Underwater oil storage tank based on shape memory polymer composite material

Abstract

The invention provides an underwater oil storage tank based on a shape memory polymer composite material, and relates to the technical field of oil storage equipment, the underwater oil storage tank based on the shape memory polymer composite material comprises a tank body, and the tank body comprises a corrugated structure section; the corrugated structural section has an unfolded state and a contracted state, and the corrugated structural section changes between the unfolded state and the contracted state. The corrugated structural section of the tank body has an unfolded state and a contracted state, the corrugated structural section changes between the unfolded state and the contracted state, the corrugated structural section can be in the contracted state during ground transportation, transportation and installation of the tank body are facilitated, the corrugated structural section is in the unfolded state during underwater use, and the tank body has huge volume. Therefore, the production efficiency of petroleum is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil storage equipment, and more particularly, to an underwater oil storage tank based on shape memory polymer composites. Background Art

[0002] With the continuous exploitation of oil resources, most onshore oil fields will face the problem of declining production. However, the seabed is rich in oil resources, so the exploitation of offshore oil has become the general trend of future oil development. Due to the harsh environment of the deep-sea seabed, a large amount of infrastructure funds and operating funds are required to effectively exploit deep-sea oil and gas resources using conventional exploitation technologies, and the economic benefits are minimal. The emergence of underwater production systems has greatly reduced the exploitation cost of deep-sea oil and gas resources. However, deep-sea oil fields are far from the shore, and it is impossible to directly transport the well outputs to the land through pipelines. A common method is to store the exploited well outputs in an oil storage device and then regularly transfer them by shuttle tankers. If the capacity of the oil storage device is large enough, even if the sailing schedule of the shuttle tanker is delayed, the oil storage device can ensure the continuous exploitation of the oil field, thereby improving the exploitation efficiency of the well outputs. Currently, offshore oil storage is mainly divided into three modes: above-water, on-water, and underwater.

[0003] The above-water and on-water oil storage modes are more common and easier to control, and the technology is more mature. However, above-water oil storage will cause a large weight on the upper part of the oil production platform, resulting in an increase in the platform structure, environmental load, and foundation stress, and the platform cost is very high. For on-water oil storage, the oil storage capacity of floating oil storage devices is generally more than 50,000 cubic meters, and it is greatly affected by external factors such as wind waves, ocean currents, and water surface icing. Therefore, for the development of some small oil fields, the economic efficiency of the above-water and on-water oil storage modes is poor.

[0004] The underwater oil storage mode not only avoids using a fixed platform to support the oil storage tank body, saving the construction cost of the oil production platform, but also avoids the influence of ice force and wave force on the oil storage device, and can still ensure the continuous production of oil wells without interruption in severe sea conditions. In addition, the oil storage device of the underwater oil storage technology is not affected by disasters such as lightning strikes or fire sources, and can avoid dangerous accidents such as fire and explosion, improving safety and reducing the loss of oil and gas resources. However, the underwater oil storage device has a huge volume, which brings greater challenges and difficulties to the transportation and installation stages while improving production efficiency, and the transportation and installation costs increase significantly, thereby increasing the cost of the underwater oil storage device during its entire life cycle. Summary of the Invention

[0005] The problem solved by the present invention is how to solve the problem of difficult operation during the transportation and installation of the underwater oil storage device and the high cost caused thereby.

[0006] To solve the above problems, the present invention provides an underwater oil storage tank based on a shape memory polymer composite material.

[0007] The present invention provides an underwater oil storage tank based on a shape memory polymer composite material, including a tank body, and the tank body includes a corrugated structure section;

[0008] Wherein, the corrugated structure section has an expanded state and a contracted state, and the corrugated structure section is used to expand and contract along the axial direction of the tank body to change between the expanded state and the contracted state.

[0009] Optionally, the corrugated structure section includes a plurality of single-ring structures connected in sequence, and the plurality of single-ring structures are arranged along the axial direction of the tank body.

[0010] Optionally, the single-ring structure has an expanded shape and a contracted shape. When the single-ring structure is in the expanded shape, the corrugated structure section is in the expanded state; when the single-ring structure is in the contracted shape, the corrugated structure section is in the contracted state.

[0011] Optionally, the corrugated structure section includes an inner earthworm-link array origami layer and an outer earthworm-link array origami layer, and a first honeycomb array sandwich layer is provided between the inner earthworm-link array origami layer and the outer earthworm-link array origami layer.

[0012] Optionally, the inner earthworm-link array origami layer and the outer earthworm-link array origami layer are shape memory polymer composite materials. When heated to above the glass transition temperature of the shape memory polymer composite material, pressure can be applied to the inner earthworm-link array origami layer and the outer earthworm-link array origami layer to cause the corrugated structure section to change from the expanded state to the contracted state; when an external excitation is applied to the shape memory polymer composite material, the corrugated structure section changes from the contracted state to the expanded state.

[0013] Optionally, the first honeycomb array sandwich layer is formed by stacking a plurality of regular hexagon structures arranged, the first honeycomb array sandwich layer is a polyether ether ketone material, and the cross-section of the regular hexagon structure is parallel to the inner earthworm-link array origami layer or the outer earthworm-link array origami layer, and is used to support and fix the inner earthworm-link array origami layer and the outer earthworm-link array origami layer.

[0014] Optionally, the tank body further includes a sandwich structure section, the corrugated structure section and the sandwich structure section are connected to each other along the axial direction of the tank body, the sandwich structure section includes an inner rigid layer and an outer rigid layer, and a second honeycomb array sandwich layer and a special-shaped honeycomb tube array layer are provided between the inner rigid layer and the outer rigid layer; the sandwich structure section includes a circumferential wall surrounding a cylindrical shape and a bottom wall in a flat plate shape, the second honeycomb array sandwich layer is located between the inner rigid layer and the outer rigid layer of the circumferential wall, and the special-shaped honeycomb tube array layer is located between the inner rigid layer and the outer rigid layer of the bottom wall.

[0015] Optionally, the second honeycomb array sandwich layer is formed by stacking a plurality of regular hexagon structures arranged in a stack. The regular hexagon structure is made of polyether ether ketone material. The cross-section of the regular hexagon structure is parallel to the inner rigid layer or the outer rigid layer, and is used to support and fix the inner rigid layer and the outer rigid layer.

[0016] Optionally, the special-shaped honeycomb tube array layer is formed by stacking a plurality of special-shaped honeycomb tubes arranged in a stack. The special-shaped honeycomb tube is made of alloy material. The cross-section of the special-shaped honeycomb tube is a hexagon, and at least two opposite sides of the hexagon are recessed towards the inside of the hexagon to form arc-shaped sides. The cross-section of the special-shaped honeycomb tube is perpendicular to the plane where the bottom wall of the sandwich structure section is located.

[0017] Optionally, the underwater oil storage tank based on the shape memory polymer composite further includes a pipeline and a pile body. The pipeline is connected to the corrugated structure section and is used to communicate the inside and outside of the tank body. The pile body is connected to the sandwich structure section.

[0018] The beneficial effects of an underwater oil storage tank based on a shape memory polymer composite according to the present invention are as follows: The corrugated structure section of the tank body has a deployed state and a contracted state. The corrugated structure section changes between the deployed state and the contracted state, enabling the corrugated structure section to be in the contracted state during ground transportation, facilitating the transportation and installation of the tank body, and the corrugated structure section to be in the deployed state during underwater use, realizing that the tank body has a huge volume, thereby improving the production efficiency of petroleum. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of an underwater oil storage tank in the deployed state according to an embodiment of the present invention;

[0020] Figure 2 It is a schematic structural diagram of an underwater oil storage tank in the contracted state according to an embodiment of the present invention;

[0021] Figure 3 It is a schematic structural diagram of an expanded single-ring structure according to an embodiment of the present invention;

[0022] Figure 4 It is a schematic structural diagram of a contracted single-ring structure according to an embodiment of the present invention;

[0023] Figure 5 It is a schematic structural diagram of a corrugated structure section in the deployed state according to an embodiment of the present invention;

[0024] Figure 6 It is a schematic structural diagram of a corrugated structure section in the contracted state according to an embodiment of the present invention;

[0025] Figure 7 It is a schematic exploded structural diagram of a corrugated structure section according to an embodiment of the present invention;

[0026] Figure 8 It is a schematic exploded structural diagram of a sandwich structure section according to an embodiment of the present invention;

[0027] Figure 9 It is a schematic structural diagram of the special-shaped honeycomb tube according to an embodiment of the present invention;

[0028] Figure 10 It is a schematic structural diagram of the cross-section of the special-shaped honeycomb tube according to an embodiment of the present invention;

[0029] Figure 11 It is a schematic structural diagram of the special-shaped honeycomb tube array layer according to an embodiment of the present invention.

[0030] Explanation of reference numerals:

[0031] 1. Tank body; 11. Corrugated structure section; 1101. Single-ring structure; 111. Inner earthworm-link array origami layer; 112. Outer earthworm-link array origami layer; 113. First honeycomb array sandwich layer; 12. Sandwich structure section; 121. Inner rigid layer; 122. Outer rigid layer; 123. Special-shaped honeycomb tube array layer; 124. Second honeycomb array sandwich layer; 1231. Special-shaped honeycomb tube; 2. Pipeline; 3. Pile body. Detailed implementation manners

[0032] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in the specification are only for the purpose of describing specific implementation manners and are not intended to limit the present invention;

[0034] The term "including" and its variants used herein are open-ended, that is, "including but not limited to"; the term "based on" is "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiment". The relevant definitions of other terms will be given in the following description.

[0035] In view of the problems existing in the above related technologies, this embodiment provides an underwater oil storage tank based on a shape memory polymer composite material.

[0036] As Figure 1 and Figure 2 shown, an underwater oil storage tank based on a shape memory polymer composite provided by an embodiment of the present invention includes a tank body 1, and the tank body 1 includes a corrugated structure section 11;

[0037] Among them, the corrugated structure section 11 has an expanded state and a contracted state, and the corrugated structure section 11 is used to expand and contract along the axial direction of the tank body 1 to change between the expanded state and the contracted state.

[0038] In this embodiment, the corrugated structure section 11 of the tank body 1 has an expanded state and a contracted state, and the corrugated structure section 11 changes between the expanded state and the contracted state, which can realize that the corrugated structure section 11 is in the contracted state during ground transportation, facilitating the transportation and installation of the tank body 1, and the corrugated structure section 11 is in the expanded state during underwater use, realizing that the tank body 1 has a huge volume, thereby improving the production efficiency of oil.

[0039] Optionally, as Figure 3 and Figure 5 shown, the corrugated structure section 11 includes a plurality of single-ring structures 1101 connected in sequence, and the plurality of single-ring structures 1101 are arranged along the axial direction of the tank body 1.

[0040] In this optional embodiment, inspired by the earthworm configuration, a plurality of single-ring structures 1101 are arranged and connected in a direction perpendicular to the plane where the single-ring structure 1101 is located to form the corrugated structure section 11, obtaining an origami structure imitating the earthworm segment array. Since there is an array of single-ring structures 1101 in the corrugated structure section 11 that can be stretched and compressed, the corrugated structure section 11 has the characteristic of a large expansion and contraction ratio.

[0041] Specifically, as Figure 3 , Figure 4 , Figure 5 and Figure 6 shown, the single-ring structure 1101 has an expanded shape and a contracted shape. When the single-ring structure 1101 is in the expanded shape, the corrugated structure section 11 is in the expanded state; when the single-ring structure 1101 is in the contracted shape, the corrugated structure section 11 is in the contracted state.

[0042] Optionally, as Figure 7 shown, the corrugated structure section 11 includes an inner earthworm segment array origami layer 111 and an outer earthworm segment array origami layer 112, and a first honeycomb array sandwich layer 113 is provided between the inner earthworm segment array origami layer 111 and the outer earthworm segment array origami layer 112.

[0043] Among them, the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112 are shape memory polymer composites. When heated above the glass transition temperature of the shape memory polymer composites, the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112 can be deformed under the action of pressure so that the corrugated structure segment 11 changes from the unfolded state to the contracted state; when an external stimulus is applied to the shape memory polymer composites, the corrugated structure segment 11 changes from the contracted state to the unfolded state.

[0044] In this alternative embodiment, the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112 include two configurations: a compressed transportation configuration and an unfolded oil storage configuration, corresponding to the contracted state and the unfolded state of the corrugated structure segment 11 respectively. During transportation, the underwater oil storage tank is in the contracted state, and at this time, the space occupancy rate is small, which can reduce the transportation and installation costs. When the underwater oil storage tank is installed underwater, a certain stimulus is applied to the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112 made of its shape memory polymer composites to cause a shape memory effect, so as to switch to the unfolded state with a larger volume, further increasing the oil storage capacity. In addition, in the event of a strong tsunami caused by a submarine earthquake, the corrugated structure segment 11 made of the shape memory polymer composites of the underwater oil storage tank can be heated above the glass transition temperature, and then the seawater inside the tank body 1 is drained, and a compression force is applied to the tank body 1 by the action of the submarine static pressure to make it turn into a small-volume compressed transportation configuration, thereby reducing the wave force it receives; after the tsunami ends, it is restored to the unfolded oil storage configuration by using the shape memory effect. In this way, the risk of damage to the oil storage tank and leakage of oil well products can be avoided to a certain extent.

[0045] The inner and outer layers of the earthworm-segment array origami structure have two configurations, namely the compressed configuration and the deployed configuration. The inner and outer layers of the earthworm-segment array origami structure are made of a multi-stimulus-responsive shape memory polymer composite. During the ground assembly process, the earthworm-segment array origami structure is assembled into the deployed configuration. Subsequently, using the shape memory property and variable stiffness property of the shape memory polymer composite, the inner and outer layers of the earthworm-segment array origami structure are heated above its glass transition temperature and then subjected to axial compressive deformation. After cooling and unloading, it can be fixed in the compressed configuration with a small volume. The inner and outer layers of the earthworm-segment array origami structure in the compressed configuration are assembled with the mechanical metamaterial sandwich structure section 12 into the tank body 1, and then assembled with components such as the crude oil inlet and outlet pipeline 2 and the pile body 3 into an underwater oil storage tank, which is transported to the oil and gas field by a transport ship. After being installed near the oil and gas field, an external stimulus is applied to the inner and outer layers of the earthworm-segment array origami structure, and its configuration can be changed from the compressed configuration to the deployed configuration, greatly increasing the volume of the oil storage tank. In addition, in the event of a strong tsunami caused by a submarine earthquake, the two layers of the earthworm-segment array origami structure can be heated above its glass transition temperature again, and then the seawater inside the tank body 1 is drained, and a compressive force is applied through the action of the seabed hydrostatic pressure to make it change to the compressed configuration, thereby greatly reducing the wave force it receives; after the tsunami ends, it is restored to the extended configuration using the shape memory effect. In this way, the risk of damage to the shape memory origami structure can be avoided to a certain extent.

[0046] During transportation, it is in the compressed transportation configuration, at which time the space occupancy rate is small, reducing the transportation and installation costs. When the oil storage tank is installed underwater, a certain stimulus is applied to its inner and outer layers of the earthworm-segment array origami structure to cause the shape memory effect, so that the oil storage tank is converted to the deployed oil storage configuration with a larger volume, further increasing the oil storage capacity. In addition, in the event of a strong tsunami caused by a submarine earthquake, the earthworm-segment array origami structure of the oil storage tank can be heated above the glass transition temperature, and then the seawater inside the tank body 1 is drained. Using the action of the seabed hydrostatic pressure or using a giant hydraulic press to apply a certain compressive force to the tank body 1 to make it deform, and the tank body 1 is transformed into a small-volume compressed state, thereby reducing the wave force received by the tank body 1; after the tsunami ends, the tank body 1 is restored to the deployed state using the shape memory effect. In this way, the risk of damage to the underwater oil storage tank and leakage of oil well products can be avoided to a certain extent.

[0047] Specifically, the matrix of the shape memory polymer composite is an epoxy-based shape memory polymer, a cyanate ester-based shape memory polymer, a polyimide-based shape memory polymer, a styrene-based shape memory polymer, etc.; the reinforcing phase of the shape memory polymer composite is composed of carbon nanotubes, carbon fibers, Kevlar fibers, aramid fibers, etc., and the morphology of the reinforcing phase is particles, short cut fibers, continuous fibers, and / or fiber cloth, etc.

[0048] The specific implementation process of the shaping process is as follows: a) Under external excitation, heat the temperature of the corrugated structure section 11 above the glass transition temperature, and then apply a load to make the tank body 1 reach the shrinkage state; b) Lower the temperature below the glass transition temperature, and the corrugated structure section 11 can maintain this temporary configuration and can independently withstand external loads, thereby realizing the shaping of the structure of the tank body 1.

[0049] Specifically, the forms of external excitation include but are not limited to: thermal drive, electric drive, magnetic drive, radio frequency drive, microwave drive, optical drive, and / or combined drive.

[0050] Among them, if thermal drive is adopted, a resistive heater or an external heat source can be pasted on the surface of the corrugated structure section 11 for heating; if electric drive is adopted, the shape memory polymer composite material should be doped with one or more of conductive reinforcing phases such as single-walled and multi-walled carbon nanotubes, graphene, carbon black, carbon nanofiber paper, carbon nanofibers, chopped carbon fibers, continuous carbon fibers, and hybrid particle fillers, and an external power source should be connected to the above-doped phases to form a circuit; if microwave drive is adopted, the shape memory polymer composite material should be doped with nanoparticles such as carbon nanotubes, graphene oxide, and silicon carbide; if radio frequency drive is adopted, the shape memory polymer composite material should be doped with radio frequency sensitive particles such as carbon nanotubes, etc.; if optical drive is adopted, the shape memory polymer composite material should have a photosensitive material; if combined drive is adopted, the reinforcing phases doped in the shape memory polymer composite material should include two or more of the above combinations.

[0051] The driving programs of the external excitation are one or more of the following:

[0052] 1. If thermal drive is adopted: Heat the corrugated structure section 11. After the temperature reaches above the glass transition temperature, stop heating after the corrugated structure section 11 deforms from the shrinkage state to the unfolded state.

[0053] 2. If electric drive is adopted: Electrify the shape memory polymer composite material of the corrugated structure section 11. After the temperature rises above the glass transition temperature, stop electrifying after the corrugated structure section 11 deforms from the shrinkage state to the unfolded state.

[0054] 3. If microwave drive is adopted: Apply a microwave field to the shape memory polymer composite material of the corrugated structure section 11. After the temperature rises above the glass transition temperature, remove the microwave field after the corrugated structure section 11 deforms from the shrinkage state to the unfolded state.

[0055] 4. If radio frequency drive is adopted: Apply a radio frequency field to the shape memory composite material of the corrugated structure section 11. After the temperature reaches above the glass transition temperature, remove the radio frequency field after the corrugated structure section 11 deforms from the shrinkage state to the unfolded state.

[0056] 5. If the light-driven mode is adopted: Apply a light field to the shape memory composite material of the corrugated structure section 11. After the temperature reaches above the glass transition temperature, the corrugated structure section 11 deforms from the contracted state to the expanded state and then the light field is removed.

[0057] 6. If the combined drive mode is adopted: Apply corresponding excitation to the combined drive mode selected for the shape memory composite material of the corrugated structure section 11. After the temperature reaches above the glass transition temperature, the corrugated structure section 11 deforms from the contracted state to the expanded state and then the excitation is removed.

[0058] Optionally, as Figure 7 shown, the first honeycomb array sandwich layer 113 is formed by arranging and stacking a plurality of regular hexagon structures. The first honeycomb array sandwich layer 113 is made of polyether ether ketone material. The cross-section of the regular hexagon structure is parallel to the inner earthworm-link array origami layer 111 or the outer earthworm-link array origami layer 112, and is used to support and fix the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112.

[0059] In this optional embodiment, the first honeycomb array sandwich layer 113 has characteristics such as high strength, light weight, and heat insulation performance. First of all, the first honeycomb array sandwich layer 113 is made of polyether ether ketone material, and the cross-section of the regular hexagon structure is parallel to the inner earthworm-link array origami layer 111 or the outer earthworm-link array origami layer 112. When impacted, it will not produce large deformation, providing sufficient support force for the corrugated structure section 11, and can ensure that the tank body 1 in this part can withstand external disturbances such as ice force and wave force. At the same time, the existence of the first honeycomb array sandwich layer 113 can also ensure that the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112 in the corrugated structure section 11 have a relatively stable relative position, as Figure 7 shown. In this way, it is possible to avoid the asynchronous situation in the expansion and contraction process of the inner earthworm-link array origami layer 111 and the outer earthworm-link array origami layer 112, thereby improving the reliability of the entire corrugated structure section 11. Secondly, the first honeycomb array sandwich layer 113 has the characteristic of light weight due to the structural characteristics of the regular hexagon structure arrangement, which reduces the weight of the corrugated structure section 11, thereby reducing the transportation and installation costs. Finally, since the first honeycomb array sandwich layer 113 is made of polyether ether ketone material and has good heat insulation performance, it can protect the oil well production in the underwater storage tank from the influence of the underwater low temperature and high pressure environment, reduce the wax formation and hydrate phenomena of the oil well production due to the low temperature and high pressure environment, and then reduce the dosage of chemical inhibitors, thereby reducing the environmental pollution problems brought by the exploitation of oil and gas resources.

[0060] Optionally, as Figure 8As shown, the tank body 1 further includes a sandwich structure section 12. The corrugated structure section 11 and the sandwich structure section 12 are connected to each other along the axial direction of the tank body 1. The sandwich structure section 12 includes an inner rigid layer 121 and an outer rigid layer 122. A second honeycomb array core layer 124 and a special-shaped honeycomb tube array layer 123 are provided between the inner rigid layer 121 and the outer rigid layer 122. The sandwich structure section 12 includes a circumferential wall enclosing a cylindrical shape and a bottom wall in a flat plate shape. The second honeycomb array core layer 124 is located between the inner rigid layer 121 and the outer rigid layer 122 of the circumferential wall in the corrugated structure section, and the special-shaped honeycomb tube array layer 123 is located between the inner rigid layer 121 and the outer rigid layer 122 of the bottom wall in the corrugated structure section.

[0061] Specifically, the inner rigid layer 121 and the outer rigid layer 122 are prepared from mechanical metamaterials, such as stainless steel materials. Since the underwater oil storage tank needs to be installed on the bottom of the water through the pile body 3, and the rigid sandwich structure section 12 is adopted, the connection stability between the bottom of the water - the pile body 3 - the underwater oil storage tank can be improved, and it can also ensure that the underwater oil storage tank can maintain a relatively stable posture underwater. If a structure with insufficient rigidity is adopted, there will be a risk of the underwater oil storage tank capsizing.

[0062] Specifically, the sandwich structure section 12 is composed of a circumferential wall in a cylindrical shape and a bottom wall in a flat plate shape. The bottom wall is connected to one end of the circumferential wall in a cylindrical shape so that one end of the sandwich structure section 12 is sealed, and the other end of the sandwich structure section 12 is used to communicate with the corrugated structure section 11 to enclose the tank body 1. Both the circumferential wall and the bottom wall of the sandwich structure section 12 include an inner rigid layer 121 and an outer rigid layer 122. Among them, the second honeycomb array core layer 124 is distributed between the inner rigid layer 121 and the outer rigid layer 122 of the circumferential wall, and the special-shaped honeycomb tube array layer 123 is distributed between the inner rigid layer 121 and the outer rigid layer 122 of the bottom wall.

[0063] Optionally, as Figures 9 to 11 shown, the second honeycomb array core layer 124 is formed by arranging and stacking a plurality of regular hexagon structures. The regular hexagon structure is made of polyether ether ketone material. The regular hexagon cross-section of the regular hexagon structure is parallel to the inner rigid layer 121 or the outer rigid layer 122, and is used to support and fix the inner rigid layer 121 and the outer rigid layer 122.

[0064] In this alternative embodiment, the second honeycomb array sandwich layer 124 provides sufficient support for the sandwich structure section 12 composed of the inner rigid layer 121 and the outer rigid layer made of mechanical metamaterials, which can ensure that the tank body 1 in this part can withstand external disturbances such as ice force and wave force. Secondly, the second honeycomb array sandwich layer 124 has the characteristic of light weight due to its structural characteristics, which reduces the weight of the sandwich structure section 12 of the mechanical metamaterials, thereby reducing the transportation and installation costs. Finally, since the second honeycomb array sandwich layer 124 has good heat insulation performance, it can protect the oil well production in the underwater storage tank from the influence of the underwater low-temperature and high-pressure environment, reduce the phenomena such as wax deposition and hydrates of the oil well production due to the low-temperature and high-pressure environment, and then reduce the dosage of chemical inhibitors, thereby reducing the environmental pollution problems caused by the exploitation of oil and gas resources.

[0065] Optionally, the special-shaped honeycomb tube array layer 123 is arranged and stacked by a plurality of special-shaped honeycomb tubes 1231. The special-shaped honeycomb tubes 1231 are made of alloy materials. The cross-section of the special-shaped honeycomb tubes 1231 is hexagonal, and at least two opposite sides in the hexagon are recessed towards the inside of the hexagon to form arc-shaped sides. The cross-section of the special-shaped honeycomb tubes 1231 is perpendicular to the plane where the bottom wall of the sandwich structure section 12 is located.

[0066] In this alternative embodiment, the special-shaped honeycomb tubes 1231 have characteristics such as high strength, light weight, and energy absorption. First, the special-shaped honeycomb tube array layer 123 with high strength provides sufficient support for the sandwich structure section 12 of the mechanical metamaterials, which can ensure that the bottom of the tank body 1 can withstand the water pressure of the seabed. Secondly, the special-shaped honeycomb tube array layer 123 has the characteristic of light weight due to its structural characteristics, which reduces the weight of the sandwich structure section 12 of the mechanical metamaterials, thereby reducing the transportation and installation costs. Finally, since the special-shaped honeycomb tube array layer 123 has good energy absorption characteristics, when the underwater storage tank uses the oil-water displacement technology for oil storage and oil unloading, the special-shaped honeycomb tube array layer 123 can absorb most of the energy in this process, thereby reducing the pressure on the inner rigid layer 121. In addition, when natural disasters such as seabed earthquakes occur, the special-shaped honeycomb tube array layer 123 can also absorb the impact energy from the external environment, thereby avoiding the damage of the inner rigid layer 121 and the leakage of the oil well production, and reducing the possibility of resource waste and environmental pollution.

[0067] Heat insulation: Compared with solids, gases have slower heat conduction. The hollow part of the special-shaped honeycomb tube 1231 is filled with gas, enabling the special-shaped honeycomb tube array layer 123 to have a certain heat insulation ability. Energy absorption: There are double-arc structures that are concave towards the inside of the special-shaped honeycomb tube 1231 on a pair of opposite sides of the special-shaped honeycomb tube 1231, which can play a role similar to spring buffering when impacted. At the same time, the special-shaped honeycomb tube array layer 123 uses titanium alloy as the raw material, and titanium alloy will produce a certain amount of plastic deformation when deformed, which can absorb and dissipate a certain amount of energy, playing the role of energy absorption.

[0068] Among them, at least two opposite side walls of the special-shaped honeycomb tube 1231 are concave towards the inside of the special-shaped honeycomb tube 1231 in an arc shape, so that its cross-section is the above-mentioned special-shaped hexagon. The cross-section of the special-shaped honeycomb tube 1231 of the special-shaped honeycomb tube array layer 123 is perpendicular to the plane of the bottom wall of the sandwich structure section 12 (i.e., the impacted surface). When the bottom wall is impacted, the arc-shaped concave structure on the side wall of the special-shaped honeycomb tube 1231 can play a role similar to a spring and has a certain buffering effect. At the same time, its material is titanium alloy, which is a metal with good energy absorption effect. When the special-shaped honeycomb tube array layer 123 deforms due to impact, titanium alloy will produce a part of plastic deformation and absorb part of the energy, thus ensuring the safety of the overall structure; while the regular hexagon cross-section of the regular hexagon structure of the second honeycomb array sandwich layer 124 is parallel to the inner rigid layer 121 and the outer rigid layer 122. When impacted, it will not produce large deformation and has a poor buffering effect, but it can provide sufficient supporting force.

[0069] Optionally, as Figure 1 and Figure 2 shown, the underwater oil storage tank based on shape memory polymer composite materials further includes a pipeline 2 and a pile body 3. The pipeline 2 is connected to the corrugated structure section 11 for communicating the inside and outside of the tank body 1, and the pile body 3 is connected to the sandwich structure section 12.

[0070] In this optional embodiment, when storing oil, the crude oil is injected into the tank body 1 through the pipeline 2, and the same volume of seawater is squeezed out of the tank body 1 to the outside of the tank body 1. The pile body 3 is connected to the sandwich structure section 12 for stabilizing the installation layout of the tank body 1.

[0071] Specifically, the pipeline 2 is connected to the top of the corrugated structure section 11 of the tank body 1. When storing oil, the crude oil is injected from the top of the tank body 1, and the same volume of seawater is discharged from the bottom of the tank body 1. Since oil and water are immiscible and the density of oil is less than that of water, an oil-water interface will spontaneously form inside the tank body 1; when unloading oil, the crude oil is pumped out from the top of the tank body 1, and under the action of static pressure, the same volume of seawater fills the inside of the tank body 1 from the bottom of the tank body 1. The pile body 3 can be provided with three or more, and is connected at equal intervals to the lower part of the sandwich structure section 12 of the tank body 1 to stably fix the tank body 1 on the seabed.

[0072] Although the present invention is disclosed as above, the scope of protection of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the scope of protection of the present invention.

Claims

1. An underwater oil storage tank based on shape memory polymer composite material, characterized in that: It comprises a tank body (1), wherein the tank body (1) comprises a corrugated structure section (11); The corrugated structure segment (11) has an expanded state and a contracted state, and the corrugated structure segment (11) is used to expand and contract along the axial direction of the tank body (1) to change between the expanded state and the contracted state.

2. The underwater oil storage tank based on shape memory polymer composite material according to claim 1, characterized in that: The corrugated structure segment (11) comprises a plurality of single ring structures (1101) connected in sequence, and the plurality of single ring structures (1101) are arranged axially along the tank body (1).

3. The underwater oil storage tank based on shape memory polymer composite material according to claim 2, characterized in that: The single-ring structure (1101) has an expanded state and a contracted state. When the single-ring structure (1101) is in the expanded state, the corrugated structure segment (11) is in the expanded state; when the single-ring structure (1101) is in the contracted state, the corrugated structure segment (11) is in the contracted state.

4. The underwater oil storage tank based on shape memory polymer composite material according to claim 1, characterized in that: The corrugated structure segment (11) comprises an inner earthworm-simulating segment array origami layer (111) and an outer earthworm-simulating segment array origami layer (112), wherein a first honeycomb array sandwich layer (113) is provided between the inner earthworm-simulating segment array origami layer (111) and the outer earthworm-simulating segment array origami layer (112).

5. The underwater oil storage tank based on shape memory polymer composite material according to claim 4, characterized in that: The inner earthworm-simulating segment array origami layer (111) and the outer earthworm-simulating segment array origami layer (112) are shape memory polymer composite materials. When the temperature is raised to above the glass transition temperature of the shape memory polymer composite material, pressure can be applied to the inner earthworm-simulating segment array origami layer (111) and the outer earthworm-simulating segment array origami layer (112) to transform the corrugated structure segment (11) from an expanded state to a contracted state; and when external excitation is applied to the shape memory polymer composite material, the corrugated structure segment (11) transforms from a contracted state to an expanded state.

6. The underwater oil storage tank based on shape memory polymer composite material according to claim 4, characterized in that: The first honeycomb array sandwich layer (113) is formed by arranging and stacking a plurality of regular hexagonal structures. The first honeycomb array sandwich layer (113) is made of polyetheretherketone material. The cross section of the regular hexagonal structure is parallel to the inner earthworm imitation segment array origami layer (111) or the outer earthworm imitation segment array origami layer (112), and is used to support and fix the inner earthworm imitation segment array origami layer (111) and the outer earthworm imitation segment array origami layer (112).

7. The underwater oil storage tank based on shape memory polymer composite material according to claim 1, characterized in that: The tank body (1) further comprises a sandwich structure section (12), wherein the corrugated structure section (11) and the sandwich structure section (12) are connected to each other along the axial direction of the tank body (1), wherein the sandwich structure section (12) comprises an inner rigid layer (121) and an outer rigid layer (122), wherein a second honeycomb array sandwich layer (124) and a special-shaped honeycomb tube array layer (123) are provided between the inner rigid layer (121) and the outer rigid layer (122); the sandwich structure section (12) comprises a circumferential wall in a cylindrical shape and a flat bottom wall, wherein the second honeycomb array sandwich layer (124) is located between the inner rigid layer (121) and the outer rigid layer (122) of the circumferential wall, and the special-shaped honeycomb tube array layer (123) is located between the inner rigid layer (121) and the outer rigid layer (122) of the bottom wall.

8. The underwater oil storage tank based on shape memory polymer composite material according to claim 7, characterized in that: The second honeycomb array sandwich layer (124) is formed by arranging and stacking a plurality of regular hexagonal structures, wherein the regular hexagonal structures are made of polyetheretherketone material, and the cross-section of the regular hexagonal structures is parallel to the inner rigid layer (121) or the outer rigid layer (122), and is used to support and fix the inner rigid layer (121) and the outer rigid layer (122).

9. The underwater oil storage tank based on shape memory polymer composite material according to claim 7, characterized in that: The shaped honeycomb tube array layer (123) is formed by arranging and stacking a plurality of shaped honeycomb tubes (1231), the shaped honeycomb tubes (1231) are made of alloy material, the cross section of the shaped honeycomb tube (1231) is a hexagon, and at least two opposite sides of the hexagon are recessed toward the inside of the hexagon to form arc-shaped sides, and the cross section of the shaped honeycomb tube (1231) is perpendicular to the plane where the bottom wall of the sandwich structure section (12) is located.

10. The underwater oil storage tank based on shape memory polymer composite material according to claim 1, characterized in that: The underwater oil storage tank based on shape memory polymer composite material further comprises a pipeline (2) and a pile body (3), wherein the pipeline (2) is connected to the corrugated structure section (11) for connecting the inside and the outside of the tank body (1), and the pile body (3) is connected to the sandwich structure section (12).

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