A method of wet storage and retrieval of a segmented subsea flexible hose

Abstract

The application discloses a kind of segmented seabed flexible hose wet storage and recovery method, belong to marine engineering hose wet storage and recovery field, over connection hoisting tool and welding blocking blind plate to hose joint, meet the conditions of sealing and lowering hose, to realize the purpose of seabed hose wet storage and recovery, first sheet is welded to hose joint, sheet adopts hose joint mouth same steel material, reach the effect of sealing hose, and do not harm joint base material;Then hoisting tool is connected to hose joint clamping groove, four bolts are used to fasten tool, tool connects to sling such as shackle and lifting belt;Finally, using crane to connect hoisting tool and lower to seabed wet storage, recovery hose at appropriate time to continue operation.The application not only meets the operation condition of wet storage and recovery, but also can effectively seal the hose to prevent seawater from entering.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flexible pipe wet storage and recovery, in particular to a method for wet storage and recovery of segmented subsea flexible pipe. BACKGROUND

[0002] Flexible pipe is a flexible oil / gas pipeline composed of one or more segments, which is usually used to connect two platforms or underwater production systems to platforms, FPSO, for oil and gas medium transmission, and has the advantages of strong adaptability to seabed topography, good corrosion resistance, high laying efficiency, etc. It has been widely used in oil and gas field development projects. When the flexible pipe is installed at sea and encounters bad weather, sometimes the segmented pipe is stored at sea for wet storage to wait for suitable weather to improve and then recovered for continued installation operation.

[0003] Usually, the end of the segmented pipe is connected by a threaded locking pull head. This pull head is only used for temporary traction protection of the pipe on the deck, and cannot provide sealing for the wet storage pipe underwater, and cannot meet the operation load requirements of offshore wet storage and recovery. SUMMARY

[0004] The present application provides a method for wet storage and recovery of segmented subsea flexible pipe, which can wet store and recover the pipe.

[0005] In order to solve the above technical problems, the present application provides a method for wet storage and recovery of segmented subsea flexible pipe, which is realized by the following steps:

[0006] S1, preparing for wet storage of the pipe, including prefabricating a plugging blind plate and a lifting tool, and changing the position of the pipe and removing the threaded pull head at the end of the pipe;

[0007] S2, welding the plugging blind plate to the pipe joint and detecting it;

[0008] S3, installing the lifting tool on the pipe, lowering the pipe to the wet storage site, and marking it;

[0009] S4, when the operation window arrives, salvaging the pipe to the operation platform and installing the pipe on the suspension flange;

[0010] S5, removing the lifting tool, cutting the plugging blind plate, and detecting the bevel after which the wet storage and recovery of the pipe is completed.

[0011] Further, the specific steps of step S1 are:

[0012] S11, prefabricating the lifting tool and the plugging blind plate for wet storage and recovery of the pipe;

[0013] S12, offshore laying hose, predict that the bad weather will come, the site does not meet the operation conditions need to evacuate the construction site;

[0014] S13, using the crane and winch to assist the second end of the hose temporarily suspended in the water bridge operation platform;

[0015] S14, disconnect the hose and the crane and winch connection, remove the threaded drag end of the hose;

[0016] S15, the penetration detection of the bevel.

[0017] Further, the specific steps of step S2 are:

[0018] S21, after the detection is qualified, the blind plate is used to weld and block the end of the hose;

[0019] S22, after the welding is finished, the temperature reaches room temperature, and the weld is subjected to penetration inspection;

[0020] S23, after the inspection is qualified, the weld and the blind plate outside are wrapped with rubber to protect them;

[0021] S24, the construction personnel install the plug in the argon filling hole.

[0022] Further, the specific steps of step S3 are:

[0023] S31, the prefabricated tooling is installed on the joint again, 8 6.5T shackles, 4 10Tx4m lifting belts, 2 12.5T shackles, 1 17T lifting ring, and 2 25kg floating balls are installed on the tooling, 12Tx4m lifting belts, 12.5T shackles and 12.5T ROV hooks are connected to the tooling on one side of the crane;

[0024] S32, the crane slowly recovers the force, so that the tension of the end of the hose is transferred from the suspension flange to the crane;

[0025] S33, remove the suspension flange at the operation platform, and lower the end of the hose to the seabed along the route by the crane, during which the ROV monitors the mud point and controls the layback within 20-50m;

[0026] S34, when the end of the hose reaches the seabed and the crane is not under stress, the ROV disconnects the connection of the crane rigging underwater;

[0027] S35, the positioning engineer marks the abandoned position of the end in the positioning map.

[0028] Further, the specific steps of step S4 are:

[0029] S41, after the construction ship has the conditions for continuing to lay the hose, the ship is moved back to the abandoned point of the end;

[0030] S42, the crane carries the recovery tool into water and lowers it to the hose end;

[0031] S43, the ROV underwater connects the hose end tool with the recovery tool on the crane;

[0032] S44, the crane slowly recovers the force, so that the hose end leaves the mud surface;

[0033] S45, the crane recovers the steel wire rope, the work ship moves along the wet storage route, and the ROV underwater continuously observes the state of the hose end;

[0034] S46, when the hose end is lifted more than 10m from the mud surface, the ROV flies to the hose landing point to monitor;

[0035] S47, the crane continues to recover the hose, and the work ship controls the designed Layback to move the ship;

[0036] S48, when the hose end is recovered out of the water surface, the crane is rotated, and the hose end is placed on the water bridge operation platform;

[0037] S49, the suspension flange is installed on the operation platform, and the crane is slowly lowered to completely transfer the load to the suspension flange.

[0038] Further, the specific steps of step S5 are:

[0039] S51, after the crane tool is loosened, the deck personnel disconnects the tool and removes the lifting tool;

[0040] S52, the cutting piece is used to cut the blind plate, the slope is processed after the blind plate is cut, and the slope is subjected to penetration inspection after the processing is completed;

[0041] S53, after the slope penetration inspection is qualified, subsequent assembly, welding work is carried out.

[0042] The technical effect of the present application is that the present application connects the lifting tool and welds the blind plate to the hose joint, meets the sealing and lowering conditions of the hose, and realizes the purpose of wet storage and recovery of the submarine hose. First, the sheet is welded to the hose joint, the sheet adopts the same steel material as the hose joint, which achieves the effect of sealing the hose, and does not damage the joint base material. Then the lifting tool is connected to the hose joint slot, four bolts are used to fasten the tool, and the tool is connected to the sling and other tools. Finally, the crane is connected to the lifting tool and lowered to the seabed for wet storage, and the hose is recovered for further operation. The present application not only meets the operation condition of wet storage and recovery, but also effectively seals the hose to prevent seawater from entering. BRIEF DESCRIPTION OF DRAWINGS

[0043] Fig. 1This is a schematic diagram showing the connection between the sling and the lifting fixture when the hose is wetted or recycled in this embodiment;

[0044] Fig. 2 This is a three-dimensional schematic diagram of the hoisting fixture in this embodiment. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0046] Examples, such as Figs. 1-2 As shown, this invention discloses a method for wet storage and recovery of segmented flexible subsea hoses, with each step implemented as follows:

[0047] A method for wet storage and recovery of segmented flexible subsea hoses, characterized by the following steps:

[0048] S1. Preparatory work before wet storage of hoses, including prefabricating blind flanges and hoisting fixtures, as well as changing the position of hoses and removing threaded drag heads from the ends of hoses.

[0049] The specific steps of step S1 are as follows:

[0050] S11. Lifting equipment and blind flange sealing for wet storage and recycling of prefabricated flexible hoses;

[0051] S12. Offshore hose laying: Severe weather is predicted to arrive, and the site does not meet the operating conditions, so the construction site needs to be evacuated.

[0052] S13. Use a crane and winch to temporarily suspend the end of the second section of hose at the water inlet bridge operating platform.

[0053] S14. Disconnect the hose from the crane and winch, and remove the threaded pull head at the end of the hose;

[0054] S15. Conduct a permeability test on the bevel.

[0055] S2. Weld the sealing blind flange to the hose connector and perform testing.

[0056] The specific steps of step S2 are as follows:

[0057] S21. After passing the inspection, use a sealing blind flange to weld and seal the end of the hose.

[0058] S22. After welding is completed and the temperature reaches room temperature, perform a penetrant test on the weld.

[0059] S23. After passing the inspection, the weld joint and the outside of the blind flange shall be wrapped with rubber for protection.

[0060] S24, the construction personnel install the wire plug in the argon filling hole.

[0061] S3, install the lifting tool on the hose, lower the hose to the wet storage site, and mark it.

[0062] The specific steps of step S3 are:

[0063] S31, install the prefabricated tool on the joint again, install 8 6.5T shackles, 4 10Tx4m lifting belts, 2 12.5T shackles, 1 17T lifting ring, and 2 25kg floating balls on the tool, use 12Tx4m lifting belts, 12.5T shackles, and 12.5T ROV hooks on one side of the crane to connect to the tool;

[0064] S32, the crane slowly recovers the force, so that the tension of the hose end is transferred from the suspension flange to the crane;

[0065] S33, remove the suspension flange at the operation platform, and lower the hose end along the route to the seabed by the crane, during which the ROV monitors the mud point and controls the layback within 20-50m;

[0066] S34, when the hose end reaches the seabed and the crane is not under force, the ROV disconnects the crane rigging connection underwater;

[0067] S35, the positioning engineer marks the end disposal position on the positioning map.

[0068] S4, when the operation window arrives, fish the hose to the operation platform, and install the hose on the suspension flange.

[0069] The specific steps of step S4 are:

[0070] S41, after the construction ship has the conditions for continuing to lay the hose, move the ship back to the end disposal point;

[0071] S42, the crane carries the recovery rigging into the water and lowers it to the hose end;

[0072] S43, the ROV connects the hose end rigging to the recovery rigging on the crane underwater;

[0073] S44, the crane slowly recovers the force, so that the hose end leaves the mud surface;

[0074] S45, the crane recovers the steel wire rope, the work ship moves along the wet storage route at the same time, and the ROV continuously observes the state of the hose end underwater;

[0075] S46, when the hose end is lifted more than 10m from the mud surface and the force state of the crane rigging is confirmed to be normal, the ROV flies to the mud point of the hose to monitor;

[0076] S47, the crane continues to recover the hose, the vessel controls the designed Layback to move the vessel;

[0077] S48, when the hose end is recovered out of the water surface, the crane is rotated to place the hose end on the water entry bridge operation platform;

[0078] S49, the suspension flange is installed at the operation platform, the crane is slowly lowered to completely transfer the load to the suspension flange.

[0079] S5, the lifting tool is removed, the cutting and bevel detection of the blocking blind plate are performed, and then the wet storage and recovery of the hose are completed.

[0080] The specific steps of step S5 are as follows:

[0081] S51, after the crane rigging is loosened, the deck personnel disconnect the rigging and remove the lifting tool;

[0082] S52, the cutting piece is used to cut the blocking blind plate, the bevel is reprocessed after the blocking blind plate is cut, and the bevel is subjected to penetration inspection after the processing is completed;

[0083] S53, after the bevel penetration inspection is qualified, subsequent assembly, welding work is performed.

[0084] The present application first fixes the hose on the deck, welds the blocking round sheet blind plate to the joint, the thickness of the blocking sheet blind plate is 2-4mm, the material is the same steel material as the joint, then connects the lifting tool on the joint connecting clamping groove, the tool contains four lifting lugs, each lifting lug connects two 6.5Te shackles, the shackles connect the sling and the ROV hook, finally, the crane connects the tool to lower the hose to the seabed for wet storage, the ROV hooks underwater, then the ship leaves the operation site, when the operation window is met, the crane rigging is lowered, the ROV hooks underwater, the hose is recovered to the deck and fixed, the lifting tool is removed in turn, the joint blocking blind plate is cut, and the subsequent laying operation is continued. The present application can effectively ensure the wet storage and recovery quality of the flexible hose, meet the hose wet storage and recovery load, the designed lifting tool can be reused, and thus the construction cost is saved.

[0085] The above-described embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. The equivalent substitutions or transformations made by the person skilled in the art on the basis of the present application are within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A method for wet storage and recovery of segmented flexible subsea hoses, characterized by the following steps: S1. Preparatory work before wet storage of hoses, including prefabrication of blind flanges and hoisting fixtures, as well as changing the position of hoses and removing threaded drag heads from the ends of hoses; S2. Weld the sealing blind flange to the hose connector and perform testing; S3. Install lifting equipment on the hose, lower the hose to the wet storage location, and mark it. S4. When the working window is open, retrieve the hose to the operating platform and install the hose on the suspension flange; S5. Remove the hoisting equipment, cut the blind flange, and after beveling inspection, the wet storage and recycling of the hose is completed. The specific steps of step S3 are as follows: S31. Reinstall the prefabricated fixture onto the joint, using 8 6.5T shackles, 4 10Tx4m slings, 2 12.5T shackles, 1 17T lifting ring, and 2 25kg floats to install it onto the fixture. Connect the crane side to the fixture using 12Tx4m slings, 12.5T shackles, and 12.5T ROV hooks. S32. The crane slowly retracts the load, transferring the tension at the end of the hose from the suspension flange to the crane. S33. Remove the suspension flange at the operating platform, and lower the end of the hose to the seabed along the route. During this process, the ROV monitors the mud contact points and controls the Layback within 20-50m. S34. When the end of the hose reaches the seabed and the crane is no longer under load, the ROV disconnects the crane rigging connection underwater. S35. The positioning engineer marks the end-of-life abandonment location on the positioning map.

2. The method for wet storage and recovery of segmented submarine flexible hoses according to claim 1, characterized in that: The specific steps of step S1 are as follows: S11. Lifting equipment and blind flange sealing for wet storage and recycling of prefabricated flexible hoses; S12. Offshore hose laying: Severe weather is predicted to arrive, and the site does not meet the operating conditions, so the construction site needs to be evacuated. S13. Use a crane and winch to temporarily suspend the end of the second section of hose at the water inlet bridge operating platform. S14. Disconnect the hose from the crane and winch, and remove the threaded pull head at the end of the hose; S15. Conduct a permeability test on the bevel.

3. The method for wet storage and recovery of segmented submarine flexible hoses according to claim 1, characterized in that: The specific steps of step S2 are as follows: S21. After passing the inspection, use a sealing blind flange to weld and seal the end of the hose. S22. After welding is completed and the temperature reaches room temperature, perform a penetrant test on the weld. S23. After passing the inspection, the weld joint and the outside of the blind flange shall be wrapped with rubber for protection. S24. The construction personnel install the plug into the argon filling hole.

4. The method for wet storage and recovery of segmented submarine flexible hoses according to claim 1, characterized in that: The specific steps of step S4 are as follows: S41. Once the construction vessel is ready to continue laying the hose, it shall be moved back to the final disposal point. S42. The crane carries the recovery rigging into the water and lowers it to the end of the hose. S43, ROV underwater connects the hose end rigging to the recovery rigging on the crane; S44. The crane slowly retracts the load, causing the end of the hose to leave the mud surface; S45. The crane retrieves the steel wire rope, and the work vessel moves along the wetted route simultaneously. The ROV continuously observes the condition of the hose end underwater. S46. When the end of the hose is lifted more than 10m away from the mud surface, after confirming that the crane rigging is under normal stress, the ROV flies to the point where the hose touches the mud to monitor it. S47. The crane continues to retrieve the hose, and the workboat moves within the Layback area designed by the control system. S48. After the end of the hose is retrieved out of the water, rotate the crane to place the end of the hose at the water inlet bridge operating platform. S49. Install a suspension flange on the operating platform, and slowly lower the crane to completely transfer the load onto the suspension flange.

5. The method for wet storage and recovery of segmented submarine flexible hoses according to claim 1, characterized in that: The specific steps of step S5 are as follows: S51. After the crane slings are loosened, deck personnel disconnect the slings and remove the lifting equipment. S52. Use a cutting disc to cut the blind sealing plate. After cutting the blind sealing plate, reprocess the bevel. After processing, perform a permeability test on the bevel. S53. After the bevel penetration test is passed, proceed with the subsequent assembly and welding work.

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