Oil storage device, floating bottom type micro-positive pressure oil storage system, and construction method

Abstract

An oil storage device, a floating bottom type micro-positive pressure oil storage system, and a construction method. The oil storage device comprises an oil storage cavity (24); a cavity wall (4) is provided on the outer side of the oil storage cavity (24); an oil conveying channel (2) passes through the upper portion of the cavity wall (4); a communicating channel (3) passes through the lower portion of the cavity wall (4); the oil conveying channel (2) and the communicating channel (3) are both communicated with the oil storage cavity (24).

Description

Oil storage equipment, floating bottom micro-positive pressure oil storage system and construction method

[0001] This application claims priority to the Chinese invention patent application (application number 202311504428.5) filed on November 10, 2023. Technical Field

[0002] The present invention belongs to the technical field of oil storage, and specifically relates to oil storage equipment, a floating bottom micro-positive pressure oil storage system and a construction method. Background Art

[0003] Currently, crude oil storage can be generally categorized as bulk or barreled. Bulk storage can be divided into concrete and steel structures. Crude oil's volume (density) is sensitive to temperature fluctuations. Diurnal temperature fluctuations create a "breathing" effect, which can cause crude oil to volatilize, degrade quality, pollute the air, and increase the risk of fire and explosion.

[0004] The existing solution is to use steel floating roof storage tanks. The floating roof rises and falls relative to the tank wall as the storage volume of the medium in the tank increases or decreases. There is an annular sealing device between the outer edge of the floating roof and the tank wall, which can reduce oil loss by about 80%. However, this solution consumes a lot of steel, the sealing structure between the floating roof and the tank is complex, maintenance is difficult, and the storage scale is small, with general specifications less than 10,000m 3 . Summary of the Invention

[0005] The purpose of the present invention is to provide an oil storage device, a floating bottom micro-positive pressure oil storage system and a construction method to address the common problems in the background art of using floating roof storage tanks to reduce oil loss and the difficult maintenance of the sealing structure.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] An oil storage device includes an oil storage cavity, wherein the outer side of the oil storage cavity has a cavity wall, an oil delivery channel is provided through the upper part of the cavity wall, and a connecting channel is provided through the lower part of the cavity wall, and the oil delivery channel and the connecting channel are both connected to the oil storage cavity.

[0008] The upper portion of the cavity wall includes a portion of the cavity wall located at the top of the oil storage cavity, or a portion of the cavity wall located on the side of the upper portion of the oil storage cavity.

[0009] The lower portion of the cavity wall includes a portion of the cavity wall located at the bottom of the oil storage cavity, or a portion of the cavity wall located on the side of the lower portion of the oil storage cavity.

[0010] The oil storage device described in the present invention, when in use, is at least partially submerged in water, with the oil storage chamber filled with as much oil and water as possible. Because water is denser than oil, the water in the oil storage chamber is located at the bottom, while the oil is located at the top. During operation, a "floating bottom" function is achieved through a connecting channel at the bottom of the chamber wall and an oil transfer channel at the top of the chamber wall. That is, as crude oil is extracted from the oil storage chamber through the oil transfer channel, water from the outside of the oil storage device is simultaneously replenished and enters the oil storage chamber through the connecting channel. Similarly, as crude oil is transferred to the oil storage chamber through the oil transfer channel, water stored in the oil storage chamber is simultaneously discharged through the connecting channel. This ensures that the portion of the chamber wall located at the top of the oil storage chamber remains in constant contact with the crude oil, minimizing evaporation losses of the crude oil in the oil storage chamber due to the "breathing" effect.

[0011] In the above process, water is used to adjust the space in the oil storage chamber other than the crude oil. There is no need to change the volume of the oil storage chamber, so there is no need to change the structure of the chamber wall. Therefore, compared with the existing floating roof storage tank solution, the oil storage equipment described in the present invention does not require a complex sealing structure and is more convenient to maintain.

[0012] Preferably, a plurality of compartments are provided in the oil storage cavity, and adjacent compartments are separated by partition walls, the partition walls are connected to the cavity wall, and through holes are provided on the partition walls, and the through holes communicate with adjacent compartments.

[0013] By arranging a partition wall in the oil storage cavity, at least a portion of the partition wall is connected to the cavity wall, so as to enhance the structural strength of the cavity wall.

[0014] Preferably, there are at least two types of partition walls, one of which is an annular wall arranged in the oil storage cavity, and the other is a first partition wall connecting the annular wall and the cavity wall. There are several first partition walls, and the several first partition walls are radially arranged along the outer circumference of the annular wall.

[0015] Preferably, a plurality of compartments are provided in the oil storage cavity, and adjacent compartments are separated by a partition wall, and the partition wall is connected to the cavity wall. A through hole is provided on the partition wall, and the through hole connects the adjacent compartments. By providing a partition wall in the oil storage cavity, the partition wall is connected to the cavity wall to strengthen the structural strength of the cavity wall.

[0016] Preferably, a water storage tank is provided protruding downward from the bottom of the oil storage cavity, and a tank wall is provided protruding downward from the bottom of the cavity wall. The tank wall is located outside the water storage tank, and the connecting channel is located on the tank wall. For oil storage cavities of the same specifications, the water storage tank is provided protruding downward from the bottom of the oil storage cavity, which increases the overall volume of oil and water storage and reduces the installation height of the connecting channel, thereby further increasing the crude oil storage space.

[0017] Preferably, the cavity wall is an integral prefabricated structural component.

[0018] Preferably, the oil storage chamber includes at least two oil storage chamber units arranged vertically, and the chamber wall correspondingly includes at least two chamber wall units arranged vertically. The chamber wall unit is located on the outside of the corresponding oil storage chamber unit, and adjacent oil storage chamber units are connected. In order to consider batch prefabrication, improve prefabrication efficiency, and reduce installation difficulty, the chamber wall can be divided into at least two chamber wall units, which are prefabricated and transported separately and assembled on site to improve prefabrication and transportation efficiency and reduce installation difficulty.

[0019] Preferably, the oil delivery channel is provided through the uppermost cavity wall unit, and the oil delivery channel is communicated with the uppermost oil storage cavity unit.

[0020] Preferably, the communication channel is provided through the lowermost cavity wall unit, and the communication channel is communicated with the lowermost oil storage cavity unit.

[0021] Preferably, at least one circle of sealing device is provided between the vertically adjacent cavity wall units, and the communication openings between the vertically adjacent cavity wall units are located inside the sealing device to prevent crude oil from leaking from the communication openings to between the vertically adjacent cavity wall units and then leaking to the outside world, thereby polluting the surrounding environment.

[0022] Preferably, it also includes a protrusion and a first opening that cooperate with each other, and the connecting port passes through the protrusion. In the vertically adjacent cavity wall units, one of the protrusion and the first opening is arranged at the bottom of the upper cavity wall unit, and the other is arranged at the top of the lower cavity wall unit.

[0023] Preferably, the outer wall of the protrusion is set as a slope inclined from the front end of the protrusion toward the connecting port, and the side wall of the first opening is correspondingly inclined, which not only facilitates the lowering of the upper cavity wall unit, but also can accurately limit the relative displacement between the vertically adjacent cavity wall units through the inclined slope.

[0024] Preferably, a filter is provided on the communication channel to prevent organisms or sediment in the water from entering the oil storage chamber through the communication channel.

[0025] Preferably, a working platform is provided at the oil delivery channel, and the working platform is installed on the top of the cavity wall.

[0026] Preferably, the oil storage chamber volume V: 100m 3 ≤V≤300000m 3 .

[0027] Preferably, the portion of the cavity wall located on the side of the oil storage cavity comprises a reinforced concrete structure.

[0028] Preferably, the cavity wall is a reinforced concrete structure.

[0029] Preferably, it includes a concrete oil storage structure, the concrete oil storage structure has the oil storage cavity inside, the part of the concrete oil storage structure located outside the oil storage cavity forms the cavity wall, the connecting channel is arranged at the lower part of the concrete oil storage structure, and the oil delivery channel is arranged at the upper part of the concrete oil storage structure.

[0030] Preferably, the concrete oil storage structure is a rectangular parallelepiped, a cube, a cylinder, a drum, or a combined structure of a lower cylinder and an upper hemisphere.

[0031] Preferably, the concrete oil storage structure is a rectangular parallelepiped structure, and the dimensions of the rectangular parallelepiped structure are: length L: 100~120m, width W: 50~60m, height H: 20~40m.

[0032] Preferably, the cavity wall includes a first side wall, a first bottom structure and a first top structure, the first side wall, the first bottom structure and the first top structure enclose the oil storage cavity, a second side wall is arranged at intervals on the outside of the first side wall, a second bottom structure is sealed between the lower part of the second side wall and the lower part of the first side wall, the second side wall, the first side wall and the second bottom structure enclose an outer cavity, the connecting channel connects the oil storage cavity and the outer cavity, and the elevation of the top of the second side wall is greater than or equal to the elevation of the top of the oil storage cavity.

[0033] The oil storage device described in the present invention is primarily applicable to land-based environments. The outer chamber is filled with water having a greater density than crude oil. Since the top elevation of the second sidewall is greater than or equal to the top elevation of the oil storage chamber, the top elevation of the water can be greater than or equal to the top elevation of the oil storage chamber, allowing the oil storage chamber to be filled with both oil and water as much as possible. Since water is denser than oil, the water in the oil storage chamber is located at the bottom, while the oil is located at the top. During operation, the connecting passage and the oil transfer passage on the upper portion of the chamber wall achieve a "floating bottom" function. That is, when crude oil is extracted from the oil storage chamber through the oil transfer passage, water in the outer chamber is automatically replenished into the oil storage chamber through the connecting passage. Similarly, when crude oil is transferred into the oil storage chamber through the oil transfer passage, water stored in the oil storage chamber is naturally discharged from the connecting passage. This ensures that the portion of the chamber wall located at the top of the oil storage chamber remains in constant contact with the crude oil, minimizing evaporation losses of the crude oil in the oil storage chamber due to the "breathing" effect.

[0034] In the above process, water is used to adjust the space in the oil storage chamber other than the crude oil. There is no need to change the volume of the oil storage chamber, so there is no need to change the structure of the chamber wall. Therefore, compared with the existing floating roof storage tank solution, the oil storage equipment described in the present invention does not require a complex sealing structure and is more convenient to maintain.

[0035] Specifically, the oil delivery channel is provided through the first top structure, or the oil delivery channel is provided through the upper portion of the first side wall.

[0036] Preferably, the outer cavity contains a first liquid, the density of the first liquid is greater than the density of the crude oil in the oil storage cavity, and the top elevation of the first liquid is greater than or equal to the top elevation of the oil storage cavity.

[0037] The oil storage device described in the present invention is primarily applicable to land-based environments. A first liquid having a greater density than crude oil is filled within the outer chamber. Since the top elevation of the second sidewall is greater than or equal to the top elevation of the oil storage chamber, the top elevation of the first liquid can be greater than or equal to the top elevation of the oil storage chamber. The oil storage chamber is filled with both crude oil and the first liquid. Since the first liquid is denser than the crude oil, the first liquid is located at the bottom of the oil storage chamber, while the crude oil is located at the top. During operation, the connecting passage and the oil transfer passage on the upper portion of the chamber wall achieve a "floating bottom" function. That is, when crude oil is extracted from the oil storage chamber through the oil transfer passage, the first liquid in the outer chamber is automatically replenished into the oil storage chamber through the connecting passage. Similarly, when crude oil is transferred into the oil storage chamber through the oil transfer passage, the first liquid stored within the oil storage chamber is naturally discharged from the connecting passage. This ensures that the portion of the chamber wall located at the top of the oil storage chamber remains in constant contact with the crude oil, minimizing evaporation losses of the crude oil in the oil storage chamber due to the "breathing" effect.

[0038] At the same time, it is equally important that the water in the outer cavity can not only replenish the oil storage cavity in a timely manner, but also, during this process, the elevation of the top of the first liquid is always greater than or equal to the elevation of the top of the oil storage cavity. Thus, the water in the outer cavity can be used to ensure that the water pressure outside the first side wall is always greater than the crude oil pressure inside the first side wall, thereby effectively preventing crude oil from penetrating through the first side wall.

[0039] Preferably, the difference ΔH3 between the top elevation of the oil storage chamber and the top elevation of the first liquid is: -3m≤ΔH3≤0m. Preferably, a valve is provided on the communication channel, the valve being used to maintain the pressure outside the oil storage chamber greater than the pressure inside the oil storage chamber.

[0040] The difference ΔH3 between the top elevation of the oil reservoir and the top elevation of the first liquid is: -3m ≤ ΔH3 ≤ 0m. A valve is provided on the communication channel to maintain the pressure outside the oil reservoir greater than the pressure inside. This ensures that the pressure exerted by the first liquid outside the first sidewall on the first sidewall is always slightly greater than the pressure exerted by the crude oil inside the first sidewall. This not only effectively prevents crude oil from seeping through the first sidewall, but also ensures that the pressure inside and outside the first sidewall are close. The design of the first sidewall is simple, needing only to meet functional and temporary construction stress requirements, and the structural thickness of the first sidewall can be significantly optimized.

[0041] Specifically, the first liquid includes water.

[0042] Preferably, at least a portion of the first side wall is a reinforced concrete structure.

[0043] Preferably, the top of the outer cavity is open, so that external staff can observe the liquid level of the first liquid in the outer cavity in time.

[0044] Preferably, a second top structure is sealed between the upper portion of the second side wall and the upper portion of the first side wall, and the second top structure, the second side wall, the first side wall and the second bottom structure form the outer cavity to reduce evaporation of the first liquid.

[0045] Preferably, a ventilation channel is provided through the second top structure.

[0046] Preferably, the oil storage device of the present application further includes a power device, and the power device is used to transport the first liquid into the outer cavity.

[0047] During operation, when crude oil is extracted from the oil storage chamber through the oil transfer channel, the first liquid in the external cavity is automatically replenished into the oil storage chamber through the connecting channel; at the same time, the first liquid is replenished into the external cavity through the power device, thereby ensuring that the amount of the first liquid in the external cavity always meets the usage requirements. When crude oil is transported into the oil storage chamber through the oil transfer channel, the first liquid stored in the internal oil storage chamber is naturally discharged from the connecting channel into the external cavity, and the excess water in the external cavity is discharged from the top of the external cavity or other channels to the oil storage device. In this way, not only can the portion of the cavity wall located at the top of the oil storage chamber always maintain contact with the crude oil, minimizing the evaporation loss of crude oil in the oil storage chamber due to the "breathing" effect, but also the first liquid level in the external cavity can always be maintained at the target height.

[0048] Preferably, a cross brace is connected between the first side wall and the second side wall. The cross brace is arranged above the second bottom structure, and the cross brace is spaced apart from the second bottom structure.

[0049] The structural strength of the oil storage device is effectively enhanced by the cross brace, especially when the top of the outer cavity is open, the effect of enhancing the structural strength of the oil storage device is better.

[0050] Preferably, the oil storage cavity is filled with crude oil and a first liquid, and the density of the first liquid is greater than the density of the crude oil in the oil storage cavity.

[0051] The oil storage device of the present application further includes a power device, which is connected to the communication channel and is used to transport the first liquid into the communication channel.

[0052] During operation, when crude oil is extracted from the oil storage chamber through the oil transfer channel, the external first liquid is synchronously transferred through the connecting channel to be replenished into the oil storage chamber by the power device. When crude oil is transferred into the oil storage chamber through the oil transfer channel, the first liquid stored in the oil storage chamber is discharged from the oil storage chamber through the connecting channel. In this way, not only can the portion of the cavity wall located at the top of the oil storage chamber always keep in contact with the crude oil, but also the evaporation loss of the crude oil in the oil storage chamber due to the "breathing" effect can be minimized.

[0053] The present invention also discloses a floating bottom micro-positive pressure oil storage system, comprising the oil storage device according to the present invention, wherein:

[0054] The elevation of the top of the oil storage chamber is equal to or lower than the first elevation, and the elevation difference ΔH1 between the first elevation and the low tide level is: ΔH1≤3m;

[0055] The bottom of the cavity wall is provided with a seat bottom.

[0056] The floating bottom micro-positive pressure oil storage system described in the present invention is configured such that the elevation of the top of the oil storage chamber is equal to or lower than a first elevation, and the elevation difference ΔH1 between the first elevation and the low tide level is: ΔH1≤3m; during at least a portion of time, at the same elevation, the water pressure outside the chamber wall is greater than the crude oil pressure inside the chamber wall, forming a micro-positive pressure, thereby effectively improving the penetration of crude oil through the chamber wall.

[0057] Preferably, the difference ΔH2 between the top elevation of the oil storage chamber and the low tide elevation is: -3m≤ΔH2≤3m.

[0058] Preferably, the elevation of the top of the oil storage chamber is equal to or lower than the low tide elevation.

[0059] The floating bottom micro-positive pressure oil storage system described in the present invention ensures that the water pressure outside the concrete oil storage structure is always equal to or greater than the crude oil pressure inside the concrete oil storage structure by ensuring that the top elevation of the oil storage cavity is equal to or lower than the low tide level, thereby effectively preventing crude oil from penetrating through the cavity wall.

[0060] Preferably, the difference ΔH2 between the top elevation of the oil storage cavity and the low tide elevation is: -3m≤ΔH2≤0m, so that the water pressure outside the concrete oil storage structure is always slightly greater than the crude oil pressure inside the concrete oil storage structure. This not only effectively prevents crude oil from penetrating from the cavity wall, but also makes the pressure inside and outside the cavity wall close, and the cavity wall design is easy to meet, and only needs to meet the functional and temporary construction force requirements, and the structural wall thickness can be greatly optimized.

[0061] Preferably, the bottom of the cavity wall is arranged at the bottom of the water.

[0062] The total weight of the oil storage equipment underwater is approximately equal to the buoyant weight of the structure. Combined with the optimization of the wall thickness of the cavity structure, the bottom pressure of the oil storage equipment is light. When the bottom pressure of the oil storage equipment is relatively small, or even smaller than the historical stress of the subsoil, the bottom of the cavity wall can be set at the bottom of the water, thereby achieving the goal of eliminating underwater foundation treatment and greatly saving construction costs.

[0063] Preferably, a groove is provided at the surface floating mud of the bottom of the water, and the bottom of the cavity wall is provided at the bottom of the groove.

[0064] The total weight of the oil storage equipment underwater is approximately equal to the buoyant weight of the structure. Combined with the optimization of the wall thickness of the cavity structure, the bottom pressure of the oil storage equipment is light. By digging out the surface floating mud to form a pit, the foundation stress at the bottom of the pit is significantly greater than the foundation stress of the surface floating mud. The structural pressure of the oil storage equipment can be made less than the historical stress of the foundation, thereby achieving the goal of eliminating underwater foundation treatment, or making underwater foundation treatment simpler and more economical, thereby significantly saving construction costs.

[0065] Preferably, the cavity wall is arranged on a base cushion layer, and the base cushion layer is arranged on the bottom of the water.

[0066] Preferably, the cavity wall is arranged on a base cushion layer, a groove is provided at the surface floating mud of the bottom of the water, and the base cushion layer is filled in the groove.

[0067] In order to ensure that there are no local hard spots at the bottom of the pit, a foundation cushion layer is filled in the pit for leveling.

[0068] Preferably, the base cushion layer is a crushed stone cushion layer.

[0069] Preferably, the thickness of the foundation cushion layer is 0.5~1.5m.

[0070] Preferably, the lower portion of the cavity wall is in contact with a locking backfill structure, and the locking backfill structure is used to limit the lateral movement of the oil storage equipment.

[0071] Because the floating, micro-positive pressure oil storage system of the present invention can reduce subsequent settlement with minimal foundation pressure, even less than the historical stress of the subsoil, it can eliminate underwater foundation pretreatment procedures or simplify and economically simplify them. However, if the foundation pressure of the oil storage equipment is low, it may slip under loads such as waves and currents. To prevent the oil storage equipment from shifting horizontally, a locking backfill structure is installed in the contact area at the lower part of the cavity wall.

[0072] Preferably, the floating bottom micro-positive pressure oil storage system of the present invention further comprises at least one section of calm water area surrounded by a wave-breaking dam, wherein at least one of the oil storage devices is arranged in the calm water area.

[0073] The construction method for the floating bottom micro-positive pressure oil storage system described in the present invention includes a sinking step: the oil storage equipment sinks to the bottom of the water so that the elevation of the top of the oil storage cavity is equal to or lower than the first elevation, and the bottom of the cavity wall is set at the bottom.

[0074] The present invention discloses a construction method for a floating bottom micro-positive pressure oil storage system. The method comprises the following steps: ensuring that the top elevation of the oil storage chamber is equal to or lower than a first elevation, wherein the elevation difference ΔH1 between the first elevation and the low tide level is: ΔH1 ≤ 3 m. Furthermore, at the same elevation, for at least a portion of time, the water pressure outside the concrete oil storage structure is greater than the crude oil pressure inside the concrete oil storage structure, thereby effectively improving the penetration of crude oil through the chamber wall. Furthermore, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is achieved, significantly reducing storage costs and minimizing evaporation and waste of crude oil in the oil storage chamber.

[0075] Preferably, in the sinking step, the top elevation of the oil storage chamber is lower than the low tide level.

[0076] Preferably, the communication channel is opened to allow water to enter the oil storage cavity through the communication channel, making it easier for the oil storage device to sink.

[0077] Preferably, at least part of the gas in the oil storage chamber is extracted through the oil delivery channel, and then the oil delivery channel is closed.

[0078] By utilizing the air extraction equipment, at least part of the gas in the oil storage chamber is extracted through the oil transfer channel, so that a closed chamber is formed inside the oil storage chamber, and negative pressure is formed in the oil storage chamber. At this time, the connecting channel is opened, so that the oil storage equipment obtains a sinking suction force, and the suction force works together with the gravity of the oil storage equipment to cause the oil storage equipment to sink. By pre-pressing the foundation with negative pressure, the later settlement of the oil storage equipment is completed as soon as possible, thereby optimizing and reducing the settlement problem during the use of the oil storage equipment.

[0079] Preferably, before the sinking step, the soft mud on the bottom of the water is removed to form a trench pit;

[0080] In the sinking step, the oil storage equipment sinks into the pit so that the bottom of the cavity wall is set at the bottom of the pit.

[0081] Preferably, before the sinking step, a foundation cushion layer is filled in the trench;

[0082] In the sinking step, the bottom of the cavity wall is arranged on the base cushion layer.

[0083] The construction method for a floating bottom micro-positive pressure oil storage system described in the present invention forms a pit by excavating the surface floating mud. This can ensure that the structural pressure of the oil storage equipment is less than the historical stress of the foundation, thereby eliminating the need for underwater foundation treatment. In addition, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is realized, which greatly reduces storage costs and reduces the evaporation and waste of crude oil in the oil storage chamber.

[0084] Preferably, the construction method for a floating bottom micro-positive pressure oil storage system according to the present invention is based on the fact that the oil storage cavity comprises at least two vertically arranged oil storage cavity units, and the cavity wall correspondingly comprises at least two vertically arranged cavity wall units, the cavity wall units are located outside the corresponding oil storage cavity units, and adjacent oil storage cavity units are connected;

[0085] The specific sinking steps are:

[0086] S1. The lowest wall unit is sunk and the bottom seat is set;

[0087] S2. Place the remaining adjacent cavity wall units in order from bottom to top, and make the vertically adjacent cavity wall units sealed and the vertically adjacent oil storage cavity units connected.

[0088] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0089] 1. The oil storage device described in the present invention is placed underwater when in use, and the oil storage chamber is filled with oil and water as much as possible. Since the density of water is heavier than that of oil, the water in the oil storage chamber is at the bottom and the oil is at the top. During operation, the "floating bottom" function is realized through the connecting channel at the bottom of the chamber wall and the oil transfer channel at the top of the chamber wall. That is, when crude oil is extracted from the oil storage chamber through the oil transfer channel, the water outside the oil storage device is automatically replenished into the oil storage chamber through the connecting channel. Similarly, when crude oil is transported to the oil storage chamber through the oil transfer channel, the water stored in the oil storage chamber is naturally discharged from the connecting channel. In this way, the portion of the chamber wall located at the top of the oil storage chamber always keeps in contact with the crude oil, minimizing the evaporation loss of crude oil in the oil storage chamber due to the "breathing" effect;

[0090] Since the cavity wall is used to reduce the evaporation loss of crude oil in the oil storage cavity due to the "breathing" effect, it effectively reduces the consumption of steel compared to the existing floating roof storage tank solution. At the same time, water is used to adjust the space in the oil storage cavity other than the crude oil, and there is no need to change the structure of the cavity wall. Compared with the existing floating roof storage tank solution, it does not require a complex sealing structure and is more convenient to maintain.

[0091] 2. The floating bottom micro-positive pressure oil storage system described in the present invention, by raising the top elevation of the oil storage cavity below the low tide level, ensures that the water pressure outside the concrete oil storage structure is always greater than the crude oil pressure inside the concrete oil storage structure, thereby effectively preventing crude oil from penetrating through the cavity wall.

[0092] 3. The construction method for a floating bottom micro-positive pressure oil storage system described in the present invention, by excavating the surface floating mud to form a pit, can ensure that the structural pressure of the oil storage equipment is less than the historical stress of the foundation, thereby eliminating the need for underwater foundation treatment. In addition, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is realized, which greatly reduces storage costs and reduces the evaporation and waste of crude oil in the oil storage chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] FIG1 is a schematic diagram of the longitudinal cross-sectional structure of an oil storage device of the present invention (integral type, without partition walls).

[0094] FIG2 is a schematic diagram of a longitudinal cross-sectional view of an oil storage device of the present invention (integral type, with partition walls).

[0095] FIG3 is a schematic diagram of a longitudinal cross-sectional view of an oil storage device of the present invention (integral type, with partition walls and water storage tanks).

[0096] FIG4 is a schematic diagram of a longitudinal cross-sectional view of an oil storage device of the present invention (integral type, without partition walls, with a water storage tank).

[0097] FIG5 is a schematic diagram of a longitudinal cross-sectional view of an oil storage device of the present invention (assembled, with at least two oil storage chamber units).

[0098] FIG6 is an enlarged schematic diagram of portion B in FIG5 of the present invention.

[0099] FIG7 is a schematic diagram of the installation of a floating bottom micro-positive pressure oil storage system of the present invention (an integral oil storage device, installed in a tank pit, without a gravel cushion layer).

[0100] FIG8 is a schematic diagram of the installation of a floating bottom micro-positive pressure oil storage system of the present invention (an integral oil storage device, installed in a pit, with a water storage tank and no gravel cushion layer).

[0101] FIG9 is a schematic diagram of the installation of a floating bottom micro-positive pressure oil storage system of the present invention (an integral oil storage device, installed in a tank pit, with a gravel cushion layer).

[0102] FIG10 is a schematic diagram of the installation of a floating bottom micro-positive pressure oil storage system of the present invention (assembled oil storage equipment, installed in a tank pit, without a gravel cushion layer).

[0103] Figure 11 is a schematic diagram of the installation of a floating bottom micro-positive pressure oil storage system of the present invention (assembled oil storage equipment, installed in a tank pit with a gravel cushion layer).

[0104] FIG12 is a schematic diagram of the liquid pressure inside and outside the cavity wall of the present invention (when the water is at a low water level).

[0105] FIG13 is an enlarged schematic diagram of portion B in FIG12 of the present invention.

[0106] FIG14 is a schematic diagram of the liquid pressure inside and outside the cavity wall of the present invention (when the water is at a high water level).

[0107] FIG15 is a schematic diagram of the location of soft mud on the underwater surface in a construction method for a floating bottom micro-positive pressure oil storage system according to the present invention.

[0108] FIG16 is a schematic diagram of the underwater surface soft mud excavation process in a construction method for a floating bottom micro-positive pressure oil storage system according to the present invention.

[0109] FIG17 is a schematic diagram of the process of constructing a gravel cushion layer in a construction method for a floating bottom micro-positive pressure oil storage system according to the present invention.

[0110] FIG18 is a schematic diagram of the oil storage equipment sinking process in a construction method for a floating bottom micro-positive pressure oil storage system of the present invention (integrated oil storage equipment).

[0111] FIG19 is a schematic diagram of the process of sinking the oil storage equipment into place in a construction method for a floating bottom micro-positive pressure oil storage system of the present invention (integrated oil storage equipment).

[0112] FIG20 is a schematic diagram of the sinking process of the lower cavity wall unit in a construction method for a floating bottom micro-positive pressure oil storage system of the present invention (assembled oil storage equipment).

[0113] FIG21 is a schematic diagram of the process of sinking the lower cavity wall unit into place in a construction method for a floating bottom micro-positive pressure oil storage system of the present invention (assembled oil storage equipment).

[0114] FIG22 is a schematic diagram of the sinking process of the upper cavity wall unit in a construction method for a floating bottom micro-positive pressure oil storage system of the present invention (assembled oil storage equipment).

[0115] FIG23 is a schematic diagram of the outer shape of the concrete oil storage structure of the present invention (a combination of a lower cylinder and an upper hemisphere).

[0116] FIG24 is a schematic diagram of the outer shape of the concrete oil storage structure of the present invention (rectangular parallelepiped).

[0117] FIG25 is a schematic diagram of the outer shape of the concrete oil storage structure of the present invention (cylinder).

[0118] FIG26 is a schematic diagram of the outer shape of the concrete oil storage structure of the present invention (drum body).

[0119] FIG27 is a schematic diagram of the longitudinal cross-sectional structure of an oil storage device of the present invention (with a power device).

[0120] FIG28 is a schematic diagram of the longitudinal cross-sectional structure of an oil storage device of the present invention (having a second side wall, a closed top of the outer cavity, and a first liquid input into the outer cavity from the lower part of the outer cavity).

[0121] FIG29 is a schematic sectional view taken along line AA in FIG28 of the present invention.

[0122] FIG30 is a schematic diagram of the longitudinal cross-sectional structure of an oil storage device of the present invention (having a second side wall, a closed top of the outer cavity, and a first liquid input into the outer cavity from the top of the outer cavity).

[0123] FIG31 is a schematic diagram of the longitudinal cross-sectional structure of an oil storage device of the present invention (the top of the outer cavity is open).

[0124] Icons: 1-working platform, 2-oil transfer channel, 3-connecting channel, 4-cavity wall, 5-partition wall, 6-oil-water interface, 7-crude oil, 8-seawater, 9-top surface of concrete oil storage structure, 10-surface mud, 11-foundation cushion, 12-water pressure of water outside the concrete oil storage structure on the cavity wall, 13-compartment, 14-through hole, 15-water storage tank, 16-water pressure of crude oil inside the concrete oil storage structure on the cavity wall, 17-sealing device, 20-concrete oil storage structure, 21-first top structure, 22-first side wall, 23-first bottom structure, 24-oil storage cavity; 25-tank wall; 26-oil storage cavity unit; 27-cavity wall unit; 29-protrusion; 30-first opening; 31-slot; 33 - second side wall; 34 - second bottom structure; 35 - first liquid; 36 - outer cavity; 37 - power unit; 38 - air permeability channel; 39 - cross brace; 40 - annular wall; 41 - first partition wall; 42 - water pipe. DETAILED DESCRIPTION

[0125] The present invention will be described in detail below with reference to the accompanying drawings.

[0126] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0127] As shown in Figure 1, the oil storage device described in this embodiment includes an oil storage chamber 24, and the outer side of the oil storage chamber 24 has a chamber wall 4, an oil delivery channel 2 is provided through the upper part of the chamber wall 4, and a connecting channel 3 is provided through the lower part of the chamber wall 4, and the oil delivery channel 2 and the connecting channel 3 are both connected to the oil storage chamber 24.

[0128] The oil delivery channel 2 is an oil delivery pipeline, and the communication channel 3 is a pipe or a through hole.

[0129] The number of the oil delivery channel 2 on the upper portion of the same oil storage chamber 24 may be one or at least two.

[0130] The number of the communicating passage 3 at the lower portion of the same oil storage chamber 24 may be one or at least two.

[0131] The upper part of the cavity wall 4 includes the part of the cavity wall 4 located at the top of the oil storage cavity 24, or the part of the cavity wall 4 located at the upper side of the oil storage cavity 24, that is, the oil delivery channel 2 can be arranged through the part of the cavity wall 4 located at the top of the oil storage cavity 24, and the oil delivery channel 2 can also be arranged through the part of the cavity wall 4 located at the upper side of the oil storage cavity 24.

[0132] The lower part of the cavity wall 4 includes the part of the cavity wall 4 located at the bottom of the oil storage cavity 24, or the part of the cavity wall 4 located at the lower side of the oil storage cavity 24, that is, the connecting channel 3 can be arranged through the part of the cavity wall 4 located at the bottom of the oil storage cavity 24, and the connecting channel 3 can also be arranged through the part of the cavity wall 4 located at the lower side of the oil storage cavity 24.

[0133] The oil storage device described in this embodiment is placed in seawater 8 or lake water when in use, and the oil storage chamber 24 is filled with oil and water as much as possible. During operation, the "floating bottom" function is realized through the connecting channel 3 at the bottom of the chamber wall 4 and the oil transfer channel 2 at the top of the chamber wall 4. That is, when crude oil 7 is extracted from the oil storage chamber 24 through the oil transfer channel 2, the external seawater 8 or lake water is automatically replenished into the oil storage chamber 24 through the connecting channel 3. Similarly, when crude oil 7 is transported to the oil storage chamber 24 through the oil transfer channel 2, the seawater 8 or lake water stored in the oil storage chamber 24 is naturally discharged from the connecting channel 3. In this way, the portion of the chamber wall 4 located at the top of the oil storage chamber 24 always maintains contact with the crude oil 7, thereby minimizing the evaporation loss of the crude oil 7 in the oil storage chamber 24 due to the "breathing" effect.

[0134] In addition to the above, a further preferred embodiment is to provide a filter on the communication channel 3. To prevent organisms or sediment in the seawater 8 or lake water from entering the oil storage chamber 24 through the communication channel, a filtering device is installed on the communication channel. For example, a filter, such as a coarse filter, is provided on the communication channel. If the coarse filter is full, it is replaced or cleaned at regular intervals.

[0135] In the above scheme, when the external seawater 8 or lake water is automatically replenished into the oil storage chamber 24 through the connecting channel 3, a portion of the organisms or sediment in the seawater 8 or lake water will accumulate at the suction port of the filter. When the seawater 8 or lake water stored in the oil storage chamber 24 is naturally discharged from the connecting channel 3, at least a portion of the organisms or sediment at the suction port can be flushed back into the seawater 8 or lake water, thereby effectively reducing the number of times the coarse filter needs to be cleaned or replaced.

[0136] On the basis of the above, in a further preferred embodiment, a working platform 1 is provided at the oil delivery channel 2 , and the working platform 1 is installed on the top of the cavity wall 4 .

[0137] Specifically, the volume V of the oil storage chamber 24 is 0m 3 ≤V≤300000m 3 .

[0138] More preferably, the oil storage chamber 24 has a volume V of 100m 3 ≤V≤300000m 3 .

[0139] The preferred dimensions of oil storage equipment are: length: 100~120m, width: 50~60m, height: 20~40m.

[0140] The oil storage device described in this embodiment can also be used on land. When in use, the oil storage chamber 24 is filled with oil and water as much as possible. During operation, the "floating bottom" function is realized through the connecting channel 3 at the bottom of the chamber wall 4 and the oil delivery channel 2 at the top of the chamber wall 4. That is, when crude oil 7 is extracted from the oil storage chamber 24 through the oil delivery channel 2, water is simultaneously added to the oil storage chamber 24 through the connecting channel 3. Similarly, when crude oil 7 is delivered to the oil storage chamber 24 through the oil delivery channel 2, the water stored in the oil storage chamber 24 is simultaneously discharged from the connecting channel 3. In this way, the portion of the chamber wall 4 located at the top of the oil storage chamber 24 always keeps in contact with the crude oil 7, thereby minimizing the evaporation loss of the crude oil 7 in the oil storage chamber 24 due to the "breathing" effect.

[0141] In the above solution of this embodiment, the oil storage cavity 24 is filled with crude oil 7 and a first liquid 35 , and the density of the first liquid 35 is greater than the density of the crude oil 7 in the oil storage cavity 24 .

[0142] The first liquid 35 is a solution having a density greater than that of the crude oil 7 , and is preferably seawater 8 , lake water, or artificially pumped water.

[0143] Beneficial effects of this embodiment: The oil storage equipment described in this embodiment uses the cavity wall 4 to reduce the evaporation loss of the crude oil 7 in the oil storage cavity 24 due to the "breathing" effect. At the same time, seawater 8 or lake water is used to regulate the space in the oil storage cavity 24 other than the crude oil 7. There is no need to change the volume of the oil storage cavity 24, so there is no need to change the structure of the cavity wall 4. Compared with the existing floating roof storage tank solution, it does not require a complex sealing structure and is more convenient to maintain. Example 2

[0144] As shown in Figures 1-6, the oil storage equipment described in this embodiment is based on Example 1, and a plurality of compartments 13 are provided in the oil storage cavity 24. The adjacent compartments 13 are separated by a partition wall 5, and the partition wall 5 is connected to the cavity wall 4. The partition wall 5 needs to be permeable to water and oil. The partition wall 5 is provided with a through hole 14, and the through hole 14 connects the adjacent compartments 13. By providing the partition wall 5 in the oil storage cavity 24, at least a portion of the partition wall 5 is connected to the cavity wall 4 to enhance the structural strength of the cavity wall 4.

[0145] As shown in Figure 29, a specific method is: there are at least two types of partition walls 5, one of which is an annular wall 40 arranged in the oil storage chamber 24, and the other is a first partition wall 41 connecting the annular wall 40 and the chamber wall 4. There are several first partition walls 41, and the several first partition walls 41 are arranged radially along the outer circumference of the annular wall 40.

[0146] A water storage tank 15 is provided protruding downward from the bottom of the oil storage cavity 24, and a tank wall 25 is provided protruding downward from the bottom of the cavity wall 4. The tank wall 25 is located outside the water storage tank 15, and the connecting channel 3 is located on the tank wall 25. For oil storage cavities 24 of the same specifications, the water storage tank 15 is provided protruding downward from the bottom of the oil storage cavity 24, which increases the overall volume of oil and water storage and reduces the installation height of the connecting channel 3, thereby further increasing the storage space for crude oil 7. Example 3

[0147] As shown in Figures 1-6, the oil storage equipment described in this embodiment, based on Example 1, comprises at least a portion of the cavity wall 4 located on the side of the oil storage cavity 24, comprising a reinforced concrete structure, which is more corrosion-resistant in water than steel structures. Furthermore, during installation, the water pressure outside the reinforced concrete structure is slightly greater than the pressure of the crude oil 7 inside, effectively preventing leakage of the crude oil 7 from the concrete wall.

[0148] On the basis of the above, in a further preferred embodiment, the cavity wall 4 is a reinforced concrete structure.

[0149] Specifically, the oil storage equipment described in this embodiment includes a concrete oil storage structure 20, the concrete oil storage structure 20 has an oil storage cavity 24 inside, the portion of the concrete oil storage structure 20 located outside the oil storage cavity 24 forms the cavity wall 4, the connecting channel 3 is arranged at the lower part of the concrete oil storage structure 20, and the oil transfer channel 2 is arranged at the upper part of the concrete oil storage structure 20, and the connecting channel 3 and the oil transfer channel 2 connect the oil storage cavity 24 and the outside world.

[0150] As shown in Figures 1-4, the cavity wall 4 is an integral prefabricated structural component.

[0151] Furthermore, the concrete oil storage structure 20 is an integral prefabricated structure, that is, a monolithic structure.

[0152] As shown in Figures 23-26, the concrete oil storage structure 20 is a rectangular parallelepiped, a cube, a cylinder, a drum, or a combined structure of a lower cylinder and an upper hemisphere.

[0153] Specifically, when the concrete oil storage structure 20 is a rectangular parallelepiped structure, the dimensions of the rectangular parallelepiped structure are preferably: length L: 100-120 m, width W: 50-60 m, and height H: 20-40 m. Example 4

[0154] As shown in Figures 5 and 6, the oil storage equipment described in this embodiment is based on Example 1 and differs from Example 2 or 3 in that: the oil storage chamber 24 includes at least two oil storage chamber units 26 arranged vertically, and the cavity wall 4 correspondingly includes at least two cavity wall units 27 arranged vertically, and the cavity wall unit 27 is located on the outside of the corresponding oil storage chamber unit 26, and the oil storage chamber unit 26 is connected to at least one adjacent oil storage chamber unit 26.

[0155] In order to consider batch prefabrication, improve prefabrication efficiency, and reduce installation difficulty, the cavity wall 4 can be divided into at least two cavity wall units 27, which are prefabricated and transported separately and assembled on site to improve prefabrication and transportation efficiency and reduce installation difficulty.

[0156] The concrete oil storage structure 20 is divided into several vertical parts, each of which includes an oil storage cavity unit 26 and a cavity wall unit 27 outside the oil storage cavity unit 26 .

[0157] The oil delivery channel 2 is provided through the uppermost cavity wall unit 27 and communicates with the uppermost oil storage cavity unit 26. The communication channel 3 is provided through the lowermost cavity wall unit 27 and communicates with the lowermost oil storage cavity unit 26.

[0158] At least one circle of sealing devices 17 is provided between the vertically adjacent cavity wall units 27 , and the communication ports 28 between the vertically adjacent cavity wall units 27 are located inside the sealing devices 17 to prevent the crude oil 7 from leaking from the communication ports 28 to between the vertically adjacent cavity wall units 27 and then leaking to the outside world, thereby polluting the surrounding environment.

[0159] The oil storage device described in this embodiment also includes a protrusion 29 and a first opening 30 that cooperate with each other. The connecting port 28 passes through the protrusion 29 and is vertically adjacent to the cavity wall unit 27. One of the protrusion 29 and the first opening 30 is arranged at the bottom of the upper cavity wall unit 27, and the other is arranged at the top of the lower cavity wall unit 27.

[0160] In the vertically adjacent cavity wall units 27, the bottom of the upper cavity wall unit 27 is provided with a protrusion 29 protruding downward, the communication port 28 is located in the middle of the protrusion 29 and is vertically through-set, and the top of the lower cavity wall unit 27 is provided with a first opening 30, and the protrusion 29 and the first opening 30 are positioned and matched with each other.

[0161] Preferably, the outer wall of the protrusion 29 is set as a slope inclined from the front end of the protrusion 29 toward the connecting port 28, and the side wall of the first opening 30 is correspondingly inclined, which not only facilitates the lowering of the upper cavity wall unit 27, but also can accurately limit the relative displacement between the vertically adjacent cavity wall units 27 through the inclined slope.

[0162] A plurality of compartments 13 may also be provided in the oil storage cavity unit 26, and adjacent compartments 13 are separated by a partition wall 5, and the partition wall 5 is connected to the cavity wall 4. A through hole 14 is provided on the partition wall 5, and the through hole 14 connects the adjacent compartments 13. By providing a partition wall 5 in the oil storage cavity unit 26, the partition wall 5 is connected to the cavity wall unit 27 to strengthen the structural strength of the cavity wall unit 27, and the through hole 14 makes the partition wall 5 permeable to water and oil. Example 5

[0163] The floating bottom micro-positive pressure oil storage system described in this embodiment includes the oil storage device described in Example 1, 2, 3, or 4. Furthermore, a valve 32 is preferably provided on the communication passage 3 to maintain a micro-pressure differential between the inside and outside of the oil storage chamber 24. The top elevation of the oil storage chamber 24 is equal to or lower than a first elevation, and the elevation difference ΔH1 between the first elevation and the low tide level is ΔH1 ≤ 3 m. The bottom of the chamber wall 4 is disposed in a bottom-to-bottom manner.

[0164] In this field, low tide is also called low water level.

[0165] Among them, there are two cases for the first elevation:

[0166] Case 1: The first elevation is above the low tide level. At this time, ΔH1 satisfies the condition: 0 m ≤ ΔH1 ≤ 3 m. In this case, at least for a portion of the time, at the same elevation, the water pressure 12 exerted by the water outside the cavity wall 4 on the cavity wall is greater than the water pressure 16 exerted by the crude oil inside the cavity wall 4 , effectively reducing the penetration of the crude oil 7 through the cavity wall 4 .

[0167] Case 2: As shown in Figure 7-14, the first elevation is at or below the low tide level, that is, the elevation of the top of the oil storage chamber 24 is equal to or lower than the elevation of the low tide level. At this time, ΔH1 is: ΔH1≤0m. By setting the elevation of the top of the oil storage chamber 24 equal to or lower than the low tide level, the water pressure 12 of the water outside the cavity wall 4 on the cavity wall at the same elevation is always greater than the water pressure 16 of the crude oil inside the cavity wall 4 on the cavity wall at almost all times, thereby effectively preventing the crude oil 7 from penetrating the cavity wall 4.

[0168] In this case, the oil storage equipment can use a reinforced concrete structure. The water pressure 12 of the water outside the reinforced concrete structure on the cavity wall 4 is always greater than the water pressure 16 of the crude oil inside the reinforced concrete structure on the cavity wall 4, which effectively prevents the crude oil 7 from penetrating from the cavity wall 4.

[0169] As shown in FIG12 , based on the above, a further preferred embodiment is that the difference ΔH2 between the top elevation of the oil storage cavity 24 and the low tide elevation is: -3m≤ΔH2≤0m, so that the pressure of the seawater 8 or lake water outside the concrete oil storage structure 20 is always slightly greater than the pressure of the crude oil 7 inside the concrete oil storage structure 20. This not only effectively prevents the crude oil 7 from penetrating from the cavity wall 4, but also makes the pressures inside and outside the cavity wall 4 close. The cavity wall 4 is easy to design and only needs to meet the functional and temporary construction stress requirements. The structural wall thickness can be greatly optimized, which also greatly reduces the manufacturing cost.

[0170] The cavity wall 4 and the lower foundation may not be connected, but may be stacked up and down.

[0171] The bottom seat of the cavity wall 4 includes at least the following designs:

[0172] Preferred mode 1: the bottom of the cavity wall 4 is set at the bottom of the water.

[0173] In order to ensure that there are no local hard spots on the bottom of the water, a foundation cushion layer 11 is set on the bottom of the water, and the bottom of the cavity wall 4 is set on the foundation cushion layer 11. During construction, the foundation cushion layer 11 is directly constructed on the surface mud of the bottom of the water, compacted and leveled, and after it settles steadily, the cavity wall 4 is set on the foundation cushion layer 11.

[0174] As shown in FIG16 , preferred method two is as follows: a trough 31 is provided in the surface floating mud of the bottom of the water, and the bottom of the cavity wall 4 is provided at the bottom of the trough 31. The total weight of the oil storage equipment underwater is approximately equal to the structural buoyancy weight. Combined with the optimization of the structural wall thickness of the cavity wall 4, the bottom pressure of the oil storage equipment is light. By digging out the underwater surface soft mud 10 that does not meet the bearing requirements and forming the trough 31, the structural pressure of the oil storage equipment can be made less than the historical stress of the foundation, thereby enabling the elimination of underwater foundation treatment, or making underwater foundation treatment simpler and more economical, thereby significantly saving construction costs.

[0175] The bottom surface mud 10 is also commonly referred to as bottom surface soft mud or bottom surface floating mud.

[0176] As shown in FIG. 17 , in order to ensure that there are no local hard spots at the bottom of the groove 31 , the groove 31 is filled with a base cushion layer 11 for leveling, and the cavity wall 4 is arranged on the base cushion layer 11 .

[0177] At the same time, since the present invention describes a floating bottom micro-positive pressure oil storage system, the bottom of the cavity wall 4 is set at the bottom of the water. Since there is a requirement that the elevation of the top of the oil storage cavity 24 is lower than the low tide level, the elevation of the top of the oil storage cavity 24 can also be controlled by setting different thicknesses of the foundation cushion layer 11 to ensure that the elevation of the top of the oil storage cavity 24 is lower than the low tide level, which meets the construction requirements.

[0178] On the basis of the above, in a further preferred embodiment, the thickness of the base cushion layer 11 is 0.5-1.5 m.

[0179] Specifically, the foundation cushion layer 11 is a crushed stone cushion layer or a concrete cushion layer.

[0180] The lower portion of the cavity wall 4 is in contact with a locking backfill structure, and the locking backfill structure is used to limit the lateral movement of the oil storage equipment.

[0181] The oil storage equipment in this embodiment is placed on the seabed and sinks by wet deadweight. This invention investigates the low foundation pressure exerted by oil storage equipment, which is due to the high cost of underwater foundation treatment. The present invention employs a floating, micro-positive pressure oil storage system that uses low foundation pressure, even less than the historical stress of the subsoil, to reduce subsequent settlement, eliminating underwater foundation pretreatment procedures or simplifying and reducing costs. However, if the foundation pressure of the oil storage equipment is low, it may slip under loads such as waves and currents. To prevent the oil storage equipment from shifting in planar position, a locking backfill structure can be installed at corners or throughout the entire area. Example 6

[0182] As shown in Figures 1-11, the floating bottom micro-positive pressure oil storage system described in this embodiment includes the oil storage equipment described in Example 1, 2, 3, or 4. The difference between it and Example 5 is that: this embodiment describes a preferred situation during construction: the oil storage equipment mainly includes a concrete oil storage structure 20, a connecting channel 3 at the bottom, a working platform 1 for taking and delivering crude oil 7 at the top, and an oil transfer channel 2.

[0183] The concrete oil storage structure 20 is a prefabricated reinforced concrete component. It measures 100-120 meters in length (L), 50-60 meters in width (W), and 20-40 meters in height (H). During installation, the top elevation of the concrete oil storage structure 20 is equal to or lower than the water depth at low water level.

[0184] The concrete oil storage structure 20 is a bottom-mounted structure. Before the bottom-mounted structure is constructed, the soft mud 10 on the bottom surface of the water is removed.

[0185] The concrete oil storage structure 20 may not be connected to the bottom of the water, but may be simply stacked up and down.

[0186] The oil storage chamber 24 is filled with crude oil 7 and water, which is seawater 8 or lake water. Taking seawater 8 as an example, since seawater 8 is heavier than oil, the seawater 8 is at the bottom and the crude oil 7 is at the top in the oil storage chamber 24.

[0187] The top of the oil delivery channel 2 is connected to an oil extraction device, such as an oil pump, which extracts crude oil 7 from the oil storage chamber 24 through the oil delivery channel 2 or delivers crude oil 7 to the oil storage chamber 24.

[0188] The connecting channel 3 at the bottom of the oil storage chamber 24, combined with the upper oil extraction device, achieves a "floating bottom" function. That is, as crude oil 7 is extracted from the top, external seawater 8 is automatically replenished and enters the oil storage chamber 24 through the connecting channel 3 at the bottom. Similarly, as crude oil 7 is transported from the top into the oil storage chamber 24, the internally stored seawater 8 is naturally discharged through the connecting channel 3 at the bottom. This ensures that the portion of the concrete oil storage structure 20 located at the top of the oil storage chamber 24 remains in constant contact with the crude oil 7, minimizing evaporation losses from the "breathing" of the crude oil 7 within the oil storage chamber 24.

[0189] Several structural compartments 13 are provided inside the oil storage cavity 24. Adjacent compartments 13 are separated by partition walls 5. If the internal space is large, partition walls 5 are arranged horizontally and vertically. The partition walls 5 are made of steel or concrete to strengthen the concrete oil storage structure 20. The partition walls 5 allow water and crude oil 7 to pass through. For example, through holes 14 are provided in the partition walls 5.

[0190] As shown in Figure 7, by high-precision dredging at a depth of about 20 to 40 meters underwater, the concrete oil storage structure 20 can be directly placed on the seabed. As shown in Figure 9, if necessary, in order to ensure that there are no local hard spots, a 0.5 to 1.5 meter thick foundation cushion layer 11 can be laid to level it.

[0191] As shown in FIG8 , in order to further increase the storage space for crude oil 7 and minimize the elevation of the oil-water interface 6 between crude oil 7 and seawater 8 or lake water, a water storage tank 15 may be provided at the bottom of the concrete oil storage structure 20 .

[0192] As shown in Figures 12-14, by setting the elevation of the top surface 9 of the concrete oil storage structure at the same level as or slightly lower than the low tide level, the elevation of the top of the oil storage cavity 24 is lower than the low tide level, so that the pressure of the seawater 8 or lake water outside the concrete oil storage structure 20 is always slightly greater than the pressure of the crude oil 7 inside the concrete oil storage structure 20, which effectively prevents the crude oil 7 from penetrating through the cavity wall 4.

[0193] Moreover, the pressure inside and outside the cavity wall 4 is close, and the design of the cavity wall 4 is easy to meet. It only needs to meet the functional and temporary construction force requirements, and the structural wall thickness can be greatly optimized.

[0194] The total weight of the oil storage equipment underwater is approximately equal to the structural buoyancy weight. Combined with the optimization of the wall thickness of the cavity wall 4, the bottom pressure of the oil storage equipment is light. By digging out the surface floating mud to form the groove 31, the structural pressure of the oil storage equipment can be made less than the historical stress of the foundation, thereby achieving the goal of eliminating underwater foundation treatment.

[0195] The cavity wall 4 can be prefabricated as a whole or in layers:

[0196] As shown in Figures 10 and 20-22, for a water depth of 30~40m, batch prefabrication is considered to improve prefabrication efficiency. The cavity wall 4 can also be considered to be prefabricated in two layers, which are assembled on site. The upper and lower parts of the assembly parts are connected by upper and lower plug-in connections and sealed by a sealing device 17. For example, the sealing device 17 can be sealed with an annular rubber waterstop structure.

[0197] In addition to the box shape, the reinforced concrete oil storage structure 20 may also be cylindrical, drum-shaped, or have a lower cylindrical upper hemisphere shape.

[0198] In summary, the advantages of the oil storage equipment of this embodiment are summarized as follows:

[0199] First, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is realized, which greatly reduces storage costs and reduces the evaporation and waste of crude oil 7 in the oil storage chamber 24.

[0200] Second, the cavity wall 4 adopts a reinforced concrete structure, which is more conducive to corrosion resistance in water than a steel structure.

[0201] Third, the water pressure outside the cavity wall 4 is slightly greater than the pressure of the crude oil 7 inside, thereby preventing the crude oil 7 from penetrating and leaking from the concrete wall.

[0202] 4. The pressure on both sides of the inner and outer walls of the reinforced concrete cavity wall 4 is basically the same. Combined with the shielding structure, the oil storage equipment is subjected to very little force during use, and the wall thickness of the cavity wall 4 structure can be greatly optimized. Among them, the shielding structure is preferably a wave-breaking dike.

[0203] 5. In combination with the fourth point, the concrete oil storage structure 20 is a reinforced concrete structure, whose underwater weight is substantially equal to its buoyant density, and the foundation pressure is low. By excavating the soft floating mud on the surface, the foundation pressure can be made lower than the historical stress of the foundation, thereby realizing a solution of no underwater foundation treatment or significantly reducing the cost and difficulty of underwater foundation treatment.

[0204] 6. The concrete oil storage structure 20 uses a reinforced concrete structure, which is easy to construct and has a base-type construction, and can be built on a large scale. Example 7

[0205] The construction method of the floating bottom micro-positive pressure oil storage system described in this embodiment includes a sinking step: the oil storage equipment sinks to the bottom of the water so that the top elevation of the oil storage cavity 24 is equal to or lower than the first elevation, and the bottom of the cavity wall 4 is set at the bottom.

[0206] The present embodiment describes a construction method for a floating bottom micro-positive pressure oil storage system. By ensuring that the top elevation of the oil storage cavity 24 is equal to or lower than a first elevation, and the elevation difference ΔH1 between the first elevation and the low tide level is: ΔH1 ≤ 3 m, the pressure of the seawater 8 or lake water outside the concrete oil storage structure 20 is greater than the pressure of the crude oil 7 inside the concrete oil storage structure 20 at the same elevation for at least a portion of time, effectively improving the penetration of the crude oil 7 from the cavity wall 4. Furthermore, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is achieved, significantly reducing storage costs and minimizing evaporation and waste of crude oil 7 inside the oil storage cavity 24.

[0207] On the basis of the above, in a further preferred manner, during the sinking step, the top elevation of the oil storage chamber 24 is lower than the low tide level.

[0208] On the basis of the above, a further preferred method is to open the connecting channel 3 before or during the sinking step, so that water can enter the oil storage chamber 24 through the connecting channel 3, making it easier for the oil storage equipment to sink.

[0209] On the basis of the above, a further preferred embodiment is that before or during the sinking step, at least part of the gas in the oil storage chamber 24 is extracted through the oil transfer channel 2, and then the oil transfer channel 2 is closed.

[0210] At least part of the gas in the oil storage chamber 24 is extracted through the oil transfer channel 2 by using a vacuum device, so that a closed chamber is formed inside the oil storage chamber 24, and negative pressure is formed in the oil storage chamber 24. At this time, the connecting channel 3 is opened, so that the oil storage equipment obtains a sinking suction force, and the suction force works together with the gravity of the oil storage equipment to cause the oil storage equipment to sink. By pre-pressing the foundation with negative pressure, the later settlement of the oil storage equipment is completed as soon as possible, thereby optimizing and reducing the settlement problem during the use of the oil storage.

[0211] On the basis of the above, a further preferred method is that before the sinking step, the underwater foundation cushion layer 11 is constructed; in the sinking step, the oil storage equipment sinks onto the foundation cushion layer 11, and the foundation cushion layer 11 is preferably a gravel cushion layer or a concrete cushion layer. Example 8

[0212] As shown in Figures 15-19, the construction method of the floating bottom micro-positive pressure oil storage system described in this embodiment is different from that of embodiment 7 in that it includes the following steps:

[0213] S1. Excavate the bottom surface mud 10 to form a groove pit 31;

[0214] S2. The oil storage equipment is sunk into the trough 31 so that the top elevation of the oil storage cavity 24 is lower than the low tide level, and the bottom of the cavity wall 4 is set at the bottom of the trough 31.

[0215] The construction method for a floating bottom micro-positive pressure oil storage system described in this embodiment forms a pit 31 by excavating the surface floating mud. This can ensure that the structural pressure of the oil storage equipment is less than the historical stress of the foundation, thereby eliminating the need for underwater foundation treatment. In addition, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is realized, which greatly reduces storage costs and reduces the evaporation and waste of crude oil 7 in the oil storage chamber 24.

[0216] On the basis of the above, in a further preferred manner, in step S1 , a base cushion layer 11 is filled in the groove 31 ; and in step S2 , the bottom of the cavity wall 4 is disposed on the base cushion layer 11 .

[0217] The construction method for a floating bottom micro-positive pressure oil storage system described in this embodiment forms a pit 31 by excavating the surface floating mud. This can ensure that the structural pressure of the oil storage equipment is less than the historical stress of the foundation, thereby eliminating the need for underwater foundation treatment. In addition, by utilizing natural water pressure, a floating bottom design of the oil storage equipment is realized, which greatly reduces storage costs and reduces the evaporation and waste of crude oil 7 in the oil storage chamber 24. Example 9

[0218] As shown in Figures 20-23, this embodiment describes a construction method for the floating bottom micro-positive pressure oil storage system described in Example 5 or 6. This construction method differs from that of Example 7 or 8 in that: the oil storage cavity 24 includes at least two vertically arranged oil storage cavity units 26, and the cavity wall 4 correspondingly includes at least two vertically arranged cavity wall units 27. The cavity wall units 27 are located outside the corresponding oil storage cavity units 26, and adjacent oil storage cavity units 26 are connected.

[0219] Adjacent cavity wall units 27 are sealed by an annular rubber waterstop structure.

[0220] The specific sinking steps are:

[0221] S1. The bottom wall unit 27 is sunk and the bottom seat is set;

[0222] S2. Place the remaining adjacent cavity wall units 27 in order from bottom to top, and make the vertically adjacent cavity wall units 27 sealed, and the vertically adjacent oil storage cavity units 26 connected.

[0223] The construction method of the floating bottom micro-positive pressure oil storage system described in this embodiment can be prefabricated in batches to improve prefabrication efficiency. The upper and lower assemblies are assembled on site, and the assembly parts adopt upper and lower plug-in connections, which are simple and convenient to install. Example 10

[0224] As shown in Figures 27-31, an oil storage device described in this embodiment, based on Example 1, provides an oil storage device that can be used on land: specifically, the cavity wall 4 includes a first side wall 22, a first bottom structure 23 and a first top structure 21, the first side wall 22, the first bottom structure 23 and the first top structure 21 enclose the oil storage cavity 24, a second side wall 33 is arranged at intervals on the outside of the first side wall 22, a second bottom structure 34 is sealed between the lower part of the second side wall 33 and the lower part of the first side wall 22, the second side wall 33, the first side wall 22 and the second bottom structure 34 enclose an outer cavity 36, the connecting channel 3 connects the oil storage cavity 24 and the outer cavity 36, and the top elevation of the second side wall 33 is greater than or equal to the top elevation of the oil storage cavity 24.

[0225] The oil storage equipment described in the present invention is mainly applied to terrestrial environments when in use. The outer cavity 36 is filled with water having a density greater than that of crude oil 7. Since the top elevation of the second side wall 33 is greater than or equal to the top elevation of the oil storage cavity 24, the top elevation of the water can be made greater than or equal to the top elevation of the oil storage cavity 24. The oil storage cavity 24 is filled with oil and water as much as possible. Since the density of water is heavier than that of oil, the water in the oil storage cavity 24 is at the bottom and the oil is at the top. During operation, the "floating bottom" function is realized through the connecting channel 3 and the oil transfer channel 2 on the upper part of the cavity wall. That is, when crude oil is extracted from the oil storage cavity 24 through the oil transfer channel 2, the water in the external cavity 36 is automatically replenished into the oil storage cavity 24 through the connecting channel 3. Similarly, when crude oil is transported to the oil storage cavity 24 through the oil transfer channel, the water stored in the oil storage cavity 24 is naturally discharged from the connecting channel. In this way, the portion of the cavity wall located at the top of the oil storage cavity 24 always keeps in contact with the crude oil, which can minimize the evaporation loss of the crude oil in the oil storage cavity 24 caused by the "breathing" effect.

[0226] In the above process, water is used to adjust the space in the oil storage chamber 24 other than the crude oil. There is no need to change the volume of the oil storage chamber 24, so there is no need to change the structure of the chamber wall. Therefore, compared with the existing floating roof storage tank solution, the oil storage equipment described in the present invention does not require a complex sealing structure and is more convenient to maintain.

[0227] Specifically, the oil delivery channel 2 is provided through the first top structure 21 , or the oil delivery channel 2 is provided through the upper portion of the first side wall 22 .

[0228] During operation, the outer cavity 36 contains a first liquid 35 , the density of the first liquid 35 is greater than the density of the crude oil 7 in the oil storage cavity 24 , and the top elevation of the first liquid 35 is greater than or equal to the top elevation of the oil storage cavity 24 .

[0229] The oil storage equipment described in the present invention is mainly applied to onshore environments when in use. A first liquid 35 with a density greater than that of crude oil 7 is filled in the outer cavity 36. Since the top elevation of the second side wall 33 is greater than or equal to the top elevation of the oil storage cavity 24, the top elevation of the first liquid 35 can be made greater than or equal to the top elevation of the oil storage cavity 24. The oil storage cavity 24 is filled with crude oil 7 and the first liquid 35. Since the density of the first liquid 35 is heavier than that of the crude oil 7, the first liquid 35 is at the bottom and the crude oil 7 is at the top in the oil storage cavity 24. During operation, the "floating bottom" function is realized through the connecting channel 3 and the oil transfer channel 2 on the upper part of the cavity wall. That is, when crude oil is extracted from the oil storage cavity 24 through the oil transfer channel 2, the first liquid 35 in the outer cavity 36 is automatically replenished into the oil storage cavity 24 through the connecting channel 3. Similarly, when crude oil is transported to the oil storage cavity 24 through the oil transfer channel, the first liquid 35 stored in the oil storage cavity 24 is naturally discharged from the connecting channel 3. In this way, the portion of the cavity wall located at the top of the oil storage cavity 24 always keeps in contact with the crude oil, which can minimize the evaporation loss of the crude oil in the oil storage cavity 24 caused by the "breathing" effect.

[0230] At the same time, it is equally important that the water in the outer cavity 36 can not only replenish the oil storage cavity 24 in a timely manner, but also, during this process, the top elevation of the first liquid 35 is always greater than or equal to the top elevation of the oil storage cavity 24. Thus, the water in the outer cavity 36 can be used to ensure that the water pressure outside the first side wall 22 is always greater than the pressure of the crude oil 7 inside the first side wall 22, thereby effectively preventing the crude oil 7 from penetrating through the first side wall 22.

[0231] In the above case, at least a portion or the entirety of the first side wall 22 may be made of reinforced concrete structure, thereby greatly reducing the structural cost and the anti-leakage requirements for the reinforced concrete structure.

[0232] Specifically, the first liquid 35 includes water.

[0233] On the basis of the above, in a further preferred embodiment, the elevation difference ΔH3 between the top of the oil storage chamber 24 and the top of the first liquid 35 is: -3m≤ΔH3≤0m. Thus, the water in the outer chamber 36 is used to ensure that the pressure of the first liquid 35 on the first side wall 22 outside the first side wall 22 is always slightly greater than the pressure of the crude oil 7 on the first side wall 22 inside the first side wall 22. This not only effectively prevents the crude oil 7 from penetrating the first side wall 22, but also ensures that the pressure inside and outside the first side wall 22 are close. The design of the first side wall 22 is easy to meet, and only needs to meet the functional and temporary construction stress requirements. The structural wall thickness of the first side wall 22 can be greatly optimized.

[0234] Preferably, a cross brace 39 is connected between the first side wall 22 and the second side wall 33. The cross brace 39 is arranged above the second bottom structure 34, and the cross brace 39 is spaced apart from the second bottom structure 34. The structural strength of the oil storage equipment is effectively enhanced by the cross brace 39.

[0235] Specifically, in the above solution, the first bottom structure 23 can be a steel structure or a reinforced concrete structure, which has higher anti-leakage requirements, or the surface of the first bottom structure 23 is coated with an anti-seepage layer, and the first bottom structure 23 can be a plate.

[0236] Specifically, in the above solution, the first top structure 21 can be a steel structure or a reinforced concrete structure, which has higher anti-leakage requirements, or the surface of the first top structure 21 is coated with an anti-seepage layer, and the first top structure 21 can be a plate.

[0237] Specifically, in the above solution, the second bottom structure 34 may be a steel structure or a reinforced concrete structure, and the second bottom structure 34 may be a plate. Example 11

[0238] As shown in Figure 31, the oil storage equipment described in this embodiment is different from that of Examples 1, 2, 3, 4 or 10 in that the top of the outer chamber 36 is open, which enables external staff to observe the liquid level of the first liquid 35 in the outer chamber 36 in time.

[0239] In the above situation, the first liquid 35 may evaporate quickly. At this time, the power device 37 is used to transport the first liquid 35 into the outer cavity 36, and timely replenish a sufficient amount of the first liquid 35 into the outer cavity 36, so that the first liquid 35 in the outer cavity 36 meets the working requirements.

[0240] Specifically, the power device 37 is disposed outside the second side wall 33 , or the power device 37 is disposed on the top of the second side wall 33 .

[0241] In another way, the power device 37 is arranged at the outer bottom of the second side wall 33, and the output end of the power device 37 is connected to the water pipe 42, which can be laid to the top of the outer cavity 36, thereby achieving the purpose of transporting the first liquid 35 into the outer cavity 36.

[0242] Specifically, the power device 37 is a water pump.

[0243] Preferably, a cross brace 39 is connected between the first side wall 22 and the second side wall 33. The cross brace 39 is arranged above the second bottom structure 34, and the cross brace 39 is spaced apart from the second bottom structure 34. The cross brace 39 can effectively enhance the structural strength of the oil storage equipment, especially when the top of the outer cavity 36 is open, the effect of enhancing the structural strength of the oil storage equipment is better. Example 12

[0244] As shown in Figures 28-30, the oil storage equipment described in this embodiment is different from that of Examples 1, 2, 3, 4, 10 or 11 in that a second top structure 34 is sealed between the upper portion of the second side wall 33 and the upper portion of the first side wall 22, and the second top structure 34, the second side wall 33, the first side wall 22 and the second bottom structure 34 form the outer cavity 36 to reduce the evaporation of the first liquid 35.

[0245] Specifically, in the above solution, the second top structure 34 may be a steel structure or a reinforced concrete structure, and the second top structure 34 may be a plate.

[0246] In the above case, a ventilation channel 38 is provided through the second top structure 34 . Specifically, the ventilation channel 38 is a pipe.

[0247] In the above case, a power device 37 is generally provided, and the power device 37 is used to transport the first liquid 35 into the outer cavity 36 .

[0248] During operation, when crude oil is extracted from the oil storage chamber 24 via the oil transfer channel 2, the first liquid 35 in the external chamber 36 is automatically replenished into the oil storage chamber 24 via the connecting channel 3. Simultaneously, the first liquid 35 is replenished into the external chamber 36 via the power unit 37, thereby ensuring that the amount of the first liquid 35 in the external chamber 36 always meets the required level. When crude oil is transferred to the oil storage chamber 24 via the oil transfer channel 2, the first liquid 35 stored in the oil storage chamber 24 naturally drains from the connecting channel 3 into the external chamber 36, and excess water in the external chamber 36 is drained from the top of the external chamber 36 or other channels to the oil storage device. This ensures that the portion of the chamber wall located at the top of the oil storage chamber 24 remains in contact with the crude oil, minimizing evaporation losses of the crude oil in the oil storage chamber 24 due to the "breathing" effect, and that the level of the first liquid 35 in the external chamber 36 is always maintained at the target height.

[0249] Specifically, the power device 37 is disposed outside the second side wall 33 .

[0250] When the second top structure 34 is provided, a liquid level meter is provided on the second side wall 33 , so as to facilitate the staff to observe the liquid level of the first liquid 35 in the outer cavity 36 . Specifically, a transparent observation window can be sealed and provided on the second top structure 34 . Example 13

[0251] As shown in Figure 27, the oil storage device described in this embodiment is different from that of Examples 1, 2, 3, 4, 10, 11 or 12 in that: the oil storage device of the present application also includes a power device 37, which is connected to the connecting channel 3, and the power device 37 is used to transport the first liquid 35 into the connecting channel 3.

[0252] The oil storage chamber 24 is filled with crude oil 7 and a first liquid 35. The density of the first liquid 35 is greater than that of the crude oil 7 in the oil storage chamber 24. During operation, when crude oil is extracted from the oil storage chamber 24 via the oil delivery channel 2, the external first liquid 35 is simultaneously delivered to the oil storage chamber 24 through the connecting channel 3 by the power device 37. When crude oil is delivered to the oil storage chamber 24 via the oil delivery channel 2, the first liquid 35 stored in the oil storage chamber 24 is discharged from the oil storage chamber 24 through the connecting channel 3. This ensures that the portion of the cavity wall 4 located at the top of the oil storage chamber 24 remains in contact with the crude oil and minimizes evaporation losses of the crude oil in the oil storage chamber 24 due to the "breathing" effect.

[0253] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil storage device, characterized in that: The oil storage chamber (24) comprises an oil storage chamber (24), the outer side of which is provided with a chamber wall (4), an oil delivery passage (2) penetrating the upper part of the chamber wall (4), and a connecting passage (3) penetrating the lower part of the chamber wall (4), the oil delivery passage (2) and the connecting passage (3) both being connected to the oil storage chamber (24).

2. An oil storage device according to claim 1, characterized in that: A plurality of compartments (13) are arranged in the oil storage cavity (24), and adjacent compartments (13) are separated by partition walls (5), at least part of the partition walls (5) are connected to the cavity wall (4), and through holes (14) are arranged on the partition walls (5), and the through holes (14) are connected to adjacent compartments (13).

3. An oil storage device according to claim 2, characterized in that: The partition walls (5) are provided in at least two types, one of which is an annular wall (40) provided in the oil storage cavity (24), and the other is a first partition wall (41) connecting the annular wall (40) and the cavity wall (4), and a plurality of the first partition walls (41) are provided, and the plurality of the first partition walls (41) are radially arranged along the outer circumference of the annular wall (40).

4. The oil storage device according to claim 2, characterized in that: A water storage bin (15) is protruding downward from the bottom of the oil storage cavity (24), and a bin wall (25) is correspondingly protruding downward from the bottom of the cavity wall (4). The bin wall (25) is located outside the water storage bin (15), and the connecting channel (3) is located on the bin wall (25).

5. The oil storage device according to claim 1, characterized in that: The cavity wall (4) is an integral prefabricated structural component.

6. The oil storage device according to claim 1, characterized in that: The oil storage chamber (24) comprises at least two oil storage chamber units (26) arranged vertically, and the chamber wall (4) correspondingly comprises at least two chamber wall units (27) arranged vertically, wherein the chamber wall unit (27) is located outside the corresponding oil storage chamber unit (26), and the oil storage chamber unit (26) is connected to at least one adjacent oil storage chamber unit (26).

7. An oil storage device according to claim 6, characterized in that: The oil delivery channel (2) is arranged through the uppermost cavity wall unit (27), and the oil delivery channel (2) is connected to the uppermost oil storage cavity unit (26).

8. The oil storage device according to claim 6, characterized in that: The communication channel (3) is arranged to penetrate the bottom cavity wall unit (27), and the communication channel (3) is connected to the bottom oil storage cavity unit (26).

9. The oil storage device according to claim 6, characterized in that: At least one circle of sealing devices (17) is provided between the vertically adjacent cavity wall units (27), and the communication openings (28) between the vertically adjacent cavity wall units (27) are located inside the sealing devices (17).

10. An oil storage device according to claim 9, characterized in that: It also includes a protrusion (29) and a first opening (30) that cooperate with each other, the communication port (28) passes through the protrusion (29) and is vertically adjacent to the cavity wall unit (27), one of the protrusion (29) and the first opening (30) is arranged at the bottom of the upper cavity wall unit (27), and the other is arranged at the top of the lower cavity wall unit (27).

11. An oil storage device according to claim 10, characterized in that: The outer wall of the protruding portion (29) is arranged as a slope that is inclined from the front end of the protruding portion (29) toward the connecting opening (28), and the side wall of the first opening (30) is arranged to be inclined accordingly.

12. The oil storage device according to claim 1, characterized in that: A filter is provided on the communication channel (3).

13. The oil storage device according to claim 1, characterized in that: A working platform (1) is provided at the oil delivery channel (2), and the working platform (1) is installed on the top of the cavity wall (4).

14. The oil storage device according to claim 1, characterized in that: The oil storage chamber (24) has a volume V of 100m 3 ≤V≤300000m 3 .

15. An oil storage device according to any one of claims 1 to 14, characterized in that: The portion of the cavity wall (4) located on the side of the oil storage cavity (24) comprises a reinforced concrete structure.

16. The oil storage device according to claim 15, characterized in that: The cavity wall (4) is a reinforced concrete structure.

17. An oil storage device according to any one of claim 16, characterized in that: The invention comprises a concrete oil storage structure (20), wherein the concrete oil storage structure (20) has an oil storage cavity (24) inside, a portion of the concrete oil storage structure (20) located outside the oil storage cavity (24) forms the cavity wall (4), the connecting channel (3) is arranged at the lower part of the concrete oil storage structure (20), and the oil delivery channel (2) is arranged at the upper part of the concrete oil storage structure (20).

18. An oil storage device according to claim 17, characterized in that: The concrete oil storage structure (20) is a rectangular parallelepiped, a cube, a cylinder, a drum, or a combined structure of a lower cylinder and an upper hemisphere.

19. The oil storage device according to claim 17, characterized in that: The concrete oil storage structure (20) is a rectangular parallelepiped structure, and the dimensions of the rectangular parallelepiped structure are: length L: 100-120 m, width W: 50-60 m, height H: 20-40 m.

20. The oil storage device according to claim 17, characterized in that: The cavity wall (4) comprises a first side wall (22), a first bottom structure (23) and a first top structure (21); the first side wall (22), the first bottom structure (23) and the first top structure (21) enclose the oil storage cavity (24); a second side wall (33) is arranged outside the first side wall (22); a second bottom structure is sealed between the lower part of the second side wall (33) and the lower part of the first side wall (22); the second side wall (33), the first side wall (22) and the second bottom structure (34) enclose an outer cavity (36); the connecting passage (3) connects the oil storage cavity (24) and the outer cavity (36); the top elevation of the second side wall (33) is greater than or equal to the top elevation of the oil storage cavity (24).

21. An oil storage device according to claim 20, characterized in that: A first liquid (34) is contained in the outer cavity (36); the density of the first liquid (35) is greater than the density of the crude oil (7) in the oil storage cavity (24); and the top elevation of the first liquid (35) is greater than or equal to the top elevation of the oil storage cavity (24).

22. An oil storage device according to claim 21, characterized in that: The difference ΔH3 between the top elevation of the oil storage chamber (24) and the top elevation of the first liquid (35) is: -3m≤ΔH3≤0m.

23. The oil storage device according to claim 21, characterized in that: A valve (32) is provided on the communication channel, and the valve (32) is used to maintain the pressure outside the oil storage chamber greater than the pressure inside the oil storage chamber.

24. The oil storage device according to claim 20, characterized in that: At least part of the first side wall (22) is a reinforced concrete structure.

25. The oil storage device according to claim 20, characterized in that: The outer cavity (36) is open at the top.

26. The oil storage device according to claim 20, characterized in that: A second top structure (34) is sealed between the upper portion of the second side wall (33) and the upper portion of the first side wall (22); the second top structure (34), the second side wall (33), the first side wall (22) and the second bottom structure (34) enclose the outer cavity (36).

27. An oil storage device according to claim 26, characterized in that: A ventilation channel (38) is provided through the second top structure (34).

28. The oil storage device according to claim 21, characterized in that: It also includes a power device (37), wherein the power device (37) is used to transport the first liquid (35) into the outer cavity (36).

29. The oil storage device according to claim 20, characterized in that: A cross brace (39) is also connected between the first side wall (22) and the second side wall (33); the cross brace (39) is arranged above the second bottom structure (34), and the cross brace (39) and the second bottom structure (34) are spaced apart.

30. The oil storage device according to claim 1, characterized in that: The oil storage cavity (24) is filled with crude oil (7) and a first liquid (35), and the density of the first liquid (35) is greater than the density of the crude oil (7) in the oil storage cavity (24).

31. An oil storage device according to claim 30, characterized in that: It also comprises a power device (37), the power device (37) being in communication with the communication channel (3), the power device (37) being used to transport the first liquid (35) into the communication channel (3).

32. A floating bottom micro-positive pressure oil storage system, characterized in that: The oil storage device comprises the oil storage device according to any one of claims 1 to 19, wherein: The top elevation of the oil storage chamber (24) is equal to or lower than a first elevation, and the elevation difference ΔH1 between the first elevation and the low tide level is: ΔH1≤3m; The bottom of the cavity wall (4) is arranged at the bottom of the seat.

33. A floating bottom micro-positive pressure oil storage system according to claim 32, characterized in that: The difference ΔH2 between the top elevation of the oil storage chamber (24) and the low tide elevation is: -3m≤ΔH2≤3m.

34. A floating bottom micro-positive pressure oil storage system according to claim 32, characterized in that: The top elevation of the oil storage chamber (24) is equal to or lower than the low tide elevation.

35. A floating bottom micro-positive pressure oil storage system according to claim 34, characterized in that: The difference ΔH2 between the top elevation of the oil storage chamber (24) and the low tide elevation is: -3m≤ΔH2≤0m.

36. A floating bottom micro-positive pressure oil storage system according to claim 32, characterized in that: The bottom of the cavity wall (4) is arranged at the bottom of the water; or, A groove pit (31) is provided at the surface floating mud of the water bottom, and the bottom of the cavity wall (4) is provided at the bottom of the groove pit (31).

37. A floating bottom micro-positive pressure oil storage system according to claim 32, characterized in that: The cavity wall (4) is arranged on a base cushion layer (11), wherein: The base cushion layer (11) is arranged on the bottom of the water; or, A groove pit (31) is provided at the floating mud on the surface of the water bottom, and the foundation cushion layer (11) is filled in the groove pit (31).

38. A floating bottom micro-positive pressure oil storage system according to claim 37, characterized in that: The base cushion layer (11) is a crushed stone cushion layer.

39. A floating bottom micro-positive pressure oil storage system according to claim 37, characterized in that: The thickness of the foundation cushion layer (11) is 0.5-1.5 m.

40. A floating bottom micro-positive pressure oil storage system according to claim 37, characterized in that: The lower part of the cavity wall (4) is in contact with a locking backfill structure, and the locking backfill structure is used to limit the lateral movement of the oil storage equipment.

41. A construction method for a floating bottom micro-positive pressure oil storage system according to any one of claims 32 to 40, characterized in that: The method comprises a sinking step: the oil storage equipment is sunk to the bottom of the water, so that the top elevation of the oil storage cavity (24) is equal to or lower than the first elevation, and the bottom of the cavity wall (4) is arranged at the bottom.

42. The construction method according to claim 41, characterized in that: During the sinking step, the top elevation of the oil storage chamber (24) is lower than the low tide level.

43. The construction method according to claim 41, characterized in that: The communication channel (3) is opened to allow water to enter the oil storage chamber (24) through the communication channel (3).

44. The construction method according to claim 43, characterized in that: At least part of the gas in the oil storage chamber (24) is extracted through the oil delivery channel (2), and then the oil delivery channel (2) is closed.

45. The construction method according to claim 41, characterized in that: Before the sinking step, the soft mud (10) on the bottom of the water is removed to form a trench (31); In the sinking step, the oil storage equipment sinks into the groove pit (31), so that the bottom of the cavity wall (4) is arranged at the bottom of the groove pit (31).

46. ​​The construction method according to claim 41, characterized in that: The oil storage cavity (24) comprises at least two oil storage cavity units (26) arranged vertically, and the cavity wall (4) correspondingly comprises at least two cavity wall units (27) arranged vertically, wherein the cavity wall units (27) are located outside the corresponding oil storage cavity units (26), and adjacent oil storage cavity units (26) are connected; The specific sinking steps are: S1. The lowermost cavity wall unit (27) is sunk and set at the bottom; S2. The remaining adjacent cavity wall units (27) are placed in order from bottom to top, and the vertically adjacent cavity wall units (27) are sealed and the vertically adjacent oil storage cavity units (26) are connected.

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