Patent Application
20250002122
This invention relates generally to offshore floating platforms, and more particularly to a floating platform structure assembled from floating platform modules having a threefold symmetrical shape.
As the population of the world increases and large cities expand over crowded shores, offshore platforms have become an acceptable location for strategic and commercial activities. In particular, offshore platforms can be used for a variety of applications, such as offshore islands that may support industrial buildings and dwelling houses, deep-water drilling equipment for scientific purposes, oil and gas recovery installations, and other facilities for industrial activity and urban life.
In general, offshore platforms are divided into two groups, such as “fixed” platforms and “floating” platforms. Fixed platforms comprise an equipment deck, that is supported above the water by legs that extend down to and are seated on the sea floor. While relatively stable, such fixed platforms are typically limited to shallow waters, e.g., depths of about 50 meters or less.
Floating platforms are typically employed in water depths of 50 meters and greater, and are held in position over the well site by mooring lines or chains anchored to the sea floor. Although floating platforms are more complex to operate because of their greater movement in response to wind and wave conditions, they are capable of operating at substantially greater depths than fixed platforms. Floating platforms are also more mobile, and hence, easier to move to other offshore well sites.
Floating platforms can, for example, be used for offshore deployment of solar panels having photovoltaic (PV) cells that collect light from the sun and convert the incident solar irradiance to electricity. Thus, floating platforms can be used for hosting PV farms which are built at sea, close to the city, where consumption takes place.
Floating platforms having a threefold symmetrical shape are known in the art. Due to the symmetry, such platforms can also be used for building floating offshore structures including many chained individual floating platform modules, thereby providing a large surface area on which solar panels and/or any other infrastructure for industry or leisure can be installed.
For example, U.S. Pat. No. 5,435,262 describes a semi-submersible offshore platform comprising a hull having at least one oil storage tank and a fixed centralized support member. The hull has a peripheral edge. The platform further comprises a deck coupled to the support member and a plurality of stabilizer buoys. Each of the buoys is coupled to the hull and is positioned adjacent the peripheral edge of the hull, whereby the buoys pitch, roll, heave, sway, and surge relative to the hull. Also provided is a system for stabilizing a semi-submersible offshore platform having a submersible hull.
U.S. Pat. No. 6,037,031 describes a platform, breakwater, or endless track including an array of molded cells interconnected by a system of elongate flexible members, such as wire ropes or lines. The molded cells are cast in molds located at overlapping portions of the cables. The molds may be flexible nylon bags having openings for receiving the cables through them and a fill port to receive material. The molds may be retained on cast cells or removed and reused. A buoyant material, such as expanding self-hardening foam is pumped from foam mixing and pumping equipment into the molds to cast the cells for floating on water, although negatively buoyant cells could be cast for some applications. The cells may be cast on site or elsewhere and then transported to the work site.
Despite prior art in the area of offshore floating platforms, there is still a need in the art for further improvement in order to provide a novel floating offshore structure that can be modular, inexpensive, easily constructed, and deployed at sea.
It would be useful to provide a novel floating offshore structure, which can be utilized to support photovoltaic panels (PV) in an offshore environment.
It would also be beneficial to have a floating offshore structure that would be relatively environmentally benign.
The present invention partially eliminates disadvantages of the above referenced techniques and provides a novel floating offshore structure. The floating structure includes one or more floating platform modules having a threefold symmetry.
According to an embodiment of the present invention, each floating platform module includes a set of buoyant prismatic submodules. In turn, each buoyant prismatic submodule includes a core and a reinforcement shell surrounding the core of the buoyant prismatic submodule along its periphery defined by a top base face, a bottom base face, and side faces of said buoyant prismatic submodules. The core of the buoyant prismatic submodule includes a material having a density less than the water density.
The buoyant prismatic submodules are attached to each other, so as to form a threefold symmetrical shape of said at least one floating platform module. According to an embodiment of the present invention, the threefold symmetrical shape of each floating platform module is a hexagonal prismatic shape.
According to an embodiment of the present invention, the buoyant prismatic submodules forming the floating platform module(s) have a rhombic prismatic shape.
According to an embodiment of the present invention, the buoyant prismatic submodules forming the floating platform module(s) have a triangular prismatic shape.
According to an embodiment of the present invention, the set of the buoyant prismatic submodules includes at least one triangular prismatic submodule.
According to an embodiment of the present invention, the set of the buoyant prismatic submodules includes six triangular prismatic submodules.
According to an embodiment of the present invention, the set of the buoyant prismatic submodules includes three rhombic prismatic submodules.
According to an embodiment of the present invention, the set of the buoyant prismatic submodules includes a combination of rhombic and triangular prismatic submodules.
According to an embodiment of the present invention, the buoyant prismatic submodules include an expanded polymer foam. A polymer used in expanded polymer foam can be selected from at least one of polystyrene and polyurethane.
According to an embodiment of the present invention, the buoyant prismatic submodules can include recycled plastic bottles, hollow beads plastic bags and/or natural materials, such as wood.
According to an embodiment of the present invention, the reinforcement shell of the buoyant prismatic submodules includes a concrete material. When desired, the concrete material can be reinforced with a rebar cell and/or alternative grid structure.
According to an embodiment of the present invention, the floating offshore structure includes two or more floating platform modules in a stack of modules arranged one on top of another.
According to an embodiment of the present invention, the floating offshore structure further includes a top reinforcement plate mounted on a plane top surface of the floating platform module formed by the top base faces of the buoyant prismatic submodules.
According to a further embodiment of the present invention, the floating offshore structure also includes a bottom reinforcement plate mounted on a plane bottom surface of the floating platform module formed by the bottom base faces of the buoyant prismatic submodules.
According to an embodiment of the present invention, the floating offshore structure includes a plurality of reinforcement bars mounted on a plane top surface of the floating platform module formed by the top base faces of the buoyant prismatic submodules, and on a plane bottom surface of the floating platform module formed by the bottom base faces of the buoyant prismatic submodules.
According to an embodiment of the present invention, the floating offshore structure includes a set of mooring lines configured for anchoring the floating offshore structure to a seabed.
According to an embodiment of the present invention, the floating offshore structure includes a plurality of floating platform modules.
According to an embodiment of the present invention, the floating offshore structure includes an attachment arrangement for any two adjacent floating platform modules.
According to an embodiment of the present invention, the attachment arrangement includes a plurality of connecting lines between sides of each two adjacent platform modules. The connecting lines have a predetermined length that allows sway motion of the modules. The attachment arrangement also includes damping units tied to the sides of each platform module where it faces another platform, so as to avoid damage of the modules due to their mechanical impact.
The floating offshore structure of the present invention has many of the advantages of the prior art platforms, while simultaneously overcoming some of the disadvantages normally associated therewith.
The floating offshore structure of the present invention has a modular construction that allows building a large platform space with multiple smaller platforms that can be added in steps. It should be noted that the structure can meet rough weather conditions, and less structural stress can occur than on a single platform of similar dimensions. Sub-modular construction of each platform makes it simpler, more manageable, and allows easy transportation on land and assembling at sea.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows hereinafter may be better understood. Additional details and advantages of the invention will be set forth in the detailed description, and in part will be appreciated from the description, or may be learned by practice of the invention.
In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
The principles and operation of the floating offshore structure according to the present invention may be better understood with reference to the drawings and the accompanying description. It should be understood that these drawings are given for illustrative purposes only and are not meant to be limiting. It should be noted that the figures illustrating various examples of the system of the present invention are not to scale, and are not in proportion, for purposes of clarity. The same reference numerals and alphabetic characters are utilized for identifying those components which are common in the floating offshore structure and its components shown in the drawings throughout the present description of the invention. Examples of constructions are provided for selected elements. Those versed in the art should appreciate that many of the examples provided have suitable alternatives which may be utilized.
Referring to
The floating offshore structure 10 includes a floating platform module 11 having a threefold symmetry. The floating platform module 11 includes a set of buoyant prismatic submodules 12.
According to an embodiment of the present invention, each buoyant prismatic submodule 12 includes a core 121, and a reinforcement shell 122 surrounding the core 121 of the buoyant prismatic submodule 12 along its periphery defined by a top base face 123, a bottom base face 124, and side faces 125 of the buoyant prismatic submodule 12. The core 121 of the buoyant prismatic submodule 12 is made from a buoyant material having a density less than the water density. The buoyant prismatic submodules 12 are attached to each other to form a threefold symmetrical shape of the floating platform module 11.
According to an embodiment of the present invention, the core 121 can, for example, be made from an expanded polymer foam. Examples of polymers used in expanded polymer foam include, but are not limited to, polystyrene and polyurethane. In particular, an expanded polystyrene foam, such as Styrofoam™, can be suitable for fabrication of the core 121, however, other materials having density less than the water density are also contemplated.
According to an embodiment of the present invention, the buoyant prismatic submodules can include recycled plastic bottles, hollow beads plastic bags and/or natural materials, such as wood.
Examples of materials suitable for the reinforcement shell 122 include, but are not limited to concrete, a concrete reinforced with a grid cell structure, fibers, metal net, etc.
According to an embodiment of the present invention, the grid cell structure includes a rebar cage (not shown) having a plurality of rebar rods forming a framework of the rebar cage. The rebar rods can, for example, be made from steel and have a bar cross-sectional diameter in the range of about 0.5 cm to 2 cm. The bars in the grid can, for example, be bound to each other by welding, thereby to form a grid weldment structure. Alternatively, the rebar rods can be bound by tying them with steel wires. A size of a grid cell of the weldment structure can, for example, be in the range of about 5 cm to 30 cm. It should be noted that fiber-reinforced plastic rebar can also be used due to the high-corrosion environment of sea water.
In the present description, the term “about” means within a statistically meaningful range of a value. The allowable variation encompassed by the term “about” depends on the particular structure under consideration, and can be readily appreciated by one of ordinary skill in the art. This approximation for the purpose of the present invention can, for example, be interpreted so as to include an error of 20% at least, as long as there is no considerable change in the performance of the floating offshore structure 10 due to the deviation.
According to the embodiment shown in
It should be noted that when desired, the set of the buoyant prismatic submodules 12 forming the floating platform module 11 can includes more than three rhombic prismatic submodules 12. Thus, in order to have a threefold symmetry, the floating platform module 11 can be built from 6, 12, 18 or more rhombic prismatic submodules 12.
As shown in
It should be noted that a combination of rhombic prismatic submodules with triangular prismatic submodules in the floating platform module 11 is also contemplated.
As shown in
It should be noted that the sub-modularity of the floating platform module 11 has several advantages over a monolith structure of a floating platform module that is built from a single piece of a buoyant material. Indeed, instead of having to construct a heavy single piece structure, the present invention teaches to construct several separate submodules that can be assembled together. For example, for a module having 8 m width and 2 m height, and having the whole structure weigh approximately 40 tons, each can weigh approximately 13-14 tons for three rhombic prismatic structures and approximately 6-7 tons for six triangular prismatic structures. Thus, it can be significantly easy to build larger structures by attaching more rhombic and/or triangular prisms together. It should be understood that such a sub-modular structure can easily be assembled in the water. Thus, by using the sub-modularity, a hexagonal prismatic module of 12 m side (and/or greater) can also be easily fabricated. Moreover, if any of these rhombic or triangular prismatic submodules 12 in the floating platform module 11 are damaged or become defective, the defective units can be readily repaired or replaced.
In this case, the entire height of the platform is double the height of the two floating platform modules 11, thereby providing further rigidity to the floating offshore structure. To provide attachment between the upper and lower hexagonal floating platform modules 11, one of the modules 11 can, for example, be bolted, welded or otherwise attached on top of another hexagonal floating platform module 11. It should be noted that when desired, the connection between the upper and lower hexagonal floating platform modules 11 can include semi-cylindrical, cylindrical and/or semi-spherical protrusions arranged at a bottom of the upper module 11 and corresponding grooves and/or recesses matching the protrusions arranged at a top of the lower module 11, similar to the provision described in
Moreover, top and back surfaces formed by top base faces and bottom base faces of the hexagonal floating platform modules 11 that are placed on top of each other can be rougher, when compared to the side faces of the buoyant prismatic submodules 12 forming the hexagonal floating platform modules 11. This feature can also facilitate the connection between the upper and lower hexagonal floating platform modules 11.
It should be understood that, when desired, the floating offshore structure may include more than two floating platform modules in a stack of modules arranged one on top of another.
Examples of materials suitable for the reinforcement plates 41 and 42 include, but are not limited to, steel and reinforced concrete. It should be understood that provision of the reinforcement plates 41 and 42 can provide further rigidity to the floating offshore structure.
A method of fabrication of the buoyant prismatic submodule 12 includes providing a mould having inner dimensions equal to the outer dimension of the prismatic submodule 12. The mould can, for example, be made of wood or another suitable material.
As described hereinabove, the buoyant prismatic submodules 12 of the floating offshore structure 10 described herein above are built from a buoyant inner core 121 surrounded by a reinforcement outer shell 122. In order to fabricate the reinforcement outer shell 122, first, a layer of the desired thickness of concrete is poured on the bottom of the mould. According to an embodiment, the concrete can be reinforced either by introducing composite fibres in the mix, or by placing composite or steel rods or a rebar net within the concrete bulk of this newly created reinforcement layer. The rods, fibres, or rebar net can extend beyond the bottom layer on the sides, in the reinforcement layer, to form the concrete sides of the reinforcement shell of the buoyant prismatic submodules 12.
According to an embodiment of the present invention, once the bottom of the mould is poured, in order to make up the buoyant inner core 121, a pre-cut solid Styrofoam piece can be introduced to fill the desired volume in the mould.
According to another embodiment of the present invention, the core is formed from several stages. First, several solid pieces made of a plastic, cardboard, plywood, Styrofoam, or other material forming the desired dimensions of the core, are placed in the mould to form the shell of the desired outer dimensions of the core. Then, an expanded polymer foam (e.g., Styrofoam™ or other material having a density lower than the water density) is sprayed into the mould to form the desired rigid inner core.
The aim of the core is to provide buoyancy. It should be noted that the core should not be a hollow volume, because this would pose a danger if there were water ingress over the years through, for example, a crack in the wall of the module.
According to an embodiment of the present invention, when spray foam is used, recycled bottles or other hollow objects could be introduced in the volume of the core. This would not only be a good way of finding an alternate use for some recycled material, but would also reduce the volume of spray foam needed, and thus the manufacturing cost.
According to a further embodiment of the present invention, the core can be made of recycled plastic, which would have continuous outer walls, but is made of many compartments (e.g., a honeycomb), thus minimizing the danger of significant water ingress in the eventuality of a crack in the outer walls.
Likewise, the core can be formed of plastic or other material, first, to form a rigid shell for the core having moderately thick walls. The hollow inside volume of the shell can then be filled with empty plastic bottles or other containers, thereby eliminating the risk of significant amounts of water filling the core space, since a significant portion of the space is occupied by containers.
Referring to
According to an embodiment of the present invention, the mooring cleats 113 include metal parts configured to hold the mooring lines 112 attached to the mooring cleats 113 such as to allow turning and slippage of the mooring lines 112. The mooring cleats 113 can, for example, be embedded in the concrete of the reinforcement shell (122 in
According to an embodiment of the present invention, multi-point mooring systems are used that moor the floating support structure 10 to the seabed using multiple mooring lines. The floating support structure 10 is positioned in a fixed heading location, which is determined by the sea and weather conditions. The symmetrical arrangement of anchor points 114 helps to keep the floating support structure 10 on its fixed heading location.
In the mooring configuration shown in
Each mooring line 112 can, for example, be made of a chain and/or rope. A length of the mooring lines can, for example, be between three and six times the water depth. A free hanging catenary mooring configuration is shown in
The floating support structure 10 is anchored to the seabed 115. The floating support structure 10 can, for example, be rigidly fixed to the seabed 115 at the anchor points 114 through structural elements including a set of driven piles (not shown) that can be inserted in the seabed 15. Likewise, the floating support structure 10 can be fixed to the seabed 115 through ballasts resting on the seabed, or by anchors, depending on the type of the seabed and on the depth of the installation site.
Referring to
As shown herein above in
It should be understood that floating support structure 10 can be used for a host of other purposes-anything that could benefit from having a platform at sea, especially with the availability of power. Examples of applications of the floating support structure 10 include, but are not limited to, desalination, energy storage, leisure, boating, scientific studies, environmental monitoring, etc.
Referring to
For example, when a single hexagonal prismatic module 11 provides an area of about 42 m2 to 166 m2, a platform built by seven such modules can provide an area of about 290 m2 to 1160 m2.
Referring to
According to an embodiment of the present invention, the attachment arrangement 91 includes chains and/or ropes, having a predetermined length that allows sway motion of the modules. The attachment arrangement 91 also includes damping units 93, such us tires or similar bumping objects, tied to the sides of each platform module where it faces another platform, to avoid damage of the modules due to their mechanical impact. A ratio of the dimension of floating platform modules 11 and the distance between the modules 11 can, for example, be in the range of 0.5 meters to 2 meters.
It should be understood that the process of building large platforms can be repeated for any number of the floating platform modules 11.
It should be understood that providing a floating offshore structure, including many chained individual platform modules, accomplishes the goal of getting a large surface area on which solar panels and/or any other infrastructure may be used, for industry or leisure. Mooring would still be on only some of the platforms, since the other platforms are held in place by their attachment to other platforms.
Moreover, given that the floating platform modules 11 of the floating support structure 10 absorb wave energy and therefore partially dampen incoming waves, large partially sheltered spaces could be created in the middle of an installation of several floating platform modules 11 or away from the incoming wave direction. These spaces could be used for large platforms for specific uses, aquaculture, leisure, or other uses.
As such, those skilled in the art to which the present invention pertains, can appreciate that while the present invention has been described in terms of preferred embodiments, the concept upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, systems and processes for carrying out the several purposes of the present invention.
Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
Finally, it should be noted that the word “comprising” as used throughout the appended claims is to be interpreted to mean “including but not limited to”.
It is important, therefore, that the scope of the invention is not construed as being limited by the illustrative embodiments set forth herein. Other variations are possible within the scope of the present invention as defined in the appended claims. Other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to different combinations or directed to the same combinations, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the present description.
| Number | Date | Country | Kind |
|---|---|---|---|
| 286961 | Oct 2021 | IL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IL2022/051044 | 10/2/2022 | WO |
