An underwater oil storage tank foundation structure

Abstract

An underwater oil storage tank foundation structure, including a bottom plate, a lower pile plate, a pile foundation frame, an upper pile plate, and a strengthening ring, can meet the requirements of the foundation structure for an underwater oil storage tank arranged in the offshore area. The present invention adopts a double-layer anti-settlement plate design and is combined with skirt plates and pile foundations, which can meet the bearing requirements under the full-load condition of the underwater oil storage tank. At the same time, the overall structure is located below the seabed and will not affect the navigation of ships.

Description

Technical Field

[0001] The present invention relates to a foundation structure for an underwater oil storage tank, specifically a foundation structure for providing support for an underwater oil storage tank arranged in the offshore area. Background Art

[0002] Currently, underwater oil storage technology has been applied in some oil fields. It does not occupy land or offshore platform space, especially when used in conjunction with drilling and production platforms, making oil and gas storage and transportation more convenient and efficient.

[0003] In the case where the land space in the port is limited and new oil storage facilities cannot be built, arranging an underwater oil storage tank in the offshore area of the port to enhance the port's crude oil receiving and storage capabilities is an effective solution. And the underwater oil storage tank requires a matching foundation structure to enable it to be installed on the seabed, so the research on the underwater oil storage tank foundation structure is very necessary. Summary of the Invention

[0004] To enhance the port's crude oil receiving and storage capabilities, the present invention proposes a supporting foundation structure for an underwater oil storage tank arranged in the offshore area. This foundation structure meets the installation and bearing requirements of the underwater oil storage tank, and at the same time does not affect the navigation of offshore vessels.

[0005] The technical solution adopted by the present invention to solve its technical problems is: The underwater oil storage tank and its foundation structure are installed below the seabed. First, it is necessary to excavate a deep pit of a certain size on the seabed through underwater operations, and the oil storage tank and its foundation structure are installed in the deep pit. The foundation structure adopts a double-layer anti-settlement plate design according to the characteristics of the oil storage tank and the installation mode of the deep pit, and is combined with pile foundations and skirt plates, which can meet the bearing requirements under the full load of the oil storage tank. At the same time, its design of being installed below the seabed ensures that it does not affect the navigation of vessels.

[0006] An underwater oil storage tank foundation structure of the present invention includes a bottom plate 1, a lower pile plate 2, a pile foundation frame 3, an upper pile plate 4, and a reinforcing ring 5;

[0007] A circular ring skirt plate 1-1 and a cross skirt plate 1-2 are welded below the bottom plate 1; the ring skirt plate 1-1 and the cross skirt plate 1-2 are embedded in the sediment at the bottom of the pit;

[0008] The lower pile plate 2 includes a lower pile plate anti-settlement plate 2-1 and a lower pile plate pile foundation 2-2; the upper structure of the lower pile plate 2 is the lower pile plate anti-settlement plate 2-1, and the lower pile plate pile foundation 2-2 is connected below the lower pile plate anti-settlement plate 2-1; the fan-shaped stepped structure of the lower pile plate anti-settlement plate 2-1 of the lower pile plate 2 is installed at the fan-shaped opening position of the bottom plate 1;

[0009] The pile foundation frame 3 includes a pile foundation frame bearing plate 3-1, a pile foundation frame anti-sinking plate 3-2, a main pile column 3-3, a transverse pile column 3-4, and a boss 3-5; the pile foundation frame bearing plate 3-1 is located on the transverse pile column 3-4 on the side close to the main pile column 3-3, and the bottom of the pile foundation frame bearing plate 3-1 is connected to the transverse pile column 3-4 through a reinforcing rib; the pile foundation frame anti-sinking plate 3-2 is located on the transverse pile column 3-4 on the side away from the main pile column 3-3, and the lower part of the frame anti-sinking plate 3-2 is connected to the transverse pile column 3-4 through a reinforcing rib; a boss 3-5 is provided on the upper end of the main pile column 3-3;

[0010] The upper part of the upper pile plate 4 is the upper pile plate anti-sinking plate 4-1, and the lower part of the upper pile plate 4 is the upper pile plate pile foundation 4-2; the upper pile plate 4 is installed in the middle of the pile foundation frame anti-sinking plates 3-2 of two adjacent pile foundation frames 3; the upper pile plate pile foundation 4-2 is inserted into the mud and sand at the position of the platform 6-1; when the upper pile plate pile foundation 4-2 is inserted to the bottom position, the upper pile plate anti-sinking plate 4-1 is placed in the "I"-shaped ladder structure on the upper parts of the two adjacent pile foundation frame anti-sinking plates 3-2;

[0011] The pile foundation frame 3 is welded to the base plate 1 and the reinforcement ring 5 when assembled; the main structure of the reinforcement ring 5 is placed on the pile foundation frame bearing plate 3-1, the boss 3-5 is inserted into the circular hole of the reinforcement ring 5 and the reinforcement ring 5 and the boss 3-5 are welded together.

[0012] Furthermore, the bottom plate 1 includes four symmetrically distributed fan-shaped openings.

[0013] Furthermore, the lower pile plate anti-sinking plate 2-1 is a stepped fan-shaped plate with through holes.

[0014] Furthermore, the lower side of the lower pile plate anti-sinking plate 2-1 is a fan-shaped stepped structure.

[0015] Furthermore, the transverse pile column 3-4 has a circular cross-section at one end connected to the main pile column 3-3, and has a fan-shaped cross-section at the other end connected to the pile foundation frame anti-sinking plate 3-2; the transverse pile column 3-4 has a pile foundation frame bearing plate 3-1 on the side close to the main pile column 3-3, and the main body of the pile foundation frame bearing plate 3-1 is cut from an annular plate; the transverse pile column 3-4 has a pile foundation frame anti-sinking plate 3-2 at one end of the fan-shaped cross-section, and the main body of the pile foundation frame anti-sinking plate 3-2 is also cut from an annular plate, and there are through holes on the plate surface for seawater to flow.

[0016] Furthermore, the upper side of the pile foundation frame anti-sinking plate 3-2 is a stepped structure shaped like an "I" character, with arc openings on both sides.

[0017] Furthermore, the upper pile plate anti-sinking plate 4-1 has through holes.

[0018] Furthermore, the reinforcement ring 5 is an annular plate with a through hole at a central circumferential position.

[0019] The beneficial effects of the present invention are as follows: Considering the characteristics of the underwater storage tank and the seabed operation mode comprehensively, the present invention adopts the method of using double-layer anti-settlement plates in combination with pile foundations and skirt plates to meet the bearing requirements of the underwater storage tank. At the same time, its design of being installed below the seabed does not affect the navigation of ships. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a schematic diagram after the present invention and the underwater storage tank are installed.

[0022] Figure 3 It is a schematic diagram of the deep seabed pit adapted to the present invention.

[0023] Figure 4 It is a schematic diagram of the underwater storage tank adapted to the present invention.

[0024] Figure 5 It is a schematic diagram of the bottom plate of the present invention in the upward viewing direction.

[0025] Figure 6 It is a schematic diagram of the lower pile plate of the present invention.

[0026] Figure 7 It is a schematic diagram of the pile foundation frame of the present invention from the top-down view angle.

[0027] Figure 8 It is a schematic diagram of the pile foundation frame of the present invention from the upward viewing angle.

[0028] Figure 9 It is a schematic diagram of the upper pile plate of the present invention.

[0029] Among them, 1. Bottom plate, 1-1. Ring skirt plate, 1-2. Cross skirt plate, 2. Lower pile plate, 2-1. Lower pile plate anti-settlement plate, 2-2. Lower pile plate pile foundation, 3. Pile foundation frame, 3-1. Pile foundation frame bearing plate, 3-2. Pile foundation frame anti-settlement plate, 3-3. Main pile column, 3-4. Cross pile column, 3-5. Boss, 4. Upper pile plate, 4-1. Upper pile plate anti-settlement plate, 4-2. Upper pile plate pile foundation, 5. Reinforcing ring, 6. Seabed, 6-1. Platform, 6-2. Slope, 7. Underwater storage tank, 7-1. Upper cylinder of the storage tank, 7-2. Lower cylinder of the storage tank. Detailed Embodiment

[0030] As Figure 5 shown, the bottom plate 1 is a circular plate structure, symmetrically processed with fan-shaped through openings, and circular holes are processed at the position near the edge of the circumference. The annular ring skirt plate 1-1 and the cross skirt plate 1-2 are welded below the bottom plate 1.

[0031] As Figure 6As shown in the figure, the upper structure of the lower pile plate 2 is the anti-settlement plate 2-1 of the lower pile plate, which is a stepped sector plate with through holes for seawater to flow through, and is connected to the lower pile plate pile foundation 2-2 below.

[0032] As shown in Figure 7 and 8 the main structure of the pile foundation frame 3 is composed of a main pile column 3-3 and a cross pile column 3-4 connected vertically, with a column rod in the middle to increase the strength. There is a boss 3-5 at the upper end of the main pile column 3-3. One end of the cross pile column 3-4 connected to the main pile column 3-3 has a circular cross-section, and the other end has a sector cross-section. There is a bearing plate 3-1 of the pile foundation frame on the side of the cross pile column 3-4 close to the main pile column 3-3, the main body of which is cut from an annular plate and is connected to the cross pile column 3-4 at the bottom through a reinforcing rib. There is an anti-settlement plate 3-2 of the pile foundation frame at one end of the sector cross-section of the cross pile column 3-4, the main body of which is also cut from an annular plate, with through holes on the plate surface for seawater to flow through, arc openings on both sides, a stepped structure similar to the shape of "I" at the upper part, and is connected to the cross pile column 3-4 at the lower part through a reinforcing rib.

[0033] As shown in Figure 9 the upper part of the upper pile plate 4 is the anti-settlement plate 4-1 of the upper pile plate cut from an annular plate with through holes, and the lower part is the upper pile plate pile foundation 4-2.

[0034] As shown in Figure 3 during the installation process, first, a deep pit of a certain size needs to be dug on the seabed, and the overall device is placed below the seabed 6. The deep pit needs to have a platform 6-1, and the slope 6-2 is to reduce the construction operation difficulty and avoid the problems of high operation cost caused by vertical downward excavation and easy collapse of the platform 6-1 under stress.

[0035] As shown in Figure 4 considering the operation cost of seabed excavation and ensuring the smallest excavation operation and the largest storage tank volume, the underwater storage tank 7 is designed as a two-layer structure, with the upper part being the upper cylinder 7-1 of the storage tank and the lower part being the lower cylinder 7-2 of the storage tank.

[0036] As shown in Figure 1 and 3As shown in Figures 5, 6, 7, 8, and 9, during installation, first lower the bottom plate 1 to the bottom of the pit under the slope 6-2, and embed the ring skirt plate 1-1 and the cross skirt plate 1-2 into the sediment at the bottom of the pit. Then assemble the four lower pile plates 2 according to the fan-shaped opening position of the bottom plate 1. The upper part of the stepped plate of the anti-settlement plate 2-1 of the lower pile plate covers the bottom plate 1, and the lower part of the stepped plate is inserted into the fan-shaped opening of the bottom plate 1. The pile foundation 2-2 of the lower pile plate is inserted into the sediment at the bottom of the pit. Then install the pile foundation frame 3, insert the main pile column 3-3 into the circular hole on the circumference of the bottom plate 1, and insert the lower end of the main pile column 3-3 into the sediment at the bottom of the pit for fixation. When the lower end of the main pile column 3-3 is inserted into the sediment at the bottom of the pit, the anti-settlement plate 3-2 of the pile foundation frame is located at the platform 6-1 position, and the fan-shaped part of the cross-sectional area of the horizontal pile column 3-4 and the reinforcing ribs connected to this part are embedded into the sediment at the platform 6-1 position. At this time, weld the main pile column 3-3 to the bottom plate 1. Then install the upper pile plate 4, insert the pile foundation 4-2 of the upper pile plate into the space formed by the arc openings on both sides of the adjacent two anti-settlement plates 3-2 of the pile foundation frame, and insert the pile foundation 4-2 of the upper pile plate into the sediment at the platform 6-1 position. When the pile foundation 4-2 of the upper pile plate is inserted to the bottommost position, the anti-settlement plate 4-1 of the upper pile plate is placed in the "I"-shaped stepped structure on the upper part of the adjacent two anti-settlement plates 3-2 of the pile foundation frame. Finally, install the reinforcing ring 5. The reinforcing ring 5 is an annular plate with circular holes, and the position and size of its circular holes are adapted to the position of the boss 3-5 when the assembly is completed. The main body structure of the reinforcing ring 5 is placed on the bearing plate 3-1 of the pile foundation frame, and the boss 3-5 is inserted into the circular hole of the reinforcing ring 5 and weld the reinforcing ring 5 to the boss 3-5.

[0037] From Figure 1 、 3As shown in Figures 4, 5, 6, 7, 8, and 9, after the basic structure is installed, the underwater storage tank 7 is installed. The lower cylinder 7-2 of the storage tank is placed at the bottom of the pit. The bottom of the lower cylinder 7-2 of the storage tank contacts the anti-settlement plate 2-1 of the lower pile plate. At this time, the bottom of the upper cylinder 7-1 of the storage tank contacts the strengthening ring 5, the anti-settlement plate 3-2 of the pile foundation frame, and the anti-settlement plate 4-1 of the upper pile plate. The ring skirt plate 1-1 and the cross skirt plate 1-2 are fixed to the bottom plate 1 at the same time to endow it with a certain load-bearing capacity. The main pile column 3-3 welded to the bottom plate 1 further strengthens the load-bearing capacity of the bottom plate 1 through the part inserted into the bottom of the pit. This part of the load-bearing capacity acts on the anti-settlement plate 2-1 of the lower pile plate through the bottom plate 1, and jointly bears the pressure from the lower cylinder 7-2 of the storage tank with the fan-shaped stepped part of the anti-settlement plate 2-1 of the lower pile plate and the pile foundation 2-2 of the lower pile plate. The heavy pressure from the upper cylinder 7-1 of the storage tank acts on the strengthening ring 5, the anti-settlement plate 3-2 of the pile foundation frame, and the anti-settlement plate 4-1 of the upper pile plate. The cross-section of the cross pile column 3-4 is a fan-shaped part and the reinforcing ribs connected to this part are embedded in the sediment at the position of the platform 6-1 to provide support and position fixation for the pile foundation frame 3. The anti-settlement plate 4-1 of the upper pile plate in the stepped structure of the "I" shape on the upper part of the anti-settlement plate 3-2 of the pile foundation frame strengthens the pile foundation frame 3 by inserting the pile foundation 4-2 of the upper pile plate into the sediment at the position of the platform 6-1. At the same time, the pile foundation 4-2 of the upper pile plate provides the load-bearing capacity for the upper pile plate 4. While the strengthening ring 5 bears the heavy pressure of the upper cylinder 7-1 of the storage tank and transmits it to the load-bearing plate 3-1 of the pile foundation frame, the connection strength between different pile foundation frames 3 is enhanced by welding it to the main pile column 3-3.

Claims

1. An underwater oil storage tank foundation structure, characterized in that, It includes a bottom plate (1), a lower pile plate (2), a pile foundation frame (3), an upper pile plate (4), and a reinforcing ring (5); The bottom plate (1) is a circular plate structure, symmetrically processed with fan-shaped through openings; Four lower pile plates (2) are assembled according to the fan-shaped opening positions of the bottom plate (1); The main pile column (3-3) is welded to the bottom plate (1); The lower pile plate (2) includes a lower pile plate anti-settlement plate (2-1) and a lower pile plate pile foundation (2-2); The upper structure of the lower pile plate (2) is the lower pile plate anti-settlement plate (2-1), and the lower pile plate pile foundation (2-2) is connected below the lower pile plate anti-settlement plate (2-1); The fan-shaped stepped structure of the lower pile plate anti-settlement plate (2-1) of the lower pile plate (2) is installed at the fan-shaped opening position of the bottom plate (1); The pile foundation frame (3) includes a pile foundation frame bearing plate (3-1), a pile foundation frame anti-settlement plate (3-2), a main pile column (3-3), a cross pile column (3-4), and a convex platform (3-5); The main pile column (3-3) and the cross pile column (3-4) are vertically connected; The pile foundation frame bearing plate (3-1) is located on the side of the cross pile column (3-4) close to the main pile column (3-3), and the bottom of the pile foundation frame bearing plate (3-1) is connected to the cross pile column (3-4) through a reinforcing rib; The pile foundation frame anti-settlement plate (3-2) is located on the side of the cross pile column (3-4) far from the main pile column (3-3), and the lower part of the pile foundation frame anti-settlement plate (3-2) is connected to the cross pile column (3-4) through a reinforcing rib; There is a convex platform (3-5) at the upper end of the main pile column (3-3); The upper part of the upper pile plate (4) is an upper pile plate anti-settlement plate (4-1), and the lower part of the upper pile plate (4) is an upper pile plate pile foundation (4-2); The upper pile plate (4) is installed in the middle of the pile foundation frame anti-settlement plates (3-2) of two adjacent pile foundation frames (3); The reinforcing ring (5) is an annular plate with through holes at the circumferential position near the center; The main structure of the reinforcing ring (5) is placed on the pile foundation frame bearing plate (3-1), and the convex platform (3-5) is inserted into the round hole of the reinforcing ring (5) and the reinforcing ring (5) is welded to the convex platform (3-5).

2. The underwater oil storage tank foundation structure according to claim 1, characterized in that, The bottom plate (1) contains (4) symmetrically distributed fan-shaped openings.

3. The basic structure of an underwater oil storage tank according to claim 1, characterized in that, The lower pile plate anti-settlement plate (2-1) is a stepped fan-shaped plate with through holes.

4. The basic structure of an underwater oil storage tank according to claim 1, characterized in that, The lower side of the lower pile plate anti-settlement plate (2-1) is a fan-shaped stepped structure.

5. The basic structure of an underwater oil storage tank according to claim 1, characterized in that, One end of the cross pile column (3-4) connecting the main pile column (3-3) has a circular cross-section, and the other end of the cross pile column (3-4) connecting the pile foundation frame anti-settlement plate (3-2) has a fan-shaped cross-section; There is a pile foundation frame bearing plate (3-1) on the side of the cross pile column (3-4) close to the main pile column (3-3), and the main body of the pile foundation frame bearing plate (3-1) is cut from an annular plate; There is a pile foundation frame anti-settlement plate (3-2) at one end of the fan-shaped cross-section of the cross pile column (3-4), and the main body of the pile foundation frame anti-settlement plate (3-2) is also cut from an annular plate, and there are through holes on the plate surface for seawater to flow through.

6. The underwater oil storage tank foundation structure according to claim 1, characterized in that, The upper side of the pile foundation frame anti-settlement plate (3-2) is a stepped structure in the shape of "I", and there are arc openings on both sides.

7. The underwater oil storage tank foundation structure according to claim 1, characterized in that, The upper pile plate anti-settlement plate (4-1) has through holes.

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