Method for lifting FPSO external seawater riser segments
Patent Information
- Application Number
- CN202611314689.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-27
- Publication Date
- 2026-10-23
AI Technical Summary
[0004]针对现有技术的不足，本发明提供了FPSO外置海水提升管分段的吊装方法，解决了上述背景中提到海水提升管在吊装过程中姿态难以平稳转换的问题
1、本发明，通过上小车与下小车协同操作同时起吊海水提升管，再将上小车松钩，使载荷平稳转移至下小车单独承载，实现载荷的平稳转移和姿态调整，避免载荷突变产生的冲击晃动，提高了吊装安全性和稳定性。
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Figure CN122957734A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of segmented installation technology of seawater riser pipes, specifically a method for hoisting segments of external seawater riser pipes for FPSOs. Background Technology
[0002] As a relatively advanced deep-sea oil production platform, the demand for the construction or conversion of Floating Production Storage and Offloading (FPSO) vessels continues to increase with the continuous development of deep-sea oil fields. Seawater lift pumps are an essential component of FPSOs. Seawater lift pipes are usually installed on the outer side of the FPSO hull. They work below sea level and lift seawater through the seawater lift pipes to the FPSO platform, providing cooling water and production water for other equipment on the FPSO.
[0003] In the process of hoisting the existing FPSO side-mounted seawater lift pipe in the dry dock, due to the large length, heavy weight and special installation position of the seawater lift pipe, conventional single-hook hoisting is difficult to achieve a smooth attitude transition of the seawater lift pipe from a horizontal state to a vertical installation state on the assembly platform within a limited space, and the hook is prone to impact and swaying when the force is transferred. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method for hoisting FPSO external seawater riser pipes in sections, which solves the problem mentioned in the background that the seawater riser pipe's posture is difficult to change smoothly during hoisting.
[0005] This invention provides the following technical solution: a method for hoisting sectional external seawater riser pipes of an FPSO, comprising the following steps: Step S1: Transport the seawater lift pipe to the assembly platform below the gantry crane, which is located on one side of the FPSO hull. Step S2: Connect the hook and the lifting lug. Connect the first hook of the upper trolley of the gantry crane to the first lifting lug set on the seawater lifting pipe, and connect the second hook of the lower trolley of the gantry crane to the second lifting lug set on the seawater lifting pipe. Step S3: The upper and lower trolleys are lifted simultaneously. The upper and lower trolleys of the gantry crane are started so that the first hook and the second hook are lifted at the same time to lift the seawater lifting pipe. Step S4: The upper trolley is gradually released, and the first hook of the upper trolley is activated to release the hook, so that the second hook of the lower trolley is subjected to force from the second lifting lug until the upper trolley is completely released. The second hook of the lower trolley alone bears the entire weight of the seawater riser pipe. At this time, the seawater riser pipe is in a vertical state. The seawater riser pipe is lifted to the installation position of the FPSO hull for positioning and placement. Step S5: Cut off the first and second lifting lugs. After the seawater riser is installed and positioned, cut off the first and second lifting lugs located above the seawater riser.
[0006] Preferably, in step S2: there are two first lifting lugs, two first hooks, two second hooks, and two second lifting lugs; the two first hooks are connected to the two first lifting lugs respectively, and the two second hooks are connected to the two second lifting lugs respectively. The first lifting lug and the second lifting lug are arranged at intervals along the length of the seawater riser pipe and are respectively located near both ends of the seawater riser pipe.
[0007] Preferably, in step S2: two second lifting lugs are symmetrically welded to the top flange face of the seawater riser pipe; The first lifting lug is attached to the outer surface of the seawater riser pipe, and the first lifting lug is located at the end of the seawater riser pipe away from the second lifting lug along its length.
[0008] Preferably, in step S3, the specific method of gradually releasing the hook of the upper trolley is as follows: the first hook of the upper trolley descends at a constant speed of 0.5 to 1.5 m / min until the second hook fully bears the entire weight of the seawater lift pipe.
[0009] Preferably, in step S4, the seawater riser pipe is hoisted to the outside of the FPSO hull side outer plating for installation.
[0010] Preferably, in step S5, the first and second lifting lugs that are cut off are the portions extending out of the seawater riser structure.
[0011] Preferably, in step S5, the first and second lifting lugs are cut by flame cutting or plasma cutting, and the cut marks are polished after cutting.
[0012] Preferably, the gantry crane is a 600T gantry crane.
[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention involves simultaneously lifting the seawater riser pipe by coordinating the operation of the upper and lower trolleys, and then releasing the hook of the upper trolley to smoothly transfer the load to the lower trolley for independent support. This achieves smooth load transfer and attitude adjustment, avoids impact and swaying caused by sudden load changes, and improves the safety and stability of the lifting operation.
[0014] 2. In this invention, the first and second lifting lugs are removable structures extending from the seawater riser pipe. After being mounted and positioned, the lifting lugs are cut off by flame or plasma cutting and the cut marks are ground off. This facilitates high-altitude dismantling operations in narrow spaces on the side of the ship, reduces safety risks, avoids damage to the seawater riser pipe body, and ensures the integrity of the pipe body structure.
[0015] 3. In this invention, the second lifting lug is symmetrically welded to the top flange face and the first lifting lug is located at the bottom of the pipe body. When the lower trolley is carrying the load alone, the lifting point is located at the top of the pipe body, and the pipe body is in a vertically suspended state. The force is evenly distributed, which avoids excessive bending moment or deformation caused by eccentric force during the hoisting process and ensures the structural safety of the pipe body during hoisting. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 For the present invention Figure 1 Enlarged structural diagram at position A in the middle; Figure 3 This is a schematic diagram of the seawater riser pipe, the first lifting lug, and the second lifting lug of the present invention; Figure 4 This is a schematic diagram of the hoisting method for the segmented external seawater riser pipe of the FPSO according to the present invention.
[0017] In the diagram: 1. FPSO hull; 2. Assembly platform; 3. Seawater lift pipe; 4. Gantry crane; 5. Upper trolley; 6. First hook; 7. Lower trolley; 8. Second hook; 9. First lifting lug; 10. Second lifting lug. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] Please see Figure 1-4 The method for hoisting FPSO external seawater riser sections includes the following steps: Step S1: Transport the seawater lift pipe 3 to the assembly platform 2 below the gantry crane 4. At this time, it is located on one side of the FPSO hull 1 of the seawater lift pipe 3. The gantry crane 4 is a 600T gantry crane 4. Step S2: Connect the first hook 6 of the upper trolley 5 of the gantry crane 4 to the first lifting lug 9 set on the seawater lifting pipe 3, and connect the second hook 8 of the lower trolley 7 of the gantry crane 4 to the second lifting lug 10 set on the seawater lifting pipe 3. Please refer to Figures 2-3 There are two of each of the first lifting lug 9, the first hook 6, the second hook 8, and the second lifting lug 10. The two first hooks 6 are connected to the two first lifting lugs 9 respectively, and the two second hooks 8 are connected to the two second lifting lugs 10 respectively. The first lifting lugs 9 and the second lifting lugs 10 are arranged at intervals along the length of the seawater riser pipe 3 and are respectively set close to both ends of the seawater riser pipe 3. Specifically, two second lifting lugs 10 are symmetrically welded to the top flange face of the seawater riser pipe 3, and the first lifting lug 9 is connected to the outer surface of the seawater riser pipe 3, with the first lifting lug 9 located at the end of the seawater riser pipe 3 away from the second lifting lug 10 along its length. Step S3: Start the upper trolley 5 and lower trolley 7 of the gantry crane 4 so that the first hook 6 and the second hook 8 can be lifted at the same time to lift the seawater lift pipe 3; The specific method for gradually releasing the hooks on the upper trolley 5 is as follows: the first hook 6 of the upper trolley 5 descends at a constant speed of 0.5 to 1.5 m / min until the second hook 8 fully bears the entire weight of the seawater riser pipe 3. Step S4: Start the first hook 6 of the upper trolley 5 to release the hook, so that the second hook 8 of the lower trolley 7 is stressed from the second lifting lug 10 until the upper trolley 5 is completely released. The second hook 8 of the lower trolley 7 will bear the entire weight of the seawater lift pipe 3 alone. At this time, the seawater lift pipe 3 is in a vertical state. The seawater lift pipe 3 is lifted to the installation position of the FPSO hull 1 for positioning. Specifically, the seawater lift pipe 3 is lifted to the outside of the side outer plate of the FPSO hull 1 for installation. Step S5: After the seawater riser 3 is installed and positioned, the first lifting lug 9 and the second lifting lug 10 located above the seawater riser 3 are cut off. The first lifting lug 9 and the second lifting lug 10 are the parts that protrude from the structure of the seawater riser 3. The first lifting lug 9 and the second lifting lug 10 are cut by flame cutting or plasma cutting. After cutting, the cut marks are polished.
[0020] In one specific implementation, the seawater riser pipe 3 is hoisted as a whole to the outside of the side plate of the FPSO hull 1 and installed. The seawater riser pipe 3 is a cylindrical structure with a height of 33.5m, a pipe radius of 950mm, and a total weight of 55t. The seawater riser pipe 3 is prefabricated as a whole on the assembly platform 2, including pipe welding, flange installation and internal component assembly. The outer side of the FPSO hull 1 is the final installation position for the seawater lift pipe 3. The assembly platform 2 is located below the gantry crane 4 to support the seawater lift pipe 3 to be lifted. The gantry crane 4 is a 600T gantry crane, and its span and lifting height are selected according to the actual size of the dock and the size of the seawater lift pipe 3. The gantry crane 4 is located above the dock and includes an upper trolley 5 and a lower trolley 7. The upper trolley 5 is located on the main beam of the gantry crane 4 and can move along the main beam. Two first hooks 6 are connected below the upper trolley 5. The lower trolley 7 is located on the main beam of the gantry crane 4 and can move independently along the main beam. Two second hooks 8 are connected below the lower trolley 7. The upper trolley 5 and the lower trolley 7 are independently controlled by the control system of the gantry crane 4, and can realize their respective lifting and moving actions.
[0021] The top of the seawater riser pipe 3 is provided with a flange face, on which two second lifting lugs 10 are symmetrically welded. The two second lifting lugs 10 are symmetrically arranged on the flange face and extend a certain height above the top flange face of the seawater riser pipe 3 to facilitate the cutting operation after the hoisting is completed. Each second lifting lug 10 has a hoisting hole for the second lifting hook 8 to pass through. Two first lifting lugs 9 are welded to the outer surface of the seawater riser pipe 3 near the bottom. The two first lifting lugs 9 are symmetrically arranged on both radial sides of the seawater riser pipe 3 and are located on the same horizontal plane. The first lifting lugs 9 and the second lifting lugs 10 are arranged at intervals along the length of the seawater riser pipe 3. The first lifting lugs 9 extend a certain distance from the outer surface of the seawater riser pipe 3 to facilitate the cutting operation after the hoisting is completed. Each first lifting lug 9 has a hoisting hole for the first lifting hook 6 to pass through.
[0022] The hoisting method of the present invention specifically includes the following steps: Step S1: Transporting the seawater riser pipe: After the seawater lift pipe 3 has been prefabricated and inspected on the assembly platform 2, it is placed horizontally and transported to the assembly platform 2 below the gantry crane 4. At this time, the seawater lift pipe 3 is located on one side of the outer plating of the FPSO hull 1, with its length parallel to the outer plating of the FPSO hull 1. The top end of the seawater lift pipe 3 faces the lower trolley 7 of the gantry crane 4, and the bottom end faces the upper trolley 5, so as to facilitate the subsequent connection and attitude change of the hook.
[0023] Step S2: Connect the hook and the lifting lug: Start the gantry crane 4 and move the upper trolley 5 to the position above the bottom of the seawater riser pipe 3. Connect the two first hooks 6 of the upper trolley 5 to the two first lifting lugs 9 on the outer surface of the seawater riser pipe 3 respectively. Specifically, insert the first hooks 6 into the lifting holes of the first lifting lugs 9 and confirm that the connection between the hooks and the lifting lugs is reliable. At the same time, the lower trolley 7 is moved to the position above the top of the seawater riser pipe 3, and the two second hooks 8 of the lower trolley 7 are connected to the two second lifting lugs 10 on the flange surface at the top of the seawater riser pipe 3 respectively. Specifically, the second hooks 8 are inserted into the lifting holes of the second lifting lugs 10, and it is confirmed that the connection between the hooks and the lifting lugs is reliable. After the connection is completed, the connection status of all hooks and lifting lugs is checked to ensure that each hook is subjected to uniform force and that there is no twisting or jamming of the hooks.
[0024] Step S3: Simultaneous lifting of the upper and lower trolleys: Start the upper trolley 5 and lower trolley 7 of the gantry crane 4, so that the first hook 6 and the second hook 8 rise simultaneously to lift the seawater lift pipe 3 from the main assembly platform 2. During the lifting process, the upper trolley 5 and lower trolley 7 rise synchronously, with the lifting speed controlled at 2-3 m / min, so that the seawater lift pipe 3 leaves the main assembly platform 2 smoothly in a horizontal position. When the seawater lift pipe 3 is completely detached from the main assembly platform 2 and reaches a certain height, usually about 0.5-1 m from the upper surface of the main assembly platform 2, stop lifting and check the balance of the seawater lift pipe 3. At this time, the first hook 6 of the upper trolley 5 and the second hook 8 of the lower trolley 7 jointly bear the entire weight of the seawater lift pipe 3, with the first hook 6 bearing the weight of the bottom area of the seawater lift pipe 3 and the second hook 8 bearing the weight of the top area of the seawater lift pipe 3.
[0025] Step S4: The upper trolley is gradually unhooked, the load is transferred to the lower trolley, and it is vertically mounted and positioned.
[0026] Start the upper trolley 5, causing its first hook 6 to descend at a constant speed of 0.5–1.5 m / min. During the descent of the first hook 6, the second hook 8 of the lower trolley 7 remains stationary or is slightly adjusted according to the attitude changes of the seawater riser 3. As the upper trolley 5 continues to release the hook, the bottom of the seawater riser 3 gradually descends, and the seawater riser 3 slowly rotates around the connection point of the second lifting lug 10, gradually changing from a horizontal to a vertical attitude. During this process, the gravity load of the seawater riser pipe 3 is gradually transferred from the first hook 6 to the second hook 8. When the upper trolley 5 is completely unhooked, that is, when the wire rope between the first hook 6 and the first lifting lug 9 is completely slack, the first hook 6 no longer bears the weight of the seawater riser pipe 3, and the entire weight of the seawater riser pipe 3 is borne solely by the two second hooks 8 of the lower trolley 7. At this time, the seawater riser pipe 3 is in a vertically suspended state, with its top end suspended on the second hook 8 through the second lifting lug 10 and its bottom end pointing vertically downward. After ensuring that the seawater riser pipe 3 is in a stable vertical position, start the lower trolley 7 to lift the vertical seawater riser pipe 3 to the predetermined installation position above the outer side plate of the FPSO hull 1. Then, control the lower trolley 7 to slowly descend, so that the bottom of the seawater riser pipe 3 gradually approaches the installation base. Adjust the circumferential orientation of the seawater riser pipe 3 to align it with the positioning mark on the installation base. Continue to descend until the bottom of the seawater riser pipe 3 contacts the installation base and is in place. After confirming that the installation position of the seawater riser pipe 3 meets the design requirements, temporarily fix the seawater riser pipe 3 to the installation base.
[0027] Step S5: Remove the first and second lugs: After the seawater riser pipe 3 is installed and positioned, the lifting lugs are removed. Using flame cutting or plasma cutting, the two second lifting lugs 10 located on the top flange surface of the seawater riser pipe 3 and the two first lifting lugs 9 located on the bottom of the outer surface of the seawater riser pipe 3 are removed. The portions of the first lifting lugs 9 and the second lifting lugs 10 that protrude from the structure of the seawater riser pipe 3 are also removed. During the cutting process, care should be taken to protect the base material of the seawater riser pipe 3 from damage. After the cutting is completed, the cut marks are polished with an angle grinder to remove the burrs and oxide layer, making the surface of the cut marks smooth and flat. After polishing, the cut marks are repaired with anti-corrosion coating. The coating thickness is consistent with the surrounding area to ensure the corrosion resistance of the seawater riser pipe 3 in the marine environment. In another embodiment, plasma cutting is used for removal, which is suitable for situations where higher removal quality is required. Plasma cutting has the characteristics of narrow kerf and small heat-affected zone, which can further reduce the impact of the removal operation on the heat input of the seawater riser pipe 3 base material. After the removal is completed, grinding and anti-corrosion coating repair are also performed.
[0028] By utilizing the coordinated operation of the upper trolley 5 and lower trolley 7 of the gantry crane 4, the seawater riser pipe 3 is first lifted simultaneously by the upper trolley 5 and lower trolley 7. Then, the upper trolley 5 is gradually released, allowing the load to be smoothly transferred from the two lifting points to the two lifting points of the lower trolley 7. This enables the seawater riser pipe 3 to automatically and smoothly transition from a horizontal to a vertical posture during the lifting process. During this process, the speed of the first hook 6 of the upper trolley 5 decreases at a uniform speed, allowing the load to be smoothly transferred to the lower trolley 7 for sole support. This achieves smooth load transfer and posture adjustment, avoiding impact and swaying caused by sudden speed changes during load transfer, ensuring the stability and safety of the lifting process, and overcoming the technical defects of difficulty in posture adjustment during the overall lifting of large tubular components in existing technologies. The first lifting lug 9 and the second lifting lug 10 are removable structures extending from the seawater riser pipe 3, using fire... The lifting lugs extending from the seawater riser pipe 3 structure are removed using flame cutting or plasma cutting, and the cut marks are then ground down. The cutting operation can be carried out on the outer side of the hull plate, with the cutting surface far from the pressure-bearing pipe wall of the seawater riser pipe 3. This facilitates the cutting operation in a narrow space at high altitude, reduces the safety threat to the workers, avoids damage to the main body of the seawater riser pipe 3, and ensures the structural integrity of the seawater riser pipe 3 for long-term service. After the seawater riser pipe 3 is prefabricated as a whole on the assembly platform 2, it is directly lifted as a whole to the predetermined position on the outer side of the FPSO hull plate by the gantry crane 4. Compared with the method of high-altitude docking after sectional lifting, this reduces the amount of high-altitude welding and painting work in the dock stage, shortens the dock occupation period, reduces the management difficulty of cross-operation of multiple trades, and significantly improves the overall efficiency of FPSO construction.
[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for hoisting FPSO external seawater riser pipe in sections, characterized in that, Includes the following steps: Step S1: Transport the seawater lift pipe (3) to the assembly platform (2) below the gantry crane (4), at which point it is located on one side of the FPSO hull (1) of the seawater lift pipe (3); Step S2: Connect the hook and the lug. Connect the first hook (6) of the upper trolley (5) of the gantry crane (4) to the first lug (9) set on the seawater lift pipe (3). Connect the second hook (8) of the lower trolley (7) of the gantry crane (4) to the second lug (10) set on the seawater lift pipe (3). Step S3: The upper trolley (5) and the lower trolley (7) are lifted at the same time. The gantry crane (4) is started so that the upper trolley (5) and the lower trolley (7) lift the first hook (6) and the second hook (8) at the same time, and lift the seawater lifting pipe (3). Step S4: The upper trolley (5) is gradually unhooked, and the load is transferred to the lower trolley (7). It is then vertically mounted and positioned. The first hook (6) of the upper trolley (5) is activated to unhook the load, so that the second hook (8) of the lower trolley (7) is subjected to force from the second lifting lug (10) until the upper trolley (5) is completely unhooked. The second hook (8) of the lower trolley (7) then bears the entire weight of the seawater lift pipe (3) alone. At this time, the seawater lift pipe (3) is in a vertical state. The seawater lift pipe (3) is then lifted to the installation position of the FPSO hull (1) for positioning. Step S5: Cut off the first lifting lug (9) and the second lifting lug (10). After the seawater lift pipe (3) is mounted and positioned, cut off the first lifting lug (9) and the second lifting lug (10) located above the seawater lift pipe (3).
2. The method for hoisting FPSO external seawater riser sections according to claim 1, characterized in that, In step S2: there are two of each of the first lifting lug (9), the first hook (6), the second hook (8), and the second lifting lug (10). The two first hooks (6) are connected to the two first lifting lugs (9) respectively, and the two second hooks (8) are connected to the two second lifting lugs (10) respectively. The first lifting lug (9) and the second lifting lug (10) are arranged at intervals along the length of the seawater lift pipe (3) and are respectively located near both ends of the seawater lift pipe (3).
3. The method for hoisting FPSO external seawater riser sections according to claim 2, characterized in that, In step S2: two second lifting lugs (10) are symmetrically welded to the top flange face of the seawater riser pipe (3); The first lifting lug (9) is attached to the outer surface of the seawater riser pipe (3), and the first lifting lug (9) is located at the end of the seawater riser pipe (3) away from the second lifting lug (10) along its length.
4. The method for hoisting FPSO external seawater riser sections according to claim 1, characterized in that, In step S3, the specific method of gradually releasing the hook of the upper trolley (5) is as follows: the first hook (6) of the upper trolley (5) descends at a constant speed of 0.5 to 1.5 m / min until the second hook (8) fully bears the entire weight of the seawater lift pipe (3).
5. The method for hoisting FPSO external seawater riser sections according to claim 1, characterized in that, In step S4, the seawater lift pipe (3) is hoisted to the outside of the FPSO hull (1) for installation.
6. The method for hoisting FPSO external seawater riser sections according to claim 1, characterized in that, In step S5, the first lifting lug (9) and the second lifting lug (10) that are cut off are the parts that extend out of the structure of the seawater riser pipe (3).
7. The method for hoisting FPSO external seawater riser sections according to claim 6, characterized in that, In step S5, the first lug (9) and the second lug (10) are cut by flame cutting or plasma cutting, and the cut marks are polished after cutting.
8. The method for hoisting FPSO external seawater riser sections according to claim 1, characterized in that, The gantry crane (4) is a 600T gantry crane (4).