Flexible storage

Abstract

A storage system for storing a fluid in an underwater environment is disclosed. The storage system comprises an outer casing and a first bladder. The outer casing comprises: an outer layer arranged to form a cavity; and an inner layer, located within the cavity formed by the outer layer, and defining an interior surface of the outer casing; wherein the cavity comprises a first cavity and a second cavity; wherein the first cavity is formed between the outer layer and the inner layer; wherein the second cavity is defined by the interior surface of the outer casing; and wherein the outer casing is configured to receive and hold a first substance in the first cavity. The first bladder is suitable for storing the fluid to be stored; and the first bladder is configured to receive and hold a second fluid, wherein the first bladder is located within the second cavity.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a storage system for storing a fluid and a method of providing a storage system for storing a fluid.BACKGROUND

[0002] Presently, gas is mainly stored in two different systems: a fixed volume container (e.g., a tank), or a variable volume container (e.g., a flexible container). In a tank, the maximum mass of a fluid that can be stored is defined by the volume of the tank and the maximum allowable pressure applied over the fluid. Tanks are usually cylindrical, made of steel or composite material.

[0003] In a flexible container, the maximum mass of a fluid that can be stored is defined by the maximum possible displacement of the boundary limits of the container, at a given pressure, usually in equilibrium with the environmental pressure. Flexible containers may be made of telescopic cylinders, or flexible elements, such as rubber membranes, to provide variations in internal volume and pressure equilibrium with the external environment.

[0004] Often, there is a desire to store fluids underwater. When such systems are deployed underwater, one or more tanks can be installed in a single system, or one or more flexible containers are deployed within a system.

[0005] There are numerous problems associated with providing storage systems, particularly in underwater environments. For example, the systems may be cumbersome resulting in difficulty in transportation and installation of the systems, especially when the system is being installed underwater and thus the system may need to be transported far from a manufacturing facility. Furthermore, when providing the systems underwater, they need to be well anchored to the seabed such that they do not float due to the buoyancy of the fluid being stored. Moreover, the systems need to be well protected from objects dropped from above (regardless of where the storage system is deployed) such that the storage system maintains its integrity and leaks do not arise.

[0006] The present disclosure aims to address at least one of the problems associated with storing fluids in storage systems, particularly when the fluid is intended to be stored underwater.SUMMARY

[0007] According to embodiments of the present disclosure, a storage system for storing a fluid (e.g., liquid and / or gas) in an underwater environment is provided. The storage system comprises an outer casing and a first bladder;

[0008] wherein the outer casing comprises:

[0009] an outer layer arranged to form a cavity; and

[0010] an inner layer, located within the cavity formed by the outer layer, and defining an interior surface of the outer casing;

[0011] wherein the cavity comprises a first cavity and a second cavity;

[0012] wherein the first cavity is formed between the outer layer and the inner layer;

[0013] wherein the second cavity is defined by the interior surface of the outer casing; and

[0014] wherein the outer casing is configured to receive and hold a first substance in the first cavity; and

[0015] wherein the first bladder is suitable for storing the fluid to be stored; and

[0016] wherein the first bladder is configured to receive and hold a second fluid, wherein the first bladder is located within the second cavity.

[0017] Embodiments as disclosed herein thus provides an improved storage system for storing a fluid (e.g., liquid and / or gas) which is particularly suitable for use in underwater environments. The outer casing of the storage system is thus configured to provide a protective casing for the first bladder such that the first bladder is protected from damage (e.g., piercing or tearing damage from the force of dropped objects), which in turn improves the integrity of the storage system and reduces instances of leakage and loss of the stored fluid.

[0018] In some embodiments, the protective advantage offered by the outer casing may be (e.g., partially or solely) attributed to the first substance received and held within the first cavity. For example, the first substance may be selected to impart desirable characteristics to the outer casing, i.e., strength and resistance, such that the kinetic energy of a falling impact is (at least partly) absorbed by the outer casing without damaging the first bladder.

[0019] The outer casing also provides the advantageous effect of adding weight to the storage system which can counteract the buoyancy of the stored gas and thus (at least partially) contribute to anchoring the storage system in an underwater environment. In some embodiments, anchorage of the storage system may be (e.g. substantially) entirely effected by the outer casing. In embodiments, the anchorage effect is primarily attributable to the weight provided by the first substance held in the first cavity.

[0020] In some embodiments, the first substance has a density greater than the density of water, e.g., a density greater than about 1 g / cm3 for pure water at approximately 4° C. or 1.03 g / cm3 for sea water. For example, the density of the first substance may be greater than 1.05 g / cm3, greater than 1.1 g / cm3, greater than 1.2 g / cm3, greater than 1.3 g / cm3, greater than 1.4 g / cm3, greater than 1.5 g / cm3, greater than 1.6 g / cm3, greater than 1.7 g / cm3, greater than 1.8 g / cm3, greater than 1.9 g / cm3, greater than 2 g / cm3, or greater than 2.5 g / cm3. In some embodiments, the density of the first substance may be between 1 g / cm3 to 10 g / cm3, between 1.1 g / cm3 and 5 g / cm3, between 1.5 g / cm3 and 2.5 g / cm3, or between 2 g / cm3 and 2.5 g / cm3.

[0021] In some embodiments, the first substance is a fluid. The first substance being a fluid provides the advantage that the first substance may be easily input (e.g., inserted or injected) into the first cavity by any suitable and desirable means by taking advantage of the fluid characteristics. For example, the first substance could be injected or poured into the first cavity such that it adopts the shape of first cavity as defined by the outer and inner layers.

[0022] In some embodiments, the first substance is a curable fluid. For example, the first substance may be a fluid when it is input (e.g., inserted or injected) into the first cavity and then cured to a solid such that when the storage system is installed, the first substance is in a solid state. The curable fluid may be cured via any suitable and / or desirable means such as by heating, drying or irradiating the outer casing. In some embodiments, the curable fluid is concrete.

[0023] In some embodiments, the first substance is a solid having bulk fluid characteristics (i.e., a pseudo-fluid). For example, the first substance may be made up of a plurality of small solid units, e.g., a granular material. For example, the first substance may comprise sand. For example, the first substance may comprise metal, e.g., metal dust.

[0024] The outer layer (and / or inner layer) of the outer casing may contribute to the protection imparted by the outer casing by themselves being made from hard-wearing (i.e., strong and / or resistant) materials. For example, the materials used for the outer casing may lessen the effective force experienced by the bladder (i.e., the force transferred through the system) due to an object being dropped onto the system by the outer (and / or inner) layers being made from a material with high tensile strength. In some embodiments, the outer layer and / or the inner layer are made from a material comprising a textile fabric.

[0025] In some embodiments, the outer layer defines at least part of an exterior surface of the storage system. In some embodiments, the outer casing (substantially entirely) encloses the second cavity such that the first bladder is protected from (substantially) all sides. In other embodiments, the outer casing provides at least the exterior surface of the storage system that engages the floor (e.g., the ground, the seabed, or the river bed) and the exterior surface which provides protection from objects being dropped from (e.g., directly) above. In other words, in some embodiments, the outer casing does not fully enclose the second cavity and / or the first bladder.

[0026] In some embodiments, the outer casing is tubular in shape. For example, the outer casing comprises at least one wall that defines a tubular cavity. Within the meaning of the present disclosure, a tubular shape (e.g., a tube) is a hollow structure comprising at least one wall (e.g., formed by the outer casing) that encloses a cavity (e.g., the second cavity) which extends from one end of the tube to the other end of the tube to effectively provide a passageway therethrough. The tube may have a circular or a non-circular cross-section (e.g., the cross-section in the plane perpendicular to the walls is circular or non-circular, e.g., the walls of the tube define a non-circular cavity shape). In some embodiments, the non-circular cross-section may be a regular (e.g., ovular, square, or rectangular) or irregular shape (e.g., a rectangle with rounded edges, a flattened over, or any other modified shape).

[0027] In some embodiments, the (e.g., tubular) outer casing comprises two ends. In some embodiments, the outer layer and the inner layer are fixedly attached together at at least one of the two ends such that the first substance may be input (e.g., inserted or injected) into the first cavity and held therein. In some embodiments, the outer casing is (e.g., partially) open at one end such that the outer casing comprises an opening at one end to allow input (e.g., insertion or injection) of the first substance into the first cavity.

[0028] The outer casing may be formed in any suitable and / or desirable way. For example, the outer casing may be formed by two separate sheets of material (wherein each sheet forms one of the outer layer and the inner layer) which are attached together to provide the (e.g., tubular) outer casing.

[0029] In some embodiments, the first cavity is continuous (e.g., in at least one direction). For example, the first cavity is unitary. For example, the first cavity continuously extends (e.g., without interruption) from the outer layer to the inner layer and / or from a first end of the (e.g., tubular) outer casing to a second end of the (e.g., tubular) outer casing. As such, when the continuous first cavity receives the first substance, the first substance adopts the shape of the continuous first cavity (e.g., the first substance forms a unitary shape). In such embodiments, the thickness of the first cavity (and thus the thickness of the first substance contained therein) is substantially uniform across the outer casing.

[0030] In some embodiments, the first cavity comprises at least two (e.g., a plurality of) discrete cavity segments. In some embodiments, the cavity segments are formed by (e.g., fixedly) attaching the outer layer to the inner layer at at least one (e.g., a plurality of) attachment site(s) between the two ends of the outer casing. For example, the outer and inner layers of the outer casing may be fixedly attached at each end (i.e., to prevent leakage of the first substance) and then attached at an attachment site located at a position between each end of the outer casing.

[0031] Put another way, in some embodiments, the first cavity is discontinuous (e.g., split into discrete cavity segments). For example, the first cavity discontinuously extends from the outer layer to the inner layer and / or discontinuously extends from a first end of the (e.g., tubular) outer casing to a second end of the (e.g., tubular) outer casing and / or discontinuous in at least one direction. For example, if a cross-section is taken of the storage system, the first cavity may be discontinuous in the plane parallel to the cross-sectional plane and (substantially) continuous in the plane perpendicular to the cross-sectional plane, e.g., from one end of the storage system to the other end of the storage system. As such, when the first cavity receives the first substance, the first substance adopts the shape of the discontinuous shape of the first cavity. In such embodiments, the thickness of the first cavity (and thus the thickness of the first substance contained therein) is non-uniform across the outer casing.

[0032] In some embodiments, the at least one attachment site is linear. For example, the attachment site comprises a length and a width over which the outer layer and the inner layer are attached together, wherein the length is greater than the width. In embodiments, the length of the attachment site is smaller than the overall length (i.e., from end to end) of the (e.g., tubular) casing. In some embodiments the attachment site is continuous (i.e., the outer and inner layer are fixed together along the entire length of the attachment site). In some embodiments, the attachment site is discontinuous (i.e., the outer and inner layer are not fixedly attached along the entire length of the attachment site).

[0033] In some embodiments, the outer layer and the inner layer are fixedly attached together at a plurality of attachment sites (e.g., between the two ends). In some embodiments, at least two of the plurality of attachment sites may be arranged on a common axis (e.g., the longitudinal axes of at least two attachment sites lie on the same common axis) such that at least two attachment sites together form a discontinuous line. In some embodiments, the common axis is parallel to the axis defined from one end of the outer casing to the other end of the outer casing (i.e., the common axis runs along the (e.g., tubular) outer casing). In some embodiments, the common axis is perpendicular to the axis defined from one end of the outer casing to the other end of the outer casing (i.e., the common axis runs around the (e.g., tubular) outer casing). It will be appreciated that two linear attachment sites arranged along a common axis with a space arranged between the two attachment sites effectively corresponds to a single discontinuous linear attachment site.

[0034] In some embodiments, the plurality of attachment sites are arranged such that the first cavity is divided into a plurality of (e.g., substantially evenly sized) discrete cavity segments. In some embodiments, each of the cavity segments are fluidly connected to at least one other cavity segment by a channel which allows the first substance to flow between the connected cavity segments. In some embodiments, the channels are formed at the location of spaces between two attachment sites or discontinuities within an attachment site.

[0035] It will be appreciated that providing channels between the cavity segments means that the first substance may be input (e.g., inserted or injected) into the entire first cavity via a single opening (rather than requiring each segment to be filled separately). In embodiments, the channels are suitably sized such that, when the first substance is a curable fluid, upon movement of the outer casing (e.g., in response to an underwater current or when an object is dropped on the outer casing) results in the cured fluid is subject to breakage. This then allows the cavity segments to move independently of each other. In other words, the outer casing is articulated with a flexible joint (e.g., formed by the attachment site(s) and breakage of the solidified (e.g., cured) first substance in the channels) between two cavity segments. This articulation further allows the outer casing to better absorb external forces (e.g., dropped objects) without damaging the first bladder. The articulation also provides the advantage of allowing the outer casing to adapt to the shape of the first bladder.

[0036] In some embodiments, the plurality of attachment sites are arranged in a regular pattern running along (e.g., end to end) and / or across (e.g., around or circumferentially) the outer casing. In an embodiment, the regular pattern comprises a plurality of linear attachment sites that form a plurality of (e.g., discontinuous or continuous) parallel lines running along (e.g., from end to end) the outer casing, wherein the outer layer and inner layer are attached along the length of each of the parallel lines such that a cavity segment is provided between the parallel lines.

[0037] It will be appreciated that the pattern of attachment sites may provide a suitable and / or desirable array of cavity segments. For example, the attachment sites may be arranged such that the outer casing is substantially quilted.

[0038] The outer layer and the inner layer may be attached together in any suitable and / or desirable way at the attachment sites. In some embodiments, the outer layer and the inner layer are glued together at the attachment sites. In some embodiments, the outer layer and the inner layer are stitched together at the attachment sites.

[0039] As discussed above, the use of a bladder (e.g., a flexible or variable container) provides the advantage that a variable mass of fluid (e.g., gas and / or liquid) may be effectively stored. In some embodiments, the first bladder is arranged to provide a first inflated shape when the first bladder comprises (e.g., holds) a second fluid. In some embodiments, the first inflated shape is adopted when the bladder comprises a pre-defined mass of fluid. For example, the pre-defined mass of fluid may be selected such that the first bladder is expanded to a point (e.g., close to but) below the elastic limit of the first bladder. It will be appreciated that the elastic limit is the furthest point at which a material (e.g., the (material of) the first bladder) can be stretched, deformed, or expanded and still be able to return to its previous shape (i.e., the deformation is not permanent). As such, when at or close to the elastic limit, the first bladder is able to contain the maximum amount of fluid whilst still retaining elastic properties. The first bladder may therefore be considered to be “full” when it adopts the first inflated shape (i.e., near to the elastic limit).

[0040] It will be appreciated that, (e.g., if the first cavity is empty or filled with a fluid substance in a fluid state) as the first bladder is filled with the second fluid, the first bladder will expand and displace the outer casing. As such, the outer casing is arranged to adopt a shape complementary to the first inflated shape (e.g., when the first cavity is empty or contains a fluid). In some embodiments, the first cavity is only filled with the first substance after the first bladder has been filled with the second fluid to provide the first inflated shape, such that the outer casing (e.g., the first cavity) adopts a shape complementary to the shape of the first bladder. Then, if the first is a curable fluid, as long as the first substance is cured whilst the first bladder is in the first inflated shape, the first substance will be cured into the shape complementary to the first inflated shape. As such, the outer casing may maintain the complementary shape even after the first bladder has been (at least partially) deflated. Alternatively, it may be envisaged that the first cavity may comprise a curable fluid in its fluid state prior to input of the second fluid into the first bladder, wherein the curable fluid is then cured only after the first inflated shape has been attained. As such the outer casing may maintain the complementary shape even after the first bladder has been (at least partially) deflated.

[0041] As such, in embodiments, the outer casing adopts a complementary shape to the first inflated shape of the first bladder. Similarly, when the first cavity comprises a curable fluid in its cured state, the outer casing (substantially) maintains a shape complementary to the first inflated shape, even when the bladder no longer adopts the first inflated shape. For example, the outer casing is a self-supported structure taking the shape complementary to the first inflated shape of the bladder.

[0042] In some embodiments, the second fluid is a liquid or a gas. In some embodiments, the second fluid may be the fluid (e.g., liquid or gas) to be stored. In some embodiments the second fluid comprises (e.g., consists of) hydrogen gas. In some embodiments the second fluid comprises water (e.g., seawater).

[0043] In some embodiments, the second fluid is a different fluid to the gas to be stored. For example, the second fluid (which is used to fill the first bladder such that the first bladder adopts the first inflated shape) may be water which is then removed (e.g., after the first substance has been cured) and replaced with the fluid (e.g., liquid or gas) to be stored. Thus, in some embodiments, the first bladder may be configured to reversibly receive and hold the second fluid before the second fluid is removed and then the first bladder is configured to receive and store a third fluid (e.g., the fluid to be stored). In other embodiments, the second fluid is the fluid (e.g., gas or liquid) to be stored.

[0044] It will be appreciated that the first inflated shape (and thus the shape complementary to it adopted by the outer casing) is a three-dimensional shape (e.g., the shape of the storage system). In some embodiments, the three dimensional shape is a substantially rectangular prism (e.g., with filleted edges). In some embodiments, the three dimensional shape is substantially a mattress shape.

[0045] In some embodiments, when the first bladder adopts the first inflated shape and the first cavity comprises a cured first substance, the outer casing has a length dimension, a width dimension and a height dimension. In some embodiments, the length dimension is between 50 m and 2000 m, e.g., 100 m and 1500 m, between 300 m and 1000 m, between 500 m and 800 m, or approximately 800 m. In some embodiments, the width dimension is between 0.5 m and 100 m, e.g., between 1 m and 80 m, between 5 m and 50 m, between 10 m and 30 m, or approximately 20 m. In some embodiments, the height dimension (which may be equal to the width dimension if the cross-section of the outer casing is circular) is between 0.01 m and 100 m, 0.05 m and 80 m, between 0.1 m and 50 m, between 0.25 m and 25 m, between 0.5 m and 5 m, or approximately 0.5 m.

[0046] In some embodiments, the first bladder is arranged such that it extends through the second cavity when it adopts the first inflated shape or is filled with the fluid to be stored. In some embodiments, when the first bladder adopts the first inflated shape, the first bladder is only be partly located within the second cavity, i.e., part of the first bladder extends out of the second cavity defined by the outer casing. In some embodiments, at least 50% of the (e.g., volume of) the first bladder is located within the second cavity when the first bladder adopts the first inflated shape. As such, 50% of (e.g., volume of) the first bladder is protected by the outer casing when the first bladder adopts the first inflated shape. In some embodiments, at least 60% (e.g., at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) of the (e.g., volume of) the first bladder is located within the second cavity when the first bladder adopts the first inflated shape.

[0047] In some embodiments, when the first bladder contains the fluid (e.g., gas or liquid) to be stored, the first bladder is only be partly located within the second cavity, i.e., part of the first bladder extends out of the second cavity defined by the outer casing. In some embodiments, at least 50% of the (e.g., volume of) the first bladder is located within the second cavity when the first bladder contains the fluid to be stored. As such, 50% of (e.g., volume of) the first bladder is protected by the outer casing when the first bladder contains the fluid to be stored. In some embodiments, at least 60% (e.g., at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) of the (e.g., volume of) the first bladder is located within the second cavity when the first bladder contains the fluid to be stored.

[0048] In some embodiments, the storage system further comprises a second bladder, wherein the second bladder is located within the second cavity. The second bladder is configured to receive and hold a third fluid (e.g., liquid or gas). In some embodiments, the second fluid and the third fluid are different. In some embodiments, the second fluid is a fluid (e.g., water or seawater) used to provide the first inflated shape of the first bladder, and the third fluid is the fluid (e.g., gas or liquid) to be stored in the second bladder. Providing two bladders offers the advantage that the bladder being used to store the fluid (e.g., gas or liquid) to be stored does not get initially contaminated with a different fluid.

[0049] For example, in a storage system comprising only one bladder (i.e., the first bladder), the first bladder may first be filled with the second fluid (e.g., water) to provide the first inflated shape. Then, after the first substance may have been cured, the second fluid is removed and replaced with the fluid to be stored (e.g., the third fluid). When the storage system is being installed underwater, using water as the second fluid is very convenient because water is naturally present and thus there are substantially no costs or significant logistical considerations required to provide the second fluid to the system. However, water is a very sticky substance, and thus, if water is used as the second fluid it may be nearly impossible to remove all of water from the second bladder before inputting (e.g., inserting or injecting) the third fluid (e.g., the fluid to be stored). The fluid to be stored will therefore be contaminated. Providing a second bladder reduces (or eliminates) this contamination as the two bladders are each used for a distinct and separate purpose.

[0050] In some embodiments, the second bladder comprises the third fluid when the first bladder is substantially empty. In some embodiments, the first bladder comprises the second fluid contemporaneously with the second bladder comprising the third fluid. In such embodiments, when the second bladder comprises a third fluid, the first bladder does not adopt the first inflated shape. Indeed, in some embodiments, the first inflated shape is made as a summation of the shapes adopted by the first bladder and the second bladder at (or close to, but not greater than) the elastic limit. In embodiments, the first bladder adopts the first inflated shape when the second bladder is (e.g., substantially or substantially completely) empty. Then the first bladder is (at least partially) emptied of the second fluid before the third fluid is introduced into the second bladder.

[0051] In some embodiments, the first bladder and the second bladder have substantially identical characteristics, i.e., they may be made from the same materials and have the same elastic limits. In some embodiments, the first and second bladders may have different characteristics, i.e., they may be made from different materials and thus may have different elastic limits.

[0052] In some embodiments, the outer casing further comprises a connecting formation configured to connect the outer casing to a first substance source. The connecting formation thus provides a means by which the first substance may be input (e.g., inserted or injected) into the first cavity. In some embodiments, the connecting formation allows fluid communication between the first cavity and a source of the first substance. In some embodiments, the connecting formation comprises a pipe or line. In some embodiments, the connecting formation comprises a (e.g., one-way) valve to control the flow of the first substance into the first cavity. In some embodiments, the connecting formation comprises a remotely operated underwater vehicle connection.

[0053] In some embodiments, the first bladder comprises a connecting formation configured to connect the first bladder to a second fluid source. The connecting formation thus provides a means by which the second fluid may be input (e.g., inserted or injected) into the first bladder. In some embodiments, the connecting formation allows fluid communication between the first bladder and a source of the second fluid. In some embodiments, the connecting formation comprises a pipe or line. In some embodiments, the connecting formation comprises a (e.g. two-way) valve to control the flow of the second fluid into and / or out of the first bladder. In some embodiments, the connecting formation comprises a remotely operated underwater vehicle connection.

[0054] In some embodiments, the second bladder comprises a connecting formation configured to connect the second bladder to a third fluid source. The connecting formation thus provides a means by which the third fluid may be input (e.g., inserted or injected) into the second bladder. In some embodiments, the connecting formation allows fluid communication between the second bladder and a source of the third fluid. In some embodiments, the connecting formation comprises a pipe or line. In some embodiments, the connecting formation comprises a (e.g., two-way) valve to control the flow of the second fluid into and / or out of the second bladder. In some embodiments, the connecting formation comprises a remotely operated underwater vehicle connection.

[0055] In embodiments of the present disclosure, a method of providing a storage system for storing a gas is provided. The method comprises the steps of:

[0056] providing a storage system comprising:

[0057] an outer casing and comprising:

[0058] an outer layer arranged to form a cavity; and

[0059] an inner layer, located within the cavity formed by the outer layer, and defining an interior surface of the outer casing;

[0060] wherein the cavity comprises a first cavity and a second cavity;

[0061] wherein the first cavity is formed between the outer layer and the inner layer;

[0062] wherein the second cavity is defined by the interior surface of the outer casing; and

[0063] wherein the outer casing is configured to receive and hold a first substance in the first cavity; and

[0064] a first bladder suitable for storing the fluid to be stored, wherein the first bladder is configured to receive and hold a second fluid, wherein the first bladder is located within the second cavity;

[0065] positioning the storage system in the desired environment;

[0066] inputting the second fluid into the first bladder such that the first bladder adopts a first inflated shape; and

[0067] inputting a first substance into the first cavity such that, when the first bladder adopts the first inflated shape, the outer casing adopts a complementary shape to the first inflated shape.

[0068] It will be appreciated that the storage system used in the method of the second aspect corresponds to the storage system of the first aspect. As such, the features and embodiments described above in relation to the first aspect apply directly to the features of the second aspect. In other words, the independent features described above relating to different embodiments of the first aspect are combinable in any suitable combination with the features of method of the second aspect.

[0069] Embodiments of the present disclosure provide a method by which the improved storage system of the first aspect may be installed, even in underwater environments.

[0070] It will be appreciated that the desired environment is the environment in which the fluid (e.g., gas and / or liquid) is to be stored. In some embodiments, the desired environment is an underwater environment such as a riverbed or a seabed.

[0071] In some embodiments, the method comprises positioning (e.g., installing) the storage system in the desired environment before inputting (e.g., inserting or injecting) the second fluid into the first bladder. For example, the method may comprise inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, to provide the first inflated shape after positioning the storage system in the desired environment (e.g., underwater or on a seabed). In some embodiments, the method comprises inflating the first bladder (e.g., at least partially or to provide the first inflate shape) in an underwater environment.

[0072] In some embodiments, the method comprises positioning (e.g., installing) the storage system in the desired environment after inputting (e.g., inserting or injecting) the second fluid into the first bladder. For example, the method may comprise (at least partially) inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, to provide the first inflated shape before positioning the storage system in the desired environment (e.g., underwater or on a seabed). In some embodiments, the method comprises partially inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, before positioning the storage system in the desired environment (e.g., underwater or on a seabed), and then, once the storage system has been positioned, further inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, to provide the first inflated shape.

[0073] In some embodiments, the method comprises positioning (e.g., installing) the storage system in the desired environment before inputting (e.g., inserting or injecting) the first substance into the first cavity. For example, the method may comprise inputting (e.g., inserting or injecting) the first substance into the first cavity after positioning the storage system in the desired environment (e.g., underwater or on a seabed). Thus, in some embodiments, the first cavity does not comprise the first substance when the storage system is positioned in the desired environment (e.g., underwater or on a seabed). In some embodiments, the method comprises inputting (e.g., inserting or injecting) the first substance in an underwater environment.

[0074] In some embodiments, the method comprises positioning (e.g., installing) the storage system in the desired environment after inputting (e.g., inserting or injecting) the second fluid into the first bladder. Thus, in some embodiments, the first cavity comprises the first substance (e.g., in a liquid state or in a cured (e.g., solid) stage) when the storage system is positioned in the desired environment (e.g., underwater or on a seabed). For example, the method may comprise (at least partially) inputting the first substance into the first cavity before positioning the storage system in the desired environment (e.g., underwater or on a seabed). As the first substance adds weight to the storage system, by inserting the first substance into the storage system before positioning the storage system, the additional weight may help the storage system to sink to the bed of an underwater environment.

[0075] In some embodiments, the method comprises (at least partially) inputting (e.g., inserting or injecting) a curable fluid into the first cavity and curing the curable fluid in the first cavity before positioning the storage system in the desired environment (e.g., underwater or on a seabed). In some embodiments, the method comprises (at least partially) inputting (e.g., inserting or injecting) a curable fluid into the first cavity before positioning the storage system in the desired environment (e.g., underwater or on a seabed), and then curing the curable fluid in the first cavity after the storage system has been positioned.

[0076] In some embodiments, the method comprises inputting (e.g., inserting or injecting) the second fluid into the first bladder before inputting (e.g., inserting or injecting) the first substance into the first cavity. For example, the method may comprise inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, to provide the first inflated shape before inputting (e.g., inserting or injecting) the first substance into the first cavity.

[0077] In some embodiments, the method comprises inputting (e.g., inserting or injecting) the second fluid into the first bladder after inputting (e.g., inserting or injecting) the first substance into the first cavity. For example, the method may comprise inflating the first bladder, by inputting (e.g., inserting or injecting) the second fluid, to provide the first inflated shape after inputting (e.g., inserting or injecting) the first substance into the first cavity.

[0078] In embodiments where the first substance is a curable fluid, the method further comprises curing the curable fluid after inflating the first bladder (by inputting (e.g., inserting or injecting) the second fluid) to provide the first inflated shape. For example, the method comprises curing the curable fluid when the first bladder adopts the first inflated shape. In so doing, the first substance is cured in a shape complementary to the first inflated shape such that when the first bladder is deflated, the outer casing maintains that complementary shape. However, it may be possible to cure the curable fluid before inflating the first bladder to provide the first inflated shape if the outer layer is (e.g., sufficiently) articulated such that the outer casing, even after the first substance has been cured, may adapt to the shape of the first bladder as it is inflated to provide the first inflated shape. For example, in an embodiment comprising a plurality of cavity segments and channels provided between the cavity segments, (as described fully with regard to the first aspect,) the force exerted on the outer casing by the first bladder as the first bladder inflates (e.g., expands) may be sufficient to break the solidified fluid in the channels such that the cavity segments can move independently of each other and thus the outer casing is able (by virtue of the articulated joints formed by the broken first substance in the channels and the attachment sites) form a shape complementary to the first inflated shape of the first bladder.

[0079] In some embodiments, the method further comprises replacing the second fluid in the first bladder with a third fluid (e.g., gas and / or liquid). After the second fluid has been replaced (e.g., substantially entirely) with the third fluid, the first bladder adopts a second inflated state. In embodiments, the second fluid is the fluid (e.g., liquid and / or gas) used to inflate the first bladder to form the first inflated shape. In some embodiments, the third fluid is the fluid (e.g., gas) to be stored in the storage system. In some embodiments, when the first substance is a curable fluid, the step of replacing the second fluid in the first bladder with the third bladder occurs after the steps of inputting (e.g., inserting or injecting) the curable fluid into the first cavity and curing the curable fluid in the first cavity.

[0080] In some embodiments, the step of replacing the second fluid comprises removing the second fluid from the first bladder (substantially) entirely before inserting the first bladder with the third fluid (e.g., gas and / or liquid). In some embodiments, the step of replacing the second fluid comprises displacing the second fluid in the bladder with the third fluid (e.g., the first bladder may comprise both the second fluid and third fluid during the replacing step).

[0081] In some embodiments, the method further comprises providing the storage system in a compact (e.g., folded) state and unfolding the storage system at (e.g., a location close to) the desired environment. In some embodiments, the method further comprises transporting the storage system to a location close to the desired environment. In some embodiments, the method comprises transporting the storage system to a location close to the desired environment whilst the storage system is in a compact (e.g., folded) state.

[0082] In some embodiments, the method further comprises (e.g., at least partially) inflating the first bladder with a fourth fluid before the step of transporting the storage system to (e.g., a location close to) the desired environment (e.g., the first bladder is transported in a (e.g., partially) inflated state). In some embodiments, the method further comprises (e.g., at least partially) inflating the first bladder with the fourth fluid whilst the first bladder is in a folded state. In some embodiments, the method further comprises deflating the first bladder before positioning the storage system in the desired environment. Deflating the first bladder may comprise removing the fourth fluid from the bladder at (e.g., a location close to) the desired environment. In embodiments where the first bladder is deflated (e.g., by removing the fourth fluid) before positioning the storage system in the desired location, the method further comprises re-inflating the first bladder with the second fluid. The second fluid and the fourth fluid may be the same fluid (e.g., gas, liquid, water, or seawater) or different fluids.

[0083] In some embodiments, the desired environment is proximate to at least one of a production facility, wind turbine, or offshore structure.

[0084] In some embodiments, the method further comprises connecting the outer casing to a first substance source. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the first substance into the first cavity via a connecting formation. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the first substance in the first cavity via a pipe or line. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the first substance in the first cavity via a (e.g., one-way) valve. In some embodiments, the method further comprises controlling the flow of the first substance into the first cavity (e.g., using a one-way valve). In some embodiments, the method comprises inputting (e.g., inserting or injecting) the first substance into the first cavity via a remotely operated underwater vehicle connection.

[0085] In some embodiments, the method further comprises connecting the first bladder to a second fluid source. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the second fluid into the first bladder via a connecting formation. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the second fluid in the first bladder via a pipe or line. In some embodiments, the method comprises inputting (e.g., inserting or injecting) second fluid in the first bladder via a (e.g., one-way or two-way) valve. In some embodiments, the method further comprises controlling the flow of the second fluid into the first bladder (e.g., using a two-way valve or using a one-way valve). In some embodiments, the method comprises inputting (e.g., inserting or injecting) the second fluid into the first bladder via a remotely operated underwater vehicle connection.

[0086] In some embodiments, the storage system further comprises a second bladder, wherein the second bladder is located within the second cavity. In such embodiments, the method further comprises removing the second fluid from the first bladder and inputting a third fluid (e.g., gas and / or liquid) into the second bladder. In some embodiments, the step of removing the second fluid from the first bladder occurs before inputting the third fluid into the second bladder.

[0087] In some embodiments, the step of removing the second fluid from the first bladder occurs after inputting (e.g., inserting or injecting) the first substance (e.g., curable fluid) into the first cavity. In some embodiments, the steps of removing the second fluid from the first bladder occurs after inputting (e.g., inserting or injecting) the curable fluid into the first cavity and curing the curable fluid in the first cavity.

[0088] In some embodiments, the method further comprises replacing the first bladder with the second bladder. For example, the method comprises removing the first bladder from the second cavity and inserting the second bladder into the second cavity. In some embodiments, removing the first bladder from the second cavity occurs before inserting the second bladder into the second cavity. In some embodiments, removing the first bladder from the second cavity occurs after inserting the second bladder into the second cavity. In some embodiments, removing the first bladder from the second cavity occurs (e.g., substantially simultaneously) while inserting the second bladder into the second cavity.

[0089] In some embodiments, the method further comprises removing the second fluid from the first bladder, optionally before removing the first bladder from the second cavity. In some embodiments, the method further comprises removing the second fluid from the first bladder after removing the first bladder from the second cavity.

[0090] In some embodiments, the method further comprises inputting (e.g., inserting or injecting) the third fluid into the second bladder. In some embodiments, inputting (e.g., inserting or injecting) the third fluid into the second bladder occurs before inserting the second bladder into the second cavity. In some embodiments, inputting (e.g., inserting or injecting) the third fluid into the second bladder occurs after inserting the second bladder into the second cavity.

[0091] In some embodiments, the method further comprises connecting the second bladder to a third fluid source. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the third fluid into the second bladder via a connecting formation. In some embodiments, the method comprises inputting (e.g., inserting or injecting) the third fluid in the second bladder via a pipe or line. In some embodiments, the method comprises inputting (e.g., inserting or injecting) third fluid in the second bladder via a (e.g., one-way or two-way) valve. In some embodiments, the method further comprises controlling the flow of the third fluid into the second bladder (e.g., using a two-way valve or using a one-way valve). In some embodiments, the method comprises inputting (e.g., inserting or injecting) the third fluid into the second bladder via a remotely operated underwater vehicle connection.

[0092] In some embodiments, the method further comprises generating a Light Detection and Ranging (LIDAR) map of the storage system topography. In some embodiments, the method further comprises measuring the volume of the curable fluid using LIDAR. In some embodiments, the method further comprises monitoring the storage system periodically (e.g., at regular time intervals) using LIDAR. In some embodiments, the method further comprises monitoring the storage system for leaks using acoustic sensors.

[0093] At least one of the above embodiments provides one or more solutions to the problems and disadvantages with the background art. Other technical advantages of the present disclosure will be readily apparent to one skilled in the art from the following description and claims. Various embodiments of the present application obtain only a subset of the advantages set forth. No one advantage is critical to the embodiments. Any disclosed embodiment may be technically combined with any other disclosed embodiment or embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0094] The accompanying drawings illustrate embodiments of the disclosure and serve to explain, by way of example, the principles of the disclosure.

[0095] FIG. 1 shows a cross-section of a storage system in accordance with an embodiment of the disclosure;

[0096] FIG. 2 shows a cross-section of a storage system in accordance with an embodiment of the disclosure with a second fluid within the bladder;

[0097] FIG. 3 shows a cross-section of a storage system in accordance with an embodiment of the disclosure with a second fluid within the bladder and a first substance within the first cavity;

[0098] FIG. 4 shows a cross-section of a storage system in accordance with an embodiment of the disclosure;

[0099] FIG. 5 shows a cross-section of the storage system of in accordance with an embodiment of the disclosure with a second fluid within the bladder;

[0100] FIG. 6 shows a cross-section of the storage system of FIG. 5 where the bladder is partly filled with a fluid to be stored;

[0101] FIG. 7 shows a cross-section of a storage system in accordance with an embodiment of the disclosure; and

[0102] FIGS. 8 and 9 show a method of installing a storage system in an underwater environment in accordance with an embodiment of the disclosure.DETAILED DESCRIPTION

[0103] A number of embodiments are described with reference to the drawings. A storage system for storing a fluid in an underwater environment and a method of providing a storage system for storing a gas are described with reference to the drawings.

[0104] FIG. 1 shows a cross-section of a storage system 100 having an outer casing 110 and a bladder (e.g., the first bladder) 120. The outer casing 110 provides the outer surface of the storage system 100 such that the bladder 120 is enclosed within the cavity 118 (i.e., the second cavity). The outer casing 110 has an outer layer 112, which forms the outer surface of the outer casing and defines a cavity inside which the inner layer 114 and the bladder 120 are located. The inner layer 114 effectively acts to subdivide the cavity formed by the outer layer into a first cavity 116 and a second cavity 118. The first cavity 116 is formed as part of the outer casing and is located between the outer layer 112 and the inner layer 114. The second cavity 118 is defined by the inner layer 114 and is thus the space inside which the bladder 120 is inserted. In storage system 100, the outer layer 112 and the inner layer 114 are unattached such that the first cavity 116 is essentially continuous in all directions.

[0105] The storage system 100 of FIG. 1 is shown in a deflated or unfilled state, i.e., the storage system 100 does not include a first substance within the first cavity 116 or a second fluid within the bladder. The storage system 100 is therefore in a state by which it could be folded and transported easily to a location where the storage of a fluid is required.

[0106] FIG. 2 shows a storage system 200. There are two differences between the storage system 200 of FIG. 2 and the storage system 100 of FIG. 1. The first difference is that the outer layer 214 and inner layer 216 of storage system 200 are connected at a number of attachment sites 224 which subdivides the first cavity 216 into a plurality of cavity segments such that the first cavity 216 is discontinuous in the plane of the cross-section (but continuous in the plane perpendicular to the cross-sectional plane). The second difference is that a second fluid 222 has been provided within the bladder 220 of the storage system 200. Notwithstanding these differences, the features of storage system 100 apply similarly to storage system 200.

[0107] As shown in FIG. 2, after a second fluid 222 has been provided within the bladder 220, the bladder is inflated and provides a first inflated shape. As the outer casing 210 does not (yet) include a first substance within the first cavity 216, the outer casing 210 is able to adapt to form a shape complementary to the first inflated shape provided by the bladder 220 when it is filled with the second fluid 222.

[0108] FIG. 3 shows a storage system 300 where the outer casing 310 has a plurality of attachment sites 324 that connect the outer layer 312 and the inner layer 314. The attachment sites 324 are shown to be substantially equally distributed along the outer casing 310 such that the first cavity 316 is subdivided into a plurality of substantially evenly sized cavity segments 316a-d with a substantially hexagonal cross-section. Each cavity segment 316a-d essentially forms a tubular structure (having a hexagonal cross-section) such that the first cavity 316 is discontinuous in the cross-sectional plane shown (and continuous in the plane perpendicular to the cross-sectional plane). Thus, the storage system 300 differs from storage system 200 in the arrangement of the cavity segments 316a-d, and that the first cavity 316 (and thus the cavity segments 316a-d) are filled with the first substance.

[0109] Because of the presence of the first substance, the first cavity 316 is inflated and adopts a shape complementary to the first inflated shape of the bladder 320. If the first substance is a curable substance (e.g., a curable fluid), the first substance is cured within the first cavity 316. The outer casing 310 thus essentially provides a hard outer shell which can protect the flexible bladder 320 from external forces (such as items being dropped from above) which may break or tear the bladder 320 and result in leakage of the fluid contained therein.

[0110] It will be appreciated from FIG. 3 that, due to the attachment sites 324, the outer casing is articulated and the cavity segments 316a-d can move with respect to each other, even after the first substance is cured. As such, as the bladder 320 is deflated (and thus no longer adopts the first inflated shape), the outer casing 320 may suitably adapt to compensate for this change in shape.

[0111] In contrast to FIG. 3, FIG. 4 shows a storage system 400 where the outer casing is not articulated due to an absence of attachment sites between the outer layer 412 and the inner layer 414. As a result, when the first cavity 416 is filled with a curable first substance, the outer casing will maintain the first inflated shape of the bladder 420 (i.e., the shape it adopts when it is filled with the second fluid 422), even after the second fluid is at least partially removed. Thus, the outer casing of the storage system 400 essentially provides a solid outer shell in the form of a pipe when the first substance within the first cavity 416 is cured.

[0112] FIGS. 4 and 5 show a storage system 500 where the outer casing is not articulated, but the first cavity 516 is subdivided into a plurality of cavity segments 516a-b due to the presence of attachment sites 524, which connect the outer layer 512 to the inner layer 514. The lack of articulation (e.g., in contrast to the storage system 300 shown in FIG. 3) may be attributed to the significant length over which the outer layer 512 and the inner layer 514 are connected in the cross-sectional plane (i.e., the attachment site is two-dimensional in the cross-sectional plane shown). As such, the attachment sites 524 essentially provide rigid walls between cavity segments 516a and 516b. In contrast, the attachment sites 324 of the storage system 300 in FIG. 3 are substantially 1-dimensional in the cross-sectional plane such that the attachment sites 324 act as a hinge or articulated joint about which the cavity segments may move.

[0113] FIG. 4 therefore shows that, when the bladder 520 is filled with the second fluid 522, the outer casing adopts a shape complementary to the first inflated shape of the bladder 520. A first substance may then be inserted into the first cavity segments 516a-b such that the outer casing is similarly inflated around the first bladder 520 and adopts a shape complementary to the first inflated shape.

[0114] FIG. 5 shows that, when the first substance is curable (e.g., concrete), after the first substance is cured, the outer casing will maintain the shape complementary to the first inflated shape even after the bladder 520 no longer adopts the first inflated shape (e.g., after the second fluid is partially removed and / or as the fluid to be stored is syphoned off).

[0115] FIG. 7 shows a storage system 700, which includes a plurality of storage systems 600a-c. It should be noted that any of the storage systems shown in FIGS. 1-6 (or equivalents thereto) may replace one or all of the storage systems 600a-c. Furthermore, the storage system 700 is not limited to including only three storage systems, but the depiction has been kept at three for clarity.

[0116] FIGS. 8 and 9 show a pictorial representation of an example method of installing a storage system 800 in an underwater environment 830. The storage system 800 may be of any desired configuration (i.e., any one of FIGS. 1-6 or equivalents thereto).

[0117] As shown in FIG. 9, the storage system 800 can be provided in a folded state for transportation to the desired installation point. In FIG. 8a, the storage system 800 is provided in a partially inflated state by partially filling the bladder of the storage system with a fluid (e.g., a gas) that allows the storage system 800 to be at least partially buoyant on the surface of the water 830. This allows the storage system 800 to be towed to the desired position by a boat 900 (or other suitable means). When the storage system 800 has been transported to the desired location, the bladder may be deflated such that the storage system 800 can sink (i.e., is less buoyant) as shown in FIG. 8b.

[0118] The storage system 800 may then be unfolded (shown in FIG. 9) such that it can be lowered to and laid on the ground 840 of the underwater environment (e.g., the seabed). To facilitate the storage system 800 being lowered, the first cavity may be partially filled with a first substance that is denser than water such that the storage system 800 sinks more quickly and can be positioned more precisely.

[0119] Once the storage system is installed on the ground 840, a second fluid can be installed into the first bladder such that the first bladder adopts the first inflated shape. Then the first cavity can be (completely) filled with the first substance (and cured if the first substance is curable) such that the outer casing provides a hard protective shell for the bladder (e.g., first or second).

[0120] Although the above examples have been shown with particular cross-sectional shapes and / or configurations, these are examples only and not intended to be limiting on the nature of the embodiments disclosed herein. It will be appreciated that any suitable variation of the examples shown may be used as long as the resulting storage system falls within the scope of the appended claims.

Claims

1. -15. (canceled)16. A storage system for storing a fluid in an underwater environment, the storage system comprising:an outer casing and a first bladder, the outer casing including:an outer layer arranged to form a cavity; andan inner layer located within the cavity formed by the outer layer, the inner layer defining an interior surface of the outer casing, the cavity including a first cavity and a second cavity, the first cavity formed between the outer layer and the inner layer, the second cavity defined by the interior surface of the outer casing, the outer casing configured to receive and hold a first substance in the first cavity,wherein the first bladder is suitable for storing the fluid to be stored, the first bladder configured to receive and hold a second fluid, the first bladder being an inflatable and deflatable container located within the second cavity.

17. The storage system of claim 16, wherein the first substance is selected to be one of a fluid, a curable fluid, or a solid having bulk fluid characteristics.

18. The storage system of claim 16, wherein the outer casing is tubular in shape, and wherein the tubular shape has a circular or non-circular cross-section.

19. The storage system of claim 16, wherein the outer casing comprises two ends and the first cavity is continuous from one end to the other end.

20. The storage system of claim 16, wherein the first cavity comprises at least two discrete cavity segments.

21. The storage system of claim 20, wherein the outer casing comprises two ends and the discrete cavity segments are formed by attaching the outer layer to the inner layer at at least one attachment site between the two ends.

22. The storage system of claim 20, wherein each of the at least two discrete cavity segments is fluidly connected to at least one other cavity segment by a channel.

23. The storage system of claim 20, wherein the at least two cavity segments can move independently of each other such that the outer casing is articulated.

24. The storage system of claim 16, wherein the first bladder is arranged to provide a first inflated shape when the first bladder comprises the second fluid, and the outer casing is arranged to adopt a shape complementary to the first inflated shape.

25. The storage system of claim 24, wherein the first substance is a curable fluid and the first cavity comprises the curable fluid in its cured state such that the outer casing substantially maintains the shape complementary to the first inflated shape, even when the bladder no longer adopts the first inflated shape.

26. The storage system of claim 25, wherein the storage system further comprises a second bladder located within the second cavity, wherein the second bladder is configured to receive and hold a third fluid.

27. A method of providing a storage system for storing a fluid, the method comprising:providing a storage system comprising:an outer casing comprising:an outer layer arranged to form a cavity; andan inner layer, located within the cavity formed by the outer layer, and defining an interior surface of the outer casing,wherein the cavity comprises a first cavity and a second cavity, the first cavity is formed between the outer layer and the inner layer, the second cavity is defined by the interior surface of the outer casing, the outer casing is configured to receive and hold a first substance in the first cavity; anda first bladder suitable for storing the fluid to be stored, the first bladder configured to receive and hold a second fluid, the first bladder located within the second cavity;positioning the storage system in the desired underwater environment;inputting the second fluid into the first bladder such that the first bladder adopts a first inflated shape; andinputting a first substance into the first cavity such that, when the first bladder adopts the first inflated shape, the outer casing adopts a complementary shape to the first inflated shape.

28. The method of claim 27, wherein the first substance is a curable fluid and the method further comprises:curing the curable fluid after the step of inputting the second fluid into the first bladder such that the first bladder adopts the first inflated shape.

29. The method of claim 27, wherein method further comprises:replacing the second fluid in the first bladder with a third fluid.

30. The method of claim 27, wherein the storage system further comprises a second bladder, and the method further comprises:removing the second fluid from the first bladder; andinputting a third fluid into the second bladder.

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