Stabilizing device, a subsea system and use of the stabilizing device

Abstract

A stabilization device (22) for a subsea cable unit (18) is disclosed, where the stabilization device (22) extends between a seabed (17) and a cable inlet (13) on a subsea structure (11), where the cable inlet (13) is located above the seabed (17). The subsea cable unit (18) comprises a subsea cable with a cable protection system (20) or only a subsea cable, and the stabilization device (22) comprises at least one stabilization base (24, 25) and at least one pile element (54) for anchoring the at least one stabilization base (24, 25) to the seabed (17) or the scour protection layer (15). The at least one pile element (54) is adapted to be driven into the seabed (17) or into the scour protection layer (15) such that the at least one stabilizing base (24, 25) is securely anchored to the seabed (17). The stabilizing device (22) further comprises a first clamping device (27) securely attached at one end to the at least one stabilizing base (24, 25), where the first clamping device (27) is curved and adapted to at least partially surround the subsea cable unit (18), and when the at least one stabilizing device (24, 25) and the subsea cable unit (18) are installed, the first clamping device (27) is configured to clamp the at least one stabilizing base (24, 25). A first clamping device (27) for holding the subsea cable unit (18); and a second clamping device (28) securely attached at one end to the at least one stabilizing base (24, 25), where the second clamping device (28) is curved and adapted to at least partially surround the subsea cable unit (18), and when the stabilizing device (22) and the subsea cable unit (18) are mounted, the second clamping device (28) holds the subsea cable unit (18).

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480017573.7 (22) Application Date 2024.03.07 (30) Priority Data 20230240 2023.03.07 NO (85) PCT International Application Entering National Phase Date 2025.09.08 (86) PCT International Application Application Data PCT / NO2024 / 050058 2024.03.07 (87) PCT International Application Publication Data WO2024 / 186220 EN 2024.09.12 (71) Applicant Henrik Bon-Andreassen Address Bergen, Norway (72) Inventor Henrik Bon-Andreassen (74) Patent Agency Chengdu Fandian Intellectual Property Agency Co., Ltd. 51258 Patent Attorney Zhang Xiangyao (51) Int.Cl. H02G 1 / 10 (2006.01) F16L 1 / 16 (2006.01) F16L 3 / 04 (2006.01) H02G 9 / 02 (2006.01) (54) Invention Title Stabilizing Device, Submarine System and Use of Stabilizing Device (57) Abstract A stabilizing device (22) for a submarine cable unit (18) is disclosed, wherein the stabilizing device (22) extends between the seabed (17) and a cable inlet (13) on the submarine structure (11), wherein the cable inlet (13) is located above the seabed (17). The submarine cable unit (18) includes a submarine cable with a cable protection system (20) or only a submarine cable, and a stabilization device (22) including at least one stabilizing base (24, 25) and at least one pile element (54) for anchoring at least one stabilizing base (24, 25) to the seabed (17) or the scour protection layer (15). At least one pile element (54) is adapted to be driven into the seabed (17) or the scour protection layer (15) such that at least one stabilizing base (24, 25) is securely anchored to the seabed (17). The stabilizing device (22) further includes: a first clamping device (27) securely attached at one end to at least one stabilizing base (24, 25), wherein the first clamping device (27) is curved and adapted to at least partially surround the submarine cable unit (18), and the first clamping device (27) holds the submarine cable unit (18) when at least one stabilizing device (24, 25) and the submarine cable unit (18) are installed; and a second clamping device (28) securely attached at one end to at least one stabilizing base (24, 25), wherein the second clamping device (28) is curved and adapted to at least partially surround the submarine cable unit (18).The second clamping device (28) holds the submarine cable unit (18) around the submarine cable unit (18) and when the stabilizing device (22) and the submarine cable unit (18) are installed. Claims 3 pages Description 25 pages Drawings 25 pages CN 120898342 A 2025.11.04 CN 1 20 89 83 42 A 1. A stabilizing device (22) for a submarine cable unit (18) extending between a cable inlet (13) on a seabed (17) and a seabed structure (11), wherein the cable inlet (13) is located above the seabed (17), wherein the submarine cable unit (18) includes a submarine cable having a cable protection system (20) or only includes a submarine cable, and wherein the stabilizing device (22) includes: - at least one stabilizing base (24, 25), - A first clamping device (27), which is securely attached at one end to the at least one stabilizing base (24, 25), is curved and adapted to at least partially surround the submarine cable unit (18), and holds the submarine cable unit (18) when the at least one stabilizing device (22) and the submarine cable unit (18) are installed; - A second clamping device (28), which is securely attached at one end to the at least one stabilizing base (24, 25), is curved and adapted to at least partially surround the submarine cable unit (18), and holds the submarine cable unit (18) when the stabilizing device (22) and the submarine cable unit (18) are installed; - At least one piling element (54), which is used to hold the at least one stabilizing base (24, 25) in place. 25) Anchored to the seabed (17) or to the scour protection layer (15), the at least one pile element (54) is adapted to be driven into the seabed (17) or the scour protection layer (15) such that when the stabilizing device is installed, the at least one stabilizing base (24, 25) is firmly anchored to the seabed (17) or the scour protection layer (15), and the stabilizing device (22) is positioned on top of the contact point (34) of the submarine cable unit (18). 2. The stabilizing device according to claim 1, wherein the first clamping device (27) and the second clamping device (28) are attached to the at least one stabilizing base (24, 25) such that the first clamping device (27) is closer to the seabed structure (11) than the second clamping device (28), and wherein the first clamping device (27) is flexible.3. The stabilizing device according to claim 1 or 2, wherein the second clamping device (28) is more rigid than the first clamping device (27). 4. The stabilizing device according to any one of claims 1 to 3, wherein the at least one stabilizing base (24, 25) includes at least one through hole (42), and the at least one pile element (54) is adapted to pass through the at least one through hole (42). 5. The stabilizing device according to any one of claims 1 to 4, wherein the stabilizing device (22) includes at least one clamping element (39), the at least one clamping element (39) including at least one through hole (42) for the at least one pile element (54). 6. The stabilizing device according to any one of claims 1 to 5, wherein the at least one pile element (54) is provided with an expansion device (59), the expansion device (59) applying a force toward the seabed (17) or the scour protection layer (15) on the at least one stabilizing base (24, 25). 7. The stabilizing device according to claim 6, wherein the expansion device (59) is adapted to expand in the event of corrosion of the seabed (17) or the erosion protection layer (15) to continuously apply a force toward the seabed (17) or the erosion protection layer (15) on the at least one stabilizing base (24, 25). 8. The stabilizing device according to claim 6 or 7, wherein the at least one pile element (54) is provided with an adjustment device (62) for adjusting the tension in the expansion device (54) and thereby adjusting the force applied to the at least one stabilizing base (24, 25). 9. The stabilizing device according to any one of claims 1 to 8, wherein the stabilizing device (22) further comprises a cover unit (45) for bending control of the submarine cable unit (22), wherein the cover (45) is curved and at least partially surrounds the submarine cable unit (22) in the circumferential direction, and the cover unit (45) and the submarine cable unit (22) are held by the first clamping device (27) and the second clamping device (28). 10. The stabilizing device according to claim 9, wherein the cover unit (45) is also curved in the longitudinal direction of the submarine cable unit (22) to prevent the cable from bending beyond a desired angle. 11. The stabilizing device according to claim 9 or 10, wherein the cover unit (45) is provided with at least one motion-stopping element (51) on the side facing the submarine cable unit (22), wherein the at least one motion-stopping element (51) presses against the submarine cable unit (22). 12. The stabilizing device according to any one of claims 1 to 11,The stabilizing device (22) includes a first stabilizing base (24) and a second stabilizing base (25), each including at least one through-hole (42) for at least one pile element (54), the at least one pile element (54) being adapted to be fitted into the at least one through-hole (42) and driven into the seabed (17) or the scour protection layer (15), such that the first stabilizing base (24) and the second stabilizing base (25) are securely anchored to the seabed (17) or the scour protection layer (15). 13. The stabilizing device according to claim 12, wherein the first clamping device (27) is securely attached to the first stabilizing base (24) at one end and to the second stabilizing base (25) at the other end, and the second clamping device (28) is securely attached to the first stabilizing base (24) at one end and to the second stabilizing base (25) at the other end. 14. The stabilizing device according to any one of claims 1 to 13, wherein the first clamping device (4) comprises at least one dynamic absorber device (30) anchored at one end to the first stabilizing base (24) and / or the second stabilizing base (25) and at the other end to the cover unit (45). 15. The stabilizing device according to any one of claims 12 to 14, wherein the first stabilizing base (24) and / or the second stabilizing base (25) are provided with a plurality of through holes (42) for pile elements (54), the pile elements (54) being adapted to be fitted into the respective through holes (42) and driven into the seabed (17) or the scour protection layer (15), such that the first stabilizing base (24) and / or the second stabilizing base (25) can be securely anchored to the seabed by the plurality of pile elements (54). 16. The stabilizing device according to claims 4 to 15, wherein the at least one through-hole (42) is provided with a guiding element (43) to facilitate the entry of the at least one piling element (54) into the at least one through-hole (42) during installation of the stabilizing device (22). 17. The stabilizing device according to any one of claims 1 to 16, wherein the at least one piling element (54) is adapted to be operated by an ROV. 18. The stabilizing device according to any one of claims 1 to 17, wherein the subsea cable unit (22) is provided with a cable protection system (20). 19. The stabilizing device according to any one of claims 1 to 18, wherein the subsea structure (11) is securely mounted in or securely attached to the seabed (17).20. A subsea system (10) comprising: a subsea structure (11) securely mounted in or to a seabed (17); and a subsea cable unit (18) extending between the seabed (17) and a cable inlet (13) on the subsea structure (11), wherein the cable inlet (13) is located above the seabed (17), wherein the subsea cable unit (18) comprises a subsea cable having a cable protection system (20) or comprises only a subsea cable, and wherein the subsea system (10) includes a stabilizing device (22) according to any one of claims 1 to 19 for stabilizing the subsea cable unit (18). 21. The subsea system according to claim 20, wherein the stabilizing device (22) is disposed on a scour protection layer (15) disposed on the seabed (17) adjacent to the subsea structure. 22. The subsea system according to claim 20, wherein the stabilizing device (22) is directly disposed on the seabed (17). 23. The subsea system according to any one of claims 20 to 22, wherein the subsea structure (10) is a monopile (12) of a wind power station, the monopile (12) being securely mounted to the seabed (17) or securely mounted in the seabed (17). 24. Use of the stabilizing device (22) according to any one of claims 1 to 19 and / or the subsea system (10) according to any one of claims 20 to 23 for stabilizing a subsea cable unit (18) from an offshore wind power plant. Claims 3 / 3 Page 4 CN 120898342 A Stabilizing device, subsea system and use of stabilizing device Technical Field

[0001] The present invention relates to stabilizing devices and subsea systems for stabilizing cables in a subsea environment and cable protection systems. Background Art

[0002] The fixed-foundation offshore wind power industry has developed a suite of cutting-edge methods around cables, such as cable installation and protection. For a number of good reasons, cost being only one of them, the industry has been seeking static cable designs used for so-called inter-array grids. These are cables that interconnect individual wind turbine generators (WTGs) with transformer stations (substations). Furthermore, the outlet cables of offshore substations or the onshore cables connecting to onshore substations are based on static cable designs. These static cable designs can be operated with very limited movement (i.e., dynamic). Apart from very limited movement during the operational generation phase (typically between 20 and 40 years) and the decommissioning phase at the end of the offshore lease, such movement is generally limited primarily to coiling or winding during the manufacturing and installation phases.

[0003] The finite dynamic life of a static cable design is limited by the cable design constraints, and for repetitive motion (dynamics), a set of curvature and tension parameters limits the fatigue life of the cable design. The greater the dynamics (increased curvature and / or increased tension) the cable experiences, the shorter the cable fatigue life.

[0004] It has been demonstrated that cable installation and operation will be difficult without cable protection when handling during pull-in operations and when exposed to accelerated water particle velocities (current flow).

[0005] The industry-leading cable protection involves burying the cable in the seabed between foundation installations. In addition to complying with existing regulations, the industry has developed numerous standards and recommended practices.

[0006] From early times, J-tubes have been the standard configuration for cables in wind turbine generators, but due to economic reasons, the pursuit has been for monopiles without J-tubes (referred to as J-tube-free designs), where holes in the monopile wall are used for mechanical connections to so-called cable protection systems.

[0007] In the trajectory between the borehole of a monopile without a J-tube or the flare of any J-tube and the seabed, providing stability to the cables inside the cable protection system is the expected primary characteristic of the cable protection system. However, stability may be a misconception. In fact, cable protection systems exposed to accelerating water particle velocities are not stable and will move around. Various bending strain management or limiting solutions in cable protection systems reduce the mobility of the cable protection system, but it is periodic, and therefore the cables enclosed inside are forced to move with the cable protection system.

[0008] The cable protection system is forced to move with the surrounding water particles, which are accelerated by meteorological conditions (wind, waves, and flow animals). Until 2020 and 2021, it was believed that software such as Orcaflex and similar software were able to model the situation and provide realistic scenarios regarding the scale and impact of water particle flow velocities.

[0009] The cable protection system is modeled in software (Orcaflex or similar software) as follows: In this model, the trajectory of the cable protection system from the monopile borehole or J-tube bell mouth through the contact point to the seabed or scour protection is actually a chain, and then continues across the scour protection / seabed to the burial point in the seabed. The force mainly acts on the chain because the water particle velocity is highest when closest to the foundation, and lower at the seabed burial point farther from the foundation. The worst case occurs under the most extreme sea conditions, which is represented as the limit state—the dynamic tension generated by the cable protection system is the highest and the bending is the most severe. Specification 1 / 25 pages 5 CN 120898342 A

[0010] These dynamic forces exist in the form of tension in the seabed portion of the cable protection system. In order to make the cable protection systemTo maintain position, a greater anchoring strength than the maximum potential tension (from the calculated limit state) is required. This anchoring strength is called "hold-back capacity" and requires a portion of the cable protection system to be buried in the seabed. The density or friction of the seabed, as well as the characteristics of the seabed, will determine how long this seabed needs to be. The modeled hold-back capacity (the assumed value used in the analysis) requires that the seabed characteristics are known and remain constant (i.e., the seabed characteristics are constant or better).

[0011] Current procedures mainly follow the track that cable protection system suppliers must perform analyses (using Orcaflex or similar software) to demonstrate that:

[0012] a) cable design constraints (minimum bending radius and tension) are unaffected, and

[0013] b) the cable fatigue life exceeds the project lifespan (typically a safety factor of 10, so a 32-year project requires a minimum 320-year cable fatigue life).

[0014] Since 2019, a staggering number of faulty cable protection systems and a small number of faulty cables have been discovered. These can be categorized as environmentally driven and engineering-driven.

[0015] In terms of the environment, two important factors stand out.

[0016] 1) The acceleration of water particles around the vertical foundation installation is more severe than predicted by analysis. This is also evidenced by scour protection, where D-90 stones (typically 275 kg in air) have been identified in the past few years, whereas just 6-7 years ago, D-30 stones (typically 50 kg in air) were sufficient.

[0017] 2) Another equally important environmental driver for this invention is seabed characteristics. The seabed characteristics of the upper two to three meters were generally not known in the 2010s, but were known from 2017 to 2018 through cone penetration testing (CPT) activities.

[0018] CPT is used as an important tool for cable burial risk assessment (CBRA), which focuses on the burial depth below the existing / original seabed and provides a prediction of the minimum reduction depth of the cable below the original seabed level.

[0019] Cone penetration testing is at best a misleading measure for assessing the impact of seabed characteristics on the buried portion of a cable protection system. This is because the original seabed from which CPT data is obtained is disturbed during installation and burial activities. Therefore, the assessment leading to the analysis of the buried portion of the cable protection system is based on a model in which the analysis must assume and define parameters of soil spring characteristics and pull-out resistance. Even without optimistically choosing these assumptions to allow the analysis to pass, there is no practical method to verify them.

[0020] In addition to seabed characteristics, installation tolerances further increase the uncertainty of the cable protection system relative to the burial point of the foundation. This amplifies the uncertainty, which is at best based on limited assumptions (neither explicitly stated nor explicitly defined).The seabed features / soil spring-seabed connection, and not the precise location of the soil spring during installation).

[0021] In addition to these uncertainties, there are unknown future variations in the operation of the cable protection system.

[0022] Until 2021, at least most analyses indicated that when the backfill material on top of the cable protection system reached the top of the trench, the backfill material was similar to the original seabed (compacted solid) (but this assumption, at best, sets a higher ballast weight than is realistic, and the coverage of the cable protection system and / or cable is also unrealistic). Furthermore, the anchoring strength of the cable protection system is assumed to be higher than conservatively considered strength by a burial angle that is generally smaller than assumed, and further away from wind turbine generators or substation structures.

[0023] Both of these environmental conditions promote and amplify the mobility of the cable protection system in the scour protection area and / or seabed, i.e., the analyses presented as a "conservative model" provide an unrealistically low mobility for the cable protection system. Therefore, the cable protection system behaves more dynamically, forcing the cable to reach higher curvature and tension (which shortens the cable fatigue life specification 2 / 25 page 6 CN 120898342 A and may violate cable design limits). The increased curvature and tension in the cable protection system subject the seabed interface soil spring to more severe loads and the pull-out resistance to greater forces. As a result, the tension in the cable protection system overcomes the pull-out resistance of the anchor and pulls the buried portion of the cable protection system out of its burial location. This results in a longer portion of the cable protection system being exposed to dynamics and mobility, thereby transferring higher tension to the cable at a more severe curvature.

[0024] In addition, a number of engineering defects also play a role, one of which is the use of bend limiters. According to the American Petroleum Institute's API-17 standard (Specifications and Recommendations for Flexible Pipe Auxiliary Equipment), this standard establishes recommended practices for flexible components, and bend limiters are strictly prohibited on non-static pipe sections (e.g., but not limited to the "static" sections of steeply or gently suspended annular flexible risers, where dynamic isolation from above is above the seabed float and the seabed is unaffected by surface weather).

[0025] The analysis assumes that the group of bend limiters operates in a uniform vertebral manner. Therefore, the analysis distributes all motion across the entire group, while in reality, small differences between each connector will cause the connector with the least friction to act first and most significantly. Secondly, when the group of bend limiters is pulled across the scour protection section and / or the seabed; the group of bend limiters rolls. Repeated motion reduces the initial friction (between the connectors), and the group of bend limiters becomes a near-circular wheel-like structure, rolling over the scour protection section and / or the seabed with decreasing friction.

[0026] This effect, along with the designers' and analysts' expectations of a "clean seawater environment" inside the cable protection system, hindered the understanding of the following conditions: in turbid seawater near the seabed, silt particles exert a very strong abrasive effect. In fact, rotating the bend limiter in the presence of a highly abrasive silt mixture inside not only wears down the bend limiter itself but also causes wear on the cable from within the cable protection system.

[0027] The discovery of these failures prompted the industry—particularly Orsted during 2021 and 2022—to stabilize the cable protection system to prevent movement of the cable protection system and the cable (Orsted stabilized a total of five wind farms equipped with bend limiter-based cable protection system designs).

[0028] Against this backdrop, in 2022, the insurance industry serving the offshore wind power sector mandated "stabilization" of the cable protection system and the cable before being able to issue new policies.

[0029] While stabilization with rocks addressed the mobility of the cable protection system in the scour protection section and / or on the seabed, it did alter the condition of the cable protection system. The seabed trajectory is stabilized, but the chain section remains in a dynamic environment. Although the cable protection system under the rocks is no longer moving, the characteristics and location of the soil spring model remain uncertain. The fixing effect of the stabilized cable protection system increases the bending moment in the local fixing area. The local bending moment and tension in the fixing point or fixing area are increased by the cable protection system and the fixing of the cable under the stabilized ballast. This shortens the fatigue life of the cable and poses challenges to the cable protection system due to the unconsidered bending moment.

[0030] Another aspect of stabilizing the cable or stabilizing the cable protection system and the cable is the cost of stabilization materials and installation. The cost of stabilization materials and installation varies, but it is estimated that the cost is three to five times that of the cable protection system in the North Sea region of Europe. The cost is about three times or more in the United States and about six times or more in the Asia-Pacific region.

[0031] In the already tight offshore logistics operations of wind farm construction, the stabilizer needs to be in place in a relatively short time after the cable is pulled in. This increases the risk, complexity and cost of the installation process. Most developers prioritize heavy lifting operations, and stabilization processing extends operation time, with the risk of severe fatigue in the cable protection system and cable before it is stabilized.

[0032] Therefore, the object of the present invention is to provide cable protection systems and / or cable stabilization to eliminate the risk of seabed characteristics or seabed variations.

[0033] The object also is to provide cable and / or cable protection system stabilization with a bend management system to eliminate the risk of impaired cable fatigue life, i.e., to eliminate the risk of cable failure during the cable's operational life.

[0034] Another objective is to provide stability within the cable pull-in sequence.

[0035] Yet another objective is to stabilize the cable protection system and / or the cable without using ballast materials—such as stones, stone filter bags, mats, etc.

[0036] Yet another objective is to provide stability of the cable protection system and / or the cable without using cranes and lifting operations.

[0037] Yet another objective is to provide stability of the cable protection system and / or the cable without proximity to wind turbines, generators, or substations.

[0038] Yet another objective is to provide a wide range of tolerances for the positioning of the stabilizing device for the cable protection system and / or the cable.

[0039] These objectives are achieved by the stabilizing device as defined in claim 1, the subsea system as defined in claim 20, and the use of the stabilizing device and subsea system as defined in claim 25. Further embodiments of the invention are defined in the dependent claims.

[0040] Therefore, a stabilization device for a submarine cable unit is provided, the submarine cable unit extending between a seabed and a cable inlet on a seabed structure, the cable inlet on the seabed structure being located above the seabed, wherein the submarine cable unit includes a submarine cable with a cable protection system or includes only a submarine cable, and wherein the stabilization device includes:

[0041] - at least one stabilizing base,

[0042] - a piling element for anchoring the at least one stabilizing base to the seabed, the piling element being adapted to be driven into the seabed such that the at least one stabilizing base can be firmly anchored to the seabed,

[0043] - a first clamping device, one end of the first clamping device being firmly attached to the at least one stabilizing base, the first clamping device being bent and adapted to at least partially surround the submarine cable unit and hold the submarine cable unit when the stabilization device and the submarine cable unit are installed, and

[0044] - A second clamping device, one end of which is securely attached to a stabilizing base, the second clamping device being curved and adapted to at least partially surround the subsea cable unit and hold the subsea cable unit in place when the stabilizing device and the subsea cable unit are installed.

[0045] The first and second clamping devices may be attached to the stabilizing base such that the first clamping device is closer to the subsea structure than the second clamping device, and wherein the first clamping device is flexible.

[0046] Preferably, the second clamping device is more rigid than the first clamping device.

[0047] Preferably, at least one stabilizing base includes at least one through-hole through which the pile element is adapted.

[0048] Preferably, the stabilizing device includes at least one support structure including at least one through-hole for the pile element.

[0049] The pile element may be provided with an expansion device that applies a force toward the seabed on at least one stabilizing base.

[0050] Preferably, the expansion device is adapted to expand in the event of seabed erosion, thereby continuously applying a force toward the seabed on at least one stabilizing base.

[0051] For example, the expansion device may include a spring element.

[0052] Alternatively, the expansion device includes a hydraulic element. Specification 4 / 25 pages 8 CN 120898342 A

[0053] Alternatively, the expansion device also includes a swelling element that swells in water.

[0054] The pile element may be provided with an adjustment device for adjusting the tension in the spring element, and thus adjusting the force applied to at least one stabilizing base.

[0055] Preferably, the stabilizing device further includes a cover unit for bending control of the submarine cable unit, wherein the cover is bent in the circumferential direction of the submarine cable unit and at least partially surrounds the submarine cable unit, and the cover unit and the submarine cable unit are held by a first clamping device and a second clamping device.

[0056] The cover unit may also be bent in the longitudinal direction of the submarine cable unit to prevent the cable from bending beyond a desired angle. Alternatively, the cover unit can be generally straight, and one end of the cover unit is more flexible, so that after installation, the cover unit follows the chain shape of the submarine cable unit, and therefore the cover unit is curved in the longitudinal direction.

[0057] The cover unit may be provided with at least one motion-stopping element on the side facing the submarine cable unit, wherein the at least one motion-stopping element presses against the submarine cable unit.

[0058] The stabilizing device may include a first stabilizing base and a second stabilizing base, each of the first and second stabilizing bases including at least one through hole for a piling element adapted to be fitted into the at least one through hole and driven into the seabed, such that the first and second stabilizing bases can be firmly anchored to the seabed.

[0059] Preferably, the first and second stabilizing bases are located on opposite sides of the submarine cable unit.

[0060] Preferably, the first clamping device is securely attached to a first stabilizing base at one end and to a second stabilizing base at the other end; and preferably, the second clamping device is securely attached to the first stabilizing base at one end and to the second stabilizing base at the other end.

[0061] The first clamping device may include at least one dynamic absorber, one end of which is anchored to the first stabilizing base and / or the second stabilizing base, and the other end of which is anchored to the cover unit.

[0062] The first stabilizing base and / or the second stabilizing base are provided with a plurality of through holes for pile units adapted to be fitted into the corresponding through holes and driven into the seabed, such that the first stabilizing base and / or the second stabilizing base can be securely anchored to the seabed by the plurality of pile units.

[0063] Preferably, at least one through hole is provided with a guiding element to facilitate the entry of the pile unit during installation.

[0064] The piling element can be adapted to be manipulated by an ROV.

[0065] The submarine cable unit can be provided with a cable protection device.

[0066] Preferably, the cable protection device surrounds the cable.

[0067] Preferably, the cable protection device extends at least through the stabilizing device. However, in some cases, the stabilizing device may not extend through the entire stabilizing device.

[0068] Preferably, the submarine structure is securely mounted in or to the seabed.

[0069] A submarine system is also provided, comprising: a submarine structure securely mounted in or to the seabed, and a submarine cable unit extending between the seabed and a cable inlet on the submarine structure, the cable inlet at the submarine structure being located above the seabed, wherein the submarine cable unit comprises a submarine cable with a cable protection system or comprises only a submarine cable, and wherein the submarine system includes the stabilizing device as defined above for stabilizing the submarine cable unit, and does not include the above-described additional features, or includes one, several, or all of the above-described additional features.

[0070] The subsea system may be provided with multiple stabilizing devices arranged longitudinally along the seabed cable unit.

[0071] The stabilizing devices may be disposed on a scour protection layer, which is disposed on the seabed adjacent to the subsea structure. Specification 5 / 25 page 9 CN 120898342 A

[0072] Alternatively, the stabilizing devices may be disposed directly on the seabed.

[0073] The subsea structure may be a monopile of a wind power plant that is securely mounted to or in the seabed. The subsea structure may also be other subsea structures that are securely mounted to the seabed. Alternatively, the subsea structure may be a semi-submersible structure, for example, a semi-submersible structure operating at a relatively shallow depth—for example, at a depth of up to 200-250 meters.

[0074] Use of the stabilizing devices and / or the subsea system described above for stabilizing subsea power cables from offshore wind power plants is also provided.

[0075] Therefore, the stabilization device according to the invention provides a foundation for the stable anchoring of cables to the seabed (fixed relative to the foundation of a wind turbine generator or substation, with or without scour protection) of cable protection systems and / or cables to the seabed, with specific and permanent flexural stress relief regardless of current or future seabed characteristics or changes. The stabilization device also provides measurable flexural strain relief without needing to know or assume the risk of seabed characteristics or changes.

[0076] This allows typical state-of-the-art seabed positioning tolerances (for foundations, orifice heights, scour protection, and cables and cable protection systems) in installations to be intercepted and captured in the flexural management system and stabilization.

[0077] Therefore, the invention of this application has at least the following advantages:

[0078] • The stabilization of the cable protection system is performed in the scour protection section and / or on the seabed.

[0079] • Bending stress is managed by a built-in bending stress relief device.

[0080] • Stabilization is performed on the seabed (through the scour protection section or on the movable seabed).

[0081] • Bending stress relief and bending management are independent of the seabed features (engineered bending management will be retained, independent of the seabed features) and are unaffected by seabed changes (flow, scour, sand waves, seabed subsidence, etc.).

[0082] • Stabilization is performed without rock (or other ballast material).

[0083] • Stabilization is performed during cable pulling.

[0084] • The stabilization device can be recovered (during operation due to cable replacement or other reasons and at the time of scrapping).

[0085] • Stabilization can be applied to existing (operable) cable protection systems, thereby contributing to the above-mentioned operational features (stabilization with known bending management response).

[0086] Stabilization is performed by a remotely operated vehicle (ROV) with a tool pry bar, eliminating the need for close-range vessel operations (very low impact risk to the foundation and cable / cable protection system).

[0087] The weather window is not limited to platform access.

[0088] Furthermore, the stabilization device according to the invention also facilitates the following:

[0089] The stabilization device allows for the isolation of dynamic forces from the chain portion of the cable protection system (the curvature and tension in the cable protection system terminate at the stabilization device), thus eliminating most of the risks and fatigue problems associated with cable protection requirements from the stabilization device to the burial point.

[0090] The invention reduces the dynamic forces borne by the chain portion of the cable protection system.

[0091] The cable protection system experiences less curvature and lower stress.

[0092] The cable protection system is supported by a bending management system at the point of contact with the ground (i.e., at the stabilization device).

[0093] The tension from the chain portion of the cable protection system is controlled in the stabilization device, thereby eliminating tension on the seabed.

[0094] • Reduced curvature and tensile strain on the cable.

[0095] • Increased cable fatigue life. Specification 6 / 25 pages 10 CN 120898342 A

[0096] • The stabilizing device allows for type identification of the cable protection system (allowing for various cable designs to meet cable fatigue life requirements and with wider installation tolerances).

[0097] • The stabilizing device allows for the use of flexible structures in the cable protection system, which can be made of polyurethane or any other suitable material besides polyurethane.

[0098] • The stabilizing device allows for cost-effective cable protection system designs.

[0099] For example, the stabilizing device can be used as a reliable seabed connection for fixed offshore wind turbine foundations, but the stabilizing device does not...This is not limited to this purpose. Stabilizers can obviously be used with other types of equipment in other offshore industries with fixed foundations. Stabilizers can also be used in other areas where the dynamics of marine meteorological conditions may affect flexible lines such as cables, umbilical cables, etc. in seabed docking points, and stabilization can be applied. This can be a floating structure or other suitable offshore structure.

[0100] Bending Stress Management / Bending Stress Relief

[0101] The object of the present invention is to provide specific bending curvature for cables and cable protection systems, regardless of the nature of the seabed or variations therein, thereby ensuring that the design limitations of the cables and cable protection systems are not exceeded and that the cable fatigue life is extended to above the required minimum.

[0102] A bending management system including a cover unit will provide bending stress relief features (such as typical bending reinforcements) for cables and cable protection systems, even if it covers at most 180 degrees of the circumference of the cable or cable protection system. In most cases, the frequent dynamics of seawater particles are directed towards horizontal movement perpendicular to the direction of the cable and cable protection system.

[0103] Furthermore, the stabilizing device can provide a feature that encloses the tension and compression in the cable and cable protection system to the scour protection section or seabed.

[0104] The stabilizing device can include a bend reinforcement structure and alternative solutions, such as, but not limited to, a compression / elongation resistant device that performs two-dimensional bend management, such as a spring-like or hydro-hydraulic absorber type device.

[0105] Alternatively, the following combination can be used, wherein the combined bend stiffness of the cover unit can be provided by more than one feature, for example by the stiffness of the cover unit and the stiffness of the struts or absorber cylinders.

[0106] On the side of the stabilizing base, or if the stabilizing unit is provided with multiple stabilizing bases, a bend stress management device, i.e., the cover unit, is positioned at the center of the stabilizing base, and the bend stress management device is shaped to have a semi-cone to slide on top of the cable protection system. Such a semi-cone or dome-shaped structure is called a cover.

[0107] This provides a bend management system that can be arranged on the submarine cable unit. The bending management system can be positioned close to the contact point (where the cable or cable protection system chain contacts the seabed or scour protection section) without requiring absolute positioning at the contact point.

[0108] The cover unit has a tip that can be raised above the wing structure to maintain a smooth curvature of the cable protection system and the cable chain.

[0109] The bending stiffness can be gradually increased from the tip. This provides the cable and cable protection system with a seabed mating section for bending management, i.e., a bending reinforcement towards a stable position. This reduces the bending stress on the cable and cable protection system managed by the stabilizing device.

[0110] The effect on the cable and cable protection system is that the curvature is limited to the bending allowed by the design of the stabilizing device.Torque. Removing severe curvature reduces overall mobility and reduces local tension-slip-compression of the cable conductor. This reduces cable wear and significantly increases cable fatigue life.

[0111] Although the cover is intended to contact the circumferential portion of the cable protection system and / or the cable at 180 degrees, if the cable protection system and / or the cable chain descends below the arcuate portion of the cover, the tip portion may have a reinforced vertical wall to provide Z-axis stability. This allows for a wide berth of tolerance relative to the bottom of the cable and cable protection system when the system is positioned on top of the cable protection system and the cable.

[0112] At the rear end “away from the wind turbine generator”, the structural stiffness is preferably very high and can be robust, thus creating a gradually increasing stiffness along the entire length of the cover.

[0113] The length of the bending stress management system provides a minimum limiting curvature (and is greater than the design limitations of the cable and cable protection system) that exceeds the cable fatigue life requirement. The stiffness and length of the shield structure can be designed to provide sufficiently low curvature to ensure minimal cable fatigue life.

[0114] The bending stiffness of the shield can preferably be supported by one or more absorber supports (stags) at the base, thereby increasing horizontal Z-axis stiffness and limiting vertical (Y-axis) movement.

[0115] As mentioned above, the rear end of the shield can end with a rigid (non-flexible) portion. Preferably, this end is held fixed to one or more stabilizing bases.

[0116] Alternatively, the stabilizing base (of any shape) can be an enclosure structure with a flexible (elastic) front end joint. The bend management is provided with the required stiffness (elasticity) to achieve the desired curvature limit and the ability to absorb bending moments from the elastic joint, shield structure, or combination thereof.

[0117] Alternatively, the bend management system can be arranged to progressively restrict the cable protection system and / or the free movement of the cable. This can be arranged in a semi-conical trumpet shape, or preferably, it can be arranged in a series of rods according to the internal shape of the rod, or according to the structural stiffness of the rod, or according to a combination of the internal shape and structural stiffness of the rod. Preferably, the arrangement can be achieved by a single rigid rod or more rigid rods or a similar arrangement to provide an area for tension strain management.

[0118] Stabilizing Base

[0119] The purpose of one or more stabilizing bases is to provide a connection between the bending and tension strain management system and the foundation entering the seabed.

[0120] The purpose of one or more stabilizing bases is also to provide a structure in which the structure is positioned above or embedded in the underlying material (scour protection and / or seabed) when held toward the scour protection and / or seabed.

[0121] The device includes at least one robust stabilizing base (open frame or block), which may be arranged on one side of the flexure management system, or, if more than one stabilizing base is present, on both sides.

[0122] One or more stabilizing bases preferably have vertical openings for at least one pile element within their surface or on their sides.

[0123] The mating portions of one or more stabilizing bases for at least one pile element may be arranged as generally vertical holes or reinforced openings located within or outside the base. Alternatively, a separate mechanical mating portion on at least one pile may provide for transferring the stability of the foundation to one or more stabilizing bases.

[0124] One or more vertical holes or one or more attachment points may be spaced apart to allow initial penetration on both sides of the large armor stone on the scour protection topcoat.

[0125] Each stabilizing base may have one or more slots to provide variable positions for driving at least one pile. Alternatively, securing can be achieved using clamps or brackets (not fixed to the stabilizing base), which are fitted to the pile foundation and prevent one or more stabilizing bases from being anchored to the seabed.

[0126] Alternatively, the stabilizing base (of any shape) can be an enclosure structure, wherein the rear end joint is secured to the cover unit, or a rigid portion of the cover unit is incorporated into the base. One or more stabilizing bases can be single-sided or double-sided, located on each side of the bend management system, i.e., the cover unit.

[0127] One or more stabilizing bases can be designed to have full anchoring capability with a single stabilizing base, but the option of one or more stabilizing bases can be provided.

[0128] Preferably, one or more stabilizing bases can be equipped with a guiding device, which is, for example, but not limited to, a guide for one or more pile elements.

[0129] Tension Strain Management / Friction or Mechanical Fixing

[0130] The purpose of the friction feature is to prevent the submarine cable unit from moving longitudinally. Dynamic forces terminate at the friction section. This prevents dynamic forces on the chain portion of the track that transmits tension during further cabling from affecting the cable or cable protection system.

[0131] The cover unit may include multiple features to facilitate the following functions.

[0132] As described above, the cover unit may be provided with an initial low bending stiffness towards the chain and bent into an upward arc shape with protruding tip ends, and with an increased bending stiffness towards the anchor plate.

[0133] At the rear end, away from the chain portion and / or cable of the cable protection system, the bending stiffness of the cover unit increases until the cover unit gradually becomes rigid. In this rigid "rear end" of the cover, the cover prevents the submarine cable unit from moving.

[0134] In the rigid friction portion of the cover unit, layers and pads can provide gripping for the cable or cable protection system. Force comes from at least one piling element and expansion device, thereby pushing the cover unit downward against the surface of the cable protection system.

[0135] Providing the cover unit with a surface corresponding to the outer surface of the cable protection system and / or cable (e.g., but not limited to, providing an internal convex surface to follow the concave shape of the cable protection system and / or cable and / or protrusions to fit into grooves, etc.) will provide mechanical restraint of the cable protection system inside the cover unit. This will provide a strong anchoring of the cable protection system and / or cable within the rigid portion of the cover.

[0136] For operational stabilization devices, i.e., those with cable protection systems and cable systems installed, the cover unit preferably has a portion with a high-friction pad that will be compressed against the surface of the cable protection system during installation of one or more stabilization bases. Using a compression plate will allow for changes in the cable protection system, marine biofouling, and sediment.

[0137] If the cable protection system or cable has a variable outer diameter, the cover unit can mirror that external shape to prevent longitudinal movement of the cable protection system when tensioned.

[0138] For dedicated cable protection systems, position fixation can be provided by cams and sets of grooves.

[0139] The rigid portion of the cover can have friction pads or friction structures internally to provide sufficient friction at the top 180 degrees of the cable protection system to stop the cable protection system.

[0140] Dedicated cable protection system mating portions with grooved portions can engage with mating structures on the inside of the cover unit (e.g., cams protruding into any groove will stop the cable protection system and prevent longitudinal movement of the cable protection system when tensioned).

[0141] Foundation

[0142] The purpose of the foundation is to provide a fixed horizontal position relative to a seabed structure, such as a wind turbine generator or substation foundation, regardless of the mobility or changes of the surface seabed.

[0143] The preferred method for the foundation is to use at least one pile element or grounding screw or the like. At least one pile element facilitates the carrying of the base / bend management system and foundation (one or more piles / one or more screws, etc.) in a tool sled by a remotely operated vehicle driven by an ROV. The tool sled can carry / dock the required pile elements / screws / anchors for one or more stabilizing base / shroud units and a cable end.

[0144] Preferably, the operation is performed remotely, i.e., by flipping and penetrating the drive (preferably vibratory piling, torque turning, or suction anchor piling).

[0145] At least one pile element can be a typical pile (e.g., steel or concrete or capable of being driven through scour protection).

[0146] Preferably, each pile element, screw, etc., is capable of holding the stable base to the seabed until the end of the project's service life. This includes, but is not limited to, absorbing vertical and horizontal forces of installation impact, combined operation, and compression.

[0147] During the installation of at least one pile element, hammering, vibration, screwing, suction, or any combination thereof can be used.

[0148] At least one pile element can be an H-beam or X-beam, sheet pile, timber pile, tubular member, etc. (hammering or vibration) in any shape or profile. For example, at least one pile element can be a grounding screw or a suction pile or a cone. At least one pile can also be anchored in solid rock.

[0149] At least one pile element can be equipped with an expansion device, such as an expandable (compressible) coupling. Compression can be achieved by the force when at least one pile is driven into the seabed.

[0150] Preferably, the expansion device is compressed and assembled to the pile, etc., before installation. The arrangement structure that maintains the compression can be arranged to degrade or release shortly after installation, thereby releasing the compressive force to the base.

[0151] Alternative Foundation

[0152] Alternative foundation devices for submarine cable units are also provided, which include cables or cables provided with cable protection systems to mitigate seabed subsidence without altering the chain-like shape of the installed submarine cable unit. Such subsidence of the seabed may be due to local seabed erosion or scouring below the submarine cable unit or seabed erosion or scouring in all areas surrounding the submarine cable unit.

[0153] Therefore, the advantage of this alternative foundation device is that it enables the installation of the submarine cable unit in a location where erosion creates a free span of the submarine cable unit between the contact point of the constructed submarine cable unit and the original seabed level or scour layer level before erosion. Therefore, the alternative foundation allows the submarine cable unit to be installed such that it is suspended above the seabed level, thereby providing an artificial grounding base for the cable and CPS raised above the seabed level without altering the chain shape and therefore without changing the tension in the cable.

[0154] The foundation can also be used in situations where erosion is expected due to localized water flow conditions, or when laying the submarine cable unit on a recess in the seabed would result in excessive bending of the submarine cable unit.

[0155] Therefore, a foundation is provided for a submarine cable unit comprising a submarine cable with a cable protection system or simply a submarine cable, the foundation comprising:

[0156] a stake element adapted to be driven into the seabed or scour protection layer,

[0157] - An attachment unit, which is installed to the upper portion of the pile element,

[0158] - A support element, which is attached to the attachment unit and adapted to support the submarine cable unit when the foundation is installed.

[0159] - A locking element, which is attached to the attachment unit and adapted to at least lock the submarine cable unit to the foundation unit.

[0160] Preferably, a bending reinforcement unit is also provided, which includes a bending reinforcement body adapted to be arranged on the submarine cable unit to control the bending of the submarine cable unit, and the bending reinforcement unit further includes at least one attachment element attached to the bending reinforcement body and extending outward from the outer surface of the bending reinforcement body, wherein the attachment element is adapted to be positioned between the support element and the locking element.

[0161] The bending reinforcement unit preferably has at least two attachment elements arranged on one side of the bending reinforcement body and spaced apart in the longitudinal direction of the bending reinforcement body. Preferably, the distance between the two attachment elements is adapted to the size of the locking element, i.e., adapted to the tapered shape of the locking element.

[0162] The support element and / or locking element are preferably mounted on the attachment unit in an adjustable manner.

[0163] The attachment unit may be threaded, and the support element and / or locking element may be threaded in a corresponding manner, such that the position of the support element and / or locking element on the attachment unit is adjustable.

[0164] The support element may be provided with a tapered support element contact surface on which the submarine cable unit rests. Considering the tilt position of the pile element relative to the seabed or scour protection layer after installation, the tapered shape of the support element is preferably adapted to provide the best possible support for the submarine cable unit.

[0165] The bending reinforcement body of the bending reinforcement unit preferably has a semi-domed shape. This means that when the bending reinforcement unit is arranged on the submarine cable unit, the bending reinforcement body approximately covers the upper half of the outer surface of the submarine cable unit.

[0166] The bending reinforcement unit is preferably provided with a wedge-shaped attachment element having a corresponding attachment element contact surface adapted to abut against the locking element.

[0167] The locking element is preferably provided with a locking element locking surface facing one or more tapered attachment elements of the bending reinforcement unit.

[0168] Preferably, the locking element locking surface abuts against the attachment element contact surface of the attachment element of the bending reinforcement unit after the base device is installed.

[0169] The bending reinforcement unit is also preferably provided with four attachment elements, wherein two attachment elements are arranged on the bending reinforcement unit.The two sides of the curved reinforcement body are spaced apart in the longitudinal direction of the curved reinforcement body.

[0170] Preferably, the distance between the two pairs of attachment elements located on both sides of the curved reinforcement body is adapted to the size of the locking element, i.e., adapted to the tapered shape of the locking element to be arranged or mounted on the attachment unit having two stake elements.

[0171] A method for providing a foundation for a submarine cable unit is also provided, wherein the submarine cable unit includes a submarine cable equipped with a cable protection system or only includes a submarine cable, the method comprising the following steps:

[0172] - providing two foundation devices according to any of the embodiments described above,

[0173] - partially arranging the piling elements of the foundation devices in the seabed and / or scour protection layer such that the piling elements of the foundation devices are inclined relative to the seabed or scour protection layer, and such that a support element arranged on an attachment unit is positioned to support the submarine cable unit,

[0174] - if the submarine cable unit has not yet been installed, installing the submarine cable unit such that the submarine cable unit is supported by the support element of the foundation devices,

[0175] - arranging a locking element on the attachment unit of its respective piling element such that the submarine cable unit is locked in the position of the submarine cable unit on the support element.

[0176] The method further includes arranging a bending reinforcement unit on the submarine cable unit such that the attachment element is adjacent to the attachment unit of the piling element, and then arranging the locking element on the attachment unit.

[0177] Preferably, locking elements are arranged on the attachment units of their respective pile elements such that the locking elements abut against the attachment elements of the bending reinforcement unit and lock the bending reinforcement unit and the submarine cable unit into place.

[0178] Preferably, the two pile elements are arranged such that the support element supports the submarine cable unit after installation. The position of the support element on the attachment can be adjusted to the desired position so that the support element supports the submarine cable unit.

[0179] After the two pile elements are arranged in their desired positions and the support element supports the submarine cable, the bending reinforcement body is preferably arranged on top of the submarine cable unit such that the attachment element of the bending reinforcement unit is adjacent to the attachment unit on the pile element.

[0180] The pile elements are arranged such that the pile elements are inclined relative to the seabed or scour protection layer. Thus, the pile elements have a scissor-like shape. The arrangement of these two foundation devices will provide stable support for the submarine cable unit.

[0181] Compressed to the seabed

[0182] The purpose of this feature is to maintain vertical contact between the base and the bending management system and the seabed in the event of a horizontal drop in the scour protection section or the seabed.

[0183] It is necessary to compress the stabilizing device onto the lower seabed or the scour protection section to ensure that the cable protection system is secured.Inside the enclosure. To provide support in case of potential sinking of the scour protection or displacement of the seabed due to sinking and scour, the vertical foundations of one or more bases are connected to the at least one pile element, rod, column, etc., via a pre-tensioned expansion device. This expansion device forces one or more stabilizing bases downward against the seabed or scour protection, thereby ensuring that one or more stabilizing bases remain at the level of the seabed or scour protection after the level of the seabed or scour protection eventually drops. The expansion device may include a compression spring device, such as a spring element, or any other device capable of extending in length and simultaneously pressing one or more stabilizing bases downward against the seabed or scour protection. The extension length is preferably designed to at least reach the maximum possible drop in the level of the seabed or scour protection.

[0184] The expansion device can be pre-tensioned and compacted using biodegradable clamps, ropes, or the like, and released after a predetermined time following installation.

[0185] Space is reserved for the descent (sinking) of the wind turbine generator foundation.

[0186] The purpose of this feature is to ensure that the cable protection system and cable curvature are not compressed when the wind turbine generator foundation sinks to the seabed after cable installation.

[0187] By pre-setting the curvature of the cable protection system and positioning the base on a chain inside the cable protection system contact point, the reduction in aperture height can be absorbed while maintaining a large bending radius, while ensuring that the cable routing distance within the cable protection system and MP foundation is not shortened. This will prevent compression of the internal cable structure (which increases cable fatigue).

[0188] Installation Features

[0189] The purpose of these features is to minimize the impact on the critical path of offshore construction activities, reduce risks, and simultaneously provide stability for the installed cables and cable protection system.

[0190] The stabilizing device is designed to be placed on top of the cable or cable protection system, so that the cable or cable protection system laid above the lower seabed will be covered by the structure. The versatility of the subsurface seabed anchoring allows for the use of a single pile element or more pile elements to make one or more stabilizing bases as a stable foundation.

[0191] The stabilizing device and one or more pile elements can be transported by a remotely operated vehicle (ROV), whose tool rails can dock the stabilizing device and one or more pile elements before the ROV is launched. Upon reaching the underwater position, for example, a robotic arm is used to release the stabilizing device and place it on top of the cable protection system, and then the tool rails invert at least one pile element(e.g.), and when its bottom end is in the docking portion of the stabilizing base, the pile is driven in by the ROV's power unit, for example a hydraulic power unit for a hydraulically driven ROV, or an electric unit.

[0192] This installation does not require heavy lifting or bringing a surface vessel close to the seabed structure.

[0193] Furthermore, stabilization can be performed simultaneously with cable pulling and integrated into the pulling procedure without affecting the key path. For example, stabilization can be performed during the time between the cable protection system being locked to the orifice or flare and the establishment of a temporary cable suspension. Typically, a 30-60 minute period for the ROV to monitor the subsea docking point is sufficient, so using this time for foundation installation will not affect cable laying efficiency. This means that stabilization of the cable protection system and / or the cable can be performed during cable pulling and can be achieved by utilizing an idle observation station ROV during the typically 30-60 minute waiting period between the cable protection system latching / interlocking and the temporary cable suspension within the tower. In this way, the stabilization device is removed from the critical path of cable installation, thus not delaying cable installation and providing stability immediately upon pulling.

[0194] This installation will not affect the cable within the cable protection system, for example, stabilization can be performed after the cable protection system is locked, thereby allowing the cable to be pulled to the switch cabinet after stabilization.

[0195] This installation can also be carried out from a CLV (Cable Laying Vessel) operated by an ROV.

[0196] Materials

[0197] Cost is a key obstacle to the development of offshore wind power. This invention allows the use of “low-grade” industrially available materials, such as glass fiber reinforced epoxy, carbon steel, etc., and can provide anode-equipped steel, as well as designs that allow water absorption to meet design standards—including end-of-life. Therefore, the use of special materials, such as high-cost steel, composite materials, or polymers, can be avoided.

[0198] Using general industrial materials that are not specifically designed for cable protection or other specialized markets not only ensures low-cost materials but also allows for industrial production in most areas, thereby avoiding transportation costs and CO2 emissions and creating local supply chain opportunities within the wind farm installation area.

[0199] Type Identification

[0200] This invention provides optional type identification for a variety of cable designs (within a wide tolerance range for the basic butt joint height, chain length, and position of this invention). The reason for the feasibility of this type identification is that stability with a specified bending response eliminates the task of cable protection systems dealing with the curvature and stress of the chain when it touches the ground. This enables the invention to be designed to withstand worst-case scenarios, thereby reducing the bending moments and tensions applied to and managed by the cable protection system. This capability ensures that even the most demanding cable designs meet cable fatigue life requirements.

[0201] This guarantees that cable boundary conditions considered during the cable design phase can be optimized. Cable design parameters for the primary functions (power and signal transmission) and related costs can be optimized without considering extreme curvature and tension parameters of the cable design.

[0202] The stabilization device offers several advantages in terms of installation:

[0203] • No need to approach the base vessel.

[0204] • No need for heavy ballast material hoisting.

[0205] • Immediate stabilization (during cable installation).

[0206] • Quick operation (completed within 15 to 25 minutes).

[0207] • Can be performed on the seabed or through the scour protection section.

[0208] Any auxiliary vessel capable of ROV operation can install the stabilization device into an operable cable protection system and cable system, which means:

[0209] 1. No need to approach the base vessel.

[0210] 2. No need for heavy ballast material hoisting.

[0211] 3. No need for personnel to enter the tower. Instruction manual 13 / 25 pages 17 CN 120898342 A

[0212] 4. Quick operation (completed within 15 to 25 minutes).

[0213] Therefore, the present invention has many advantages:

[0214] • The present invention provides stabilization of cable protection systems and / or cables, thereby eliminating risks arising from seabed characteristics or seabed changes.

[0215] • The cable protection system and / or cables are stabilized, thereby eliminating the effects of seabed characteristics, risks, and uncertainties—including but not limited to seabed mobility and variability.

[0216] • The present invention achieves stabilization through a bend management system, thereby eliminating risks affecting cable fatigue life (eliminating the risk of cable failure during its service life).

[0217] • A bend management system is provided that can mitigate severe bending of the cable protection system and / or cables, reducing the effects of localized tension-slip-compression on the cables, thereby extending cable fatigue life.

[0218] • The present invention provides stabilization during cable installation.

[0219] • The stabilization device enables immediate stabilization during cable installation without affecting the critical path.

[0220] • The present invention provides stabilization without the need for ballast materials (rock, rock filter bags, pads, etc.).

[0221] The stabilization device can operate without ballast material.

[0222] The present invention provides stabilization without the need for crane / lifting operations.

[0223] No hoisting or crane operation is required.

[0224] The present invention provides stabilization without the need to be near the wind turbine generator or substation.

[0225] Surface vessels do not need to be near the offshore foundation for operation.

[0226] The present invention provides a wider tolerance range for positioning.

[0227] No cumbersome and often difficult-to-achieve positioning accuracy is required.

[0228] The present invention captures the drop of the MP foundation after installation.

[0229] No cable protection system and / or cable compression are required, thus avoiding the sinking (dropping) of the monopile of the wind turbine generator.

[0230] In short, this system provides a solution for addressing cable protection systems and / or cable fatigue life threats, eliminating uncertainties at seabed joints and eliminating the need for ballast materials, thus providing a stable bending management system that absorbs seabed and installation variations.

[0231] Not only are ballast materials, transportation, and installation eliminated, but the risks and uncertainties of using ballast materials to stabilize cables and / or cable protection systems are also eliminated. Brief Description of the Drawings

[0232] Non-limiting embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0233] FIG1 shows the stabilization device and subsea system from a side view.

[0234] FIG2 shows the stabilization device and subsea system in a perspective view.

[0235] FIG3 shows the stabilization device.

[0236] FIG4 shows the stabilization device with a piling element and an expansion device for the piling element.

[0237] FIG5 shows the stabilization device and piling element driven into the seabed and / or scour protection layer.

[0238] FIG6 shows the cover unit of the stabilization device with a first clamping device and a second clamping device.

[0239] Figure 7 shows a stabilization device without a pile element.

[0240] Figure 8 shows the stabilization device shown in Figure 7 viewed from the front. Specification 14 / 25 pages 18 CN 120898342 A

[0241] Figure 9 shows a stabilization device including two stabilizing bases, namely a first stabilizing base and a second stabilizing device disposed on both sides of the cover unit.

[0242] Figure 10 shows a stabilization device including a separate and unfastened clamping element, which includes at least one hole for a pile element.

[0243] Figure 11 shows a stabilization device with a separate and unfastened clamping element as shown in Figure 10 viewed from below.

[0244] Figure 12 shows a stabilization device including separate and unfastened clamping elements of different designs, which also include at least one hole for a pile element.

[0245] Figure 13 shows a stabilization device including a dynamic damper.

[0246] Figure 14 shows a stabilization device including two dynamic dampers attached to the cover unit and to a first stabilizing base and a second stabilizing base, respectively.

[0247] Figure 15 shows a cover unit provided with a motion-stopping element adapted to engage with a submarine cable passing through the cover unit of the stabilization unit or, if the submarine cable is equipped with a cable protection system, with a cable protection system.

[0248] Figure 16 shows a cover unit provided with the motion-stopping element shown in Figure 15, viewed from a slightly different angle.

[0249] Figure 17 shows a cover unit provided with a motion-stopping element in the form of a slot / cavity / groove / notch, adapted to engage with a cable protection system and / or a portion of the cable passing through the cover unit.

[0250] Figure 18 shows a stabilizing device centrally positioned on top of the contact point of the cable protection system and / or cable.

[0251] Figure 19 shows a stabilizing device positioned outside the contact point of the cable protection system and / or cable system.

[0252] Figure 20 shows two locations of the central portion of the stabilizing device, one stabilizing device located outside the contact point of the cable protection system and / or cable system on the left side of the figure, and the other stabilizing device located inside the contact point of the cable protection system and / or cable system on the right side of the figure.

[0253] Figure 21 shows a stabilizing device arranged on a scour protection section.

[0254] Figure 22 shows a stabilizing base, wherein holes for piling elements are provided with corresponding guide elements.

[0255] Figure 23 shows an expansion device of the stabilizing device, which is in a compressed state in the middle part of the figure and in a relaxed state on the right side of the figure.

[0256] Figure 24 shows a stabilizing device installed on a scourted seabed.

[0257] Figure 25 shows the stabilizing device in two positions under seabed leveling conditions. The upper part of the figure shows the installation height corresponding to the seabed level during installation, and the lower part shows the installation height after the seabed leveling.

[0258] Figure 26 shows the stabilizing device before seabed leveling.

[0259] Figure 27 shows the stabilizing device after seabed leveling.

[0260] Figure 28 shows a bending management system that can be used as an alternative to the cover unit shown in Figures 1 to 26.

[0261] Figure 29 shows the bending management system shown in Figure 28 viewed from the side.

[0262] Figure 30 shows a stabilizing system with multiple clamping devices forming a semi-flare shape, i.e., the length of the clamping devices gradually increases from one end to the other.

[0263] Figure 31 shows the stabilizing system with multiple clamping devices shown in Figure 30 viewed from above.

[0264] Figure 32 shows a stopping device that deforms the outer surface of the cable protection system in a defined manner, as described on pages 15 / 25 of the specification, 19 CN 120898342 A, to enhance the longitudinal stopping effect.

[0265] Figure 33 shows the stabilizing device shown in Figure 32 as viewed from below.

[0266] Figure 34 shows a submarine cable equipped with a cable protection system, which is arranged on the seabed or on a scour protection layer on the seabed.

[0267] Figure 35 shows the cable with the cable protection system shown in Figure 34, wherein the seabed or scour protection layer has dropped a distance D due to erosion or other reasons, causing the cable and cable protection system to be suspended above the seabed or scour protection layer.

[0268] Figure 36 shows a submarine cable unit and two foundation devices arranged on...In the seabed and / or scour protection layer, and inclined relative to the seabed or scour protection layer to form a scissor shape, and supporting the submarine cable unit suspended above the seabed or scour protection layer.

[0269] FIG37 shows the submarine cable unit supported by two support elements, which are respectively arranged on two pile elements of the foundation, and the bending reinforcement unit is lowered to the top of the submarine cable unit.

[0270] FIG38 shows the same process as FIG37 in a side view, that is, the bending reinforcement unit is lowered to the top of the submarine cable unit.

[0271] FIG39 shows the submarine cable unit, wherein the bending reinforcement unit is installed on the top of the submarine cable unit, and the submarine cable and the bending reinforcement unit are locked in place by locking elements provided on the pile elements.

[0272] FIG40a and FIG40b show the same content as FIG39 in a front view and a side view, respectively. First, it should be noted that the submarine cable unit 18 of the present invention can be a single cable or a cable provided with a cable protection system 20. Detailed Description

[0273] Figures 1 and 2 illustrate a stabilization device 22 and a subsea system 10 according to the invention, wherein the subsea system includes a monopile 12. A particular application of the stabilization device 22 according to the invention is for the offshore wind power industry, wherein a known cable protection system 20 is used for a monopile foundation 12 without a J-tube assembly—referred to as “J-free”. Here is a cable inlet or hole 13 on the monopile foundation 12, wherein the cable protection system 20 of the subsea cable unit 18 is mechanically locked in the hole 13 via a mechanical connector / latch / dock unit 14 of the cable protection system 20.

[0274] The stabilization device 22 is inserted into the seabed 17 via one or more pile elements 54, which penetrate the upper layer, the top layer affected by movement, and possibly the scour protection layer 15.

[0275] Although the stabilization device 22 shown in the figures is for a subsea cable unit of a monopile foundation 12, it is also applicable to other types of foundations and docking points. For example, including but not limited to J-tube flared joints for wind turbine generators, and can be applied to other subsea joints in which underwater lines (cables, flexible cables, umbilical cables, etc.) will benefit from a controlled bend management system.

[0276] FIG3 shows the stabilization device 22 according to the invention in more detail. Preferably, the stabilization device 22 is designed to be mounted on top of the subsea cable unit 18, thereby placing it on top of the cable protection system 20. Preferably, the stabilization device 22 is fixed to its position relative to the wind turbine generator or substation foundation by a piling element 54, wherein the piling element 54 has a processing joint 57 (see FIG23) on its top portion 56, which is used for, for example, via an ROV.Handling and inversion. One or more pile elements 54 provide horizontal stability to the stabilizing device 22. The pile elements 54 also provide vertical stability to the stabilizing device 22 relative to the seabed 17 and / or the scour protection layer 15. Preferably, the top portion 56 of the pile elements 54 of the stabilizing device 22 may be equipped with an expansion device 59 having expansion capacity. This provides a vertical force to at least one stabilizing base 24, 25 provided for the stabilizing device 22, thereby ensuring that the stabilizing device 22 remains compressed toward the seabed 17, even if the level of the seabed 17 drops due to, for example, erosion.

[0277] The stabilizing device 22 provides a bending stress relief function for the submarine cable unit 18, which is preferably arranged as a dome-shaped cover unit 45. The cover unit 45 covers 180 degrees, preferably more than 180 degrees, of the upper circumferential portion of the submarine cable unit 18. To cooperate with the bending management system, the cover unit 45 may be provided with: a flexible docking portion facing the submarine cable unit 18 and / or the cable chain, the docking portion preferably being in the form of a first clamping device 27, which is attached to at least one stabilizing base 24, 25; and a more rigid docking portion facing the other end of the at least one stabilizing base 24, 25 (i.e., the end away from the submarine cable unit chain), the more rigid docking portion preferably being in the form of a second clamping device 28, the bending moment of the second clamping device 28 being greater than that of the first clamping device 27.

[0278] As shown in FIG4, the stabilizing device 22 may be arranged on the top of the submarine cable unit 18, i.e., the cable protection system 20 and / or the cable, and at least one stabilizing base 24, 25 of the stabilizing device 22 may be arranged on one side of the submarine cable unit 18, or on both sides of the submarine cable unit 18 as shown in FIG4. The double-sided stabilizing bases 24 and 25, arranged on both sides of the submarine cable unit 18 passing through the stabilizing device 22, namely including a first stabilizing base 24 and a second stabilizing base 25, can be used to improve stability on uneven surfaces (e.g., but not limited to large-sized armored rocks, such as, but not limited to, D90 rocks (900 mm in diameter)). Both the first stabilizing base 24 and the second stabilizing base 25 are provided with at least one attachment device, such as a through-hole 42, for attaching a piling element 54. In Figure 4, the first stabilizing base 24 and the second stabilizing base 25 are each provided with three through-holes 42 through which the piling element 54 can pass. In this example, each of the first stabilizing base 24 and the second stabilizing base 25 is stabilized by a single piling element 54, but the piling element 54 could also be provided in each through-hole 42. The top portion 56 of the piling element 54 has sufficient length to provide an expansion device 59 as shown, which can be used to drive the piling element 54 into place.During the compression process, or preferably, as shown in the figure, the expansion device 59 is pre-compressed to a set compression length before the installation of the stabilizing device 22.

[0279] As shown in Figure 5, the stabilizing device 22 can be positioned on the seabed without the scour protection layer 15, and the pile element 54 will penetrate into the seabed 17. The penetration length portion 55 of the pile element 54 will be maintained together with the expansion device 59 in a horizontal position relative to the monopile 12 of the wind turbine generator or substation foundation, thereby clamping the vertical position of at least one stabilizing base 24, 25 and thus the cover unit 45 and the first clamping device 27 and the second clamping device 28 onto the submarine cable unit 18.

[0280] As shown in Figure 6, the cover unit 45 of the bending management system can be configured as a dome shape in the longitudinal direction of the cover unit 45. Preferably, the cover unit 45 has a flexible tip 46, which allows the dome shape of the cover unit 45 to follow the trajectory of the chain of the submarine cable unit 18. It has a relatively soft tip end, such that: when the dome-shaped central portion 47 and the horizontal portion 48 of the cover unit 45 are pressed downward around the submarine cable unit 18, the lower stiffness tip end 46 of the cover unit 45 will a) follow the chain shape of the submarine cable unit 18, b) ensure a tapered bending stress relief member with minimal force at the starting point of the dome-shaped portion. The side portion 49 of the dome-shaped portion can be lowered to allow guidance of the submarine cable unit 18, even if the submarine cable unit is not compressed toward the inner top plate of the dome-shaped portion of the cover unit.

[0281] The stiffness of the cover unit 45 of the bending management system is similar to that of a conventional bending stress relief member, with the stiffness increasing along the length of the dome-shaped cover unit 45 when the softer tip end 46 is provided. At the end opposite to the softer, raised tip end 46, the bending stress relief member is preferably terminated to a rigid end portion. The rigid end can be an integral part of at least one stabilizing base 24, 25 (not shown in FIG. 6), or the rigid end can be connected to at least one stabilizing base 24, 25 by a rigid support frame in the form of a second clamping device 28, as shown in FIG. 6.

[0282] This arrangement is similar to the rigid termination of a conventional bending stress relief / end reinforcement. In the case of an arrangement where the base is a rigid metal flange, the stiffness of the bending stress relief / end reinforcement is designed to provide a flexible section, such as a flexible streamline, strip, cable, or line, having a predetermined curvature that depends on the force and angle at which the flexible section is pulled (usually shown in pole figure form). In order for the flexible streamline, strip, cable, or line to have a sufficiently long fatigue life, the bending management system must meet its design limits and fatigue curvature and tension pair.

[0283] This can be achieved by using a dome-shaped shroud unit 45, which itself maintains sufficient increased stiffness along its length, or the dome-shaped portion can be assisted by a flexible support or damping device located between the distal end and the rigid end—as shown in the dome-shaped central portion 47 in Figure 6—so that the overall management system provides a flexible streamline, strip, cable, or line with sufficiently low curvature to provide sufficient fatigue life.

[0284] The nature of the stabilizing device 22 only allows for 180-degree free movement in the upper part. The trajectory of the seabed 17 (or scour protection 15) and the subsea cable unit 22 from the base interface will restrict the lateral (omnidirectional) and upward (heavy) movement of the subsea cable unit. Therefore, the dome-shaped shroud unit 45 must only manage the dynamic movement of the subsea cable unit 18 in these directions.

[0285] Figures 7 and 8 show the stabilizing plane of at least one stabilizing base 24, 25, which has an integral through-hole 42 for the piling element 54 in an open structure. The through-hole 42 may be provided with one or more guide elements 43 (not shown in Figures 6 and 7, but see Figure 22) to facilitate the insertion of the piling element 6 into the hole.

[0286] The horizontal portion 48 of the dome-shaped cover unit 45 is designed to hold the submarine cable unit 18 toward the seabed 17 (or scour protection 15), as described below.

[0287] Alternatively, at least one stabilizing base 24, 25 may be provided only on one side of the cover unit 45, and the number of through-holes 42 for the piling element 54 may be one or more as described above.

[0288] Alternatively, stabilizing bases 24, 25 may be provided on both sides of the cover unit 45. Similarly, the number of through-holes 42 for the piling element 54 in the stabilizing bases 24, 25 may be one or more.

[0289] In another alternative, as shown in Figure 9, two stabilizing bases 24, 25 may be provided on both sides of the cover unit 45.

[0290] As shown in Figures 10 and 11, the stabilizing bases 24, 25 may be designed without a designated through-hole 42 for the pile element 54. Instead, one or more loose clamping elements 39 may be used, each clamping element including at least one through-hole 42 for the pile element 54.

[0291] The clamping element 39 is provided with a groove 40 for arresting at least one stabilizing base 24, 25, or the clamping element 39 is provided with an assembly in which the groove 40 or slot in at least one stabilizing base 24, 25 may be formed with a mating portion for a faucet-like member located on the clamping element 39 (or reversibly, a protrusion of at least one stabilizing base 24, 25 may be fitted into the groove 40, recess, or slot of the clamping element 39).

[0292] Alternatively, as shown in Figure 12, at least one stabilizing base 24, 25 may be held by the clamping element 39, the clamping element...The component 39 is in the form of a clamping member, which includes at least one through hole 42 for the pile element 54.

[0293] As shown in Figures 13 and 14, as an alternative to the flexible first clamping device 27, depending on whether the stabilizing device 22 is provided with two or one stabilizing base 24, 25 respectively, the cover unit 45 of the bending management system can be supported by a dual absorber device 30 as shown in Figure 14 or a single absorber device 30 as shown in Figure 13 to obtain a preferred curvature. The absorber device 30 can be anchored at one end to a first anchoring portion 31 on a single stabilizing base 24, 25 as shown in Figure 13, or anchored to two stabilizing bases 24, 25 as shown in Figure 14, and at the other end to a second anchoring portion 24 on the cover unit 45.

[0294] In the case of a bending management system for replicating a bending stress relief member / end reinforcement, conventionally, the flexible member is mechanically terminated to the fixed member to reinforce the end of the bending stress relief member / end reinforcement—stabilizing device 22, specification 18 / 25 pages 22 CN 120898342 A, is preferably adapted to hold the submarine cable unit 18 in its longitudinal direction. This is to ensure that dynamic movement on the chain of the submarine cable unit does not force the submarine cable unit 18 to reposition. This feature also ensures that tension in the submarine cable unit 18 is not transmitted to the submarine cable unit 18 on the other side of the stabilizing device 22.

[0295] As shown in Figures 15 and 16, longitudinal holding of the submarine cable unit 18 can be achieved by a motion-stopping element 51, which is, for example, in the form of a high-friction layer located inside the horizontal portion 48 of a dome-shaped cover unit 45. The entire top of the cover unit 45 may be fitted with a high-friction material or substance (e.g., but not limited to, natural rubber, neoprene, preferably with a hardness grade of 67, 73, and 78).

[0296] Friction can also be provided by a motion-stopping element 51, which is in the form of a panel or friction pad located inside the dome-shaped top of the cover unit 45, as shown in Figures 15 and 16. When the dome-shaped cover unit 45 is stabilized onto the seabed 17 or the scour protection layer 15, the motion-stopping element 51 compresses against the submarine cable unit 18. Therefore, after the submarine cable unit 18 descends onto the cable protection system 20 of the submarine cable unit 18 according to the vertical base force on at least one stabilizing base 24, 25, it is forced against the friction pad. This increases friction and protects the submarine cable unit 18 from slippage and from the transmission of tension from the stabilizing device 22.

[0297] Alternatively, as shown in FIG17, the submarine cable unit 18 may be held inside the dome-shaped cover unit 45. Preferably, the submarine cable unit 18 is located within the horizontal portion 48 of the cover unit 45, the horizontal portion 48 having a motion-stopping element 51 in the form of a slot / cavity / groove / recess, the motion-stopping element 51 being adapted to dock with a specific length portion of the submarine cable unit 18.

[0298] As shown in FIG. 18, the stabilizing device 22 can be positioned near or on top of the contact point 34 of the submarine cable unit 18. In this figure, the stabilizing device 22 is shown centered on top of the contact point of the submarine cable unit 18. This would require a high degree of installation precision. To allow freedom of installation position relative to the contact point 34 of the submarine cable unit 18, the flexibility of the bend management system accommodates wide tolerances.

[0299] In FIG. 19, the central portion 31 of the stabilizing device 22 is positioned outside the contact point 34 of the submarine cable unit 18. The capacity of the bend management system can be designed to accommodate the maximum required horizontal external positioning.

[0300] Alternatively, the central portion 35 of the stabilizing device 22 can be positioned inside the contact point 34 of the submarine cable unit 18. The capacity of the bend management system can be designed to accommodate the minimum required horizontal internal positioning.

[0301] As shown in FIG. 20, this facilitates a greater degree of freedom in the horizontal positioning of the stabilizing device 22 on top of the submarine cable unit 18, as shown in the two alternative positions of the central portion 35 of the stabilizing device 22. This horizontal degree of freedom also allows for variable cable protection systems and cable orientation (compass orientation).

[0302] As shown in FIG21, for an open alternative to the stabilizing base 2, a box-shaped first stabilizing base 24 and a second stabilizing base 25 may be provided on each side of the cover unit 45 of the bend management system at the top of the submarine cable unit 18.

[0303] Wherein, one or more pile elements 54 extend from the top of the stabilizing base 2, for example, through the scour protection layer 15, to the depth of the stabilized seabed indicated by reference numeral 17.

[0304] As shown in FIG22, the through holes 42 for the pile elements 54 located in at least one stabilizing base 24, 25 may be equipped with guide elements 43 to assist the pile elements 54 in entering their respective through holes 42.

[0305] As shown in FIG23, when driving in the foundation type, i.e., the pile element 54 or screw, the compression system of the stabilizing device 22, including the expansion device 59, can be compressed from a relaxed state 61 with an uncompressed length having the expansion device 59 to a compressed state 60 with a compressed length. Alternatively, the expansion device 59 can be applied to its compressed length to have the ability to extend to its uncompressed length.

[0306] In the event of movement of the seabed 17, or in the case where the scour protection 15 is located deeper than the seabed 17, the compressed installation length of the expansion device 59 can be extended from the compressed length of the expansion device to the full length of the expansion device 59. This expansion length is the vertical descent capability of the stabilizing device to follow the descent of the seabed 17 or the scour protection 15.

[0307] As shown in FIG24, the compressed expansion device 59 releases its expansion as a force downward to at least one stabilizing base.24, 25 and the top 56 of the pile element 54 are released upwards. In this figure, the stabilizing device 22 is shown as being located in the seabed 17 without the scour protection 15, and the scour pit / scour hole 16 extends near the monopile 12.

[0308] Figure 25 shows that from the installation level 36 of the stabilizing device 22 (which is the position of the seabed level at the time of installation) to the first chain 52 of the submarine cable unit 18, the stabilizing device 22 will follow the descent of the seabed level all the way to the lowered level of the stabilizing device 22 by means of the compressed expansion device 59, during which the expansion device 59 will extend from the compressed state 60 to a more relaxed state 61 with a new expanded length, thereby forcing at least one stabilizing base 24, 25 from the installation level 36 of the stabilizing device 22 to the lowered level 37 of the stabilizing device 22 to a new lowered seabed height, thereby forcing the submarine cable unit 18 into the shape of a new second chain 53.

[0309] This will cause the contact point 34 of the natural chain shape of the submarine cable unit 18 to move, but the capacity of the bending management system remains under control despite the higher tension on the chain 53 of the second submarine cable unit.

[0310] In Figure 26, the initial seabed 17 of the stabilizing device 22 is shown (the state and position of the seabed 17 when the stabilizing device 22 is installed). At least one stabilizing base 24, 25 is provided on the submarine cable unit 18 having the shape of the first chain 52 and fixed in the seabed by a pile element 54, with the expansion device 59 in its compressed state 60.

[0311] As shown in Figure 27, in the case of a decrease in seabed / scour height, the pile element 54—the top portion 9 and the submerged lower portion 55—remains unchanged. Therefore, as the seabed 17 descends, at least one stabilizing base 24, 25 follows the level of the seabed 17 due to the expansion of the compressed expansion device 59, thereby causing the height of the top portion 56 of the pile element 54 to rise uniformly above at least one stabilizing base 24, 25 as the level of the seabed 17 descends.

[0312] The expansion device 59 may preferably be provided with a compression spring (as shown above and in the figures), or the expansion device 59 may be provided with any expansion material that can be installed or compressed in its retracted form. Thus, mechanical restraint can be stopped after installation (degradable after immersion for a predetermined time, or immersion in seawater to promote the expansion of the substrate).

[0313] As shown in Figures 28 and 29, the bending management system of the stabilizing device 22 may be configured as—for example, according to API 17—a bending stress relief type bending reinforcement. The bending stress relief base 68 is fixed, alternatively, incorporated into the stabilizing base 70. The bending stiffener portion 69 of the bending management system provides the required continuously increasing bending stiffness from the protruding tip (where the bending stiffness is minimal) towards the solid base as the bending stiffness increases.

[0314] The bending stress relief device can be pre-installed on the cable protection system before being pulled in. An alternative and preferred method is to use an open slotted bending stress relief base 68 and a bending reinforcement portion 69, allowing the stabilizing device 22 to be placed on top of the submarine cable unit 18. In addition to the advantage of separating the installation operation of the stabilizing device 22 from the operation in the cable highway of the critical path and CLS, this also allows the use of the stabilizing device 22 for stabilization on the installed submarine cable unit 18.

[0315] As shown in Figures 30 and 31, the bending management system can alternatively be configured to gradually restrict the free movement of the submarine cable unit 18. The bending management system can be configured as a flared semi-cone 72, preferably, the flared semi-cone 72 being a series of rods 73 according to its internal shape, or according to its structural stiffness, or any combination thereof. Preferably, the device can employ a single or more rigid rods or a similar arrangement to provide an area for tensile strain management.

[0316] The longitudinal friction lip provides an upward force toward the friction pad / layer on the cable protection system 20 and provides slight deformation on both sides of the cable protection system to secure the gripper to the smooth surface of the cable protection system.

[0317] As shown in FIG32, the stabilizing device 22 may be provided with a deformation device 64 that causes positive deformation of the outer surface of the cable protection system 20 of the submarine cable unit 18 to reinforce longitudinal blocking alone or together with any other motion-stopping element 51, such as the friction pad / layer described above on pages 24 of the specification 20 / 25 CN 120898342 A.

[0318] Lateral struts 65 (e.g., three on each side, but there may be one or more lateral struts 65) arranged laterally relative to the longitudinal direction of the cover unit 45 are securely attached to the cover unit 45 at one end at a corresponding attachment point 67 and push the staked element 54 and its expansion device 59 downward onto the first stabilizing base 24 and the second stabilizing base 25. The other end of the transverse support 65 is connected to a compression region 66 or pad region disposed on the first stabilizing base 24 and the second stabilizing base 25. When the transverse support 65 is not pressed down, the compression region 66 remains in a substantially horizontal position, thereby mounting the compression region 66 on the cable protection system 20 of the submarine cable unit 18.

[0319] When the piling element 54 applies pressure to the transverse support 65, and further to the first stabilizing base 24 and the second stabilizing base 25, the other end of the transverse support 65 pushes against the surface of the cable protection system 20 of the submarine cable unit 18, as shown in FIG33. This provides a firm grip on the outer surface of the cable protection system 20, thereby preventing any movement of the submarine cable unit 18.

[0320] In FIGS. 34 to 40, an alternative base device 74 for the submarine cable unit 18 is shown, which base deviceThe alternative foundation 74 comprises only cables or cables equipped with cable protection systems to mitigate the subsidence of the seabed 17 and / or the scour protection layer 15 without altering the shape of the chain of the installed subsea cable unit 18. This subsidence of the seabed and / or the scour protection layer may be due to local seabed erosion or scour beneath the subsea cable unit 18, or it may be due to global seabed erosion or scour in the area surrounding the subsea cable unit 18.

[0321] The alternative foundation 74 also has the advantage of being able to install the subsea cable unit 18 in a location where erosion has caused the subsea cable unit 18 to form a free-span between its point of contact during laying and the original uneroded seabed level or scour layer level. Therefore, the alternative base device 74 allows the submarine cable unit 18 to be installed while suspended above the seabed level 17 or the scour protection layer 15, thereby providing an artificial grounding base for the submarine cable unit 18, which is raised above the seabed level or the scour protection layer without changing the shape of the chain, thereby changing the tension in the submarine cable unit 18.

[0322] The base device 74 can also be used in cases where erosion is expected due to local water flow conditions. In this case, the base device 74 is installed before installing the submarine cable unit 18 or during the same installation process as the submarine cable unit 18.

[0323] In FIG. 34, the submarine cable unit 18 is shown, which is installed and extends from above the seabed 17 or the scour protection layer 15, for example, from the seabed structure (not shown) to the seabed 17 or the scour protection layer 15.

[0324] Over time, the seabed 17 and / or the scour protection layer 15 may erode, and the submarine cable unit 18 may eventually become suspended above the seabed 17 or the scour protection layer 15. This is shown in Figures 35 and 38, where the submarine cable unit 18 is located at a distance D above the seabed 17 or the scour protection layer 15. This will increase the tension in the submarine cable unit 18 and may cause a change in the chain-like shape of the submarine cable unit 18, thereby increasing wear on the submarine cable unit 18.

[0325] A base device 75 is shown in Figures 36 to 40, which can be used to mitigate corrosion problems of the seabed 17 and / or the scour protection layer 15 around the submarine cable unit 18.

[0326] Figure 36 shows two foundation devices 75, each foundation device 75 including a pile element 75 having: a lower portion 79 disposed in the seabed 17 and / or scour protection layer 15; an upper portion 76; and a free portion 78 located between the lower portion 79 and the upper portion 76.

[0327] The upper portion 76 of the pile element 75 is provided with an attachment unit 77. The attachment unit 77 is securely attached to the pile element 75 by suitable means such as bolts or by welding.

[0328] Each base unit 74 also includes a support element 80, which is attached to the attachment unit 77 and supports the submarine cable unit 18. Preferably, the support element 80 is attached to the attachment unit 77 in an adjustable manner, but it can also be securely attached to the attachment unit by bolts or any other suitable fastening device. To obtain the support element 80 in an adjustable manner on the attachment unit 77, the support element 80 and the attachment unit 77 may be provided with corresponding threads, such that the support element 80 can be screwed up and down on the attachment unit 77 to a desired position. When the support element 80 is in its desired position, the support element 80 can be locked to the attachment unit 77 by a suitable locking mechanism (not shown in the figure).

[0329] The support element 80 is preferably provided with a support element support surface 81, which is tapered as shown in the figure. Since the pile element 75 is positioned at an inclination relative to the vertical line within the seabed 17 and / or scour protection layer 15, the angle of the tapered support element support surface 81 can be adapted to the inclination angle of the pile element 75, allowing the subsea cable unit 18 to rest on a generally horizontal surface.

[0330] As can be clearly seen in FIG. 36, the two foundations have been installed at an inclination relative to each other and relative to the seabed 17 or scour protection layer 15, such that the two foundations form a pair of scissors. Furthermore, the subsea cable unit 18 rests on the support element support surface 81 of the support element 80.

[0331] FIG. 37 and FIG. 38 also show the installation of the bending reinforcement unit 85. The bending reinforcement unit 85 includes a bending reinforcement body 86 having an approximately semi-domed cross-section and is fitted onto the top of the subsea cable unit 18. As clearly shown in FIG. 38, the subsea cable unit 18 is supported by the support element 80 at a distance D above the horizontal level of the seabed 17 or scour protection layer 15.

[0332] The bending reinforcement unit 85 also includes four attachment elements 87, which are securely attached to and extend outward from the bending reinforcement body 86, as indicated in the figure. Two attachment elements 87 are disposed on one side of the bending reinforcement body 86, as indicated in the figure. The distance between the two attachment elements 87 located on the same side of the bending reinforcement body 86 in the longitudinal direction of the bending reinforcement body 86 is adjusted such that the attachment element 77 and the locking element 82 are fitted into the space between the two attachment elements 87.

[0333] After installation, the bending reinforcement unit 85 will control the bending of the submarine cable unit 18 and reduce the risk of damage to the submarine cable unit 18.

[0334] Figures 39 and 40a to 40b show the bending reinforcement unit disposed on the top of the submarine cable unit 18.85. As described above, the bending reinforcement body 86 of the bending reinforcement unit 85 is semi-dome-shaped and is mounted on top of the submarine cable unit 18.

[0335] When the bending reinforcement unit 85 is positioned on top of the submarine cable unit 18, a locking element 82 is provided on the attachment unit 77 such that the bending reinforcement unit 85 is locked in its position, and thus the submarine cable unit 18 is locked in its position.

[0336] Preferably, the locking element 82 is adjustablely positioned on the attachment unit 77 along the longitudinal direction of the post element 75. The locking element 82 and the attachment unit 77 may, for example, be provided with corresponding threads such that the locking element 82 can be screwed up and down along the attachment unit 77 to a desired position where the bending reinforcement unit 85 is locked to its position on top of the submarine cable unit 18. When the locking element 82 is positioned in its desired position, the locking element 82 can be locked to the attachment unit 77 by a suitable locking mechanism (not shown).

[0337] Preferably, the attachment element 87 is wedge-shaped and has an attachment element contact surface 88, as indicated in the figure. Furthermore, the locking element 82 has a tapered locking element contact surface 83, which abuts against the attachment element 82 located on the opposite side of the locking element 82 after the bending reinforcement unit 85 is installed. The wedge-shaped attachment element 87 ensures a favorable angle and thus better cooperation between the locking element contact surface 83 and the attachment element contact surface 88.

[0338] Reference numerals used in the description of the accompanying drawings: 26 CN 120898342 A, Page 22 / 25 of the specification

[0339] 27 CN 120898342 A, Page 23 / 25 of the specification

[0340] 28 CN 120898342 A, Page 24 / 25 of the specification

[0341] 29 CN 120898342 A, Page 25 / 25 of the specification, Figure 1; 30 CN 120898342 A, Page 1 / 25 of the specification, Figure 2; 31 CN 120898342 A, Figure 3; 32 CN 120898342 A, Page 3 / 25 of the specification, Figure 5; 33 CN 120898342 A, Figure 6; 7 CN 120898342 A, Page 5 / 25 of the specification, Figure 8 Figure 9. Appendix to the instruction manual, page 6 / 25, CN 120898342 A; Figure 10. Appendix to the instruction manual, page 7 / 25, CN 120898342 A; Figure 12. Appendix to the instruction manual, page 8 / 25.Page 37 CN 120898342 A Figure 14 Figure 15 Appendix 9 / 25 Page 38 CN 120898342 A Figure 16 Figure 17 Appendix 10 / 25 Page 39 CN 120898342 A Figure 18 Figure 19 Figure 20 Appendix 11 / 25 Page 40 CN 120898342 A Figure 21 Appendix 12 / 25 Page 41 CN 120898342 A Figure 22 Figure 23 Appendix 13 / 25 Page 42 CN 120898342 A Figure 24 Figure 25 Appendix 14 / 25 Page 43 CN 120898342 A Figure 26 Figure 27 Appendix 15 / 25 Page 44 CN 120898342 A Figure 28 Figure 29 Appendix 16 / 25 Page 45 CN 120898342 A Figure 30 Figure 31 Appendix to the Instruction Manual, Page 17 / 25, 46 CN 120898342 A Figure 32 Figure 33 Appendix to the Instruction Manual, Page 18 / 25, 47 CN 120898342 A Figure 34 Appendix to the Instruction Manual, Page 19 / 25, 48 CN 120898342 A Figure 35 Appendix to the Instruction Manual, Page 20 / 25, 49 CN 120898342 A Figure 36 Appendix to the Instruction Manual, Page 21 / 25, 50 CN 120898342 A Figure 37 Appendix to the Instruction Manual, Page 22 / 25, 51 CN 120898342 A Figure 38 Appendix to the Instruction Manual, Page 23 / 25, 52 CN 120898342 A Figure 39 Appendix to the Instruction Manual, Page 24 / 25, 53 CN 120898342 A Figure 40a Figure 40b Appendix to the Instruction Manual, Page 25 / 25, 54 CN 120898342 A

Claims

1. A stabilizing device (22) for a submarine cable unit (18) extending between a cable inlet (13) on a seabed (17) and a subsea structure (11), wherein, The cable inlet (13) is located above the seabed (17), wherein the submarine cable unit (18) includes a submarine cable with a cable protection system (20) or only a submarine cable, and wherein the stabilizing device (22) includes: -At least one stable base (24, 25), - A first clamping device (27) is securely attached at one end to the at least one stabilizing base (24, 25). The first clamping device (27) is curved and adapted to at least partially surround the submarine cable unit (18), and holds the submarine cable unit (18) when the at least one stabilizing device (22) and the submarine cable unit (18) are installed. - A second clamping device (28), which is securely attached at one end to the at least one stabilizing base (24, 25), is curved and adapted to at least partially surround the submarine cable unit (18), and holds the submarine cable unit (18) when the stabilizing device (22) and the submarine cable unit (18) are installed. - At least one pile element (54) for anchoring the at least one stabilizing base (24, 25) to the seabed (17) or to the scour protection layer (15), the at least one pile element (54) being adapted to be driven into the seabed (17) or the scour protection layer (15) such that when the stabilizing device is installed, the at least one stabilizing base (24, 25) is firmly anchored to the seabed (17) or the scour protection layer (15), and such that the stabilizing device (22) is positioned on top of the contact point (34) of the submarine cable unit (18).

2. The stabilizing device according to claim 1, in, The first clamping device (27) and the second clamping device (28) are attached to the at least one stabilizing base (24, 25) such that the first clamping device (27) is closer to the seabed structure (11) than the second clamping device (28), and wherein the first clamping device (27) is flexible.

3. The stabilizing device according to claim 1 or 2, in, The second clamping device (28) is more rigid than the first clamping device (27).

4. The stabilizing device according to any one of claims 1 to 3, in, The at least one stabilizing base (24, 25) includes at least one through hole (42), and the at least one pile element (54) is adapted to pass through the at least one through hole (42).

5. The stabilizing device according to any one of claims 1 to 4, in, The stabilizing device (22) includes at least one clamping element (39), which includes at least one through hole (42) for the at least one piling element (54).

6. The stabilizing device according to any one of claims 1 to 5, in, The at least one pile element (54) is provided with an expansion device (59) that applies a force toward the seabed (17) or the scour protection layer (15) on the at least one stabilizing base (24, 25).

7. The stabilizing device according to claim 6, in, The expansion device (59) is adapted to expand in the event that the seabed (17) or the scour protection layer (15) is corroded, so as to continuously apply a force toward the seabed (17) or the scour protection layer (15) on the at least one stabilizing base (24, 25).

8. The stabilizing device according to claim 6 or 7, in, The at least one pile element (54) is provided with an adjustment device (62) for adjusting the tension in the expansion device (54) and thereby adjusting the force applied to the at least one stabilizing base (24, 25).

9. The stabilizing device according to any one of claims 1 to 8, in, The stabilizing device (22) further includes a cover unit (45) for bending control of the submarine cable unit (22), wherein the cover (45) is bent and at least partially surrounds the submarine cable unit (22) in the circumferential direction, and the cover unit (45) and the submarine cable unit (22) are held by the first clamping device (27) and the second clamping device (28).

10. The stabilizing device according to claim 9, in, The cover unit (45) is also bent in the longitudinal direction of the submarine cable unit (22) to prevent the cable from bending beyond the desired angle.

11. The stabilizing device according to claim 9 or 10, in, The cover unit (45) has at least one motion-stopping element (51) on the side facing the submarine cable unit (22), wherein the at least one motion-stopping element (51) presses against the submarine cable unit (22).

12. The stabilizing device according to any one of claims 1 to 11, in, The stabilizing device (22) includes a first stabilizing base (24) and a second stabilizing base (25), each of the first stabilizing base (24) and the second stabilizing base (25) including at least one through hole (42) for at least one pile element (54), the at least one pile element (54) being adapted to be fitted into the at least one through hole (42) and driven into the seabed (17) or the scour protection layer (15), such that the first stabilizing base (24) and the second stabilizing base (25) can be firmly anchored to the seabed (17) or the scour protection layer (15).

13. The stabilizing device according to claim 12, in, The first clamping device (27) is securely attached to the first stabilizing base (24) at one end and to the second stabilizing base (25) at the other end, and the second clamping device (28) is securely attached to the first stabilizing base (24) at one end and to the second stabilizing base (25) at the other end.

14. The stabilizing device according to any one of claims 1 to 13, in, The first clamping device (4) includes at least one dynamic absorber device (30) which is anchored at one end to the first stabilizing base (24) and / or the second stabilizing base (25) and at the other end to the cover unit (45).

15. The stabilizing device according to any one of claims 12 to 14, in, The first stabilizing base (24) and / or the second stabilizing base (25) are provided with a plurality of through holes (42) for pile elements (54), the pile elements (54) being adapted to be fitted into the corresponding through holes (42) and driven into the seabed (17) or the scour protection layer (15), so that the first stabilizing base (24) and / or the second stabilizing base (25) can be firmly anchored to the seabed by the plurality of pile elements (54).

16. The stabilizing device according to claims 4 to 15, in, The at least one through hole (42) is provided with a guide element (43) to facilitate the entry of the at least one pile element (54) into the at least one through hole (42) during the installation of the stabilizing device (22).

17. The stabilizing device according to any one of claims 1 to 16, in, The at least one pile element (54) is adapted to be operated by an ROV.

18. The stabilizing device according to any one of claims 1 to 17, in, The submarine cable unit (22) is equipped with a cable protection system (20).

19. The stabilizing device according to any one of claims 1 to 18, in, The seabed structure (11) is securely installed in or to the seabed (17).

20. A subsea system (10), the subsea system (10) comprising: A subsea structure (11) securely mounted in or to the seabed (17); and a subsea cable unit (18) extending between the seabed (17) and a cable inlet (13) on the subsea structure (11), wherein the cable inlet (13) is located above the seabed (17), wherein the subsea cable unit (18) comprises a subsea cable with a cable protection system (20) or comprises only a subsea cable, and wherein the subsea system (10) includes a stabilizing device (22) according to any one of claims 1 to 19 for stabilizing the subsea cable unit (18).

21. The subsea system according to claim 20, in, The stabilizing device (22) is disposed on the scour protection layer (15), which is disposed on the seabed (17) adjacent to the seabed structure.

22. The subsea system according to claim 20, in, The stabilizing device (22) is directly mounted on the seabed (17).

23. The subsea system according to any one of claims 20 to 22, in, The subsea structure (10) is a monopile (12) for a wind power station, which is securely installed to the seabed (17) or in the seabed (17).

24. Use of a stabilizing device (22) according to any one of claims 1 to 19 and / or a subsea system (10) according to any one of claims 20 to 23 for stabilizing a subsea cable unit (18) from an offshore wind farm.

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