Anchoring gravity-triggered power-driven penetration plate anchor and its working method

Abstract

The application provides a gravity-triggered power penetration flat plate anchor with an anchor shank, comprising a head anchor plate, a middle anchor plate, a side anchor plate, a connecting shaft, a steady flow wing plate, a sand blocking plate, an anchor shank, a gravity trigger mechanism and a limiting mechanism. The device has a high speed when freely falling in water to reach the seabed surface and penetrates into the seabed soil to a certain depth. Then the mooring cable is pulled to adjust the posture of the anchor. The tension and relaxation of the mooring cable during service further adjusts the posture of the anchor. When the anchor is adjusted to the designed inclination angle, the anchor shank is released into the load bearing force compensation stage. The continuously increasing environmental load can further embed the anchor, thereby increasing the load bearing capacity of the anchor. The device integrates the comprehensive performance of gravity penetration anchors and drag anchors, has a simple self-weight penetration installation method and high load bearing performance. The device has a large burial depth and load bearing area in the seabed, and can effectively cope with the load bearing capacity weakening under the slotting effect of the anchor chain during long-term service, thereby having high load bearing performance.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and more particularly to a gravity-triggered dynamic penetration flat anchor and its working method. Background Technology

[0002] As oil and gas resource exploitation expands from shallow to deep waters, offshore platforms are transforming from traditional fixed platforms to new structures such as tension leg platforms (TLPs) and floating production storage and offloading (FPSOs). Foundation types are also shifting from large-diameter monopiles to towed anchors, normal-bearing anchors, and more. As a new type of hybrid anchor, it is easy to install, cost-effective, and highly accurate. It can fall freely into the water under its own weight without external force and penetrate a certain depth into the seabed. It retains the advantages of traditional flat anchors, such as light weight, material savings, ease of installation, recyclability, and reusability, while overcoming the shortcomings of traditional flat anchors, such as easy overturning during embedding, shallow maximum embedment depth, and low bearing capacity. Therefore, it will become a preferred choice for future offshore platform foundations. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides a gravity-triggered dynamic penetration flat plate anchor and its working method.

[0004] This invention is achieved through the following technical solution: a gravity-triggered dynamic penetration flat anchor, comprising a head anchor plate, a middle anchor plate, side anchor plates, an anchor shank, a flow-stabilizing wing plate, a connecting shaft, a sand-blocking plate, and an anchor shank limiting device. The head anchor plate is conical, and its bottom is threaded to the top of the middle anchor plate. The diameter of the middle anchor plate is the same as the bottom diameter of the head anchor plate. Two side anchor plates are symmetrically installed on the mounting grooves on the left and right sides of the middle anchor plate at an angle of 180 degrees to each other. Both side anchor plates have flow stabilizer plates fixedly installed on their outer sides. The tail end of the middle anchor plate is connected to a connecting shaft with a pre-drilled mounting hole for connecting a release chain. The anchor shank has a through hole as an anchor eye. The anchor shank is located on the upper part of the middle anchor plate. The tail end of the anchor shank is connected to the middle anchor plate through an anchor shank limiting device. The anchor shank limiting device controls the angle between the anchor shank and the middle anchor plate from 30° to 90°. The head end of the anchor shank is fixedly equipped with a barb facing inward. The upper part of the middle anchor plate is equipped with a gravity release device that matches and cooperates with the barb of the anchor shank. The gravity release device includes a double-ear connecting lug, a bearing, and a bolt for reaming holes. The double-ear connecting lug has two parallel and spaced-apart lugs, which are fixedly installed on the upper part of the central anchor plate, with both lugs parallel to the central anchor plate. Each lug has a groove, and the two grooves are shaped and positioned correspondingly. The groove is an oblong hole for the bearing to slide along a preset path. The bolt for reaming holes has its threaded section passing through the grooves of one lug and the other lug in sequence, before connecting to a fastening nut. The bolt head and the fastening nut abut against the outer surfaces of the two lugs, respectively. The bearing is fitted onto the bolt for reaming holes and located between the two lugs. The bolt for reaming holes and the bearing form a sliding assembly. The outer ring of the bearing slides against the inner wall of the groove to guide the sliding assembly to slide along the trajectory defined by the groove. A sand-blocking plate is fixedly installed on the top outer side of the anchor by a pin.

[0005] As a preferred embodiment, the flow stabilizer is bolted to the side anchor plate via a wing plate fixing clamp provided on its side.

[0006] As a preferred option, a limiting plate is fixedly installed at the tail end of the anchor shank, and the limiting plate is connected to the anchor shank limiting device.

[0007] As a preferred option, the head anchor plate, middle anchor plate, side anchor plate and flow stabilizer blade are all streamlined and rounded.

[0008] As a preferred embodiment, the length of the dynamic penetration plate anchor is 3-10 meters, the mass is 5-10 tons, and the anchor shank length is 1-5 meters.

[0009] A method for operating a gravity-triggered dynamic penetration flat plate anchor, characterized by comprising the following steps: Step 1, Gravity Penetration: After the power-driven flat anchor is transported to the designated installation location by the installation vessel, the connecting shaft is connected to the installation cable, the anchor is hoisted to the designated height to make it vertical and then released; the power-driven flat anchor falls freely in the water and has an impact velocity when it reaches the seabed surface, and the installation is completed after penetrating into the soft seabed. Step 2: Anchor plate self-adjustment, rotation, and lowering: After the initial penetration is completed, one end of the mooring cable is connected to the anchor eye on the anchor shank. The installation vessel moves away from the power-penetrating flat anchor while releasing the mooring cable. After a sufficiently long mooring cable is released, the installation vessel increases the tension on the cable to increase the load on the power-penetrating flat anchor. Under the load, the anchor adjusts its attitude, rotates, and continues to be driven into the anchor. Step 3, Load-bearing stage: Connect the mooring cable to the floating structure at sea and put it into normal working condition; Step 4, Post-load capacity compensation stage: During service, the increased environmental load causes the mooring cable to be tensioned while driving the power-driven flat anchor to rotate, and the bolt for the hinge hole slides in the groove; when the power-driven flat anchor rotates to the designed pitch angle, the barb disengages from the bearing on the bolt for the hinge hole, opens the anchor shank, and the power-driven flat anchor enters the towing and embedding mode. Step 5, Recovery Phase: Connect the cable to the installation cable on the connecting shaft using an underwater robot, and then tow it in the opposite direction using the installation vessel.

[0010] By employing the above technical solutions, this invention has the following beneficial effects compared to existing technologies: 1. Anchor shanks can be released according to the attitude of the anchor plate, enabling the anchor to dynamically adjust its attitude and load-bearing mode according to its service status.

[0011] 2. The streamlined shape of the anchor plate effectively reduces resistance during free fall in water and during penetration, resulting in greater speed and final embedment depth when the anchor contacts the seabed.

[0012] 3. The large area of ​​the anchor plate greatly increases the contact area between the anchor and the seabed soil, giving the anchor a larger bearing surface in the seabed.

[0013] 4. It has the ability to resist extreme disasters and can achieve greater burial depth when subjected to extreme load conditions, thus avoiding further damage to the anchorage foundation.

[0014] 5. It has flow stabilizers to ensure stable landing attitude, while increasing lateral resistance during service and improving its lateral load-bearing performance during long-term service.

[0015] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a three-dimensional view of the dynamic penetration plate anchor shank of the present invention before it is released; Figure 2 This is a three-dimensional view of the dynamic penetration plate anchor shank of the present invention when it has been released; Figure 3 This is a front view of the gravity-triggered dynamic penetration plate anchor of the present invention; Figure 4 This is a top view of the gravity-triggered dynamic penetration flat plate anchor of the present invention. Figure 5 This is a side view of the dynamic penetration plate anchor triggered by the gravity of the anchor shank of the present invention when the anchor shank is not released; Figure 6 This is a side view of the dynamic penetration plate anchor triggered by the gravity of the anchor shank of the present invention when the anchor shank has been released; Figure 7 This is a side view of the slide groove of the gravity triggering device for anchor weight of the present invention. Figure 8 It is the bearing of the slide groove of the gravity triggering device for anchor weight of the present invention. Figure 9 This is a side view of the gravity-triggered power penetration plate anchor gravity triggering device of the present invention. Figure 10 This is a side view of the gravity-triggered dynamic penetration plate anchor of the present invention. in, Figures 1 to 8 The correspondence between the reference numerals and components in the attached drawings is as follows: 1. Head anchor plate; 2. Middle anchor plate; 3. Side anchor plate; 4. Anchor shank; 5. Flow stabilizer wing plate; 6. Connecting shaft; 7. Wing plate fixing clamp; 8. Sand baffle plate; 9. Anchor shank limiting device; 10. Anchor eye; 11. Gravity release device; 12. Barb; 13. Pin; 14. Slide groove; 15. Bearing; 16. Bolt for reamed hole; 17. Limiting plate; 18. Double-ear connecting lug; 19. Fastening nut. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0019] The following is combined with Figures 1 to 10 The present invention will specifically describe the gravity-triggered dynamic penetration flat plate anchor of the present invention.

[0020] This invention proposes a gravity-triggered dynamic penetrating flat anchor, comprising a head anchor plate 1, a middle anchor plate 2, side anchor plates 3, an anchor shank 4, a current-stabilizing wing plate 5, a connecting shaft 6, a sand-blocking plate 8, and an anchor shank limiting device 9. The dynamic penetrating flat anchor is 3-10 meters long, weighs 5-10 tons, and has an anchor shank length of 1-5 meters. The head anchor plate 1 is conical, and its bottom is threaded to the top of the middle anchor plate 2. The diameter of the middle anchor plate 2 is the same as the bottom diameter of the head anchor plate 1. The head anchor plate is composed of a nearly streamlined conical cover and an internal threaded hole, and is threaded to the middle anchor plate. The head anchor plate can be replaced according to the actual sea conditions. Two side anchor plates 3 are symmetrically installed on the mounting grooves on the left and right sides of the middle anchor plate 2 at an angle of 180 degrees to each other. The side anchor plates can be replaced according to the seabed conditions. Two side anchor plates 3 are each fixedly mounted with a flow-stabilizing wing plate 5 on their outer sides. The flow-stabilizing wing plate 5 is bolted to the side anchor plate 3 via a wing plate fixing clamp 7 on its side. The geometry of the flow-stabilizing wing plate can be changed according to sea conditions. The tail end of the central anchor plate 2 is connected to a connecting shaft 6, which has a pre-drilled hole for connecting a release chain. The anchor shank 4 has a through hole as an anchor eye 10, through which a loading cable is passed to provide load to the anchor. The loading cable can rotate through the anchor eye. The anchor shank 4 is located on the upper part of the central anchor plate 2. The tail end of the anchor shank 4 is connected to the central anchor plate 2 via an anchor shank limiting device 9. A limiting plate 17 is fixedly mounted on the tail end of the anchor shank 4 and is connected to the anchor shank limiting device 9. The anchor shank limiting device 9 changes the maximum angle of the anchor shank by adjusting its geometry. The anchor shank limiting device can control the angle between the anchor shank 4 and the middle anchor plate 2 from 30° to 90°. The head end of the anchor shank 4 is fixedly provided with a barb 12 facing inward. The upper part of the middle anchor plate 2 is provided with a gravity release device 11 that matches and cooperates with the barb 12 of the anchor shank 4. The head anchor plate 1, middle anchor plate 2, side anchor plate 3 and flow stabilizing wing plate 5 are all streamlined and rounded to reduce the drag force of the water flow in the water and thus increase the falling speed in the water, so as to ensure safety during transportation and use. The gravity release device 11 includes a double-ear connecting lug 18, a bearing 15, and a reaming bolt 16. The double-ear connecting lug 18 has two parallel and spaced-apart lugs. The double-ear connecting lug 18 is fixedly installed on the upper part of the central anchor plate 2, and both lugs are parallel to the central anchor plate 2. Each lug has a groove 14, and the two grooves 14 are corresponding in shape and position. The groove 14 is an oblong hole for the bearing 15 to slide along a preset path. The reaming bolt 16 has its threaded section passing through the groove 14 of one side lug and the groove 14 of the other side lug in sequence, and then connected to the fastening nut 19. The bolt head of the reaming bolt 16 is connected to the fastening nut 19. Nuts abut against the outer surfaces of the two lugs to form an axial limit, preventing the bearing 15 from falling off the bolt 16 with the reamed hole. The bearing 15 is fitted onto the bolt 16 with the reamed hole and is located between the two lugs. The bolt 16 with the reamed hole and the bearing 15 form a sliding assembly. The outer ring of the bearing 15 slides against the inner wall of the groove 14 to guide the sliding assembly to slide along the trajectory defined by the groove 14. The barb 12 of the anchor shank 4 hooks onto and applies force to the bearing 15 in the initial state to limit the position of the anchor shank 4. The gravity release device 11 is connected to the groove on the middle anchor plate through the barb to fix the anchor shank during free fall. The bearing at the gravity release device can slide along the preset direction of the groove. When the anchor plate is adjusted to a predetermined angle, the barb at the gravity release device separates from the bearing, causing the anchor shank to detach. A sand-blocking plate 8 is fixedly installed on the top outer side of the anchor shank 4 by a pin 13. The sand-blocking plate 8 completely encloses the barb 12 and the gravity release device 11 to prevent fine soil particles in the seabed from entering the chute and obstructing the bearing sliding, which could lead to the shaft jamming.

[0021] A method for the operation of a gravity-triggered dynamic penetration flat plate anchor specifically includes the following steps: Step 1, Gravity Penetration: After the power-driven flat anchor is transported to the designated installation position by the installation vessel, the connecting shaft 6 is connected to the installation cable, the anchor is hoisted to the designated height to make it vertical and then released; the power-driven flat anchor falls freely in the water and has a certain impact velocity when it reaches the seabed surface, and the installation is completed after penetrating into the soft seabed. Step 2: Anchor plate self-adjustment, rotation, and lowering: After the initial penetration is completed, one end of the mooring cable is connected to the anchor eye 10 on the anchor shank 4. The installation vessel moves away from the power-penetrating flat anchor while releasing the mooring cable according to the installation speed. After releasing a sufficiently long mooring cable, the installation vessel increases the tension on the cable to increase the load on the power-penetrating flat anchor. The anchor adjusts its attitude under the load, rotates, and continues to be embedded. Step 3, Load-bearing stage: Connect the mooring cable to the floating structure at sea and put it into normal working condition; Step 4, Post-load capacity compensation stage: During service, the increased environmental load causes the mooring cable to be tensioned while simultaneously rotating the power-driven flat anchor, and the bolt 16 for the hinge hole slides in the groove 14. When the power-driven flat anchor rotates to the designed pitch angle, the barb 12 disengages from the bearing 15 on the bolt 16 for the hinge hole, opening the anchor shank 4, and the power-driven flat anchor enters the towing and embedding mode. The continued increase in environmental load acts as the towing power for the power-driven flat anchor, driving the anchor to embed deeper into the seabed, thereby improving its load-bearing capacity during long-term service. Step 5, Recovery Phase: Connect the cable to the installation cable on the connecting shaft 6 using an underwater robot, and then tow it in the opposite direction using the installation vessel.

[0022] In the description of this invention, the term "a plurality of" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0023] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gravity-triggered dynamic penetration flat anchor, comprising a head anchor plate (1), a middle anchor plate (2), a side anchor plate (3), an anchor shank (4), a flow-stabilizing wing plate (5), a connecting shaft (6), a sand-blocking plate (8), and an anchor shank limiting device (9), characterized in that, The head anchor plate (1) is a cone and its bottom is connected to the top of the middle anchor plate (2) by threads. The diameter of the middle anchor plate (2) is the same as the bottom diameter of the head anchor plate (1). The two side anchor plates (3) are symmetrically installed on the mounting grooves on the left and right sides of the middle anchor plate (2) at an angle of 180 degrees to each other. Two side anchor plates (3) are fixedly installed with flow stabilizer plates (5) on their outer sides. The tail end of the middle anchor plate (2) is connected to a connecting shaft (6). The connecting shaft (6) has a reserved installation hole for connecting the installation cable. The anchor shank (4) is provided with a through hole as an anchor eye (10). The anchor shank (4) is set on the upper part of the middle anchor plate (2). The tail end of the anchor shank (4) is connected to the middle anchor plate (2) through the anchor shank limiting device (9). The anchor shank limiting device (9) controls the angle between the anchor shank (4) and the middle anchor plate (2) from 30° to 90°. The head end of the anchor shank (4) is fixedly provided with a barb (12) facing inward. The upper part of the middle anchor plate (2) is provided with a gravity release device (11) that matches and cooperates with the barb (12) of the anchor shank (4). The gravity release device (11) includes a double-ear connecting lug (18), a bearing (15), and a reaming bolt (16). The double-ear connecting lug (18) has two parallel and spaced lugs. The double-ear connecting lug (18) is fixedly installed on the upper part of the middle anchor plate (2), and both lugs are parallel to the middle anchor plate (2). Each lug has a groove (14). The two grooves (14) are shaped and positioned correspondingly. The groove (14) is a waist-shaped hole for the bearing (15) to slide along a preset path. The screw section of the reaming bolt (16) passes through one side in sequence. The groove (14) of the ear plate and the groove (14) of the ear plate on the other side are connected to the fastening nut (19). The head of the bolt (16) for the reamed hole and the fastening nut respectively abut against the outer side of the two ear plates. The bearing (15) is fitted on the bolt (16) for the reamed hole and is located between the two ear plates. The bolt (16) for the reamed hole and the bearing (15) form a sliding assembly. The outer ring of the bearing (15) and the inner wall of the groove (14) form a sliding fit to guide the sliding assembly to slide along the trajectory defined by the groove (14). The top outer side of the anchor (4) is fixedly installed with a sand baffle (8) by a pin (13).

2. The gravity-triggered dynamic penetration flat plate anchor according to claim 1, characterized in that... The flow stabilizer (5) is bolted to the side anchor plate (3) via a wing plate fixing clamp (7) provided on its side.

3. The gravity-triggered dynamic penetration flat plate anchor according to claim 1, characterized in that... A limiting plate (17) is fixedly installed at the tail end of the anchor shank (4), and the limiting plate (17) is connected to the anchor shank limiting device (9).

4. The gravity-triggered dynamic penetration flat plate anchor according to claim 1, characterized in that... The head anchor plate (1), middle anchor plate (2), side anchor plate (3) and flow stabilizer (5) are all streamlined and rounded.

5. The gravity-triggered dynamic penetration flat plate anchor according to claim 1, characterized in that... The power-driven flat anchor has a length of 3-10 meters, a mass of 5-10 tons, and an anchor shank length of 1-5 meters.

6. The working method of a gravity-triggered dynamic penetration plate anchor as described in claims 1-5, characterized in that... Specifically, it includes the following steps: Step 1, Gravity Penetration: After the power-driven flat anchor is transported to the designated installation position by the installation vessel, the connecting shaft (6) is connected to the installation cable, the anchor is hoisted to the designated height so that it is in a vertical state and released; the power-driven flat anchor falls freely in the water and has an impact velocity when it reaches the seabed surface, and the installation is completed after penetrating into the soft seabed. Step 2: Anchor plate self-adjustment, rotation, and lowering: After the initial penetration is completed, one end of the mooring cable is connected to the anchor eye (10) on the anchor shank (4). The installation vessel moves away from the power-penetrating flat anchor while releasing the mooring cable. After releasing a sufficiently long mooring cable, the installation vessel increases the tension on the cable to increase the load on the power-penetrating flat anchor. The anchor adjusts its attitude under the load, rotates, and continues to be embedded. Step 3, Load-bearing stage: Connect the mooring cable to the floating structure at sea and put it into normal working condition; Step 4, Post-load capacity compensation stage: During service, the increased environmental load causes the mooring cable to rotate while being tensioned, and the bolt (16) for the hinge hole slides in the groove (14); when the bolt (12) for the hinge hole rotates to the designed pitch angle, the barb (12) disengages from the bearing (15) on the bolt (16) for the hinge hole, opens the anchor shank (4), and the bolt (14) for the power penetration plate anchor enters the towing and embedding mode; Step 5, Recovery Stage: Connect the cable to the installation cable on the connecting shaft (6) using an underwater robot, and then tow it in the opposite direction using the installation vessel.

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