Underwater leveling method for single-point jacket

Abstract

The invention discloses an underwater leveling method for a single-point jacket. The underwater leveling method for the single-point jacket comprises the steps that the single-point jacket is hoisted in place underwater, and four sleeves connected with the jacket are inserted into a seabed; steel piles are inserted into four sleeves connected to the single-point jacket at intervals correspondingly, and the single-point jacket is preliminarily positioned; the lowest point position of the single-point jacket in the horizontal direction is measured, and the leveler is inserted into the steel pile of the sleeve at the lowest point position; a leveling oil cylinder of the leveler is clamped on a horn mouth of the sleeve; the leveling oil cylinder retracts according to the distance between the lowest point position and the highest point position, and the sleeve is lifted; after the lowest-point sleeve is lifted, the levelness of the single-point jacket in the horizontal direction is measured again, and the lowest-point sleeve measured for the second time continues to be lifted; measuring the levelness of the single-point jacket to meet the design requirement, and recycling the leveler. According to the underwater leveling method for the single-point jacket, the leveling efficiency and the leveling precision can be improved, and dependence on divers is avoided.

Description

Technical Field

[0001] This invention belongs to the field of marine oil engineering technology, and in particular relates to an underwater leveling method for a single-point jacket. Background Technology

[0002] Single-point mooring is a tower-type system structure that allows a floating production storage and offloading (FPSO) unit to rotate 360 ​​degrees with the wind and waves and remain in production. The fluid swivel head is a key component of the single-point mooring system. It is installed on the upper part of the single-point jacket and serves as a conversion device for various fluid pipelines between the stationary part (single-point jacket) and the rotating part (FPSO).

[0003] Single-point jackets are a type of small-scale skirted jacket, with a base dimension much smaller than that of deep-water skirted jackets. However, due to the presence of a fluid rotating head at the top, they require a higher leveling precision during installation. Deep-water jackets typically have leveling rings within their skirt sleeves, allowing for the use of a chuck-type leveling device for leveling. Single-point jackets, being smaller, generally lack leveling rings, making it impossible to use chuck-type leveling devices.

[0004] Therefore, there is an urgent need to design an underwater leveling method for single-point jackets to solve the problems mentioned above. Summary of the Invention

[0005] To address the technical problem mentioned in the background art that single-point jackets are small in size, lack leveling rings, and cannot be leveled using a stake-type leveling device, an underwater leveling method for single-point jackets is provided to solve the problem of underwater leveling of single-point jackets.

[0006] To achieve the above objectives, the specific technical solution of the underwater leveling method for a single-point guide frame of the present invention is as follows: A method for underwater leveling of a single-point jacket stent mainly includes the following steps: S1. The single-point jacket is hoisted and positioned underwater, and the four sleeves connected to the jacket are inserted into the seabed. S2. Insert steel piles into the four sleeves that are connected at intervals on the single-point jacket to initially position the single-point jacket. S3. Measure the lowest point of the single-point guide frame in the horizontal direction and insert the leveler into the steel pile of the lowest point sleeve. S4. The leveling cylinder of the leveler is snapped onto the flared end of the sleeve; S5. Based on the distance between the lowest and highest points, retract the leveling cylinder and lift the sleeve; S6. After the lowest point sleeve is lifted, measure the horizontality of the single-point guide frame in the horizontal direction again, and continue to lift the lowest point sleeve after the second measurement. S7. Measure the level of the single-point guide frame to ensure it meets the design requirements, and retrieve the leveling device.

[0007] Furthermore, in S1, a first sleeve, a second sleeve, a third sleeve, and a fourth sleeve are connected circumferentially along the single-point jacket. The first sleeve, the second sleeve, the third sleeve, and the fourth sleeve are inserted into the seabed to allow the single-point jacket to be positioned underwater.

[0008] Furthermore, in S2, the first sleeve, the second sleeve, the third sleeve, and the fourth sleeve are all provided with flared openings. Multiple steel piles are inserted along the flared openings of the first sleeve, the second sleeve, the third sleeve, and the fourth sleeve, respectively, with the inserted ends of the steel piles inserted into the seabed to preliminarily position the single-point guide frame.

[0009] Furthermore, in S3, the conical plug of the leveling device is hoisted and the underwater robot assists in inserting the conical plug into the steel pile.

[0010] Furthermore, the conical plug of the leveler is inserted into the steel pile and abuts against the inner wall of the steel pile.

[0011] Furthermore, in S4, the leveling cylinder is clamped onto the bell mouth of the sleeve by clamps.

[0012] Furthermore, in S5, the leveling cylinder retracts, causing the sleeve to rise vertically by a distance equal to the distance between the lowest and highest points.

[0013] Furthermore, in S6, the first sleeve, second sleeve, third sleeve, or fourth sleeve are adjusted sequentially according to the levelness of the single-point guide frame.

[0014] The underwater leveling method for single-point guide frame of the present invention has the following advantages: By using a leveling device for leveling operations, underwater personnel are no longer required to attach and detach lifting clips, reducing underwater construction risks and reliance on ship cranes. Operations can still be carried out in adverse weather and sea conditions. Leveling is achieved by raising the lowest point or lowering the highest point of the jacket structure. This application improves leveling efficiency and accuracy, eliminates reliance on divers, reduces construction risks, and lowers the requirements for weather and sea conditions during leveling operations. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the underwater placement of the single-point guide frame of the present invention; Figure 2 This is a side view of the single-point catheter holder of the present invention; Figure 3 This is a schematic diagram of the leveler of the present invention; Figure 4 This is a side view of the other side of the single-point catheter holder of the present invention.

[0016] Explanation of markings in the diagram: 1. Single-point guide frame; 2. First sleeve; 3. Second sleeve; 4. Third sleeve; 5. Steel pile; 6. Leveler; 61. Conical plug; 62. Leveling cylinder. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0018] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0019] The commonly used leveling methods have the following problems: 1. Leveling is carried out after pile driving is completed. The horizontal direction of the guide frame is restricted by the steel piles, and the vertical lifting stroke of a single pile leg is limited. 2. Lifting measures can only be taken at the relatively low point of the jacket; 3. Ship cranes cannot achieve centimeter-level lifting accuracy; 4. Sensitive to changes in swell; significant changes in ship heave and sway can damage the boom, hooks, and jacket support points. 5. Underwater operations have strict requirements on weather and sea conditions, and divers can only work for a short period of time each time. 6. Divers attaching and detaching safety harnesses underwater involves significant labor intensity and operational risks.

[0020] The following is a reference to the appendix. Figure 1 To be continued Figure 4 The present invention describes an underwater leveling method for a single-point guide frame.

[0021] As a preferred embodiment, the underwater leveling method for a single-point guide frame in this invention mainly includes the following steps: S1. The single-point jacket 1 is lowered into underwater position. The first sleeve 2, the second sleeve 3, the third sleeve 4 and the fourth sleeve connected to the single-point jacket 1 are inserted into the seabed. After the single-point jacket 1 is lowered into underwater position, the levelness will exceed the standard, resulting in the height of the four corners of the single-point jacket 1 being inconsistent. The single-point jacket 1 is circumferentially connected by a first sleeve 2, a second sleeve 3, a third sleeve 4, and a fourth sleeve, with each sleeve forming a 90-degree angle to ensure underwater positioning of the single-point jacket 1. Simultaneously, the first sleeve 2, second sleeve 3, third sleeve 4, and fourth sleeve are aligned vertically with the four corners above the platform of the single-point jacket 1. Therefore, after the single-point jacket 1 is underwater positioned, the horizontal height difference between the first sleeve 2, second sleeve 3, third sleeve 4, and fourth sleeve is the height difference between the four corners of the single-point jacket.

[0022] In this application, the first sleeve 2, the second sleeve 3, the third sleeve 4, and the fourth sleeve are positioned in ascending order, with the first sleeve 2 being lower than the second sleeve 3, lower than the third sleeve 4, and lower than the fourth sleeve, and then the level is adjusted by the leveling device 6.

[0023] S2. Insert steel piles 5 into the first sleeve 2, the second sleeve 3, the third sleeve 4 and the fourth sleeve that are connected at intervals on the single-point jacket 1 respectively to perform preliminary underwater positioning of the single-point jacket 1. The first sleeve 2, the second sleeve 3, the third sleeve 4 and the fourth sleeve are all provided with flared openings. Multiple steel piles 5 are inserted into the flared openings of the first sleeve 2, the second sleeve 3, the third sleeve 4 and the fourth sleeve respectively. The inserted end of the steel pile 5 is inserted into the seabed to initially position the single-point guide frame 1.

[0024] S3. Measure the lowest point of the single-point guide frame 1 in the horizontal direction, that is, at the first sleeve 2, and insert the leveler 6 into the steel pile 5 of the first sleeve 2. The conical plug 61 of the leveling device 6 is suspended and placed. The underwater robot assists the conical plug 61 in inserting into the steel pile 5. The conical plug 61 is retractable in the circumferential direction so that the conical plug 61 of the leveling device 6 is tightened and fixed to the inner wall of the steel pile 5 after being inserted into the steel pile 5.

[0025] The leveler 6 is connected to the steel pile 5 by a mechanical expansion structure, which can be fixed to the inner wall of the pile head. The connection with the sleeve is a hydraulic clamp, which can be fixed to the flared edge of the sleeve of the guide frame skirt pile. The leveler 6 raises or lowers the sleeve of the guide frame by retracting or extending the leveling cylinder 62.

[0026] S4. Drive the leveling cylinder 62 of the leveling device 6 so that the leveling cylinder 62 is clamped onto the flared end of the first sleeve 2 by the clamps. The leveling cylinder 62 is equipped with a displacement sensor, which directly displays the actual extension and retraction of the cylinder, achieving millimeter-level execution accuracy.

[0027] S5. Based on the distance between the lowest and highest points, recover the leveling cylinder 62 and lift the first sleeve 2; Among them, the leveling cylinder 62 retracts, causing the first sleeve 2 to be lifted vertically, and the lifting distance is the distance between the lowest point and the highest point.

[0028] S6. After the first sleeve 2 is lifted, the levelness of the single-point guide frame 1 in the horizontal direction is measured again. The vertical height of the second sleeve 3 is adjusted according to the levelness of the single-point guide frame 1. The second sleeve 3 is lifted or pressed down by the leveling device 6. S7. Measure the vertical height of the third sleeve 4, and raise or lower the third sleeve 4 using the leveler 6.

[0029] S8. Measure the level of the single-point guide frame 1 to ensure it meets the design requirements, and then retrieve the leveler.

[0030] It should be noted that the level of a single-point guide frame can be adjusted as a whole by raising the lower-positioned sleeve using the leveler 6 and pressing down the higher-positioned sleeve using the leveler 6. After adjusting the vertical position of the first sleeve 2, the second sleeve 3, the third sleeve 4, and the fourth sleeve, the individual leveler 6 can be retracted, or they can be retracted together after the overall leveling.

[0031] In a preferred embodiment, the leveler 6 can lift or press down the first sleeve 2, the second sleeve 3, the third sleeve 4, and the fourth sleeve individually; it can also pull or press down the sleeve on one side simultaneously through two levelers 6; it can also pull or press down the two sleeves simultaneously in a symmetrical direction; it can also pull or press down the three sleeves simultaneously through three levelers 6, thereby enabling the single-point guide frame 1 to achieve single-sleeve pulling or simultaneous lifting of multiple sleeves.

[0032] During the leveling process of single-point guide frame 1, since a single sleeve adjustment can only withstand a certain amount of adjustment force, multiple sleeves are adjusted simultaneously to increase the vertical adjustment force in order to meet construction requirements.

[0033] Based on the underwater leveling method of single-point jacket, this invention uses a leveling device to perform leveling operations in 6 rows, eliminating the need for divers to attach and detach hooks underwater, reducing underwater construction risks and dependence on ship cranes. It can still be carried out under poor weather and sea conditions, and the leveling purpose is achieved by raising the lowest point of the jacket or lowering the highest point of the jacket.

[0034] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for underwater leveling of a single-point jacket, characterized in that, The main steps include: S1. The single-point jacket is hoisted and positioned underwater, and the four sleeves connected to the jacket are inserted into the seabed. S2. Insert steel piles into the four sleeves that are connected at intervals on the single-point jacket to initially position the single-point jacket. S3. Measure the lowest point of the single-point guide frame in the horizontal direction and insert the leveler into the steel pile of the lowest point sleeve. S4. The leveling cylinder of the leveler is snapped onto the flared end of the sleeve; S5. Based on the distance between the lowest and highest points, retract the leveling cylinder and lift the sleeve; S6. After the lowest point sleeve is lifted, measure the horizontality of the single-point guide frame in the horizontal direction again, and continue to lift the lowest point sleeve after the second measurement. S7. Measure the level of the single-point guide frame to ensure it meets the design requirements, and retrieve the leveling device.

2. The underwater leveling method for a single-point jacket as described in claim 1, characterized in that, In S1, a first sleeve, a second sleeve, a third sleeve, and a fourth sleeve are connected circumferentially along the single-point jacket. The first sleeve, the second sleeve, the third sleeve, and the fourth sleeve are inserted into the seabed to allow the single-point jacket to be positioned underwater.

3. The underwater leveling method for a single-point jacket as described in claim 1, characterized in that, In S2, the first, second, third, and fourth sleeves are all provided with bell mouths. Multiple steel piles are inserted into the bell mouths of the first, second, third, and fourth sleeves respectively, with the inserted ends of the steel piles inserted into the seabed to initially position the single-point guide frame.

4. The underwater leveling method for a single-point jacket as described in claim 1, characterized in that, In S3, the conical plug of the leveling device is hoisted down, and an underwater robot assists in inserting the conical plug into the steel pile.

5. The underwater leveling method for a single-point jacket as described in claim 4, characterized in that, After the conical plug of the leveler is inserted into the steel pile, it abuts against the inner wall of the steel pile.

6. The underwater leveling method for a single-point jacket according to claim 1, characterized in that, In S4, the leveling cylinder is clamped onto the bell mouth of the sleeve by clamps.

7. The underwater leveling method for a single-point jacket as described in claim 1, characterized in that, In S5, the leveling cylinder retracts, causing the sleeve to rise vertically by a distance equal to the distance between the lowest and highest points.

8. The underwater leveling method for a single-point jacket according to claim 1, characterized in that, In S6, the first sleeve, second sleeve, third sleeve, or fourth sleeve are adjusted sequentially according to the levelness of the single-point guide frame.

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