Mooring device for offshore installation

Abstract

A mooring device includes at least two outer anchors, a reactive anchor disposed between the outer anchors, and at least two anchor legs extending outwardly from the reactive anchor to the outer anchors. The reaction anchor has a multidirectional action configured to resist outward forces applied by tension in mutually opposed anchor legs. Each anchor leg includes a tensioner, an inner wire extending from the reactive anchor to the tensioner, and an outer wire extending from the tensioner to the outer anchor. The tensioner wire, which may be an inner wire or an outer wire, is secured to the tensioner, while the mooring wire extends through the tensioner. An upper section of the mooring line extends from the tensioner to the mooring float. The lower section of the mooring line forms part of the anchor leg as an inner line or an outer line.

Description

Technical Field

[0001] This invention relates to the challenges of mooring floating bodies in offshore facilities, such as those used in the subsea oil and gas and marine energy industries. In particular, this invention relates to improving the installation and performance of mooring assemblies that require the installation of multiple anchors and the tensioning of multiple mooring lines. Background Technology

[0002] As oil and gas production and energy generation occur in increasingly deeper waters, mooring or tethered floating bodies become necessary when the water is too deep to allow for installation on the seabed. For example, extended mooring is commonly used for mooring FPSOs (Floating Production, Storage and Offloading vessels) or platforms used for subsea oil and gas production. An example of an extended mooring arrangement for an FPSO is provided in No. 20170862. Mooring is also common in offshore energy generation, such as the generation of electricity by floating wind turbine arrays that will be transmitted to a substation on the seabed.

[0003] The mooring line extends downwards from the buoy to the seabed foundation, which can include piles such as suction piles or dowel piles, or anchors such as towed anchors, gravity anchors, or counterweights. Towed anchors are the preferred choice for offshore wind turbines because they are less expensive than pile foundations. Towed anchors rely on tension in the associated mooring line, which pulls the anchor across the seabed and deeper into the seabed soil. Therefore, proper tension of the mooring line is also essential for effective engagement of the towed anchor with the seabed in this case.

[0004] In many cases, mooring line tensioning is performed from the moored float, for example using a mooring winch or a "gypsy wheel" device arranged to engage the mooring chain. This ensures that each of the multiple mooring lines bears the appropriate share of the load that will be exerted upon it by the float in use. Most commonly, the float is located on the surface, but it can also be located underwater. For example, WO 2013 / 076461 describes a tensioner in the context of moored seafloor buoys used in a hybrid riser system.

[0005] As mentioned above, tensioning from the surface or just below the surface, thus significantly above the seabed, is unsuitable for all types of foundations and water depths. Tensioning in this manner works well for suction foundations or pile foundations deeply embedded in the seabed soil, resulting in strong movement relative to the seabed, but is less effective for anchors that rely on a shallow angle between the mooring line and the seabed, such as towed anchors, gravity anchors, or counterweights. Where the mooring line is steeper relative to the seabed, this anchor is more likely to be lifted off the seabed and slide across it, rather than embedding deeper with increasing tension.

[0006] For towed anchors, improvements involve providing a reaction point and a tensioner on the mooring line, as taught in US 4889065. In that disclosure, a second towed anchor is positioned relative to the tensioner vessel to define the reaction point, and the tensioner pulls the mooring line at a shallow angle. However, this approach becomes cumbersome when multiple mooring lines must be used for the same floating body. For example, FPSOs or floating wind turbines typically require three to twelve different mooring lines in each case.

[0007] US2020 / 407021 proposes anchoring multiple floating bodies, such as wind turbines, directly to a common foundation in the form of rings embedded in the seabed. The aim is to limit the number and complexity of seabed foundations, but this principle cannot be implemented using towed anchors, which have a unidirectional effect and therefore cannot be shared by multiple mooring lines.

[0008] CN 114104196 discloses a mooring arrangement for an offshore power generation platform, which incorporates a magnetic tension control device. Summary of the Invention

[0009] The present invention aims to simplify the installation of multiple anchors, especially towed anchors, to anchor one or more floating objects.

[0010] In this context, the present invention provides a mooring device comprising at least two external anchors and a reaction anchor, such as a caisson, pile, or ring, disposed between the external anchors. The external anchors may include at least one towing anchor configured to self-engage when towed toward the substantially stationary reaction anchor.

[0011] The reactive anchor is configured to resist outward forces exerted by tension in at least two anchor legs extending outward from the reactive anchor to the outer anchor. Each anchor leg includes a tensioner, an inner line extending from the reactive anchor to the tensioner, and at least one outer line extending from the tensioner to at least one of the outer anchors. Therefore, the reactive anchor may include at least two lateral connection points for connecting the respective inner lines of the anchor legs.

[0012] The external anchors can be on opposite sides of the reaction anchor, and the anchor legs can extend radially from the reaction anchor in opposite directions. For example, the anchor legs can be diametrically opposed around the reaction anchor as a pair aligned longitudinally to each other.

[0013] In some embodiments, the inner line of each anchor leg is a tension line coupled to the tensioner, and the outer line of each anchor leg is a lower section of the mooring line extending through the tensioner. In this case, the upper section of the mooring line may converge upwards to a vertical axis aligned with the reactive anchor. Thus, the mooring line may extend upwards and inwards to a float, such as an FPSO, substantially aligned with this axis, for example, to moor the float using the mooring line extending from the respective anchor legs.

[0014] Conversely, in other embodiments, the outer line of each anchor leg is a tension line coupled to the tensioner, and the inner line of each anchor leg is a lower section of the mooring line extending through the tensioner. In this case, the upper portion of the mooring line can diverge upwards from a vertical axis aligned with the reactive anchor. The upper portion of each mooring line can thus extend upwards and outwards to moor a corresponding float in an array of floats surrounding the vertical axis, such as a floating wind turbine.

[0015] Elegantly, in each case, at least one additional mooring line can extend directly from the float or each float to the reaction anchor.

[0016] Conveniently, the tensioner can be operable to apply tension in the corresponding anchor leg by pulling the upper part of the mooring line upward. Thus, the tensioner is operable to lock the mooring line when the upper part is pulled.

[0017] At least one anchor leg may terminate at a group of two or more outer anchors. For example, the group of outer anchors may be angularly spaced around the reaction anchor or aligned on a common radius extending from the reaction anchor. At least one of the anchor legs may have at least two outer lines extending from the tensioner to a corresponding one of the group of outer anchors. Moreover, the outer lines of the anchor leg may be divided into two or more auxiliary outer lines, each auxiliary outer line extending to a corresponding one of the group of outer anchors.

[0018] Accordingly, the present invention includes a method for installing a mooring device. The method includes: securing a reactive anchor to a location on the seabed; connecting at least two anchor legs to the reactive anchor, each anchor leg radiating from the reactive anchor across the seabed and terminating outward at at least one external anchor, such that the reactive anchor is positioned between the external anchors; applying tension in the anchor legs to pull the external anchors inward toward the reactive anchor; and mooring the float with at least one mooring line extending upward from each anchor leg.

[0019] In cases where each anchor leg includes a corresponding lower section of mooring line, tension can be applied to the anchor leg by pulling on the upper section of the mooring line extending upwards from the anchor leg. Advantageously, tension can be applied to the anchor leg in a direction generally parallel to the seabed or along the axis.

[0020] Embodiments of the present invention provide a mooring arrangement for anchoring one or more floating objects, the arrangement comprising: a reactive anchor for providing a reaction point when tensioning multiple mooring lines; an outer anchor spaced apart from the reactive anchor; and at least one mooring line extending from a first anchor to the floating object. The mooring line includes a tensioner and a tensioning line extending between the tensioner and a second anchor, wherein one of the first and second anchors is a reactive anchor, and the other of the first and second anchors is an outer anchor.

[0021] The reactive anchor may be or may include a caisson, a suction pile, or a ring. The reactive anchor may have at least two lateral connection points for connecting cables, whether mooring lines or tension lines.

[0022] The reactive anchor can be easily installed at a location on the seabed between or directly below one or more floating facilities to be moored.

[0023] The external anchor may include at least one towed anchor, which is towed toward the reaction anchor during the tensioning of the associated mooring line.

[0024] Conveniently, the reactive anchor itself can also be used as an anchoring point after the mooring line has been tensioned to the outer anchor. For this purpose, an additional mooring line can be pulled directly between the reactive anchor and the floating facility.

[0025] When used to install towed anchors in a symmetrical mooring configuration, the tensioner unit can simultaneously apply tension to the opposing anchor legs. In effect, each towed anchor then acts as a reaction anchor for the other in a pair of towed anchors. While this has the advantage of reducing the number of tensioning operations required, the towed anchor only has a unidirectional anchoring effect. Therefore, unlike the present invention, the towed anchor cannot be used as a multi-directional or omnidirectional static reaction anchor from which angled tension lines extend toward an external movable anchor positioned on the opposing sides of the reaction anchor. The towed anchor also cannot facilitate the connection of a submooring line whose angle with the horizontal plane is substantially greater than that of another line extending from the same towed anchor line.

[0026] In summary, the mooring device of the present invention includes at least two outer anchors, a static reactive anchor disposed between the outer anchors, and at least two anchor legs extending outward from the reactive anchor to the outer anchors. The reactive anchor is multidirectional and configured to resist outward forces exerted by tension in the opposing anchor legs.

[0027] Each anchor leg includes a tensioner, an inner line extending from the reactive anchor to the tensioner, and an outer line extending from the tensioner to the outer anchor. The tensioner line can be either an inner or outer line, and is fixed to the tensioner, while the mooring line extends through the tensioner. The upper portion of the mooring line extends from the tensioner to the mooring float. The lower portion of the mooring line forms part of the anchor leg, serving as either the inner or outer line. Attached Figure Description

[0028] To facilitate understanding of the invention, reference will now be made to the accompanying drawings by way of example, wherein:

[0029] Figure 1 and Figure 2 This is a schematic side view illustrating the operation of the tensioning system of the present invention;

[0030] Figure 3 and Figure 4 Through Figure 1 and Figure 2 A schematic side view of the mooring arrangement of the present invention with the tensioning system installed, as shown;

[0031] Figure 5 This is a schematic side view illustrating the operation of another tensioning system of the present invention;

[0032] Figure 6 Through Figure 5 A schematic side view of the mooring device of the present invention with the tensioning system installed, as shown; and

[0033] Figure 7 and Figure 8 This is a schematic top view of the mooring device of the present invention. Detailed Implementation

[0034] First, refer to the attached image. Figure 1 and Figure 2 The tensioning system 10 of the present invention is shown here as Figure 3 and Figure 4 The offshore facility shown in the illustration is in operation when its seabed anchor foundation is installed. This facility could, for example, be part of a production system for producing hydrocarbons from a subsea well.

[0035] Figure 1 and Figure 2 The tensioning system 10 shown includes a centrally located, multi-directional fixed reactive anchor 12 situated on the seabed 14. In this example, the reactive anchor 12 is a cylindrical suction pile embedded vertically into the seabed 14. The reactive anchor 12 is multi-directional in its anchoring effect because it provides substantially equal resistance to horizontal or lateral loads applied by lines arranged on mutually opposite sides of the reactive anchor 12. This differs from a towed anchor, which only has a unidirectional effect and therefore will fail if pulled from the opposite direction.

[0036] In the plan view, two or more tension lines 16 extend radially outward from the reaction anchor 12 to the corresponding seabed tensioner unit 18 at angular intervals between them; only one is shown in these figures. For this purpose, the suction pile serving as the reaction anchor 12 includes attachment points 20, such as tension lines 16 coupled to padeyes. In the plan view, the attachment points 20 are angularly spaced around the circumference of the tubular skirt of the suction pile, preferably equally spaced.

[0037] As is customary, the attachment points 20 on the reactive anchor 12 are offset toward the lower end of the skirt, such that the radially inner portion of each tension line 16 is embedded in the seabed 14. This mitigates the risk of the reactive anchor 12 tilting away from its vertical axis or capsizing under the tension applied through the tension lines 16 during use.

[0038] Each tensioner unit 18 acts on a corresponding mooring line 22, which extends radially inward from a corresponding outer anchor 24 in the plan view, the outer anchor being radially spaced from the reactive anchor 12 on the seabed 14. The outer anchors 24 are distributed in an approximately circular array at angular intervals around the reactive anchor 12.

[0039] In this example, the external anchor 24 is a towed anchor, which is embedded in and thus engaged with the seabed 14 by being pulled radially inward by the mooring line 22 toward the tensioner unit 18 and the reaction anchor 12. The reaction anchor 12 is readily pre-installed in the seabed 14 before the external anchor 24 is lowered to the seabed 14 around the reaction anchor 12.

[0040] When the mooring line 22 is tensioned as shown in these figures, the mooring line 22 extends through the tensioner unit 18 to the float 26 at the surface 28. The upper portion 22U of the mooring line 22 extends from the tensioner unit 18 to the float 26, while the lower portion 22L of the mooring line 22 extends from the tensioner unit 18 to the outer anchor 24.

[0041] Float 26 can be, for example, an installation vessel, a production vessel such as an FPSO, a platform, or a buoy. Where float 26 is a permanent part of an offshore facility designed to remain on a station above an anchor foundation throughout its operational life, such as an FPSO or platform, mooring line 22 can be used to moor float 26. Conversely, where float 26 is an installation vessel whose purpose is to embed and test the load capacity of the external anchor 24, mooring line 22 can then be transferred from the installation vessel to another float to be permanently moored.

[0042] Tensioner line 16 and mooring line 22 may each comprise one or more chains, wires, or ropes of varying lengths, including metallic or synthetic wires or ropes. For example, each mooring line 22 may include a bottom chain adjacent to the outer anchor 24, a top chain extending to the buoy 26, and an intermediate section of wire or rope disposed between the bottom and top chains. In this case, each tensioner unit 18 can conveniently act on the bottom chain of the associated mooring line 22. Conversely, the shorter tensioner line 16 may comprise a chain along its entire length or at least along its radially inner portion, adjacent to the reactive anchor 12 and embedded in the seabed 14.

[0043] The upper end of the mooring line 22 is supported by the crane 30 of the float 26, and the upper section 22U of the mooring line 22 is suspended from this upper end as a catenary extending downward to the tensioner unit 18. Alternatively, the upper end of the mooring line 22 may be supported by other lifting or tensioning equipment on the float 26, such as a winch.

[0044] exist Figure 1 and Figure 2 In this process, each tensioner unit 18 is supplied by companies such as Vryhof in the Netherlands. The chain shortening clutch is used as an example. The mooring line 22, as the driving cable, passes through the body of the tensioner unit 18, and the tensioning line 16, as the driven cable, is coupled to the body of the tensioner unit 18. Optionally, the tensioning line 16 is coupled to the body of the tensioner unit 18 via a load pin to measure the tension in the lower section 22L of the mooring line 22 extending from the tensioner unit 18 to the outer anchor 24.

[0045] Tensioner unit 18 can operate in various ways, but This utilizes the principle that applying a vertical load to a taut, normally horizontal mooring line 22 results in a significantly larger horizontal load within the mooring line 22. Specifically, when the upper portion 22U of the mooring line 22... Figure 2 As shown, when pulled upward toward the float 26, the main body of the tensioner unit 18 pivots to latch the mooring line 22 between the upper and lower portions 22U, 22L.

[0046] Raising the upper section 22U of mooring line 22 will lift the tensioner unit 18 locked thereto, and thus also lift the tension line 16 and the lower section 22L of mooring line 22 away from the seabed 14. This creates amplified tension in the tension line 16 and the lower section 22L of mooring line 22, causing the outer anchor 24 to... Figure 1 The outward starting position shown is pulled toward the reaction anchor 12. Figure 2 The inward position shown penetrates deeper into the seabed 14.

[0047] exist In this case, the unlocking line extending from the float 26 is also coupled to the body of the tensioner unit 18, although this line is omitted in these simplified diagrams. The tensioner unit 18 can be unlocked from the mooring line 22 by pulling the unlocking line upward to pivot the body of the tensioner unit 18 relative to the mooring line 22. Once unlocked, the tensioner unit 18 can then be lowered along the mooring line 22 back to the length obtained by the previous lifting step, returning to... Figure 1 The lower level shown is to prepare the tensioning system 10 for another lifting step.

[0048] Then, as the tensioner unit 18 undergoes a vertical reciprocating yo-yo motion, with each consecutive lifting of the upper portion 22 of the mooring line 22, the lifting / locking and unlocking / lowering actions are repeated, thereby causing the outer anchor 24 to ratchet in a stepwise manner. This reciprocating motion of the tensioner unit 18 continues for the necessary number of cycles to impart the desired level of tension in the lower portion 22L of the mooring line 22, thereby engaging the outer anchor 24 to the seabed 14 to the desired degree.

[0049] Once tensioning is complete, the tensioner unit 18 can remain in place as part of the mooring apparatus of the present invention. Figure 3 It shows that it can be made by Figure 1 and Figure 2 The resulting mooring device 32 is shown with the tensioning system 10 installed. This shows the anchor legs 34 facing each other around the suction pile that serves as the central reactive anchor 12.

[0050] Each anchor leg 34 includes a generally horizontal tension line 16 that, when tensioned, extends from the reactive anchor 12 to a tensioner unit 18 acting on the corresponding mooring line 22. The lower portion 22L of the mooring line 22 also extends generally horizontally from the tensioner unit 18 under tension to a towed anchor serving as an outer anchor 24. Conversely, the upper portion 22U of the mooring line 22 extends to a float 26 at surface 28, illustrated here by way of an FPSO.

[0051] In an alternative approach, the tensioner unit 18 can be retrieved by detaching the tensioning line 16, for example, using a remote coupler or ROV. The release line can then be pulled to disengage the tensioner unit 18 from the mooring line 22, allowing it to slide upwards along the mooring line 22 to the surface 28. The tensioner unit 18 can then be used for subsequent tensioning operations on another mooring line 22 and an outer anchor 24, or ultimately for another project.

[0052] in this regard, Figure 4 Another mooring device 36 is shown, which is easily constructed by... Figure 1 and Figure 2The tensioning system 10 is shown installed. Similarly, this shows the anchor legs 34 facing each other around the central reactive anchor 12, but in this case, the tensioner unit 18 has been removed to facilitate the installation of the respective outer anchors 24. Therefore, each mooring line 22 now extends directly from the respective outer anchor 24 to the float 26 as a catenary. For clarity, the tensioning lines 16 have been removed from this view, but in practice, they can simply remain on the seabed 14 once separated from the tensioner unit 18.

[0053] from Figure 3 and Figure 4 It will be noted that the float 26 is positioned centrally above and between the outer anchor 24 and the anchor leg 34, typically aligned with the reaction anchor 12. Therefore, conveniently, as shown by the dashed line, an optional auxiliary mooring line 38 can extend from the reaction anchor 12 to the float 26 without the risk of collision with the main mooring line 22 of the anchor leg 34. Thus, the reaction anchor 12 is useful not only when the outer anchor 24 is installed, but also as an auxiliary anchor during the continued use of the offshore facility.

[0054] In these examples, the auxiliary mooring line 38 is a tension line along a vertical axis intersecting the reactive anchor 12. However, the auxiliary mooring line 38 can be suspended as a catenary or other shape and does not need to be along this vertical axis.

[0055] Now go to Figure 5 and Figure 6 These figures illustrate that the principles of the invention can also be applied to a reverse arrangement, wherein mooring lines 22 radiate outward from a central reactive anchor 12, which is surrounded by an array of outer anchors 24. In this case, the reactive anchor 12 serves as, for example, Figure 6 The array of mooring floats 26 of the floating wind turbine shown shares a common main anchor. Conversely, the tension line 16 of each outrigger 34 extends radially inward from the corresponding outer anchor 24 to the corresponding tensioner unit 18.

[0056] Each tensioner unit 18 is associated with Figures 1 to 3 The same mechanism applies to the associated mooring line 22, but is simply reversed relative to the central reactive anchor 12. Furthermore, the tension generated by the tensioner unit 18 at the lower part of the mooring line 22 facilitates the engagement of the outer anchor 24 with the seabed 14 by dragging the outer anchor 24 toward the reactive anchor 12 in a converging radial inward direction. However, in this case, the inward load is applied to the outer anchor 24 via the tensioner 16 rather than via the mooring line 22.

[0057] The mooring apparatuses shown in the foregoing embodiments share the feature of at least one outer line extending from the reactive anchor 12 to the tensioner unit 18 and from the tensioner unit 18 to at least one of the outer anchors 24. Figures 1 to 3In the middle, the inner line is tension line 16, and the outer line is the lower section 22L of mooring line 22. Conversely, in Figure 5 and Figure 6 In the middle, the inner line is the lower part 22L of the mooring line 22, and the outer line is the tension line 16.

[0058] at last, Figure 7 and Figure 8 The diagrams exemplarily illustrate the mooring devices 40, 42 made possible by the invention. In each case, the anchor legs 34 radiate outward from the central reactive anchor 12 to terminate in each case at one or more external anchors 24 engaged with the seabed 14. For clarity, the upper portion 22U of the mooring line 22 is omitted in these views.

[0059] Figure 7 and Figure 8 The mooring devices 40 and 42 are each depicted with an even number of anchor legs 34, as shown in the figure. These anchor legs are easily grouped into pairs, with each pair comprising anchor legs 34 that are longitudinally aligned with each other and diametrically opposed around the reaction anchor 12. Thus, in these examples, the anchor legs 34 are spaced at equal angles around the reaction anchor 12. In other mooring arrangements of the invention with an odd number of anchor legs 34, such as three or five anchor legs 34, equal angular spacing is also possible. Generally, paired or equally spaced anchor legs 34 may be beneficial for balancing forces on the system, but are not essential.

[0060] exist Figure 7 In the mooring device 40, six anchor legs 34 radiate outward from the central reactive anchor 12, and are therefore spaced apart by an arc of nominal 60°. Thus, the anchor legs 34 are divided into three pairs of opposing anchor legs 34. In this example, the mooring is easily performed on a centrally located floating body, such as... Figure 3 As shown in the FPSO, the lower part 22L of the mooring line 22 extends to the corresponding outer anchor 24 outside the tensioner unit 18, while the tension line 16 extends to the reaction anchor 12 inside the tensioner unit 18.

[0061] exist Figure 8 In the mooring device 42, four anchor legs 34 radiate outward from the central reactive anchor 12, and are therefore spaced apart by an arc of nominally 90°. Thus, the anchor legs 34 are divided into two pairs of opposing anchor legs 34. In this example, the device is suitable for mooring objects such as... Figure 6 The floating array around the floating wind turbine shown has a tension line 16 extending outside the tensioner unit 18 to the corresponding outer anchor 24, while the lower part 22L of the mooring line 22 extends inside the tensioner unit 18 to the reaction anchor 12.

[0062] Figure 8 It is also shown that each anchor leg 34 of the mooring device may include more than one external anchor 24. For example, the external anchor 24 is depicted as being in... Figure 8 The anchor legs 34, shown from left to right, are connected in series. Here, an auxiliary tensioning line 44 extends radially outward from the tensioner unit 18 to the outermost anchor 24 of the series. Conversely, in Figure 8 The anchor leg 34 shown to the right has a parallel-acting outer anchor 24. In this example, the outer anchor 24 is arranged on an axis that converges radially inward along a corresponding auxiliary tension line 44 coupled to a three-plate 46, which in turn couples the outer anchor to a common tension line 16 extending to the tensioner unit 18. In this sense, the tension line 16 is split to form the auxiliary tension line 44. In another variation, alternatively, the auxiliary tension line 44 of the parallel-acting outer anchor 24 can be directly coupled to the tensioner unit 18.

[0063] Within the scope of this invention, many other variations are possible. For example, in principle, the mooring buoy can be positioned within a column of water below the surface, such as a seafloor buoy. Furthermore, the reactive anchor can be a different seabed structure fixed to the seabed, such as a hammer-driven pile, another form of seabed foundation, a subsea substation, or a frame or shell supporting and protecting seabed equipment.

[0064] Such as Figure 6 The mooring floats of the wind turbines can have additional mooring lines extending to other seabed foundations. Those other foundations can also utilize the mooring arrangement of this invention, for example... Figure 6 Those shown provide additional mooring lines.

Claims

1. A mooring device, comprising: At least two external anchors; as well as A reactive anchor disposed between the outer anchors and configured to resist outward forces exerted by tension in at least two anchor legs extending outward from the reactive anchor to the outer anchors; Each anchor leg includes a tensioner, an inner line extending from the reactive anchor to the tensioner, and at least one outer line extending from the tensioner to at least one outer anchor.

2. The apparatus of claim 1, wherein the external anchor is located on the opposing sides of the reaction anchor.

3. The apparatus according to claim 1 or claim 2, wherein the anchor leg extends radially from the reactive anchor in mutually opposite directions.

4. The apparatus of claim 3, wherein the anchor legs are diametrically opposed to each other in a manner that allows them to be longitudinally aligned around the reactive anchor.

5. The apparatus according to any one of the preceding claims, wherein the inner line of each anchor leg is a tension line coupled to the tensioner, and the outer line of each anchor leg is a lower section of the mooring line extending through the tensioner.

6. The apparatus of claim 5, wherein the upper portion of the mooring line converges upward with a vertical axis, the vertical axis being aligned with the reactive anchor.

7. The apparatus of claim 6, wherein the mooring line extends upward to the float, the float being substantially aligned with the vertical axis.

8. The apparatus of claim 7, wherein the float is moored by the mooring line extending from the respective anchor leg of the apparatus.

9. The apparatus of claim 7 or claim 8 further comprises an additional mooring line extending directly from the float to the reactive anchor.

10. The apparatus according to any one of claims 1 to 4, wherein the outer line of each anchor leg is a tension line coupled to the tensioner, and the inner line of each anchor leg is a lower section of the mooring line extending through the tensioner.

11. The apparatus of claim 10, wherein the upper portion of the mooring line diverges upward from a vertical axis aligned with the reactive anchor.

12. The apparatus of claim 10, wherein the upper portion of each mooring line extends to a corresponding one of the array of floats surrounding the vertical axis.

13. The apparatus of claim 6 or claim 11, wherein the tensioner is operable to impart tension in the respective anchor leg by pulling the upper section of the mooring line upward.

14. The apparatus of claim 13, wherein the tensioner is operable to lock onto the mooring line when the upper section of the mooring line is pulled.

15. The apparatus according to any one of the preceding claims, wherein at least one of the anchor legs terminates in a group of two or more of the outer anchors.

16. The apparatus of claim 15, wherein the outer anchors of the group are spaced at an angle around the reactive anchor.

17. The apparatus of claim 15, wherein the outer anchors of the assembly are aligned on a common radius extending from the reaction anchor.

18. The apparatus of claim 16 or claim 17, wherein at least one of the anchor legs comprises at least two outer lines extending from the tensioner to a corresponding outer anchor in the outer anchor of the group.

19. The apparatus of claim 16 or claim 17, wherein at least one outer line of at least one of the anchor legs is divided into two or more auxiliary outer lines, each auxiliary outer line extending to a corresponding one of the outer anchors of the group.

20. The apparatus according to any one of the preceding claims, wherein the reaction anchor is a caisson, a pile, or a ring.

21. The apparatus according to any one of the preceding claims, wherein the reactive anchor includes at least two lateral connection points for connecting the respective inner lines of the anchor leg.

22. The apparatus according to any one of the preceding claims, wherein the external anchor comprises at least one towing anchor configured to self-embed when towed toward the reactive anchor.

23. A method for installing a mooring device, the method comprising: Secure the reactive anchor at the seabed location; At least two anchor legs are connected to the reaction anchor, each anchor leg radiating from the reaction anchor through the seabed and terminating outward at least one external anchor, such that the reaction anchor is positioned between the external anchors; Tension is applied to the anchor leg to pull the outer anchor inward toward the reactive anchor; and Moor the float using at least one mooring line extending upwards from each anchor leg.

24. The method of claim 23, wherein each anchor leg includes a lower section of a corresponding one of the mooring lines, and tension is imparted in the anchor leg by pulling an upper section of the mooring line extending upward from the anchor leg.

25. The method of claim 23 or claim 24, comprising applying tension in the anchor leg in a direction substantially parallel to the seabed.

26. The method of claim 24 or claim 25, further comprising cyclically pulling the upper section of each mooring line in a series of pulls, each pull locking the upper section relative to the anchor leg.

27. The method according to any one of claims 23 to 26, comprising mooring the buoy with two or more mooring lines converging upward from the anchor leg.

28. The method according to any one of claims 23 to 26, comprising mooring two or more buoys with mooring lines radiating upward from the anchor leg.

Images