Flat Pack Buoyancy Module

Abstract

A buoyancy module is disclosed that is configured to be in at least two different configurations, including a straight configuration and a folded, assembled configuration.

Description

[Technical Field]

[0001] The present invention relates to a buoyancy module that is configured to be in at least two different configurations, including a straight configuration and a folded, assembled configuration. [Background technology]

[0002] Buoyancy modules traditionally consist of two or more separate rigid segments that wrap around a subsea structure, such as a flexible riser, steel pipe, umbilical, synthetic rope, or central steelworks. Typically, there are only two segments that make up a 180-degree circumferential range. Known separate rigid segments limit logistical efficiency, and handling individual items can hinder the effectiveness of in-line installation. Summary of the Invention [Means for solving the problem]

[0003] In a first aspect, disclosed herein is a buoyancy module for use in the sea, comprising a plurality of sub-modules, each of the sub-modules extending between an outer surface and an inner surface, the outer surface having two outer edges, the distance between the two outer edges defining an outer surface width (wo), and the inner surface having two inner edges, the distance between the two inner edges defining an inner surface width (wi), the inner surface width (wi) being smaller than the outer surface width (wo). The sub-modules are arranged next to one another such that adjacent sub-modules are connected or connectable to one another along their respective abutting outer edges to form the buoyancy module.

[0004] The buoyancy module is - a linear configuration, wherein the sub-modules are oriented in the same direction such that the outer edges of the sub-modules extend in substantially the same plane, the buoyancy module comprises a substantially flat structure, the distance between the inner edges of two adjacent sub-modules defines a separation distance (sd), and the sub-modules are molded or connected together to form a unitary buoyancy module; - a folded assembly configuration in which adjacent sub-modules are inclined towards each other so that the separation distance (sd) is eliminated or at least reduced, and the buoyancy module constitutes a structure resembling a cylinder or a polygonal prism or at least a part of such a structure; The device is configured to have at least two different forms, including:

[0005] The buoyancy module can thus provide a single segment that can be stored and transported in a flat-pack, i.e., linear, form and then efficiently installed by wrapping it circumferentially around the subsea structure in a folded, assembled form.

[0006] The buoyancy modules described above allow for a significant increase in the number of buoyancy modules that can be transported in the same shipping container compared to the known separate rigid segments that are conventionally used. The storage area required by each buoyancy module during storage and transportation is therefore significantly reduced by the buoyancy modules described above. This significantly improves packaging efficiency and ease of handling. Packaging efficiency can be improved by up to 800% depending on the dimensions of the buoyancy modules. This storage space (volume reduction) has far-reaching commercial and environmental benefits (reduced carbon emissions) when considering the reduction in: 〇Quantity of shipping containers Road, rail, sea freight, air freight and supply ship trips o Storage areas on board ships.

[0007] Sub-modules being connected to one another or connectable to one another means that the sub-modules are directly connected to one another or are configured to be connected during assembly, allowing them to obtain a linear configuration. Sub-modules being connected to one another therefore means that the sub-modules are directly connected to one another as shown in the figures. Sub-modules being connectable to one another means that the sub-modules are configured to be connected during assembly, allowing them to obtain a linear configuration. Sub-modules may therefore be individually provided with connection means for connecting them during the assembly step. The connection means may be in the form of a click connection, where each adjacent sub-module comprises, for example, male or female parts that fit or click together to form the connection. Alternatively, the connection means may be in the form of a clamping means.

[0008] Multiple sub-modules molded or connected together to form an integral buoyancy module means that adjacent sub-modules in a linear configuration are not connected by additional parts to form the linear configuration.

[0009] The linear form may be the form used during transportation, i.e., the transport form. Therefore, the linear form may also be referred to as the linear transport form.

[0010] The two outer edges may be parallel, and likewise the two inner edges may be parallel.

[0011] In one or more examples, the two end sub-modules that are furthest from each other and that are connected to only one other sub-module in the linear configuration are connected to each other in the assembled configuration, thereby causing the buoyancy module to form a closed structure resembling a cylinder or polygonal prism.

[0012] In one or more examples, two end sub-modules that are furthest from each other and that are connected to only one other sub-module in the linear configuration are connected to end sub-modules of one or more other buoyancy modules in the assembled configuration, whereby the two or more buoyancy modules together form a closed structure resembling a cylinder or polygonal prism.

[0013] In one or more examples, two end sub-modules connected together in assembled configuration are directly connected together. End sub-modules directly connected in assembled configuration may not be connected together by the use of an additional component such as a cord, for example a cord strung through an eye with a reinforcing ring as disclosed in GB 2076749.

[0014] In one or more examples, the buoyancy module includes more than four sub-modules, such as more than five sub-modules, such as more than ten sub-modules, such as more than fifteen sub-modules, such as twenty sub-modules.

[0015] Two or more buoyancy modules may be connected in-situ during assembly to form a combined closed structure together. Alternatively, a single buoyancy module may have dimensions wide enough to form a closed structure. The closed structure may have an inner surface circumference with a polygonal shape, with the number of sub-modules defining the number of polygonal shapes. If there are five sub-modules that make up the closed structure, the inner surface circumference has a pentagonal shape. Similarly, if there are eight sub-modules that make up the closed structure, the inner surface circumference has an octagonal shape, and so on.

[0016] In one or more examples, the outer edge of the outer surface is substantially straight.

[0017] In one or more examples, the inner edge of the inner surface is substantially straight.

[0018] In one or more examples, the outer surface is substantially planar.

[0019] In one or more examples, the inner surface is substantially planar.

[0020] In one or more examples, the length of the outer edge (lo) is greater than the length of the inner edge (li), such as at least 20% greater, such as at least 30% greater, such as at least 40% greater.

[0021] In one or more examples, the maximum distance between the outer surface and the inner surface defines the height (h) of the buoyant sub-module, and the length (li) of the inner edge is at least 50% greater than the height (h), such as at least 75%, for example at least 100%, for example at least 125%, for example at least 150% greater.

[0022] In one or more examples, the maximum distance between the outer surface and the inner surface is between 0.25 m and 2.5 m, for example between 0.5 m and 1.5 m. Alternative dimensions may also be envisioned.

[0023] In one or more examples, the inner surface width (wi) is at least 10% smaller than the outer surface width (wo), such as at least 20%, for example at least 30%, such as at least 40%, for example at least 50%, for example at least 60% smaller.

[0024] In a linear configuration, multiple sub-modules are molded or connected together to form a unitary buoyancy module. In one or more examples, adjacent sub-modules are directly connected along their respective abutting outer edges.

[0025] In one or more examples, the inner surface includes a centrally positioned recess extending perpendicular to the inner edges of each sub-module from one inner edge to the other inner edge. This recess may be omitted. The recess may be configured to receive a clamping system for connecting / positioning the buoyancy module onto an external structure around which it is positioned.

[0026] In one or more examples, the recess positioned centrally on the inner surface has a recess length (lr) that is at least 10%, such as at least 20%, for example at least 30%, such as at least 40%, for example at least 50%, for example at least 60% greater than the length of the inner edge (l i ).

[0027] Thus, in a second aspect, there is disclosed herein a system comprising one or more buoyancy modules as defined above and a clamping system around which the buoyancy modules are positioned in an assembled configuration, the clamping system being configured to be positioned and secured around an external structure selected from a subsea pipe, a subsea cable, a subsea riser, a subsea umbilical, a subsea flowline, a subsea steel catenary riser, an installed buoyancy module, a temporary buoyancy module, a surface buoyancy module or the like.

[0028] In one or more examples, one or more buoyancy modules and clamping systems, such as those described above, are sized and designed to fit into recesses in the sub-modules.

[0029] In a third aspect, further disclosed herein is the use of one or more buoyancy modules as described above / a system as described above in assembled form positioned around an external structure selected from a subsea pipe, a subsea cable, a subsea riser, a subsea umbilical, a subsea flowline, a subsea steel catenary riser, an installed buoyancy module, a temporary buoyancy module, a surface buoyancy module or the like, for lifting said external structure.

[0030] Various examples are described below with reference to the figures. Like reference numerals refer to like elements throughout. Thus, like elements will not be described in detail with respect to the description of each figure. It should also be noted that the figures are intended only to facilitate the description of the examples. They are not intended as an exhaustive description of the claimed invention or as limitations on the scope of the claimed invention. Furthermore, an illustrated example need not have all aspects or advantages shown. An aspect or advantage described in connection with a particular example is not necessarily limited to that example and may be implemented in any other example, even if not so shown or explicitly described. [Brief explanation of the drawings]

[0031] [Figure 1A] 1 shows a perspective view of a buoyancy module comprising multiple sub-modules. [Figure 1B] 1 shows a perspective view of a sub-module. [Figure 1C] 1 shows a buoyancy module in side view. [Figure 2A] 1 shows the buoyancy module in a step of being attached around the external structure. [Figure 2B] 1 shows the buoyancy module in a step of being attached around the external structure. [Figure 2C] 1 shows the buoyancy module in a step of being attached around the external structure. [Figure 3] 1 shows the buoyancy module attached around the external structure using a clamping system. [Figure 4] 1 shows several buoyancy modules within a shipping container. [Figure 5] FIG. 1 illustrates some known and previously used buoyancy modules within a shipping container. DETAILED DESCRIPTION OF THE INVENTION

[0032] Illustrative examples will now be described more fully below with reference to the accompanying drawings. In this regard, the examples may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the examples are simply described below with reference to the figures to explain aspects. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. When preceding a list of elements, phrases such as "at least one" modify the entire list of elements and not individual elements of the list.

[0033] In the drawings, the thicknesses of several layers and regions are exaggerated for clarity and ease of illustration. When a layer, region, element, or plate is referred to as being "on" another layer, region, element, or plate, it may be directly on the other layer, region, element, or plate, or there may be intervening layers, regions, elements, or plates. Conversely, when a layer, region, element, or plate is referred to as being "directly on" another layer, region, element, or plate, there are no intervening layers, regions, elements, or plates. Furthermore, when a layer, region, element, or plate is referred to as being "beneath" another layer, region, element, or plate, it may be directly below the other layer, region, element, or plate, or there may be intervening layers, regions, elements, or plates. Conversely, when a layer, region, element, or plate is referred to as being "directly below" another layer, region, element, or plate, there are no intervening layers, regions, elements, or plates.

[0034] Spatially relative terms such as "lower" or "bottom" and "upper" or "top," "below," "below," "below," "above," and the like may be used herein for ease of description to describe the relationship between one element or component and another element or component as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device shown in the figures were turned over, elements described as being "below" the other element, or "below" or "below" the other element, would then be oriented "above" the other element, or "above" the other element. Thus, the exemplary terms "lower" or "below" can encompass both "lower" and "upper" orientation positions, depending on the particular orientation of the figure. Similarly, if a device in one of the figures were turned over, elements described as being "below" or "below" the other element would then be oriented "above" the other element. Thus, the exemplary terms "below" or "beneath" can encompass both an orientation of above and below, and, as such, spatially relative terms can be interpreted differently depending on the orientation being described.

[0035] Throughout this specification, when an element is referred to as being "connected" to another element, the element may be "directly connected" to the other element or "electrically connected" to the other element with one or more intervening elements therebetween.

[0036] The terms used herein are for the purpose of describing particular examples only and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural, including "at least one," unless the content clearly dictates otherwise. "At least one" should not be construed as limiting "a" or "an." It will be further understood that, as used herein, the terms "comprises," "comprising," "includes," and / or "including" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0037] In this specification, terms such as "first," "second," and "third" may be used to describe various elements, but it will be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Thus, a "first element" discussed below can be referred to as a "second element" or a "third element," and "second element" and "third element" can be similarly referred to without departing from the teachings of this specification.

[0038] As used herein, "about" or "approximately" means inclusive of the stated value and within an acceptable range of deviation of a particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the error associated with measuring the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

[0039] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and it will be further understood that they should not be interpreted in an idealized or overly formal sense unless expressly defined as such in this specification.

[0040] Illustrative examples are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized examples, with like reference numerals referring to like elements throughout. Accordingly, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Accordingly, the examples described herein should not be construed as limited to the particular shapes of regions as illustrated herein, but rather as including deviations in shape that result, for example, from manufacturing. For example, a region illustrated or described as flat may have rough and / or nonlinear features. Furthermore, sharp angles that are illustrated may be rounded. Accordingly, regions illustrated in the figures are schematic in nature, and their shapes are not intended to depict the precise shape of the regions and are not intended to limit the scope of the claims. Some portions not relevant to the description may not be provided to specifically describe illustrative examples of the present disclosure.

[0041] FIG. 1A shows a buoyancy module 10 comprising multiple sub-modules 100 in a perspective view, FIG. 1B shows a single sub-module 100 in a perspective view, and FIG. 1C shows the buoyancy module 10 in a side view. The buoyancy module 10 is shown in a linear configuration 20, which may also be considered a shipping or pre-assembled configuration. The buoyancy module 10 has a width w and a length l as indicated in FIG. 1A.

[0042] Each of the sub-modules 100 extends between an outer surface 101 and an inner surface 103, as shown in FIG. 1B. The outer surface 101 has two outer edges 102, one of which is marked in FIG. 1B. The distance between the two edges 102 defines an outer surface width wo, as also shown in FIG. 1B. As shown, the two outer edges 102 may be parallel. Alternatively, they may be slightly angled relative to each other to form a tapered configuration of the sub-modules 100. If a tapered configuration is used, the direction of tapering typically alternates between adjacent sub-modules 100.

[0043] The inner surface 103 also has two inner edges 104. The distance between the inner edges 104 defines an inner surface width wi, as shown in FIG. 1B. To allow the buoyant module 10 to bend, the inner surface width wi is smaller than the outer surface width wo. This has the consequence that the distance between the inner edges 104 of two adjacent sub-modules 100 defines a separation distance sd. The two end sub-modules may be defined as a first end sub-module 100a and a second end sub-module 100b. In FIG. 1C, the separation distance between the first end sub-module 100a and its adjacent sub-module 100c is shown.

[0044] The distance between the inner surface 103 and the outer surface 101 defines the height h of the buoyant module 10 / sub-module 100 as shown in Figure 1C. The height h may vary if the sub-modules 100 include recesses 105 in the inner surface 103 as shown in Figures 1A-1B. The recesses 105 extend approximately perpendicular to the inner edges 104 of each sub-module 100 from one inner edge 104 to the other inner edge 104. The recesses 105 may alternatively be omitted.

[0045] The plurality of sub-modules 100 are arranged next to one another such that adjacent sub-modules 100 are connected or connectable to one another along their respective abutting outer edges 102 to form the buoyant module 10. The sub-modules 100 being connected to one another means that the sub-modules 100 are directly connected to one another as shown in the figures. The sub-modules 100 being connectable to one another means that the sub-modules 100 are configured to be connected during assembly, allowing them to assume a linear configuration. Accordingly, the plurality of sub-modules 100 may be individually provided with connection means for connecting them during the assembly step. The connection means may be in the form of a click connection, where each adjacent sub-module 100 comprises, for example, male or female parts that fit or click together to form a connection. Alternatively, the connection means may be a form clamping means.

[0046] The buoyancy module 10 is configured to have at least two different configurations, as shown in Figures 1A-1C and 2A-2C. In Figures 1A and 1C, the buoyancy module 10 is in a linear configuration 20, with the multiple sub-modules 100 oriented in the same direction. In this configuration, the outer edges 102 of the multiple sub-modules 100 extend substantially in the same plane, and the buoyancy module 10 forms a substantially flat structure.

[0047] In FIGS. 2A-2B, a buoyant module 10, originally in a linear configuration 20, is folded around an external structure 300 to obtain a folded assembly configuration 30, as shown in FIG. 2C. As seen in FIGS. 2A-2C, by folding the buoyant module 10, adjacent sub-modules 100 are tilted toward each other so that the separation distance sd is eliminated or at least reduced, the former shown in FIG. 2C and the latter shown in FIG. 2B. The buoyant module 10 shown in FIG. 2C forms a structure resembling a cylinder or polygonal prism. As an alternative to a buoyant module 10 that can be folded entirely around the external structure 300 to form a closed structure 31, as shown in FIG. 2C, multiple buoyant modules 10 may be connected such that each buoyant module 10 forms part of such a structure resembling a cylinder or polygonal prism. Two buoyant modules 10, each with ten sub-modules 100, or four buoyant modules 10, each with five sub-modules 100, can together form a closed structure in the folded assembly configuration 30. Alternative combinations of buoyancy modules 10 having different numbers of sub-modules 100 may be connected to form a closed structure 31 .

[0048] Although the number of sub-modules 100 in the buoyant module 10 shown in the figures is 20, it is possible to envision a buoyant module 10 having fewer or more sub-modules 100. Thus, in one or more examples, the buoyant module 10 includes more than four sub-modules 100, e.g., more than five sub-modules 100, e.g., more than ten sub-modules 100, e.g., more than fifteen sub-modules 100, e.g., twenty sub-modules 100.

[0049] 3 shows a buoyancy module 10 attached around an outer structure 300 using a clamping system 200. The clamping system 200 is adjusted to fit into a recess 105 in the inner surface 102. The outer structure 300 may be a subsea pipe, a subsea cable, a subsea riser, a subsea umbilical, a subsea flowline, a subsea steel catenary riser, an installed buoyancy module, a temporary buoyancy module, a surface buoyancy module, or the like.

[0050] As shown in Figure 1B, the length lo of the outer edge 102 may be greater than the length li of the inner edge 104. In the folded assembled configuration 30, this gives the buoyancy module 10 a structure that extends outward from the inner surface 103 positioned about, and possibly secured to, the external structure 300, toward the larger outer surface 101. Also as shown in Figure 1B, the length lr of the recess extending in the same direction as the length li of the inner edge is less than the length li of the inner edge.

[0051] A significant advantage of the buoyancy modules 10 being capable of being in both the straight configuration 20 and the folded assembly configuration 30 is that the straight configuration 20 can be used for transportation and the folded assembly configuration 30 can be used for assembly. FIG. 4 shows several buoyancy modules 10 in the straight configuration 20 for transportation within a shipping container 400. The shipping container 400 shown in FIG. 4 contains 24 buoyancy modules 10, each comprising 20 sub-modules 100. Each of the 24 buoyancy modules 10 can form a closed buoyancy module structure 31. This is a significant improvement in storage efficiency compared to the rigid, previously known buoyancy module 1 shown in FIG. 5, which is packaged in a shipping container 400 having a similar size to that shown in FIG. 4. In FIG. 5, only 10 closed buoyancy module structures are positioned within the shipping container 400, compared to 24 in FIG. 4. Packaging efficiency can be much greater than that shown when comparing FIGS. 4 and 5. [Explanation of symbols]

[0052] 1. Prior art buoyancy module 10 Buoyancy Module 20 Linear configuration of buoyancy module 30 Buoyancy module folded assembly configuration 31 Buoyancy module closed structure 100 submodules 100a First End Sub-Module 100b Second end sub-module 100c: Submodule adjacent to the first end submodule 101 Outer surface 102 Outer edge 103 Inner surface 104 inner edge 105 Inner surface recess 200 Clamping System 300 External structure 400 shipping boxes w Width of the buoyancy module h Height of the buoyancy module / submodule, distance between the inner and outer surfaces l Buoyancy module length wo outer surface width lo Length of outer edge wi Width of the inner surface li Outer edge length sd separation distance lr Recess length

Claims

1. A buoyancy module (10) for use in the sea, comprising a plurality of sub-modules (100), Each of the sub-modules (100) extends between an outer surface (101) and an inner surface (103), the outer surface (101) having two outer edges (102), the distance between the two outer edges (102) defining an outer surface width (wo), the inner surface (103) having two inner edges (104), the distance between the two inner edges (104) defining an inner surface width (wi), the inner surface width (wi) being smaller than the outer surface width (wo); the plurality of sub-modules (100) are arranged adjacent to one another such that adjacent sub-modules (100) are connected or connectable to one another along their respective abutting outer edges (102) to form the buoyancy module (10); The buoyancy module (10) - a linear configuration (20), wherein the sub-modules (100) are oriented in the same direction such that the outer edges (102) of the sub-modules (100) extend substantially in the same plane, the buoyancy module (10) constitutes a substantially flat structure, the distance between the inner edges (104) of two adjacent sub-modules (100) defines a separation distance (sd), and the sub-modules are molded or connected together to form a unitary buoyancy module (10); - a folded assembly form (30) in which adjacent sub-modules (100) are inclined towards each other so that said separation distance (sd) is eliminated or at least reduced, and said buoyancy module (10) constitutes a structure resembling a cylinder or a polygonal prism or at least a part of such a structure; The buoyancy module (10) is configured to take at least two different forms, including:

2. 2. A buoyancy module (10) as described in claim 1, wherein the two end sub-modules (100a, 100b), which are the sub-modules (100) furthest from each other and which are connected to only one other sub-module (100) in the linear configuration (20), are connected to each other in the assembled configuration (30), thereby forming a closed structure (31) resembling a cylinder or a polygonal prism.

3. A buoyancy module (10) as described in claim 1, wherein two end sub-modules (100a, 100b), which are the sub-modules (100) furthest from each other and which are connected to only one other sub-module (100) in the linear configuration (20), are connected to end sub-modules of one or more other buoyancy modules (10) in the assembled configuration (30), whereby two or more buoyancy modules (10) together form a closed structure (31) resembling a cylinder or a polygonal prism.

4. 4. A buoyancy module (10) according to claim 2 or 3, wherein the two end sub-modules (100a, 100b) connected together in the assembled configuration (30) are directly connected together.

5. 5. A buoyancy module (10) as described in claim 4, wherein in the assembled configuration (30) the directly connected end sub-modules (100a, 100b) are not connected together by the use of additional parts such as cords or the like.

6. 6. A buoyancy module (10) according to any one of claims 1 to 5, wherein adjacent sub-modules (100) are directly connected along their respective abutting outer edges (102).

7. A buoyancy module (10) according to any one of claims 1 to 6, wherein the outer edge (102) is substantially straight.

8. A buoyancy module (10) according to any one of claims 1 to 7, wherein the inner edge (104) is substantially straight.

9. A buoyancy module (10) according to any one of claims 1 to 8, wherein the outer surface (101) is substantially planar.

10. A buoyancy module (10) according to any one of claims 1 to 9, wherein the inner surface (103) is substantially planar.

11. 11. A buoyancy module (10) according to any one of claims 1 to 10, wherein the buoyancy module (10) comprises more than four sub-modules (100), for example more than five sub-modules (100), for example more than ten sub-modules (100), for example more than fifteen sub-modules (100), for example twenty sub-modules (100).

12. 12. A buoyancy module (10) according to any one of claims 1 to 11, wherein the length (lo) of the outer edge (102) is greater than the length (li) of the inner edge (104), for example by at least 20% greater, for example by at least 30% greater, for example by at least 40% greater.

13. 13. A buoyancy module (10) according to any one of claims 1 to 12, wherein the maximum distance between the outer surface (101) and the inner surface (103) defines a height (h) of the buoyancy sub-module (100), and wherein the length (li) of the inner edge (104) is at least 50%, such as at least 75%, for example at least 100%, such as at least 125%, for example at least 150% greater than the height (h).

14. A buoyancy module (10) according to any one of claims 1 to 13, wherein the maximum distance between the outer surface (101) and the inner surface (103) is between 0.25m and 2.5m, for example between 0.5m and 1.5m.

15. 15. A buoyancy module (10) according to any one of claims 1 to 14, wherein the inner surface width (wi) is at least 10%, such as at least 20%, for example at least 30%, such as at least 40%, for example at least 50%, for example at least 60% smaller than the outer surface width (wo).

16. 16. A buoyancy module (10) according to any one of claims 1 to 15, wherein the inner surface (103) has a centrally positioned recess (105) extending perpendicular to the inner edges (104) of each sub-module (100) from one inner edge (104) to the other inner edge (104).

17. 17. A buoyancy module (10) according to claim 16, wherein the centrally positioned recess (105) in the inner surface (103) has a recess length (lr) that is at least 10%, such as at least 20%, for example at least 30%, such as at least 40%, for example at least 50%, for example at least 60% greater than the length (l i ) of the inner edge (104).

18. 18. A system comprising one or more buoyancy modules (10) according to any one of claims 1 to 17 and a clamping system (200) around which the buoyancy modules (10) are positioned in the assembled configuration (30), wherein the clamping system (200) is configured to be positioned around and secured to an external structure selected from a subsea pipe, a subsea cable, a subsea riser, a subsea umbilical, a subsea flowline, a subsea steel catenary riser, an installed buoyancy module, a temporary buoyancy module, a surface buoyancy module or the like.

19. 19. The system of claim 18, wherein the one or more buoyancy modules (10) are buoyancy modules according to claim 16 or 17, and the clamping system (200) is dimensioned and designed to fit into the recess (105) of the sub-module (100).

20. 20. Use of one or more buoyancy modules (10) according to any one of claims 1 to 17, or a system according to claim 18 or 19, in said assembled form (30), positioned around an external structure (300) selected from a subsea pipe, a subsea cable, a subsea riser, a subsea umbilical, a subsea flowline, a subsea steel catenary riser, an installed buoyancy module, a temporary buoyancy module, a surface buoyancy module or the like, for lifting said external structure.

Images