invention also includes a positioning device 2; the positioning device 2 includes a positioning body 201 in the shape of a "7" and a fixing seat 202; the fixing seat 202 is disposed at the bottom of the vertical rod of the positioning body 201 and is fixed to the top of the body 3; the horizontal rod of the positioning body 201 extends above the high-pressure wellhead 8 and is used for precise positioning of the locking block 4 and the annular groove on the inner wall of the high-pressure wellhead 8.

[0036] In the above embodiments, preferably, as follows: Figure 6 and Figure 7 As shown, the present invention also includes a lower filler core 6 and a limiting ring 7; an annular groove 101 is provided on the lower outer wall of the mandrel 1; the limiting ring 7 is sleeved on the mandrel 1 and located in the annular groove 101; the lower filler core 6 is sleeved on the lower part of the mandrel 1, and its upper part is located between the main body 3 and the mandrel 1, and its lower part is fixed to the limiting ring 7; the lower filler core 6 is used to straighten the mandrel 1.

[0037] In the above embodiments, preferably, as follows: Figure 5 As shown, the head of the locking block 4 is provided with a tooth groove 401, and the high-pressure wellhead 8 is provided with a corresponding tooth groove. In the locked state, the tooth groove 401 on the head of the locking block 4 engages with the tooth groove on the high-pressure wellhead, thereby enabling the lifting of the high-pressure wellhead.

[0038] In the above embodiment, preferably, a sealing groove is provided at the tail of the locking block 4, and a sealing ring 402 is provided in the sealing groove 4 to prevent the locking block 4 from falling out freely.

[0039] In the above embodiments, preferably, as follows: Figure 1 As shown, the present invention also includes an anti-collision ring 5; the anti-collision ring 5 is sleeved on the bottom of the large-diameter cylinder of the main body 3 to avoid damaging the sealing cone surface of the high-pressure wellhead 8.

[0040] In the above embodiments, preferably, as follows: Figure 2 As shown, the present invention also includes an anti-rotation key 9; the anti-rotation key 9 is installed on the main body 3 and located between the main body 3 and the high-pressure wellhead 8, and is used to prevent the lifting tool from rotating against the inner wall of the high-pressure wellhead.

[0041] In the above embodiments, preferably, as follows: Figure 9 As shown, the anti-rotation key 9 includes an anti-rotation body 901 and a spring 902; an anti-rotation groove is provided on the inner wall of the high-pressure wellhead 8; the anti-rotation body 901 is a stepped structure with a central protrusion; the edge of the anti-rotation body 901 is fixed to the body 3 by screws 903, and its protrusion extends into the anti-rotation groove; the spring 902 is located between the anti-rotation body 901 and the body 3; when the spring 902 extends, it prevents the lifting tool from rotating against the inner wall of the high-pressure wellhead 8.

[0042] In the above embodiment, preferably, the upper end of the mandrel 1 is provided with a plurality of radial holes 102, which facilitate the application of torque to the mandrel.

[0043] The working process of this invention is as follows:

[0044] like Figure 1 As shown, hoist the tool into the high-pressure wellhead 8, as indicated. Figure 2As shown, the anti-rotation key 9 is aligned with the anti-rotation groove on the inner wall of the high-pressure wellhead 8, and the positioning device 2 fits against the end face of the high-pressure wellhead 8. Rotating the mandrel 1 to the left approximately 3.5 turns causes it to move downwards, and through a change in diameter, pushes out the locking block 4, locking the annular groove on the inner wall of the high-pressure wellhead 8, thus completing the hoisting of the high-pressure wellhead 8. Rotating the mandrel 1 to the right approximately 3.5 turns causes it to move upwards, reducing its diameter and reserving space for the locking block 4 to retract. Lifting the tool causes the annular groove on the inner wall of the high-pressure wellhead to push the locking block 4 back into the main body 3, completing the separation of the tool from the high-pressure wellhead 8.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-pressure wellhead lifting tool, characterized in that, include: The mandrel is a tubular structure that is hollow inside and has a stepped shape with a variable diameter on the outside. The mandrel has an external thread in the middle and the large diameter part of the mandrel is above the external thread. The main body is a stepped cylindrical structure with a larger top and a smaller bottom, having an axial inner hole inside. The axial inner hole of the main body is provided with an internal thread that mates with the external thread. Several mounting holes are provided along the radial direction of the main body for mounting locking blocks. The main body is sleeved on the outside of the spindle. The locking block has a stepped structure and is disposed within the mounting hole; When the mandrel is rotated in the forward direction and tightened with the body through external and internal threads, the head of the locking block is used to abut against the high-pressure wellhead, and its tail is used to abut against the large-diameter part of the mandrel to achieve locking. The lock is unlocked when the tail of the locking block disengages from the large-diameter portion of the lock shaft by rotating the spindle in the opposite direction. It also includes a positioning device, which comprises a positioning body in the shape of a "7" and a fixing seat; the fixing seat is disposed at the bottom of the vertical rod of the positioning body and is fixed to the top of the body; the horizontal rod of the positioning body extends to the top of the high-pressure wellhead and is used for precise positioning of the locking block and the annular groove on the inner wall of the high-pressure wellhead. It also includes a lower filler core and a limiting ring; the lower outer wall of the mandrel is provided with an annular groove; the limiting ring is sleeved on the mandrel and located in the annular groove; the lower filler core is sleeved on the lower part of the mandrel, and its upper part is located between the main body and the mandrel, and its lower part is fixed to the limiting ring; the lower filler core is used to straighten the mandrel; It also includes an anti-rotation key, which is installed on the main body and located between the main body and the high-pressure wellhead, and is used to prevent the lifting tool from rotating against the inner wall of the high-pressure wellhead; The anti-rotation key includes an anti-rotation body and a spring; an anti-rotation groove is provided on the inner wall of the high-pressure wellhead; the anti-rotation body is a stepped structure with a central protrusion; the edge of the anti-rotation body is fixed to the main body by screws, and its protrusion extends into the anti-rotation groove; the spring is located between the anti-rotation body and the main body; when the spring extends, it prevents the lifting tool from rotating against the inner wall of the high-pressure wellhead.

2. The high-pressure wellhead lifting tool according to claim 1, characterized in that, The locking block head is provided with a tooth groove, and the high-pressure wellhead is provided with a corresponding tooth groove. In the locked state, the tooth groove of the locking block head and the tooth groove of the high-pressure wellhead are engaged and locked together.

3. The high-pressure wellhead lifting tool according to claim 2, characterized in that, The locking block has a sealing groove at its tail, and a sealing ring is provided in the sealing groove. The sealing ring is also used to prevent the locking block from coming out freely.

4. The high-pressure wellhead lifting tool according to claim 1, characterized in that, It also includes anti-collision rings; The anti-collision ring is fitted onto the bottom of the large-diameter cylinder of the main body to prevent damage to the sealing cone surface of the high-pressure wellhead.

5. The high-pressure wellhead lifting tool according to claim 1, characterized in that, The upper end of the mandrel is provided with several radial holes, which facilitate the application of torque to the mandrel.

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