Laterally expanding spoke-type suction anchor

Abstract

The application provides a transverse expansion spoke suction anchor, which comprises an inner cylinder, an outer cylinder and a plurality of first spokes, the outer cylinder is arranged outside the inner cylinder, the longitudinal length of the outer cylinder is less than the longitudinal length of the inner cylinder, the first spokes are arranged between the outer cylinder and the inner cylinder, the outer side of the first spokes is fixedly connected with the outer cylinder, the inner side of the first spokes is fixedly connected with the inner cylinder, a plurality of first through holes are arranged on the first spokes, and the plurality of first spokes are distributed around the circumference of the inner cylinder. Through the application, the technical problem of poor bearing capacity of the suction anchor is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore oil and gas production equipment, and in particular to a transversely expanded spoke-type suction anchor. Background Art

[0002] The suction anchor is a cylindrical structure with a closed top. It is mainly used as a bearing foundation for shallow underwater hydrate extraction pipelines, underwater oil extraction pipelines and offshore wind power foundations. It has the characteristics of high bearing capacity and excellent pull-out resistance, and is an important foundation for offshore oil and gas extraction operations.

[0003] After the suction anchor is lowered, it contacts the soil layer and generates sufficient bearing capacity through the lateral friction resistance generated by the contact. Due to the small diameter of hydrate mining and underwater oil production foundation, in order to ensure that the suction anchor has sufficient bearing capacity, the longitudinal structure of the suction anchor is usually long, which makes its manufacturing and processing difficult and increases the difficulty of on-site processing.

[0004] The cylindrical suction anchor has a top plate and a wall. After installation, the top plate is located at the mud surface, while the wall is below. Its primary bearing capacity is generated by the lateral friction between the wall and the subsurface. To meet construction requirements, the wall of the anchor is typically larger in diameter or longer.

[0005] The skirt-type suction anchor is based on the barrel-type suction anchor, but the diameter of the upper top plate is enlarged. The upper top plate protrudes from the outer circle of the barrel wall, forming an annular bearing structure. When the suction anchor is lowered, the annular bearing structure is located at the mud surface and contacts the mud surface, thus providing a certain load-bearing capacity. However, if the suction anchor cannot be lowered into place or the top plate does not contact the mud surface, the annular bearing structure will not be able to provide load-bearing capacity. The upper top plate skirt bearing structure is located at the mud surface, where the soil strength is weak, and the resulting load-bearing capacity is limited.

[0006] In summary, the suction anchor in the prior art has the technical problem of poor bearing capacity. Summary of the Invention

[0007] The purpose of the present invention is to provide a transversely expanded spoke-type suction anchor to solve the technical problem of poor bearing capacity of the suction anchor.

[0008] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0009] The present invention provides a transversely expanded spoke-type suction anchor, comprising: an inner tube, an outer tube and a plurality of first spokes, wherein the outer tube is arranged outside the inner tube, and the longitudinal length of the outer tube is smaller than the longitudinal length of the inner tube, the first spokes are arranged between the outer tube and the inner tube, and the outer side of the first spoke is fixedly connected to the outer tube, and the inner side of the first spoke is fixedly connected to the inner tube, a plurality of first through holes are provided on the first spoke, and the plurality of first spokes are distributed around the circumference of the inner tube.

[0010] In a preferred embodiment, the suction anchor includes a second spoke plate, which is disposed in the inner cylinder. The outer side of the second spoke plate is fixed to the inner cylinder, and the inner side of the second spoke plate is suspended.

[0011] In a preferred embodiment, a plurality of second through holes are provided on the second web.

[0012] In a preferred embodiment, the suction anchor includes an upper top plate, the upper top plate is fixed to the top surface of the inner tube, and at least one water hole is provided on the upper top plate.

[0013] In a preferred embodiment, the outer diameter of the upper top plate is greater than or equal to the outer diameter of the inner cylinder and smaller than the outer diameter of the outer cylinder.

[0014] In a preferred embodiment, the outer cylinder is concentric with the inner cylinder, and the top surface of the outer cylinder and the top surface of the first spoke plate are both flush with the bottom surface of the upper top plate.

[0015] In a preferred embodiment, a plurality of third through holes are provided on the wall of the outer cylinder.

[0016] In a preferred embodiment, the first spoke plate and the second spoke plate are both arranged in the radial direction, and the first spoke plate and the second spoke plate are staggered in the circumferential direction.

[0017] In a preferred embodiment, the longitudinal length of the second spoke is greater than the longitudinal length of the outer cylinder, and the longitudinal length of the second spoke is equal to or less than the longitudinal length of the outer cylinder; the longitudinal length of the first spoke is equal to or less than the longitudinal length of the outer cylinder.

[0018] In a preferred embodiment, the transverse width of the second web is 0.2 to 0.3 times the inner diameter of the inner cylinder.

[0019] The characteristics and advantages of the present invention are:

[0020] (1) After being lowered into place, the surrounding soil will squeeze the side wall of the first spoke, the inner and outer walls of the inner tube, and the inner and outer walls of the outer tube, thereby generating lateral friction resistance; when the suction anchor is loaded, the soil will generate an upward friction force on the suction anchor;

[0021] (2) After the suction anchor is lowered, the first through hole on the first spoke will gradually be filled with soil due to the recovery of the soil layer. At this time, when the suction anchor is bearing, the first through hole will generate shear force on the soil layer. The soil layer provides bearing capacity for the suction anchor. Because the soil layer has a large viscosity, the shear force will be greater than the side wear resistance, providing a higher bearing capacity.

[0022] (3) The first spoke plate is distributed in a spoke-like manner and extends in the transverse direction of the suction anchor, having a larger effective contact area with the stratum, thereby effectively improving the bearing capacity and pull-out resistance of the suction anchor;

[0023] (4) The suction anchor improves lateral and vertical stability, thus meeting the requirements of deepwater shallow drilling projects for wellhead stability;

[0024] (5) The suction anchor is shortened longitudinally, so that the inner cavity is further reduced. The amount of water that needs to be pumped during the lowering process is smaller, which can reduce the time for pumping water during operation, help improve operation efficiency, reduce the difficulty of lifting operations, and reduce various costs such as labor and equipment rental during operation;

[0025] (6) The suction anchor has a shorter longitudinal length, a simpler structure, and improved overall strength. It can reduce the amount of steel used, save the cost of raw materials, reduce the difficulty of processing and manufacturing, shorten the manufacturing cycle, improve manufacturing efficiency, and save labor and machinery costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the overall structure of the transversely expanded spoke-type suction anchor provided by the present invention;

[0028] Figure 2 Another schematic diagram of the overall structure of the transversely expanding spoke-type suction anchor provided by the present invention;

[0029] Figure 3A A schematic side view of the structure of the laterally expanded spoke-type suction anchor provided by the present invention;

[0030] Figure 3B A schematic diagram of the top view of the laterally expanded spoke-type suction anchor provided by the present invention;

[0031] Figure 4AA schematic cross-sectional view of the AA surface of the laterally expanded spoke-type suction anchor provided by the present invention;

[0032] Figure 4B A schematic diagram of the laterally expanded spoke-type suction anchor provided by the present invention being subjected to soil compression force;

[0033] Figure 5-Figure 6 A schematic structural diagram of the inner cylinder in the transversely expanded spoke-type suction anchor provided by the present invention;

[0034] Figure 7 A schematic structural diagram of the second spoke plate in the transversely expanded spoke-type suction anchor provided by the present invention;

[0035] Figure 8-Figure 9 A schematic structural diagram of the outer cylinder in the transversely expanded spoke-type suction anchor provided by the present invention;

[0036] Figure 10 A schematic structural diagram of the first spoke in the transversely expanding spoke-type suction anchor provided by the present invention;

[0037] Figure 11 This is a schematic diagram of the force applied to the first spoke in the transversely expanding spoke-type suction anchor provided by the present invention.

[0038] Description of Figure Numbers:

[0039] 10. Inner tube; 20. Upper top plate; 21. Water hole;

[0040] 30. Outer cylinder; 31. Third through hole;

[0041] 40. First spoke; 41. First through hole;

[0042] 50. Second spoke plate; 51. Second through hole;

[0043] 60. Soil layer. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The present invention provides a transversely expanded spoke type suction anchor, such as Figures 1-4BAs shown, the suction anchor includes: an inner cylinder 10, an outer cylinder 30 and a plurality of first spokes 40. The outer cylinder 30 is arranged outside the inner cylinder 10, and the longitudinal length of the outer cylinder 30 is smaller than the longitudinal length of the inner cylinder 10. The first spokes 40 are arranged between the outer cylinder 30 and the inner cylinder 10. The outer side of the first spoke 40 is fixedly connected to the outer cylinder 30, and the inner side of the first spoke 40 is fixedly connected to the inner cylinder 10. A plurality of first through holes 41 are provided on the first spoke 40, and the plurality of first spokes 40 are distributed around the circumference of the inner cylinder 10.

[0046] The suction anchor has the following characteristics: (1) After being lowered into place, the surrounding soil will squeeze the side walls of the first spoke 40, the inner and outer walls of the inner tube 10, and the inner and outer walls of the outer tube 30, thereby generating lateral friction resistance; when the suction anchor is bearing load, the soil will generate an upward friction force on the suction anchor; (2) After the suction anchor is lowered, the first through hole 41 on the first spoke 40 will gradually be filled with the soil layer 60 under the action of the recovery of the soil layer 60. At this time, when the suction anchor is bearing load, the first through hole 41 will generate a shear force on the soil layer 60. The soil layer 60 provides bearing capacity for the suction anchor. Because the viscosity of the soil layer 60 is large, the shear force will be greater than the lateral friction resistance, providing a higher bearing capacity; (3) The first spoke 40 distributed in a spoke-like manner expands in the lateral direction of the suction anchor, which has a large The effective contact area with the formation effectively improves the bearing capacity and pull-out resistance of the suction anchor; (4) The suction anchor improves the lateral stability and vertical stability, so that it can meet the requirements of deep-water shallow drilling projects for wellhead stability; (5) The suction anchor is shortened in the longitudinal direction, so that the inner cavity is further reduced, and the amount of water to be pumped during the lowering process is smaller, which can reduce the time for pumping water during operation, help improve operation efficiency, reduce the difficulty of operations such as lifting operations, and reduce various costs such as labor and equipment rental during operations; (6) The suction anchor has a shorter longitudinal length, a simpler structure, and improved overall strength, which can reduce the amount of steel used, save manufacturing raw material costs, reduce processing and manufacturing difficulties, shorten the manufacturing cycle, improve manufacturing efficiency, and save labor and machinery costs.

[0047] In one embodiment, the suction anchor includes a second spoke 50, which is disposed in the inner tube 10. Figure 3B-Figure 4B and Figure 7 As shown, the outer side of the second spoke 50 is fixed to the inner tube 10. The second spoke 50 increases the contact area between the suction anchor and the soil layer, effectively improving the bearing capacity. Furthermore, the inner side of the second spoke 50 is suspended and provided with multiple second through holes 51. After the suction anchor is lowered, the second through holes 51 on the second spoke 50 will gradually fill with soil as the soil layer recovers. The second through holes 51 will generate shear force on the soil layer, which will be greater than the side wear resistance, thereby improving the bearing capacity of the suction anchor.

[0048] like Figure 4AAs shown, the suction anchor includes an upper top plate 20, which is fixed to the top surface of the inner tube 10. At least one water hole 21 is provided on the upper top plate 20. The upper top plate 20 is welded to the inner tube 10 and the second spoke plate 50 to form a closed space in the inner tube 10, and water can be sucked and injected into the interior through the water hole 21.

[0049] like Figure 5-Figure 6 As shown, the inner tube 10 is a cylindrical structure. The upper end of the inner tube 10 is welded to the upper top plate 20, and a second spoke plate 50 is welded to the inner sidewall of the inner tube 10. Preferably, the length of the inner tube 10 is 8m to 12m, and the diameter is 6m to 10m. The upper top plate 20 is a circular steel plate. The outer diameter of the upper top plate 20 is greater than or equal to the outer diameter of the inner tube 10 and smaller than the outer diameter of the outer tube 30. This creates a closed space within the inner tube 10, and the upper end of the annulus between the inner tube 10 and the outer tube 30 is open. This facilitates the soil layer to exert force on the inner and outer sides of the outer tube 30 and facilitates the lowering of the suction anchor. Preferably, the outer diameter of the upper top plate 20 is equal to the outer diameter of the inner tube 10.

[0050] like Figures 8-10 As shown, the outer cylinder 30 is a cylindrical structure, internally welded to the first spoke 40, providing support and protection for the first spoke 40. The first spoke 40 increases the contact area between the suction anchor and the soil, effectively improving the bearing capacity. The first spoke 40 can be a strip of steel plate, welded between the outer side of the inner cylinder 10 and the center of the outer cylinder 30 to provide support.

[0051] In one embodiment, a plurality of third through holes 31 are provided on the wall of the outer cylinder 30. After the suction anchor is lowered, the first through holes 41 on the first spoke 40, the second through holes 51 on the second spoke 50, and the third through holes 31 on the outer cylinder 30 are gradually filled with soil as the soil recovers. Figure 11 As shown, when the suction anchor is bearing load, the first through hole 41, the second through hole 51 and the third through hole 31 will generate shear force on the soil layer 60, and the soil layer 60 provides bearing capacity for the suction anchor. Because the viscosity of the soil layer 60 is large, the shear force will be greater than the side wear resistance, and the bearing capacity is higher.

[0052] Furthermore, the first spokes 40 and the second spokes 40 are both arranged radially, and the first spokes 40 are circumferentially distributed between the outer wall of the suction anchor inner tube 10 and the inner wall of the outer tube 30, which can increase the contact area with the soil layer and effectively improve the bearing capacity; the second spokes 50 are circumferentially distributed on the inner wall of the suction anchor inner tube 10, which can increase the contact area with the soil layer and effectively improve the bearing capacity. Figure 3B As shown, the first spoke 40 and the second spoke 50 are staggered in the circumferential direction. Figure 4B As shown, Figure 4BThe arrows pointing to the first spoke 40, the second spoke 50, the inner tube 10 and the outer tube 30 represent the squeezing force. The soil layer 60 squeezes the side walls of the first spoke 40, the side walls of the second spoke 50, the inner and outer walls of the inner tube 10 and the inner and outer walls of the outer tube 30, thereby generating lateral friction resistance. When the suction anchor is loaded, the soil layer 60 generates an upward friction force on it.

[0053] Furthermore, the outer cylinder 30 is concentric with the inner cylinder 10, and the top surface of the outer cylinder 30 and the top surface of the first spoke 40 are flush with the bottom surface of the upper top plate 20. The outer cylinder 30 wraps the first spoke 40, which can provide a certain protection for the first spoke 40. After the suction anchor is lowered, it has good anti-overturning ability.

[0054] The second spoke 50 may be a strip of steel plate welded to the inner cylinder 10 to provide support. The longitudinal length of the second spoke 50 is greater than that of the outer cylinder 30 and equal to or less than that of the outer cylinder 30. In one embodiment, the second spoke 50 is the same length as the inner cylinder 10, extending from one end to the other. The length of the second spoke 50 is preferably 8 to 12 meters, and the number of second spokes 50 may be eight. Specifically, the second spoke 50 may be made by extending multiple short steel plates. The longitudinal length of the first spoke 40 is equal to or less than that of the outer cylinder 30. Preferably, the outer cylinder 30 is 3 to 4 meters long, and the diameter of the outer cylinder 30 is 12 to 16 meters. In one embodiment, the length of the first spoke 40 is the same as that of the outer cylinder 30, extending from one end to the other end. The number of first outer cylinders 30 is preferably 8 to 12. The suction anchor can undergo processes such as steel plate rolling, cutting, assembly welding, and anti-corrosion in the factory, and after production is completed, it can be transported to the sea for lowering operations.

[0055] Furthermore, the transverse width of the second web 50 is 0.2 to 0.3 times the inner diameter of the inner cylinder 10. Figure 3B As shown, the transverse width of the second web 50 is 0.25 times the inner diameter of the inner cylinder 10 .

[0056] The above descriptions are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A transversely expanded spoke type suction anchor, characterized in that: include: An inner cylinder, an outer cylinder, and a plurality of first spokes, wherein the outer cylinder is disposed outside the inner cylinder, and the longitudinal length of the outer cylinder is smaller than the longitudinal length of the inner cylinder, the first spokes are disposed between the outer cylinder and the inner cylinder, and the outer side of the first spoke is fixedly connected to the outer cylinder, and the inner side of the first spoke is fixedly connected to the inner cylinder, the first spoke is provided with a plurality of first through holes, and the plurality of first spokes are distributed around the circumference of the inner cylinder; The suction anchor includes a second spoke plate, the second spoke plate is disposed in the inner cylinder, the outer side of the second spoke plate is fixed to the inner cylinder, the inner side of the second spoke plate is suspended, and the second spoke plate is provided with a plurality of second through holes; The suction anchor comprises an upper top plate, the upper top plate is fixed to the top surface of the inner tube, and at least one water hole is provided on the upper top plate; A plurality of third through holes are provided on the wall of the outer cylinder.

2. The transversely expanded spoke type suction anchor according to claim 1, characterized in that: The outer diameter of the upper top plate is greater than or equal to the outer diameter of the inner cylinder and smaller than the outer diameter of the outer cylinder.

3. The transversely expanded spoke type suction anchor according to claim 1, characterized in that: The outer cylinder is concentric with the inner cylinder, and the top surface of the outer cylinder and the top surface of the first spoke are flush with the bottom surface of the upper plate.

4. The transversely expanded spoke type suction anchor according to claim 1, characterized in that: The first spoke plate and the second spoke plate are both arranged in the radial direction, and the first spoke plate and the second spoke plate are staggered in the circumferential direction.

5. The transversely expanded spoke type suction anchor according to claim 1, characterized in that: The longitudinal length of the second spoke is greater than that of the outer cylinder and is equal to or less than that of the outer cylinder; the longitudinal length of the first spoke is equal to or less than that of the outer cylinder.

6. The transversely expanded spoke type suction anchor according to claim 5, characterized in that: The transverse width of the second web is 0.2 to 0.3 times the inner diameter of the inner cylinder.

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