SYMMETRIC OR PSEUDOSYMMETRIC SHARED MOORING-ANCHOR SYSTEM

Abstract

A shared mooring-anchor system may have one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource. A shared mooring-anchor system may have at least one near-surface buoy and at least one seabed anchor. A shared mooring-anchor system may orient the variable resource near, at, or above a waterline of a source of water. A shared mooring-anchor system may connect the one or more variable resource foundations to the at least one near-surface buoy, the at least one near-surface buoy is connected to the at least one seabed anchor, the at least one seabed anchor is not vertically in alignment underneath the at least one near-surface buoy, an angle between the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is not a right angle.

Claims

1. A method of organizing a system of one or more offshore variable resource structures, the method comprising the steps of: providing one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource; providing at least one near-surface buoy; providing at least one seabed anchor; orienting the variable resource near, at, or above a waterline of a body of water; and connecting the one or more variable resource foundations to the at least one near-surface buoy, the at least one near-surface buoy is connected to the at least one seabed anchor, the at least one seabed anchor is not vertically in alignment underneath the at least one near-surface buoy, an angle between the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is not a right angle.

2. The method of claim 1, further comprising introducing a degree of compliance to reduce a load on the at least one seabed anchor.

3. A shared mooring anchor system, comprising: one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource, the variable resource is oriented near, at, or above a waterline of a body of water; at least one near-surface buoy; at least one seabed anchor; wherein the one or more variable resource foundations is connected to the at least one near-surface buoy, the at least one near-surface buoy is connected to the at least one seabed anchor in an arrangement; wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, and the at least one seabed anchor is not vertically in alignment underneath the at least one near-surface buoy.

4. The system of claim 3, wherein the variable resource is positioned within a hexagonal lattice.

5. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on the rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of a unit cell being tetragonal.

6. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on the rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of a unit cell being orthorhombic.

7. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on the rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of a unit cell being monoclinic.

8. The system of claim 3, wherein the at least one near-surface buoy is placed at a face center, the at least one near-surface buoy is placed at one or more positions per a unit cell to triangulate the variable resource.

9. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on the rules of symmetry, whereby, the variable resource is positioned at vertices of a lattice of a unit cell being a rhombus.

10. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on the rules of symmetry, whereby, the variable resource is positioned at vertices of a lattice of a unit cell being a parallelogram.

11. The system of claim 3, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor are densely positioned based on a weather forecast.

12. The system of claim 3, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line.

13. The system of claim 3, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line which have been pretensioned.

14. The system of claim 3, wherein a plurality of near-surface buoys are connected in series.

15. The system of claim 3, wherein the at least one near-surface buoy is connected to the at least one seabed anchor by one or more lengths of mooring line.

16. The system of claim 3, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line which have been subdivided to provide rotational restraint to the variable resource.

17. The system of claim 3, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line which have been spliced.

18. The system of claim 3, wherein the at least one near-surface buoy is connected to the at least one seabed anchor by one or more lengths of mooring line.

19. The system of claim 3, wherein the at least one near-surface buoy is connected to the at least one seabed anchor by one or more lengths of mooring line which have been spliced.

20. The system of claim 3, further comprising: divers and an unmanned underwater vehicle to implement an installation of the system.

21. The system of claim 3, further comprising an intermediate system to mitigate a transfer of loads to the at least one seabed anchor.

22. The system of claim 21, wherein the intermediate system selected from the group consisting of a spring, an elastomer, a load collector, and a dashpot.

23. An offshore mooring system, comprising: an anchor positioned on a seabed; a buoy positioned between the anchor and a floating foundation; a first mooring line of a first axial stiffness value, connecting the anchor to the buoy; and a second mooring line of a second axial stiffness value being less than the first axial stiffness value and connecting the buoy to the floating foundation; wherein the second mooring line is configured to absorb dynamic forces from the floating foundation.

24. The offshore mooring system of claim 23, wherein the buoy is sized to generate a buoyant force to induce static restraining forces in the first mooring line and the second mooring line.

25. An offshore mooring system, comprising: an anchor positioned on a seabed; a buoy positioned between the anchor and a floating foundation; a first mooring line of a first axial stiffness value, connecting the anchor to the buoy; and a second mooring line of a second axial stiffness value being at least substantially similar to or equal to the first axial stiffness value and connecting the buoy to the floating foundation; wherein the buoy is configured to convert one or more dynamic forces from the floating foundation into buoyant potential energy.

26. The offshore mooring system of claim 25, wherein the buoy is sized to generate a buoyant force to induce small static restraining forces in the first mooring line and the second mooring line such that the buoy is not unduly restrained from motion in a lateral direction or a vertical direction.

27. The offshore mooring system of claim 25, wherein the buoy is designed to generate hydrodynamic drag forces to dissipate energy associated with the one or more dynamic forces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Claimed subject matter is particularly pointed out and distinctly claimed in the concluding portion of the specification. However, both as to organization and/or method of operation, together with objects, features, and/or advantages thereof, it may best be understood by reference to the following detailed description if read with the accompanying drawings in which:

[0020] FIG. 1 is a flowchart illustrating a method of organizing a system of one or more offshore variable resource structures, according to some embodiments of the present disclosure;

[0021] FIG. 2 is a block diagram illustrating a shared mooring-anchor system. according to some embodiments of the present disclosure;

[0022] FIG. 3 is a block diagram further illustrating unit cell features of the system, according to some embodiments of the present disclosure;

[0023] FIG. 3A is a block diagram further illustrating irregular cell features of the system, according to some embodiments of the present disclosure;

[0024] FIG. 4 is a block diagram further illustrating the intermediate system of the shared mooring-anchor system;

[0025] FIG. 4A is a schematic diagram illustrating a shared mooring-anchor system having a load collector, according to some embodiments of the present disclosure;

[0026] FIG. 5 is a table illustrating five Bravais lattices having four groups of positions of symmetry within each unit cell, according to some embodiments of the present disclosure;

[0027] FIG. 6 is a schematic diagram illustrating five regular space-filling lattices. according to some embodiments of the present disclosure;

[0028] FIG. 7 is a table illustrating buoy/anchor symmetrical placement, according to some embodiments of the present disclosure;

[0029] FIGS. 8 and SA show a schematic diagram of the method of construction a Wigner-Seitz cell boundary around a lattice point, according to some embodiments of the present disclosure;

[0030] FIGS. 9 and 9A show a schematic diagram of an embodiment of a such as a monoclinic i.e., parallelogram geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure;

[0031] FIGS. 10 shows a schematic diagram of an embodiment of a monoclinic geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure;

[0032] FIG. 10A shows a schematic diagram of an embodiment of a rectangular geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure;

[0033] FIG. 10B shows a schematic diagram of an embodiment of a hexagonal geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure;

[0034] FIG. 10C show a schematic diagram of an embodiment of a square geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure; and

[0035] FIG. 10D shows a schematic diagram of an embodiment of an irregular geometry constructed by the Wigner-Seitz cell, according to some embodiments of the present disclosure.

[0036] FIG. 11A shows a schematic diagram of an embodiment of the anchoring system of FIG. 4A connected to a floating foundation of an offshore structure, the anchoring system may employ each of the second mooring lines being split to connect to two legs of the floating foundation as part of a group of similar structures, according to some embodiments of the present disclosure.

[0037] FIG. 11B shows a schematic diagram of an embodiment of the anchoring system of FIG. 4A connected to a floating foundation of an offshore structure, the anchoring system may employ the second mooring lines each to connect to a leg of the floating foundation as part of a group of similar structures, according to some embodiments of the present disclosure.

[0038] FIG. 12 illustrates a diagram of an embodiment of the anchoring system of FIG. 4A facilitating energy dissipation through buoyant mass vertical motion as compared to strain energy, according to some embodiments of the present disclosure.

[0039] FIG. 13 illustrates a diagram of the embodiment of the anchor system of FIG. 12 in a scenario where a floating structure, such as a wind turbine platform, experiences a minor displacement from its equilibrium position, in which a buoyant force is applied to the buoy, a restoring force is applied to the floating foundation, and a tension force is in the line connected to the anchor, according to some embodiments of the present disclosure.

[0040] FIG. 14 illustrates a diagram of an embodiment of the anchoring system of FIG. 12, describing the mechanism that provides a restoring force and illustrates an initial position of the buoy and the floating foundation compared to a secondary position of the buoy and the floating foundation following the displacement, according to some embodiments of the present disclosure.

[0041] FIG. 15 illustrates a top plan view of a diagram of the embodiment of the anchoring system of FIG. 12 implementing pretensioning operations with an example tensioning sequence for connecting the floating foundations to the buoys and/or for securing the buoys to the anchors, according to some embodiments of the present disclosure.

[0042] FIG. 16 illustrates a perspective view of a diagram of the anchoring system of FIG. 15 implementing pretensioning operations with an example tensioning sequence for connecting the floating foundations to the buoys and/or for securing the buoys to the anchors, according to some embodiments of the present disclosure.

[0043] FIG. 17 shows a schematic diagram illustrating an embodiment of an offshore mooring system of FIG. 4A with one or more intermediate buoys implementing reciprocal base isolation, according to some embodiments of the present disclosure.

[0044] FIG. 18 shows a schematic diagram illustrating the offshore mooring system of FIG. 17 with the isolator or low-stiffness mooring line oriented in an extended configuration, according to some embodiments of the present disclosure.

[0045] FIG. 19 shows a schematic diagram illustrating an embodiment of an offshore mooring system with one or more intermediate buoys implementing hydrodynamic regulation, configured to dissipate energy and with a buoy having a diameter smaller in size than the embodiment of FIG. 17, according to some embodiments of the present disclosure.

[0046] FIG. 20 shows a schematic diagram illustrating the offshore mooring system of FIG. 19 with vertical motion dissipating energy, according to some embodiments of the present disclosure.

[0047] Reference is made in the following detailed description to accompanying drawings, which form a part hereof, wherein like numerals may designate like parts throughout that are corresponding and/or analogous. It will be appreciated that the figures have not necessarily been drawn to scale, such as for simplicity and/or clarity of illustration. For example, dimensions of some aspects may be exaggerated relative to others. Further, it is to be understood that other embodiments may be utilized. Furthermore, structural and/or other changes may be made without departing from claimed subject matter. References throughout this specification to claimed subject matter refer to subject matter intended to be covered by one or more claims, or any portion thereof, and are not necessarily intended to refer to a complete claim set, to a particular combination of claim sets (e.g., method claims, apparatus claims, etc.), or to a particular claim. It should also be noted that directions and/or references, for example, such as up, down, top, bottom, and so on, may be used to facilitate discussion of drawings and are not intended to restrict application of claimed subject matter. Therefore, the following detailed description is not to be taken to limit claimed subject matter and/or equivalents.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] In mathematics, the concept of symmetry has been rigorously defined. The rules of symmetry are used in fields such as materials science to describe the position of elements in space and their positions relative to one another.

[0049] An important concept is that of a lattice. A lattice is a set of points that repeats infinitely in space, in other words it is regular. This means that, as a minimum requirement, a lattice must display translational symmetry. It is possible to identify lattices that display higher symmetries, such as rotational symmetry and mirror symmetry. In three or more dimensions, other symmetries are possible.

[0050] In two dimensions, there are five configurations that meet the definition of a lattice. These are: monoclinic (also called oblique), orthorhombic (i.e., rectangular), rhombic, hexagonal, and tetragonal (i.e., square).

[0051] Each lattice can be defined by a unit cell. The unit cell is a shape that, if repeated infinitely by translation, could reproduce the lattice. The unit cell embodies the symmetries which define the lattice. The unit cell can be drawn such that its corners correspond to lattice points, for example, a square drawn onto four points of a tetragonal lattice. When the unit cell is drawn in this way, it touches several lattice points. However, the unit cell contains only one, for example, a square drawn onto four points of a tetragonal lattice contains only one-quarter of each lattice point (the remainder being contained within neighbor cells), and therefore contains a total of one lattice point. It is also possible to illustrate this by shifting the lines of the unit cells slightly in any direction while the lattice points are left in place. Each new cell will contain exactly one point somewhere within the shape. A unit cell that contains one lattice point is called a primitive unit cell.

[0052] The Wigner-Seitz method provides an alternative approach to defining a unit cell within a lattice. In this method, lines are drawn from a given lattice point to each of its nearest neighbors. Subsequently, additional lines are constructed perpendicular to these connections at their midpoints. The resulting polygon, formed by the intersections of these new lines, defines the Wigner-Seitz unit cell, which is centered on a lattice point. Notably, this unit cell contains only one lattice point, thereby classifying it as a primitive unit cell. The geometry of the Wigner-Seitz unit cell varies based on the lattice type. In a monoclinic lattice, the Wigner-Seitz unit cell is a centrally-symmetric polygon with six sides (not all equal), where no internal angles are equal to 60 or 90 degrees. For an orthorhombic lattice, the Wigner-Seitz unit cell is a rectangle with unequal side lengths. A rhombic lattice features a Wigner-Seitz unit cell in the shape of a rhombus, where no internal angles are equal to 60 or 90 degrees. In a hexagonal lattice, the Wigner-Seitz unit cell remains a rhombus but includes two internal angles of 120 degrees. The tetragonal lattice is characterized by a Wigner-Seitz unit cell in the shape of a square.

[0053] Beyond lattice points, additional symmetry positions can be identified within each unit cell. These positions adhere to specific distance constraints relative to subsets of the nearest neighbor lattice points and are most effectively examined using unit cells with corners positioned at lattice points. Among the symmetry positions are face centers, which are located at the midpoints of the edges of the unit cell. Since each unit cell shares these positions with adjacent cells, each unit cell effectively contains a total of two face centers. Centroids are located at the intersection of the diagonals of the unit cell, with each unit cell containing exactly one centroid. Body centers are positioned equidistant from three lattice points forming an angle that is not oblique, with each unit cell containing at least one and, in certain configurations, up to two body centers. In an example lattice structure, these symmetry positions may coincide. For example, in a tetragonal unit cell, the body center coincides with the centroid. However, this is not the case in a hexagonal unit cell, where two distinct body centers exist separately from the centroid. Furthermore, additional positions of sub-symmetry can be identified within a unit cell. These locations maintain equidistant relationships relative to lattice points, face centers, centroids, or body centers. Positions of increasingly complex sub-symmetry can be determined recursively, revealing deeper structural characteristics of the lattice.

[0054] The concept of a lattice, defined rigorously, only accommodates points positioned at regular intervals from one another. It is possible to adopt certain concepts for use in describing irregularly configured points. Even in irregular configurations of points, it is possible to use the Wigner-Seitz method to draw a cell around each point. Each cell may be unique. These cells are not unit cells because they cannot be repeated infinitely by translation to reproduce the original configuration. Given cells defined in this way for an irregular configuration of points, it is possible to identify positions of pseudosymmetry which show similar properties to the positions of symmetry of a unit cell, for example, points at the midpoint of cell edges which are similar to face centers. It is possible that cells defined in this way may contain a different number of positions of symmetry or a different number of positions of sub-symmetry than unit cells, for example, they may contain a total of more than two positions which are similar to face centers.

[0055] It is possible to use symmetry to define the position of objects in a system, such as the position when viewed on plan of offshore structures and the elements of a station-keeping system. If local conditions, for example soil conditions or bathymetric features, require the irregular placement of objects in a system, pseudosymmetry can be used.

[0056] Symmetry or pseudosymmetry may be used to position the elements of a station-keeping system with respect to an offshore structure or group of offshore structures, for example a floating foundation or group of floating foundations, such that the elements are shared most efficiently and the total number of elements is minimized. Use of symmetry or pseudosymmetry to most efficiently define the position of objects in a station-keeping system may allow economic advantages over other systems for station-keeping of offshore structures.

[0057] A station-keeping system can provide restraint to an offshore structure or group of structures. In shared mooring and shared anchor systems, restraining forces may arise due to the displacement of an offshore structure away from an equilibrium position; or due to pretensioning of mooring lines; or some due to some combination. Restraining forces originate in the seabed anchor and are transmitted to the offshore structure via mooring lines.

[0058] Station-keeping is optimized if restraining forces provided by the anchor are developed efficiently and applied to the offshore structure. Since offshore structures positioned near or at the waterline are most often subjected to disturbing forces in the lateral direction, for example, wind, wave, and current forces, station-keeping is optimized if restraining forces include a substantial component in the lateral direction.

[0059] In order to control fatigue demands placed on seabed anchors, it may be desirable not to connect offshore structures directly to seabed anchors. One or more buoys at an intermediate position or positions may be used to induce restraining forces in an anchor and transmit them to an offshore structure. A partially or fully submerged buoy connected to an anchor by mooring line will induce a tension force in the mooring line and a restraining force in the anchor due to its buoyancy.

[0060] Such a system may use mooring lines that are pretensioned, taut, semi-taut, or slack in the initial configuration. It may be desirable to introduce a degree of compliance to the system to reduce loads on the seabed anchor. Additional intermediate elements, for example, dashpot, elastomer, spring, or load-collecting elements, may be introduced between a buoy and an anchor to control the transmission of force between them.

[0061] In an embodiment, the anchoring system employs a Marine Ensemble Tension Station-keeping (METS) system for arranging and maintaining the position of floating offshore structures, particularly floating foundations for offshore wind turbines. The METS system differs from a taut system by introducing buoys near the waterline and topline connections between the buoys and floating foundations. The buoys in the METS system are not positioned directly above an anchor but are instead connected to multiple anchors and positioned between them. These components offer several potential advantages under static and dynamic loading conditions. Under static loading, such as steady wind in laminar conditions, the floating foundation stabilizes at a position where environmental forces are counteracted by restraint forces, which develop at the anchors and are transmitted through the mooring lines. All else being equal, smaller anchor forces are preferable, as they allow for downsizing of anchor elements. Both the METS and taut systems achieve efficient restraint forces due to the advantageous angles at which forces are applied. However, the METS system gains a slight efficiency advantage as the buoy submerges further below the waterline.

[0062] In an embodiment the METS system also enables buoyant pretensioning, where a sufficiently large buoy provides constant pretension to anchor lines once fully submerged. This increases the magnitude of static anchor forces but reduces dynamic forces and force cycles, reducing the total force and improving fatigue performance. The METS system connects buoys to multiple anchors, fixing them in both lateral and vertical directions when pretensioning is sufficiently high. While this reduces buoy dissipation of dynamic energy, it also minimizes stress cycle magnitudes, further improving fatigue performance.

[0063] In the event of mooring line breakage, the primary design requirement is to prevent progressive failure of the mooring system, while a secondary requirement is to avoid the uncontrolled release of submerged buoyant elements. The METS system is more resilient against progressive failure due to the presence of redundant anchor lines. Because the METS system connects buoys to multiple anchors, a failure in one anchor line would be counteracted by the remaining anchor lines, restraining upward buoy motion to some extent.

[0064] A buoy may be positioned floating at the surface, partially submerged, or fully submerged. A buoy floating at the surface induces no restraining force until it is displaced because it generates no buoyant force until it is partially submerged. A buoy installed partially or fully below the waterline induces a restraining force in its initial condition, i.e., before it is displaced.

[0065] A buoy near the waterline may interfere with vessel navigation unless it is installed at sufficient depth. Installation of a buoy to a desired depth may be achieved by ballasting the buoy with water until it is negatively buoyant, then evacuating the buoy after any connection via mooring line has been achieved; or by a pretensioning operation; or by use of an unmanned underwater vehicle: or by use of divers; or by some other method. A submerged buoy may be identified by some element visible at the waterline.

[0066] A network of buoys may be used to develop restraining forces in multiple directions to achieve effective station-keeping.

[0067] Station-keeping is optimized if the induced restraining forces include a substantial component in the lateral direction. The line of action between the seabed anchor and the force-inducing element should not be vertical. A buoy used to develop restraining forces on an offshore structure may be positioned so it is not vertically above the seabed anchor, i.e., an angle that is not a right angle exists between the seabed anchor, the buoy, and the offshore structure.

[0068] Station-keeping for a group of offshore structures may be provided by a station-keeping system comprised of shared moorings, shared anchors and shared buoys. Symmetry or pseudosymmetry may be used to position the elements of the station-keeping system with respect to the group of offshore structures. Such a system may provide redundancy in the event of failure of certain elements of the station-keeping system. The efficiencies of such a system may allow for structural elements to be downsized or downgraded to achieve reductions in cost.

[0069] Station-keeping for rotational restraint may be provided by subdividing a mooring line between a shared buoy and an offshore structure so as to attach to the offshore structure at multiple positions. The restraint may be more effective if the subdivision occurs at a point near to the offshore structure.

[0070] Symmetry or pseudosymmetry may be used to position other relevant elements or appurtenances, for example, power infrastructure, instrumentation, monitoring equipment, wave energy converters, floating foundations for wind turbines or other variable resources, infrastructure to support aquaculture, or features to support maritime life.

[0071] FIGS. 1-20 illustrate improved anchoring systems and methods configured to enhance stability, load distribution, and compliance while addressing the limitations of prior systems. In particular, FIGS. 1-16 illustrate systems and methods of mooring floating offshore structures in which the floating structures are moored to at least three buoys. Each buoy, in turn, is moored to at least three seabed anchors. FIGS. 17-18 describe another embodiment of offshore mooring systems and methods, using one or more intermediate buoys to implement reciprocal base isolation employing a low-stiffness mooring line and a high-stiffness mooring line, for reducing dynamic loads on seabed anchors. FIGS. 19-20 describe another embodiment of offshore mooring systems and methods, using one or more intermediate buoys to facilitate energy dissipation through buoyant mass vertical motion as compared to strain energy.

[0072] The system incorporates a combination of shared anchors and multiline anchors, utilizing a structured mooring arrangement informed by lattice geometries. These advancements improve efficiency and reliability, particularly in offshore floating wind farms. An aspect of the system is the integration of compliance mechanisms to manage dynamic loading and fatigue. Compliance is achieved through both material compliance, which involves using low-stiffness mooring materials, and geometric compliance, which modifies mooring line configurations and introduces buoyancy elements.

[0073] One such material compliance mechanism, reciprocal base isolation, uses high-stiffness mooring materials in combination with low-stiffness mooring materials, such as nylon, to absorb loads and mitigate stress concentrations.

[0074] One such geometric compliance mechanism, hydrodynamic regulation, involves the use of an intermediate buoy that moves laterally and vertically in response to tension and environmental forces, providing additional flexibility in the system. This movement acts as a shock absorber, dissipating energy from environmental loads and reducing stress on the anchors and mooring lines. Unlike a fixed restraint system, this approach allows the buoy to dynamically adjust its position, absorbing fluctuations in force and preventing excessive strain on the mooring lines. This motion helps to manage peak loads, thereby enhancing the durability of the overall anchoring system. The system may include additional components to regulate the buoy's movement. ensuring that it remains within an optimal range and does not allow excessive strain in the mooring lines or introduce unintended instability. These systems collectively contribute to a more efficient and resilient anchoring system. By leveraging lattice-informed anchor arrangements, multidirectional load-resistant anchors, and adaptive compliance mechanisms, the system enhances structural redundancy, reduces material costs, and improves long-term durability.

[0075] FIG. 1 is a flowchart that describes a method of organizing a system of one or more offshore variable resource structures, according to some embodiments of the present disclosure. In some embodiments, at 110, the method may include providing one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource. At 120, the method may include providing at least one near-surface buoy. At 130, the method may include providing at least one seabed anchor. At 140, the method may include orienting the variable resource near, at, or above the waterline of a body of water.

[0076] In some embodiments, at 150, the method may include connecting the one or more variable resource foundations to the at least one near-surface buoy, the at least one near-surface buoy may be connected to the at least one seabed anchor, the at least one seabed anchor may be not vertically in alignment underneath the at least one near-surface buoy, an angle between the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor may not be a right angle. The method may include the steps of 110 to 150. In some embodiments, the method may include introducing a degree of compliance or flexibility to reduce a load on the at least one seabed anchor. In some embodiments, the system may be downsized.

[0077] FIG. 2 is a block diagram that describes a shared mooring-anchor system 210. according to some embodiments of the present disclosure. In some embodiments, the shared mooring-anchor system 210 may include at least one near-surface buoy 214 and at least one seabed anchor 216. The shared mooring-anchor system 210 may also include one or more variable resource foundations 212, the one or more variable resource foundations 212 supporting a variable resource, the variable resource may be oriented near, at, or above the waterline of a body of water. In another embodiment, the one or more variable resource foundations 212 may be connected to the at least one near-surface buoy 214, the at least one near-surface buoy 214 may be connected to the at least one seabed anchor 216 in an arrangement to form a unit cell 220 (FIG. 3). FIG. 3 best illustrates the unit cell 220 may include a lattice point 222, a face center 224, a centroid 226, and a body center 228. In another embodiment, the one or more variable resource foundations 212 may be connected to the at least one near-surface buoy 214, the at least one near-surface buoy 214 may be connected to the at least one seabed anchor 216 in an arrangement to form an irregular cell 230 (FIG. 3A). FIG. 3A best illustrates the irregular cell 230 may include a point 232, a pseudo face center 234, a pseudo centroid 236, and a pseudo body center 238.

[0078] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of symmetry. The variable resource may be positioned at a position of symmetry of the unit cell 220 being monoclinic. In some embodiments, the at least one near-surface buoy 214 may be placed at the face center 224, the at least one near-surface buoy 214 may be placed at 3 of the 4 positions per the unit cell 220 to triangulate the variable resource.

[0079] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of symmetry. The variable resource may be positioned at a position of symmetry of the unit cell 220 being primitive rectangular orthorhombic.

[0080] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of symmetry. The variable resource may be positioned at a position of symmetry of the unit cell 220 being centered rectangular orthorhombic.

[0081] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of symmetry. The variable resource may be positioned at a position of symmetry of the unit cell 220 being tetragonal.

[0082] In some embodiments, the one or more variable resource foundations 212. the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of symmetry. The variable resource may be positioned at a position of symmetry of the unit cell 220 being a rhombus (hexagonal).

[0083] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be positioned based on rules of pseudosymmetry. The variable resource may be positioned at a position of pseudosymmetry of the irregular cell 230.

[0084] In some embodiments, the one or more variable resource foundations 212, the at least one near-surface buoy 214, and the at least one seabed anchor 216 may be densely positioned based on a weather forecast. It is within the scope of this invention for a weather forecast to include predicted wind conditions or predicted wave conditions, therefore predicted energy production. In some embodiments, the variable resource may be connected to the at least one near-surface buoy 214 by one or more lengths of mooring line. In some embodiments, a plurality of near-surface buoys may be connected in series. In some embodiments, the at least one near-surface buoy 214 may be connected to the at least one seabed anchor 216 by one or more lengths of mooring line.

[0085] FIG. 4 is a block diagram that further describes the shared mooring-anchor system 210. In some embodiments, the shared mooring-anchor system 210 may include an intermediate system 318 to mitigate a transfer of loads on the at least one near-surface buoy 214 to the at least one seabed anchor 216. The intermediate system 318 selected from the group consisting of spring 330, elastomer 340, dashpot 350, and load collector 360.

[0086] FIG. 4A illustrates an embodiment in which the intermediate system may have load collector 360. Load collector 360 may be an object positioned near seabed anchor 216 and above seafloor 400. Load collector 360 is connected to one or more mooring lines 402 coming from one or more near-surface buoys 214. Mooring line 402 may directly connect seabed anchor 216 to near-surface buoy 214 (not shown). Mooring line 402 may connect seabed anchor 216 to an intermediate system, such as load collector 360. Load collector 360 is then connected to near-surface buoy 214. One or more near-surface buoys 214 is connected to variable resource foundation 212. One or more near-surface buoys 214 is located below surface 404 of body of water 406. Variable resource foundation 212 is configured to float near, at, or on surface 404 of body of water 406. Seabed anchor 216 is not vertically in alignment underneath near-surface buoy 214. Angle 408 is formed approximately between near-surface buoy 214 and seabed anchor 216. In this example, angle 408 is less than 90 degrees. However, it is within the scope of this embodiment for angle 408 to be any angle except a right angle or a 90-degree angle. In another embodiment, a buoy may be located at the surface of a body of water (not shown). Load collector 360 is pulled by one or more mooring lines 402, allowing the forces in opposite directions to cancel, and it transmits a force to seabed anchor 216 which is closer to purely vertical.

[0087] Referring now to FIG. 5, space-filling geometries, including regular and irregular geometries, and the development of general rules for placement of structures at points of symmetry within the geometries. It is important to consider irregular geometries as well, e.g., since installation tolerances do not allow the placement of structures in precise locations, because ground conditions require placement elsewhere, and/or because wind, wave, or other conditions are such that an irregular geometry is optimal, etc.

[0088] In regards to regular space-filling geometries, in two-dimensional space there are five Bravais lattices 500. Four are considered primitive, i.e., they contain only one lattice point, and one is centered, i.e., it includes an additional lattice point at the center of the primitive cell. With a change of orientation, the centered lattice can be redrawn as primitive. The Bravais lattices 500 include monoclinic 502, orthorhombic primitive 504, orthorhombic centered 506 (equivalent to rhombic primitive 508), hexagonal 510, and tetragonal 512. It is within the scope of this invention for a unit cell 220 to correspond to the unit cell of any of the Bravais lattices 500. It is within the scope of this invention for a unit cell 220 to be drawn such that its corners are at lattice points of a Bravais lattice 500. It is within the scope of this invention for a unit cell 220 to be drawn such that its corners are not at lattice points of a Bravais lattice 500.

[0089] FIG. 6 shows five regular space-filling lattices. In an embodiment, some monoclinic and primitive orthorhombic unit cells, alternating face centers can be occupied by different objects without breaking symmetry, see position 600 vs. position 602 in the oblique (i.e., monoclinic) lattice. It is within the scope of this invention for a centroid to include, but not be limited to, the point of intersection of the diagonals. For example, each unit cell is defined by 1 and contains 1. In an embodiment, in some hexagonal cells, this position is symmetrically equivalent to the face centers, see position 604 in the hexagonal lattice. It is within the scope of this invention for body centers to include, but not be limited to, the point which occurs equidistant from three lattice points which make an angle that is not oblique. For example, each unit cell contains at least one and at most two. In an embodiment, in primitive unit cells that include right angles, these points converge onto the centroid. In another embodiment. in unit cells that do not include right angles, these occur at the points equidistant from the corners which define the acute angle of the shape, see position 606 in the hexagonal lattice.

[0090] FIG. 7 is a table illustrating buoy/anchor symmetrical placement. In an embodiment, it is not required that a buoy or anchor be placed at every position. For example, in a monoclinic arrangement 700A where buoys are placed at the face centers, they need only be placed at 3 of the 4 positions per unit cell to triangulate each variable foundation. Those positions, highlighted in grey, are likeliest to be desirable and/or economical because they minimize the ratio of anchors to variable foundations. It remains to be studied which of these are even more desirable because they also minimize the length of mooring lines. This will be a function of depth and inter-variable foundation spacing. Orthorhombic (primitive rectangular) arrangement 700B, orthorhombic (rhombus, i.e., centered rectangular) arrangement 700C, tetragonal (square) arrangement 700D, and hexagonal (rhombus) arrangement 700E have embodiments of buoy position and anchor position shown.

[0091] FIGS. 8 and 8A show the method of construction a Wigner-Seitz cell boundary around a lattice point. Irregular geometries, such as ones that might arise where the location of the variable foundations has been optimized for local wind, ground, or other conditions, do not repeat infinitely in space, and so do not form a lattice and do not contain unit cells. Still, it is possible to identify positions of pseudosymmetry within the geometry. These are relevant only to the adjacent variable foundations and do not extend beyond them. Identifying these points can be done by constructing the Wigner-Seitz cells centered on the variable foundations. This is done by drawing a line from a point to its nearest neighbors, then drawing the perpendicular bisectors of those lines. The Wigner-Seitz cell is the polygon formed by this operation.

[0092] FIG. 8 shows constructing a Wigner-Seitz cell involves drawing lines from a point to its nearest neighbors, then drawing the perpendicular bisectors to those lines (image by Arup).

[0093] FIG. SA shows Wigner-Seitz cells constructed for irregularly positioned points (image by Arup).

[0094] FIG. 9 shows Wigner-Seitz cells (highlighted in grey) for a monoclinic (i.e., parallelogram) lattice (lines in black). The triangles are the vertices of the Wigner-Seitz cells and correspond to the body centers of the original lattice (image by Arup).

[0095] FIG. 9A shows Wigner-Seitz cells (highlighted in grey) for an approximately square lattice (lines in black). Note that the black squares, which are the vertices of the Wigner-Seitz cells and correspond to the body centers of the original lattice, converge on the centroid of the original lattice as the lattice becomes tetragonal. Also note that the Wigner-Seitz geometry is identical to the original geometry and offset from it (image by Arup).

[0096] FIGS. 10, 10A, 10C, 10C, and 10D show Wigner-Seitz cell boundaries and positions of symmetry or pseudosymmetry for different unit cells or irregular cells. FIGS. 10, 10A, 10C, 10C, and 10D show variable foundations as black circles at the center of each cell, and identify the different positions of symmetry or pseudosymmetry as black triangles or squares. For regular geometries, using this method gives the same results as before. For irregular geometries, it identifies and characterizes positions of pseudosymmetry. In irregular geometries, some of these pseudosymmetric positions nearly coincide. For practical purposes during design, these may be consolidated and treated as one type or the other. With this, positions of pseudosymmetry are defined. Structures (e.g. variable foundation, anchor, buoy, etc.) can be sited in them following the same rules as defined for regular geometries.

[0097] FIG. 10 shows Wigner-Seitz cells for a monoclinic (parallelogram) lattice (image from Arup). Note that the Wigner-Seitz geometry is not identical to the original monoclinic lattice geometry, and is a centrally-symmetric polygon with six sides (not all equal), where no internal angles are equal to 60 or 90 degrees. FIG. 10A shows Wigner-Seitz cells for an orthorhombic (rectangular) lattice (image from Arup). Note that the Wigner-Seitz geometry is identical to the original orthorhombic lattice geometry and offset from it. The Wigner-Seitz cell boundaries and equivalent positions are shown. FIG. 10B shows Wigner-Seitz cells for a hexagonal lattice (image from Arup). Note that the Wigner-Seitz geometry is identical to the original hexagonal lattice geometry and offset from it, and is a centrally-symmetric polygon with six sides (all equal), where all internal angles are equal to 60 degrees. The Wigner-Seitz cell boundaries and equivalent positions are shown. Lattice 1000, body center 1002, and face center 1004 are shown in an embodiment. FIG. 10C shows Wigner-Seitz cells for a square lattice. Note that the Wigner-Seitz geometry is identical to the original square lattice geometry and offset from it (image from Arup). FIG. 10D shows Wigner-Seitz cells for an irregular configuration of points (image from Arup).

[0098] It is within the scope of this invention for offshore wind and/or wave installations to not require the use of catenary anchors for each variable foundation. This arrangement can reduce the quantity of subsea mooring cable required and minimize the impact on the seabed. The hexagonal close packed geometry allows for the densest arrangement of equidistant variable foundations. This packing configuration may be ideal in locations where the wind resource is omnidirectional. If it is not required that variable foundations be equidistant, or in locations where the wind is unidirectional, a different packing configuration, such as monoclinic or orthorhombic, may be ideal.

[0099] FIG. 11A illustrates an example of an anchoring system 1100 for a floating foundation 1102 of an offshore structure 1104, such as a wind turbine for example.

[0100] Buoys 1106A, 1106B, and 1106C are each connected to second mooring line 1108A, 1108B, and 1108C, respectively. In an embodiment, each of the second mooring lines 1108A, 1108B, and 1108C may be split 1112 to connect to two legs 1110 of the floating foundation 1102 instead of the embodiment of FIG. 11B in which the anchoring system 1150 has the second mooring line 1109A, 1109B, and 1109C, each connect to one leg 1110 of the floating foundation 1102. This may help prevent the floating foundation 1102 from rotating. The buoys may each be connected to a seabed anchor via the first mooring line (not shown). The anchoring systems 1100 and/or 1150 may be implemented in the anchoring system of FIG. 12 as part of a group of similar structures.

[0101] FIG. 12 illustrates a diagram demonstrating the anchoring system 1200 of FIG. 4A pretensioned to facilitate energy dissipation through buoyant mass vertical motion as compared to strain energy. First mooring line 1206 connects anchor 1202 to buoy 1204 positioned below a waterline 1212. Second mooring line 1208 connects buoy 1204 to floating foundation 1210.

[0102] In an embodiment, the anchoring system incorporates multiline anchors to improve load distribution and efficiency. The system relies on a structured mooring arrangement informed by lattice geometries, optimizing the placement of floating foundations to enhance energy production density and reduce wake losses. The considerations include various anchor load scenarios, evaluating the forces acting on each mooring line and the corresponding seabed reactions. Two primary mechanisms may be employed for compliance, which serve to manage dynamic loading and fatigue in offshore environments. The first mechanism focuses on material compliance, where low-stiffness mooring materials, such as nylon, are used to absorb loads and mitigate stress concentrations. The second mechanism involves geometric compliance, incorporating a buoy that moves laterally and vertically in response to variations in tension and environmental forces. This buoy serves as a hydrodynamic regulator, adjusting its position to accommodate dynamic forces. By allowing controlled vertical motion, the buoy absorbs loads, reducing peak forces transmitted to the anchors and mooring lines. The system may include additional components to ensure that the buoy remains within a specified range of movement, preventing excessive strain in the mooring lines and ensuring stability.

[0103] FIG. 13 illustrates the force balance in the anchor system 1300 of FIG. 12 in a scenario where a floating foundation 1310, such as a wind turbine platform, experiences a displacement from its equilibrium position, or second mooring line 1308 is pretension, in which a buoyant force is applied to the buoy 1304, a restoring force is applied to the floating foundation 1310, and a tension force is in the first mooring line 1306 connected to the anchor 1302. The tension force has a vertical and a horizontal component, The restoring force has a horizontal component significantly larger than its vertical component. First mooring line 1306 connects anchor 1302 to buoy 1304 located below a waterline 1312. Second mooring line 1308 connects buoy 1304 to floating foundation 1310 such as a wind turbine.

[0104] FIG. 14 illustrates a diagram of an embodiment of the anchoring system of FIG. 12, describing the mechanism that provides a restoring force and illustrates an initial position of the buoy 1412 and an initial position of the floating foundation 1416 at the waterline 1414 compared to a secondary position of the buoy 1404 and a secondary position of the floating foundation 1410 following the displacement. When the initial position of the floating foundation 1416 is pushed a distance to the second position of the floating foundation 1410, the buoy is pulled from an initial position of the buoy 1412 to a second position of the buoy 1404 and traverses vertical distance 1408 when there is displacement of the floating foundation.

[0105] In a hexagonal array arrangement of offshore wind turbines, as illustrated in FIGS. 15 and 16 below, anchors are anchored into a seabed. Each anchor has three mooring lines connected thereto at one end located opposing another end connected to a buoy. The buoy is disposed below the surface of a body of water and/or below the waterline. Each of the three buoys are each connected to a floating structure. The plurality of floating foundations 1510 are oriented in a coplanar alignment 1516 (FIG. 15). The anchor is strategically placed equidistant from the surrounding turbines to optimize mooring stability and minimize total length of mooring line. A hexagonal arrangement may be implemented in large-scale offshore wind farms because it maximizes space efficiency, reduces wake interference between turbines, and enhances energy capture. The placement of a plurality of anchors equidistant from multiple turbines ensures a balanced distribution of mooring forces, reducing excessive tension on any single mooring line and enhances system redundancy. This strategic positioning also minimizes material usage for mooring components, contributing to cost efficiency and long-term durability. By maintaining an optimal balance between buoyancy, mooring tension, and environmental loads, the anchoring system ensures reliable operation of the offshore wind farm while minimizing stress on the mooring system components. FIGS. 15 and 16 illustrate diagrams of the embodiment of the anchoring system of FIG. 12 implementing pretensioning operations with an example tensioning sequence 1500 for connecting the floating foundations to the buoys and/or for securing the buoys to the anchors, according to some embodiments of the present disclosure. First mooring line 1506 connects anchor 1502 to buoy 1504. Second mooring line 1512 connects buoy 1504 to floating foundation 1510 supporting a variable resource such as a wind turbine. The installation process begins with the placement and securement of the anchors, followed by the positioning of the buoys and the connection of all mooring lines. Once these components are in place, a pretensioning operation may be conducted to optimize load distribution and system stability. Specifically, certain mooring lines may be tensioned in a controlled sequence, such as each of the second mooring lines that is oriented from north-to-south 1514 (FIG. 15), ensuring uniform force application across the mooring system.

[0106] In an embodiment, pretensioning operations may be performed to ensure that the mooring lines and anchors are properly secured before the floating platform is deployed. Pretensioning involves applying a pre-determined load or tension to the mooring lines to ensure the structure remains stable during installation and operation, particularly in environments subject to high winds, waves, or currents, or to prevent slack lines or snatch loading. By carefully managing the sequence of these pretensioning operations, the installation process can be streamlined, minimizing the number of operations required. For example, the pretensioning of mooring lines can be done in stages, starting with the lines at one or more points, followed by additional stages for other lines or anchors. This approach ensures that the structure remains stable and aligned as each operation progresses.

[0107] Each floating foundation undergoes an individual pretensioning operation, with at least one second mooring line spliced with a chain to facilitate controlled force 1518 (FIG. 15) application, allowing for precise tension adjustments and improved load distribution across the system. This method ensures that the mooring configuration achieves target position 1516, and remains stable under varying environmental conditions, with no lines going slack, reducing excessive stress concentrations and enhancing long-term durability. In practice, the number of pretensioning operations can be reduced through careful sequencing. For instance, installing the anchors in a coordinated order that accounts for environmental conditions and the positioning of other structures can reduce the need for redundant operations. Additionally, pretensioning operations can be synchronized with other installation tasks, such as placing the floating platform or performing structural checks, to minimize time on site and increase efficiency. Proper sequencing also ensures that the forces applied during pretensioning are evenly distributed, reducing the risk of structural stress or failure during the installation phase. By employing this efficient approach to pretensioning, the installation process can be completed faster, with fewer resources and less risk of error. This not only reduces installation costs but also improves the long-term performance of the offshore structure, as the mooring system will be optimally tensioned and properly aligned from the outset.

[0108] FIG. 17 shows a schematic diagram illustrating an embodiment of an offshore mooring system 1700 with one or more intermediate buoys implementing reciprocal base isolation. A buoy 1702 is introduced between the seabed anchors 1704A and 1704B, which are connected to and/or in communication with a seabed 1706, and the floating foundation 1708, creating an isolation mechanism. An isolator 1710 connects buoy 1702 to floating foundation 1708.

[0109] Fatigue failure occurs when a structural element undergoes repeated force cycles, eventually leading to material degradation and failure. These fluctuating forces, known as dynamic loads 1714, vary over time and may reduce a structure's lifespan. Generally, the larger the magnitude of the dynamic loads, the fewer cycles the element can withstand before failure. As a result, minimizing dynamic loads is desirable for enhancing structural durability. Mooring systems for offshore structures are particularly susceptible to fatigue failure due to the cyclical nature of wind and wave forces, for example. Typically, many offshore mooring systems experience continuous dynamic loading, which weakens anchors, mooring lines, and/or other components over time.

[0110] To address this challenge, two mechanisms for reducing dynamic loads on seabed anchors have been identified. These mechanisms were initially hypothesized and later confirmed through dynamic modeling using OrcaFlex, an industry-standard simulation software. One such mechanism, reciprocal base isolation, is based on principles used in seismic engineering to protect buildings from dynamic loads caused by ground shaking. In seismic design, a low-stiffness isolating device, such as elastomeric pads, bearings, and/or sliding plates, is placed between the foundation and superstructure to absorb lateral forces. Because the isolating device has low lateral stiffness while the foundation and superstructure are highly rigid, dynamic force transmission is reduced.

[0111] Applying this principle to offshore mooring systems helps shield seabed anchors and other submerged components from dynamic loads caused by wind and waves. This is achieved by incorporating materials with different stiffness levels into the mooring system. In an embodiment, the buoy 1702 is introduced between the seabed anchor 1704A and 1704B, below the waterline, and the floating foundation 1708. High-stiffness mooring line 1712A and 1712B, connects the seabed anchor 1704A and 1704B, respectively, to the buoy 1702, ensuring minimal stretch and maintaining anchor stability. Moreover, a low-stiffness mooring line, also referred to as isolator 1710, links the buoy 1702 to the floating foundation 1708, allowing it to absorb and dissipate dynamic loads as strain energy. As the low-stiffness line, i.e. isolator 1710, stretches and relaxes, the forces transmitted to the high-stiffness mooring line 1712A and 1712B remain relatively stable, thereby reducing strain cycling and fatigue in the high-stiffness anchor lines. The introduction of buoy 1702 eliminates the need to splice any mooring line to achieve a difference in stiffness along its length, removing a likely point of failure and increasing durability.

[0112] While an alternative approach could reverse this configuration, using a low-stiffness anchor line and a high-stiffness connection to the offshore structure, the preferred method places the low-stiffness line closer to the surface. This configuration ensures that the more flexible line, which experiences higher wear, remains accessible for maintenance and replacement. The effectiveness of reciprocal base isolation also depends on buoy size. A large buoy 1702 provides a greater buoyant force, which increases static restraining forces in the first mooring lines 1712A and 1712B, reducing buoy movement and stabilizing the anchor system. This configuration helps keep the anchor lines stationary, minimizing cyclic strain in the high-stiffness mooring lines 1712A and 1712B while concentrating strain cycling in the low-stiffness line 1710. By integrating reciprocal base isolation into offshore mooring systems, the impact of dynamic loads on seabed anchors can reduced. This approach enhances the longevity and reliability of the entire mooring infrastructure, ensuring greater resistance to fatigue failure in harsh marine environments.

[0113] FIG. 18 shows the offshore mooring system 1700 of FIG. 17 with the isolator 1710 or low-stiffness mooring line oriented in an extended configuration 1800 when the force of the dynamic load 1714 pulls the floating foundation 1708 away from buoy 1702.

[0114] The term reciprocal base isolation is introduced to describe this mechanism because the primary lateral loads occur at the top of the mooring system, near the waterline, rather than at the bottom, where traditional base isolation methods are applied, such as at the foundation of a building. The term reciprocal is chosen from mathematics, where it represents the inverse of a number (e.g., the reciprocal of 3 is 1/3, found by flipping the fraction upside down). This concept is reflected in the system's approach, as it effectively inverts the orientation of conventional base isolation.

[0115] Notably, the system would also function in reverse under seismic conditions. If an earthquake were to shake the seabed anchors, a reciprocal base-isolated mooring system would protect the offshore structure by decoupling it from the seismic forces transmitted through the mooring lines. In contrast, a traditional taut mooring system, where all lines remain under high tension, would directly transfer seismic loads from the anchors to the offshore platform, potentially amplifying structural stress and damage. By incorporating a buoy or compliant element with varying stiffness properties, the reciprocal base isolation approach dissipates energy and minimizes force transmission, enhancing structural resilience in dynamic marine environments.

[0116] FIG. 19 shows a schematic diagram illustrating an embodiment of an offshore mooring system 1900 with one or more intermediate buoys 1902 configured to dissipate energy by hydrodynamic regulation, wherein the one or more intermediate buoys 1902 having a volume smaller than the embodiment of FIG. 17. In an embodiment, the one or more intermediate buoys 1902 is introduced, below the waterline, between the seabed anchor 1904A and 1904B and the floating foundation 1908. The force of the dynamic load 1914 pulls the floating foundation 1908 away from the buoy 1902.

[0117] When the floating foundation 1908 experiences lateral displacement due to the dynamic load 1914, it exerts force on the buoy 1902, displacing it from its equilibrium position. The buoy 1902 follows an arcuate trajectory, moving both laterally relative to its initial position and vertically within the water column. As the buoy 1902 moves downward, it performs work against the buoyant force. By descending to a greater depth, the buoy 1902 converts a portion of the offshore structure's kinetic energy into buoyant potential energy, with the energy converted being proportional to the vertical displacement of the buoy 1902.

[0118] A centrifugal regulator, or governor, is a mechanical device traditionally used in steam engines to maintain a stable speed. It consists of rotating arms with weighted balls at their ends. As the engine speed increases, the centrifugal force causes the balls to move outward, adjusting a throttle valve to reduce speed. The system stabilizes when equilibrium is reached between the throttle position and the outward displacement of the weights. The mechanism operates by converting excess energy into rotational kinetic energy of the weighted balls, ensuring controlled energy dissipation. A similar effect occurs in manual transmission vehicles during engine braking, where kinetic energy is transferred into rotational energy within the engine, reducing reliance on friction-based braking systems. Regulation provides two benefits. Excess energy is dissipated without causing wear on system components, unlike friction brakes that degrade over time. Additionally, rapid fluctuations in speed are mitigated, as an engine equipped with a governor resists sudden acceleration, and a vehicle in gear rolling downhill experiences controlled acceleration compared to one in neutral.

[0119] In a fluid environment, the buoyant force exerts an upward thrust on submerged or partially submerged objects, counteracting the gravitational force. To submerge an object further, energy must be applied to overcome this buoyant force. When an object is fully submerged, the buoyant force remains constant, and the work required to displace it further is proportional to the distance moved. This work represents the energy expended against the buoyant force. A mobile buoy can function as a regulatory mechanism by leveraging the principles of buoyancy. Similar to the centrifugal regulator, which converts excess energy into controlled kinetic motion, a buoy's displacement dynamics can regulate energy transfer within a fluid system. This principle enables controlled energy absorption and dissipation, preventing abrupt system fluctuations.

[0120] In an embodiment, the anchoring system incorporates a buoy 1902 positioned between the anchors 1904A and 1904B and the offshore structure 1908 to regulate the motion of the offshore structure. A relatively small buoy remains mobile due to its lower buoyant force, resulting in reduced static restraining forces in the anchor lines 1906A and 1906B.

[0121] FIG. 20 shows a schematic diagram illustrating the offshore mooring system 1900 of FIG. 19 with arctuate motion 2000 dissipating energy. In an embodiment, the anchoring system incorporates a buoy positioned between the anchor and the offshore structure to regulate motion and manage energy transfer within the system. The buoy's ability to convert kinetic energy into buoyant potential energy provides operational advantages over traditional energy storage methods, such as absorption as strain energy in mooring lines. Unlike strain energy, which is energy stored by stretching mooring lines and can cause fatigue failure, especially in steel components, buoyant potential energy does not induce material degradation. This reduces wear on the mooring system and extends its operational lifespan. The buoy also mitigates high strain rates in mooring lines. When the offshore structure experiences sudden external forces, such as wind gusts, the rapid load transfer can generate high strain rates in the mooring lines. If the buoy is sufficiently mobile, it responds quickly to these forces, redistributing energy and reducing strain-induced material deterioration. This is particularly beneficial for polymers such as polyester and nylon, which are commonly used in offshore mooring applications and are susceptible to high strain rate effects.

[0122] The system functions as a hydrodynamic regulator by converting energy to a harmless form rather than absorbing it. The mooring system benefits from a secondary energy dissipation process via fluid resistance. As the buoy oscillates vertically and laterally 2000, it encounters hydrodynamic drag, which dissipates energy with each cycle. This introduces damping to the system. The extent of energy dissipation depends on factors such as buoy velocity, displacement, and cross-sectional geometry, all of which can be optimized in the system's design. A high-drag buoy geometry may be desirable to increase fluid resistance and maximize energy dissipation.

[0123] By prioritizing energy dissipation through buoy motion rather than strain-induced heat dissipation in the mooring lines, the system minimizes material fatigue and structural wear. Unlike strain energy dissipation, which depends on inherent material properties and can be difficult to control in design when material selection is governed by various factors, fluid resistance dissipation can be engineered through multiple system parameters. To further reduce strain energy storage, it is advantageous to minimize mooring line stretching. Unlike in previous embodiments employing reciprocal base isolation, in this embodiment achieving similar stiffness in both mooring lines is beneficial. Higher stiffness reduces line elongation, and in the theoretical case of infinitely stiff, rigid mooring lines, all energy would be dissipated through buoy motion rather than strain, optimizing system longevity and performance.

[0124] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of the disclosed technology or of what may be claimed, but rather as descriptions of features that may be specific to embodiments of disclosed technologies. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment in part or in whole. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described herein as acting in certain combinations and/or initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination. Similarly, while operations may be described in a particular order, this should not be understood as requiring that such operations be performed in the particular order or in sequential order, or that all operations be performed, to achieve desirable results.

Additional Description

[0125] In an aspect, a method of organizing an offshore wind farm wherein each variable foundation is connected to at least one near-surface buoy which is connected to at least one seabed anchor where each anchor is not vertically underneath the buoy. It is within the scope of this invention for a method of organizing offshore structures of any resource such as a variable resource or a non-variable resource. It is within the scope of this invention for a variable resource to include, but not be limited to, a wind variable foundation, a wind farm, a wave energy converter, a wave farm, natural gas, and/or solar. Further, a variable resource may include a waste collection device, a desalination device, an undersea mining device, a light reflection device, and/or aquaculture (fish farming). Whereby the restraining force on the variable foundation provided by the anchor and transmitted through the mooring system is developed efficiently because the angle between the variable foundation, buoy and anchor is not a right angle. Further, some degree of compliance/flexibility may be introduced to the system so loads on the anchor are reduced. Such that the anchorage, mooring and buoy systems can be downsized. Such that costs and material use are reduced, groundworks are reduced, logistics of transport of equipment is simplified, etc.

[0126] Such a system where the components are arranged according to the rules of symmetry. Including such a system where internal symmetries are considered. For example, after the body and face centers in a hexagonal cell are identified, the centroid of the triangle defined by the lattice point, face center, and/or body center may be identified. The centroid is a position of internal symmetry. Such that the densest placement of components is achieved pursuant to local wind, sea, and ground conditions. Such that the arrangement of components is rationalized to enable more straightforward planning and execution. Such that the length of tension elements is minimized. Such a system where some or all of the variable foundations are positioned at the corners of a lattice including, but not limited to, a hexagon, and/or a parallelogram (general, or rectangle, rhombus and square special cases).

[0127] Such a system where the variable foundations are positioned in whole or in part in an irregular/non-repeating layout, for example to optimize for local wind, ground, or other conditions. Including a method to identify preferred positions of buoys and anchors based on variable foundation positions. Such a system where each variable foundation is connected to the buoy(s) by one or more lengths of mooring line. Including where one or more lengths of mooring line are subdivided. Including where one or more lengths of mooring line are pretensioned. Including where multiple buoys are connected in series.

[0128] Such a system where each buoy is connected to the anchor(s) by one or more lengths of mooring line. In an implementation, one or more buoys are connected to one another in series. Such a system where taut or semi-taut mooring lines are used between the anchor and buoy and/or buoy and variable foundation. Such a system where the mooring lines are made of anything (elastomer, heavy chain, combination of those and/or other materials). Such a system where an intermediate system is used to mitigate the transfer of loads to the anchor. Such as a spring, elastomer, dashpot, and/or load collector. Such as the use of floats and weights along the mooring line.

[0129] Such a system where other objects of interest are sited at the points of symmetry. Some objects include, but are not limited to, power infrastructure, e.g., cables, a vertical wind variable foundation, a solar variable foundation, a waste collection device, a desalination device, an undersea mining device, a wave energy converter, instrumentation/monitoring equipment, aquaculture infrastructure, a light reflecting device, and/or a feature to support maritime life.

[0130] In an embodiment, the mooring system is configured to optimize either reciprocal base isolation, hydrodynamic regulation through buoy mobility, or a balance between both mechanisms. Several factors influence the system's design, including water depth, buoy size, and the principle of least resistance. In shallow water, excessive vertical movement of the buoy may cause it to contact the seabed or rise near the water surface, posing a potential hazard for passing vessels. In such environments, a reciprocal base isolation approach may be preferable to minimize these risks.

[0131] The size of the buoy also impacts system behavior. Reciprocal base isolation requires a larger buoy to effectively decouple motion at the anchor from the offshore structure, with isolation achieved by ensuring a difference in stiffness between the anchor line and the topside mooring line. In contrast, hydrodynamic regulation through buoy mobility is more effective with a smaller buoy. To maximize energy dissipation through buoyancy effects, the mooring lines should have comparable stiffness, allowing energy to be absorbed primarily through buoy movement rather than through mooring line strain. Another design principle is the principle of least resistance, which dictates that energy dissipation occurs primarily through the system component that offers the least resistance to movement. In a reciprocal base isolation system, energy is dissipated primarily by the low-stiffness mooring line. In a hydrodynamic regulation system, the buoy should be designed as the component offering the least resistance, which can be achieved by reducing its size or modifying its hydrodynamic properties to enhance mobility. If the buoy is too small or too hydrodynamic, it may reduce overall damping effectiveness. On the contrary, if the buoy is large or has a high drag coefficient and both mooring lines are highly stiff, the system will resist movement effectively, improving station keeping, but may impart excessive strain on the mooring lines, Consequently, system optimization requires balancing buoy mobility with damping to protect the mooring lines while ensuring effective energy dissipation.

[0132] In another embodiment, buoys in the unstressed equilibrium position are completely above the water, partially submerged, and/or completely submerged. The initial expectation is that a completely submerged buoy is preferred to allow vessel navigation and to minimize fatigue demands on the anchors.

[0133] In an embodiment, since there are a five regular space-filling lattices, and since each of those contains four groups of positions of symmetry, and since there are a finite number of structures (e.g., variable foundations, buoys, anchors) to be placed, the total number of possible combinations is finite. It is within the scope of this invention for all configurations that satisfy these conditions. In a first condition, since the variable foundation and buoys are both located at, near, or on the sea surface, and since they must be separated by some distance, they cannot be located at the same positions of symmetry. In a second condition, since the anchor is located at the sea floor, but since the claim considers configurations where the angle between the buoy and the anchor is not a right angle, the anchor can be placed at the same position as the variable foundation but not the same as the buoy. However, an exception is possible: where anchors are placed at the same position as buoys, but they are connected to buoys other than the one above them. For simplicity, consider the variable foundation to be placed at lattice points. Since we consider primitive unit cells, this means there is one variable foundation per unit cell for regular geometries, and there is one variable foundation per Wigner-Seitz cell for irregular geometries.

[0134] In an embodiment, it is within the scope of this invention to position anchors in an orientation equidistant from buoys rather than vertically underneath, i.e., develop a large angle in the static state so the restoring force is large at small displacements. Buoyant force may be smaller while inducing an equal restoring force and buoy can therefore be smaller. Thus, the position of the anchors may be rationalized to reduce the number needed.

[0135] In an embodiment, a multiline anchor connection is desired to rationalize a network arrangement of multiple variable foundations. It is within the scope of this invention for an embodiment to have an intermediate system to relieve loads from hydrodynamics. 3-line anchor system achieves a variable foundation: anchor ratio of approximately 1:1. 6-line anchor system achieves a variable foundation: anchor ratio of approximately 2:1. 6-line anchor idea requires spacing the variable foundations closer than otherwise desired and may reduce overall farm efficiency.

[0136] In an embodiment, anchors may be installed as needed to achieve redundancy (i.e., a 3:2 variable foundation: anchor ratio, or even 3:3).

[0137] In some aspects, the techniques described herein relate to a method of organizing a system of one or more offshore variable resource structures, the method including the steps of: providing one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource; providing at least one near-surface buoy; providing at least one seabed anchor; orienting the variable resource near, at, or above a waterline of a source of water; and connecting the one or more variable resource foundations to the at least one near-surface buoy, the at least one near-surface buoy is connected to the at least one seabed anchor, the at least one seabed anchor is not vertically in alignment underneath the at least one near-surface buoy, an angle between the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is not a right angle.

[0138] In some aspects, the techniques described herein relate to a method, further including introducing a degree of compliance or flexibility to reduce a load on the at least one seabed anchor.

[0139] In some aspects, the techniques described herein relate to a method, wherein the system components may be downsized or downgraded.

[0140] In some aspects, the techniques described herein relate to a shared mooring-anchor system, including: one or more variable resource foundations, the one or more variable resource foundations supporting a variable resource, the variable resource is oriented near, at, or above a waterline of a source of water; at least one near-surface buoy; at least one seabed anchor; and wherein the one or more variable resource foundations is connected to the at least one near-surface buoy, the at least one near-surface buoy is connected to the at least one seabed anchor in an arrangement to form a unit cell, the unit cell including: a lattice point; a face center; a centroid; and a body center.

[0141] In some aspects, the techniques described herein relate to a system, further including a monoclinic arrangement where the at least one near-surface buoy is placed at a face center, the at least one near-surface buoy is placed at 3 of 4 positions of the unit cell to triangulate the variable resource.

[0142] In some aspects, the techniques described herein relate to a system, wherein the at least one seabed anchor is not vertically in alignment underneath the at least one near-surface buoy.

[0143] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of the unit cell being hexagonal.

[0144] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of the unit cell being tetragonal.

[0145] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of the unit cell being primitive rectangular orthorhombic.

[0146] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of the unit cell being centered rectangular orthorhombic.

[0147] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at an internal symmetry of the unit cell being monoclinic.

[0148] In some aspects, the techniques described herein relate to a system, wherein the at least one near-surface buoy is placed at the face center, the at least one near-surface buoy is placed at 3 of the 4 positions per the unit cell to triangulate the variable resource.

[0149] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at vertices of a lattice of the unit cell being a rhombus (hexagonal).

[0150] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor is positioned based on rules of symmetry, whereby, the variable resource is positioned at vertices of a lattice of the unit cell being a parallelogram.

[0151] In some aspects, the techniques described herein relate to a system, wherein the one or more variable resource foundations, the at least one near-surface buoy, and the at least one seabed anchor are densely positioned based on a weather forecast.

[0152] In some aspects, the techniques described herein relate to a system, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line.

[0153] In some aspects, the techniques described herein relate to a system, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line which have been pretensioned.

[0154] In some aspects, the techniques described herein relate to a system, wherein the variable resource is connected to the at least one near-surface buoy by one or more lengths of mooring line which have been subdivided to provide rotational restraint to the variable resource.

[0155] In some aspects, the techniques described herein relate to a system, wherein the installation of the system makes use of divers or unmanned underwater vehicles.

[0156] In some aspects, the techniques described herein relate to a system, wherein a plurality of near-surface buoys are connected in series.

[0157] In some aspects, the techniques described herein relate to a system, wherein the at least one near-surface buoy is connected to the at least one seabed anchor by one or more lengths of mooring line.

[0158] In some aspects, the techniques described herein relate to a system, further including an intermediate system to mitigate a transfer of wave loads on the at least one near-surface buoy to the at least one seabed anchor.

[0159] In some aspects, the techniques described herein relate to a system, wherein the intermediate system selected from the group consisting of a spring, an elastomer, a dashpot, and a load collector.

[0160] The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures may be identified with the same reference numerals. Reference will now be made in detail to each embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.

[0161] The phrase and/or, as used herein in the specification and in the claims, should be understood to mean either or both of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Thus, as a non-limiting example, a reference to A and/or B, when used in conjunction with open-ended language such as comprising can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0162] As used herein in the specification and in the claims, the phrase at least one, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase at least one refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one of A and B (or, equivalently, at least one of A or B. or, equivalently at least one of A and/or B) can refer, in one embodiment, to at least one, optionally including more than one. A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0163] It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0164] It is also to be understood that the description is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.

[0165] It will be further understood that the terms comprises, comprising, includes, and/or including. when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0166] The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others or ordinary skill in the art to understand the embodiments disclosed herein.

[0167] When introducing elements of the present disclosure or the embodiments thereof, the articles a, an, and the are intended to mean that there are one or more of the elements. Similarly, the adjective another, when used to introduce an element, is intended to mean one or more elements. The terms including and having are intended to be inclusive such that there may be additional elements other than the listed elements.

[0168] Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

[0169] Now that the invention has been described,