One-trip deepwater wellhead cutting and recycling device

Abstract

The invention discloses a one-trip type deepwater wellhead cutting and recycling device. The technical problems that wellhead cutting and recycling operation is complex, and the period is long are solved. The device comprises an underwater rotating head, a lifting tool, a centralizer and a cutting tool, and the grabbing tool comprises a supporting ring movably arranged on the lifting tool in a sleeving mode; the supporting cover is connected to the top of the supporting ring through a plurality of supporting rods; the receding notches are formed in the side wall of the supporting ring correspondingly; the multiple grabbing slips are movably arranged in the corresponding receding notches correspondingly, and the multiple grabbing slips are hinged to the supporting ring correspondingly; a control part is arranged between the lifting tool and the supporting ring and used for controlling the multiple grabbing slips to rotate synchronously so that the multiple grabbing slips can grab the well head together. According to the invention, one-trip cutting recovery operation can be realized, and the operation is simple, so that the operation efficiency is improved, the operation period is shortened, the operation cost is reduced, and the operation risk can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of wellhead cutting and recovery, and in particular relates to a one-trip deepwater wellhead cutting and recovery device. Background Art

[0002] With the continuous development and utilization of my country's oil and gas resources, offshore oilfield exploitation has gradually developed towards deep sea waters. After exploration in deep sea waters, abandonment of wells, completion of deep water platform exploitation, or abandonment of wells after replacement of wellbore, the deep seabed must be cleaned, that is, no abandoned objects should be left 5m below the mud line. Therefore, it is necessary to cut and salvage the deepwater wellhead and the casing at the wellhead to meet the cleanliness requirements of the deep seabed. Deepwater salvage and cutting operations of offshore drilling platforms have become a new service operation project for oilfield production services.

[0003] However, traditional underwater wellhead cutting and recovery operations require multiple steps such as casing hanging, wellbore accessories, high-pressure wellhead and low-pressure wellhead. The operation is complicated and requires multiple connections and insertion of different service tools. The operation efficiency is low, the cycle is long, and the operation risk increases with the increase of water depth, which needs to be improved. Summary of the invention

[0004] In order to solve all or part of the above problems, the purpose of the present invention is to provide a one-trip deep-water wellhead cutting and recovery device, which can realize one-trip cutting and recovery operations with simple operation, thereby improving operation efficiency, shortening operation cycle, reducing operation cost, and reducing operation risk.

[0005] The present invention provides a one-trip deepwater wellhead cutting and recovery device, comprising an underwater rotating head, a pulling tool, a centralizer and a cutting tool connected in sequence from top to bottom, wherein a grabbing tool for grabbing the wellhead is sleeved on the pulling tool, and the grabbing tool comprises:

[0006] A support ring, movably mounted on the lifting tool;

[0007] A support cover, which is annular and connected to the top of the support ring through a plurality of support rods;

[0008] There are a plurality of clearance notches, which are respectively arranged on the side walls of the support ring, and the plurality of clearance notches are arranged at equal intervals along the circumference of the support ring;

[0009] There are multiple grabbing slips, which are movably arranged in the corresponding clearance gaps, and the multiple grabbing slips are respectively hinged to the support ring, and the grabbing slips can swing in the vertical direction;

[0010] Wherein, a control unit is arranged between the pulling tool and the support ring, and the control unit is used to control the synchronous rotation of the plurality of grabbing slips so that the plurality of grabbing slips can jointly grasp the wellhead.

[0011] Optionally, each of the grabbing slips comprises:

[0012] A support block is horizontally arranged and movably arranged between the support ring and the support cover;

[0013] A grab block is vertically arranged and movably arranged in the corresponding gap, the grab block is integrally connected with the corresponding support block, and a grab groove matching the external thread of the wellhead is arranged at the bottom of the grab block;

[0014] A support column, vertically fixed on the support ring;

[0015] A rotating spherical surface is disposed on the top of the corresponding support column;

[0016] The rotating groove is arranged at the bottom of the corresponding supporting block and is tightly matched with the corresponding rotating spherical surface.

[0017] Optionally, a guiding slope is provided at the bottom of each grab block, so that the wellhead head can smoothly enter between the multiple grab blocks.

[0018] Optionally, a plurality of positioning blocks are fixedly connected to the support ring, and the plurality of positioning blocks are arranged at equal intervals along the circumference of the support ring, a positioning notch is formed between two adjacent positioning blocks, and the plurality of support blocks are tightly inserted into the corresponding positioning notches.

[0019] Optionally, the control unit includes:

[0020] A control surface, disposed on the lifting tool, and used to push the plurality of support blocks to rotate upward synchronously;

[0021] There are multiple control springs, which are respectively arranged between the support cover and the corresponding support block, and the control springs are used to push the corresponding support block to rotate downward.

[0022] Optionally, the pulling tool includes a first shaft, a second shaft and a third shaft coaxially connected from top to bottom, the outer diameters of the first shaft, the second shaft and the third shaft increase sequentially, the first shaft and the second shaft can pass through the support ring, and the shoulder position between the first shaft and the second shaft forms the control surface.

[0023] Optionally, a plurality of limit blocks are fixedly connected to the second shaft, and the limit blocks are arranged at equal intervals along the circumference of the second shaft. The inner wall of the support ring is provided with a plurality of limit notches, and the limit blocks can slidably cooperate with the corresponding limit notches.

[0024] Optionally, a limiting gasket is sleeved on the second shaft, and the limiting gasket can abut against the support ring.

[0025] Optionally, an anti-rotation key is fixedly connected to the second shaft, an anti-rotation groove is provided on the inner wall of the limiting gasket, and the anti-rotation key is tightly inserted into the anti-rotation groove.

[0026] Optionally, a plurality of anti-rotation blocks are fixedly connected to the limiting gasket, a plurality of anti-rotation grooves are provided on the supporting ring, and the anti-rotation blocks can be inserted into corresponding anti-rotation grooves.

[0027] It can be seen from the above technical solution that the one-trip deepwater wellhead cutting and recovery device provided by the present invention has the following advantages:

[0028] The device can realize one-trip cutting and recovery operations, that is, wellhead cutting and recovery operations can be completed in one trip down the well. The operation is simpler and more convenient. It can not only improve operation efficiency, shorten operation cycle, reduce operation cost, but also reduce operation risk.

[0029] Other features and advantages of the present invention will be set forth in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0031] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0032] Figure 2 is a cross-sectional view of a grabbing tool according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of a support ring in an embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of the structure of the pulling tool in an embodiment of the present invention;

[0035] Figure 5 is a cross-sectional view of a lifting tool according to an embodiment of the present invention;

[0036] Figure 6 It is a schematic diagram of the structure of the pulling tool and the grasping tool in an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1. Underwater rotating head; 2. Lifting tool; 21. First axis; 22. Second axis; 23. Third axis; 24. Limiting gasket; 3. Stabilizer; 4. Cutting tool; 5. Grabbing tool; 51. Support ring; 52. Support cover; 53. Support rod; 54. Make way gap; 55. Grabbing slip; 551. Support block; 552. Grabbing block; 553. Grabbing groove; 554. Mounting groove; 555. Support column; 556. Rotating spherical surface; 557. Rotating groove; 558. Guide slope; 56. Stabilizing slip; 6. Control unit; 61. Control surface; 62. Support groove; 63. Control spring; 7. Positioning block; 8. Connecting groove; 9. Positioning gap; 10. Limiting block; 11. Limiting gap; 12. Anti-rotation key; 14. Stop block; 15. Stop groove. DETAILED DESCRIPTION

[0039] To make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other arbitrarily without conflict.

[0040] like Figure 1-Figure 6 The figure shows an embodiment of the present invention, in which a one-trip deepwater wellhead cutting and recovery device is disclosed, comprising an underwater rotating head 1, a lifting tool 2, a centralizer 3 and a cutting tool 4 connected in sequence from top to bottom, and a grabbing tool 5 for grasping the wellhead is sleeved on the lifting tool 2. The top of the underwater rotating head 1 is used to connect with the drill pipe, and the underwater rotating head 1 is used to control the lifting tool 2 to drive the centralizer 3 and the cutting tool 4 to rotate, the centralizer 3 is used to ensure that the cutting and recovery device is centered in the wellbore, and the cutting tool 4 is used to cut the wellbore.

[0041] In one embodiment, Figure 1 , Figure 2 , Figure 3 As shown, the grabbing tool 5 includes a support ring 51 movably mounted on the lifting tool 2, an annular support cover 52 is arranged above the support ring 51, and the support cover 52 is connected to the support ring 51 through a plurality of hollow support rods 53. The side wall of the support ring 51 is provided with a plurality of clearance notches 54, and the plurality of clearance notches 54 are arranged at equal intervals along the circumference of the support ring 51, and a grabbing slip 55 is movably arranged in each clearance notch 54, and the plurality of grabbing slips 55 are respectively hinged to the support ring 51, and the grabbing slips 55 can swing in the vertical direction.

[0042] In one embodiment, Figure 2 , Figure 4As shown, a control unit 6 is provided between the lifting tool 2 and the support ring 51, and the control unit 6 is used to control the synchronous rotation of multiple grabbing clavas 55 so that the multiple grabbing clavas 55 can jointly grab the wellhead, thereby achieving the grabbing of the wellhead. When the drill pipe is lifted, the cut wellbore can be recovered.

[0043] The one-trip deepwater wellhead cutting and recovery device in this embodiment can realize one-trip cutting and recovery operations, that is, the wellhead cutting and recovery operations can be completed in one trip down the well. The operation is simpler and more convenient, which can not only improve the operation efficiency, shorten the operation cycle, and reduce the operation cost, but also reduce the operation risk.

[0044] In the present embodiment, there are three grabbing slips 55, that is, three grabbing slips 55 are arranged at intervals of 120° to achieve three-point grabbing. Of course, in other embodiments, four or six grabbing slips 55 can also be provided, and the design can be carried out according to actual needs.

[0045] In one embodiment, Figure 2 As shown, each grabbing slip 55 includes a horizontally arranged support block 551, and the support block 551 is movably arranged between the support ring 51 and the support cover 52. A grabbing block 552 is movably arranged in the clearance gap 54, and the grabbing block 552 is arranged vertically and is integrally connected with the corresponding support block 551, that is, the support block 551 and the grabbing block 552 are L-shaped. At the same time, a grabbing groove 553 matching the external thread of the wellhead is arranged at the bottom of the grabbing block 552.

[0046] In one embodiment, Figure 2 As shown, a rectangular mounting groove 554 is provided on the support ring 51, and a support column 555 is embedded in the mounting groove 554. The top of the support column 555 extends to the top of the support ring 51 and is provided with a rotating spherical surface 556. At the same time, a rotating groove 557 is provided at the bottom of the support block 551. The rotating spherical surface 556 is located in the rotating groove 557 and is tightly matched with the rotating groove 557, so that the support block 551 can rotate in the vertical direction, so that the grab block 552 can grasp or release the wellhead.

[0047] In one embodiment, Figure 2 , Figure 3 As shown, a plurality of positioning blocks 7 are fixedly connected to the support ring 51, and the plurality of positioning blocks 7 are arranged at equal intervals along the circumference of the support ring 51. A connecting groove 8 is provided at the bottom of the support cover 52, and the plurality of positioning blocks 7 can be threadedly connected with the connecting groove 8. At the same time, positioning notches 9 are respectively formed between two adjacent positioning blocks 7, and the plurality of support blocks 551 are respectively tightly inserted into the corresponding positioning notches 9 to achieve the limiting of the support blocks 551.

[0048] In this embodiment, three positioning blocks 7 are provided, the upper surface of the support block 551 is arched, and the arched position of the support block 551 abuts against the support cover 52 to limit the rotation angle of the support block 551. Of course, in other embodiments, the upper surface of the support block 551 can be horizontal, but it is necessary to ensure that there is a certain gap between the support block 551 and the support cover 52 so that the support block 551 can rotate.

[0049] In one embodiment, Figure 2 As shown, the bottom of each grab block 552 is provided with a guide slope 558, so that the wellhead can smoothly enter between the multiple grab blocks 552. At the same time, the inner wall of the support ring 51 is provided with multiple groups of righting slips 56, and the multiple groups of righting slips 56 are arranged alternately with the multiple grab blocks 552. Each group of righting slips 56 is provided with two, and the two righting slips 56 are respectively connected to the support ring 51 by fastening screws to realize the righting of the wellhead.

[0050] In one embodiment, Figure 2 , Figure 4 As shown, the control part 6 includes a control surface 61 arranged on the lifting tool 2. When the drill pipe drives the lifting tool 2 and other components to move upward, the control surface 61 can push the multiple support blocks 551 to rotate upward synchronously, so that the multiple grab blocks 552 can jointly grab the wellhead. At the same time, each support block 551 is provided with a support groove 62 on the upper surface away from the grab block 552, and a control spring 63 is provided in each support groove 62, and one end of the control spring 63 is fixedly connected to the bottom of the support groove 62, and the other end is fixedly connected to the support cover 52. At the same time, the control spring 63 is used to push the corresponding support block 551 to rotate downward, so that the grab block 552 is in a released state.

[0051] In one embodiment, Figure 4 , Figure 5 As shown, the lifting tool 2 includes a first shaft 21, a second shaft 22 and a third shaft 23 which are coaxially connected from top to bottom, the outer diameters of the first shaft 21, the second shaft 22 and the third shaft 23 increase in sequence, the first shaft 21 and the second shaft 22 can pass through the support ring 51, and the shaft shoulder position between the first shaft 21 and the second shaft 22 forms a control surface 61. At the same time, a limiting gasket 24 is sleeved on the second shaft 22, and when the control surface 61 pushes the multiple support blocks 551 to rotate upward, and the multiple grab blocks 552 grab the wellhead, the limiting gasket 24 and the top inner wall of the support ring 51 form an abutment limit to limit the upward movement of the lifting tool 2.

[0052] In one embodiment, Figure 4 , Figure 5 , Figure 6As shown, a plurality of limit blocks 10 are fixedly connected to the second shaft 22, and the plurality of limit blocks 10 are arranged at equal intervals along the circumference of the second shaft 22. A plurality of limit notches 11 are provided on the inner wall of the support ring 51, and the limit blocks 10 can slide and cooperate with the corresponding limit notches 11 to realize the positioning of the lifting tool 2 and the support ring 51.

[0053] In one embodiment, Figure 4 , Figure 5 , Figure 6 As shown, the second shaft 22 is fixedly connected with an anti-rotation key 12, the inner wall of the limiting gasket 24 is provided with an anti-rotation groove, and the anti-rotation key 12 is tightly inserted into the anti-rotation groove to achieve the limiting of the limiting gasket 24. At the same time, a plurality of anti-rotation blocks 14 are fixedly connected to the limiting gasket 24, and a plurality of anti-rotation grooves 15 are provided on the support ring 51, and the anti-rotation blocks 14 can be inserted into the corresponding anti-rotation grooves 15, thereby achieving further limiting of the lifting tool 2 and the support ring 51.

[0054] The one-trip deepwater wellhead cutting and recovery device in this embodiment is used as follows:

[0055] The grabbing tool 5 is mounted on the lifting tool 2, and the underwater rotating head 1 is installed on the top of the grabbing tool 5. Then, the underwater rotating head 1 is connected to the bottom of the drill pipe, and the cutting recovery device is lowered into the well through the drill pipe until a plurality of righting slips 56 are respectively seated at the wellhead. Then, the drill pipe is lowered further, at which time, the control surface 61 is separated from the support block 551, and the grabbing block 552 drives the support block 551 to flip under the action of the wellhead until the grabbing groove 553 is engaged with the external thread on the wellhead.

[0056] Next, continue to lower the drill pipe so that the underwater rotating head 1 is pressed down onto the support cover 52, and the lower chamfer of the underwater rotating head 1 is matched with the inner chamfer of the support cover 52 to achieve downward pressure cutting. During the process of lowering into the wellhead, the stabilizer 3 is supported on the inner wall of the casing to ensure the centering and stability of the entire cutting and recovery device, and prevent vibration and cutting deviation. After the cutting tool 4 is lowered into the predetermined cutting position, start the pump cycle and gradually increase the displacement. The high-pressure liquid passes through the nozzle to move the piston downward. The cutter rotates around the pin in the cutter body under the thrust of the piston, and the blade opens to press against the pipe wall to start cutting.

[0057] After the cutting operation is completed, the underwater rotating head 1 is used to control the rotation of the lifting tool 2 and other components, so that the multiple limit blocks 10 are aligned with the multiple limit notches 11 respectively. At this time, the multiple stop blocks 14 are aligned with the multiple stop grooves 15 respectively. Then, the lifting drill pipe drives the lifting tool 2 and other components to move upward synchronously until the limit gasket 24 abuts against the top inner wall of the support ring 51. At the same time, the multiple stop blocks 14 are respectively stuck in the corresponding stop grooves 15. At this time, the control surface 61 pushes the multiple support blocks 551 to rotate upward so that the multiple grab blocks 552 can grip the wellhead more tightly. Then, the drill pipe is slowly lifted to recover the cut wellbore.

[0058] From the above process, it can be seen that the cutting recovery device has the following advantages:

[0059] (1) The cutting and recovery device adopts an external grabbing and locking method, which avoids the risk of scratching the sealing surface of the wellhead by the internal fishing method. At the same time, the device grasps the outer contour of the wellhead by grabbing the slips 55, and can be adapted to different wellheads by replacing the grabbing slips 55 of different specifications;

[0060] (2) During the lowering and cutting process of the cutting and recovery device, the centralizer 3 is supported on the inner wall of the casing to ensure the centering and stability of the entire cutting tool 4 and prevent vibration and cutting deviation;

[0061] (3) The cutting and recovery device adopts a modular design, which can realize both conventional cutting and recovery (two-trip) and one-trip cutting and recovery of deep-water wellheads. The staff can choose the corresponding mode according to actual needs, which is more flexible and convenient to use;

[0062] (4) The cutting recovery device can realize emergency release. After the cutting is completed, if the tool string is lowered and rotated to a certain angle so that the limit block 10 is misaligned with the limit notch 11, the tool string can be lifted up. At this time, the grabbing slip 55 is in a released state and the slip is not in contact with the wellhead. When the tool string is lifted up, emergency release can be realized.

[0063] (5) The cutting and recovery device can realize the functions of cutting double-layer casing and recovering underwater wellhead in one trip of drilling by lifting and pressing. It is simple to operate and highly practical. It can greatly shorten the operation time, save drilling rig time and cost, and reduce the operation risk.

[0064] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present invention should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0065] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A one-trip deepwater wellhead cutting and recovery device, characterized in that: The invention comprises an underwater rotating head (1), a lifting tool (2), a centralizer (3) and a cutting tool (4) which are connected in sequence from top to bottom. The lifting tool (2) is provided with a grabbing tool (5) for grabbing the wellhead. The grabbing tool (5) comprises: A support ring (51) movably mounted on the lifting tool (2); A support cover (52) is annular and connected to the top of the support ring (51) via a plurality of support rods (53); There are a plurality of clearance notches (54), which are respectively arranged on the side walls of the support ring (51), and the plurality of clearance notches (54) are arranged at equal intervals along the circumference of the support ring (51); There are a plurality of grabbing slips (55) which are movably disposed in the corresponding clearance gaps (54), and the plurality of grabbing slips (55) are respectively hinged to the support ring (51), and the grabbing slips (55) can swing in the vertical direction; Wherein, a control unit (6) is provided between the pulling tool (2) and the support ring (51), and the control unit (6) is used to control the synchronous rotation of the plurality of grabbing cavas (55) so that the plurality of grabbing cavas (55) can jointly grasp the wellhead.

2. The cutting recovery device according to claim 1, characterized in that: Each of the grabbing slips (55) comprises: A support block (551) is arranged horizontally and movably disposed between the support ring (51) and the support cover (52); A grab block (552) is arranged vertically and movably arranged in the corresponding clearance gap (54); the grab block (552) is integrally connected with the corresponding support block (551), and a grab groove (553) matching the external thread of the wellhead is arranged at the bottom of the grab block (552); A support column (555) vertically fixed on the support ring (51); A rotating spherical surface (556) is disposed on the top of the corresponding supporting column (555); The rotating groove (557) is arranged at the bottom of the corresponding supporting block (551) and is tightly matched with the corresponding rotating spherical surface (556).

3. The cutting recovery device according to claim 2, characterized in that: A guiding slope (558) is provided at the bottom of each of the grab blocks (552) so that the wellhead head can smoothly enter between the multiple grab blocks (552).

4. The cutting recovery device according to claim 2, characterized in that: A plurality of positioning blocks (7) are fixedly connected to the support ring (51); the plurality of positioning blocks (7) are arranged at equal intervals along the circumference of the support ring (51); a positioning notch (9) is formed between two adjacent positioning blocks (7); and the plurality of support blocks (551) are tightly inserted into corresponding positioning notches (9).

5. The cutting recovery device according to claim 2, characterized in that: The control unit (6) comprises: A control surface (61) is disposed on the lifting tool (2) and is used to push the plurality of support blocks (551) to rotate upward synchronously; There are a plurality of control springs (63) which are respectively arranged between the support cover (52) and the corresponding support block (551), and the control springs (63) are used to push the corresponding support block (551) to rotate downward.

6. The cutting recovery device according to claim 5, characterized in that: The lifting tool (2) comprises a first shaft (21), a second shaft (22) and a third shaft (23) which are coaxially connected in sequence from top to bottom, the outer diameters of the first shaft (21), the second shaft (22) and the third shaft (23) increase in sequence, the first shaft (21) and the second shaft (22) can pass through the support ring (51), and the shoulder position between the first shaft (21) and the second shaft (22) forms the control surface (61).

7. The cutting recovery device according to claim 6, characterized in that: A plurality of limit blocks (10) are fixedly connected to the second shaft (22), and the plurality of limit blocks (10) are arranged at equal intervals along the circumference of the second shaft (22); a plurality of limit notches (11) are provided on the inner wall of the support ring (51), and the limit blocks (10) can slidably cooperate with the corresponding limit notches (11).

8. The cutting recovery device according to claim 6, characterized in that: A limiting gasket (24) is sleeved on the second shaft (22), and the limiting gasket (24) can form abutment with the support ring (51).

9. The cutting recovery device according to claim 8, characterized in that: An anti-rotation key (12) is fixedly connected to the second shaft (22), an anti-rotation groove is provided on the inner wall of the limiting gasket (24), and the anti-rotation key (12) is tightly inserted into the anti-rotation groove.

10. The cutting recovery device according to claim 9, characterized in that: A plurality of anti-rotation blocks (14) are fixedly connected to the limiting gasket (24), a plurality of anti-rotation grooves (15) are provided on the supporting ring (51), and the anti-rotation blocks (14) can be inserted into corresponding anti-rotation grooves (15).

Images