Deep and far seawater suspension oil and liquid storage device and underwater oil storage method thereof

Abstract

According to the deep and far seawater suspension oil and liquid storage device and the underwater oil storage method thereof, a layered tank body structure is adopted, and a load adjusting cabin, a flexible oil storage cabin and a water storage cabin are arranged from top to bottom. The load adjusting cabin is used for dynamically adjusting the net buoyancy of the device through seawater feeding / discharging to reduce the load of the mooring system; the oil storage cabin adopts a flexible storage bag to adapt to volume change and is linked with the water storage cabin through a movable composite heat preservation partition plate, the partition plate comprises an active heating layer and a phase change material layer, when the oil temperature is too low, the active heating layer directionally heats crude oil, the phase change layer absorbs dissipated heat, latent heat is released during external low-temperature impact to buffer temperature drop, and dynamic temperature control is achieved. The device is moored and fixed through a gravity anchor, and multiple types of sensors are arranged to monitor the posture, stress, oil temperature and leakage state of the tank body in real time. The problems of oil storage tank deformation, high pour point oil heat preservation and mooring stability under the deepwater high-pressure environment are solved, and the device has the advantages of being low in construction cost, high in environmental adaptability and efficient in operation and maintenance and is suitable for safe storage and transportation of deep and far sea oil and gas resources.

Description

Technical Field

[0001] The present invention relates to offshore oil and gas development and offshore engineering technologies, and particularly to a deep and remote underwater floating oil and liquid storage device and an underwater oil storage method thereof. Background Art

[0002] Currently, the development of deepwater oilfields mainly relies on floating oil storage devices, and typical forms include floating storage and offloading units (FSOs), semi-submersible platforms, and SPAR platforms, etc. Among them, due to its strong flexibility and adaptability, FSO has become the most widely used deep-sea oil storage mode, but it is vulnerable to environmental impacts and has high requirements for the mooring system. Its key mooring equipment is the single point mooring system.

[0003] Existing underwater oil storage technologies mainly include two structural forms: gravity-based and underwater floating. The gravity-based oil storage device has a large structure, high construction cost, and poor mobility. It is only applicable to shallow water areas, and usually requires treatment of the seabed foundation before deployment, with a long construction period and complex technology. In contrast, the underwater floating oil storage device has the advantages of relatively light structure, lower construction and operation costs, and easy deployment, and is more economical. However, the current floating oil storage device still faces many challenges in deep and remote sea applications: its mooring system needs to bear a large buoyancy load, increasing the difficulty of design and maintenance; at the same time, the water pressure in the deepwater environment increases significantly, and the oil storage tank body and insulation structure are prone to deformation or failure. Especially in the scenario of storing highly viscous oil, the insulation problem is particularly prominent, severely restricting the popularization and application of this technology in deep and remote seas.

[0004] It should be noted that the information disclosed in the above background art section is only used for understanding the background of the present application, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The main object of the present invention is to overcome the defects existing in the above background art, and provide a deep and remote underwater floating oil and liquid storage device and an underwater oil storage method thereof.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect of the present invention, a deep and remote underwater floating oil and liquid storage device includes: An oil and liquid storage tank body, the inner cavity of which is divided into a ballast tank, an oil storage tank, and a water storage tank from top to bottom, where: The ballast tank is internally provided with a ballast system for adjusting the overall net buoyancy through a seawater inlet / outlet regulating device; The oil storage tank includes a flexible storage bladder for containing oil; A movable thermal insulation partition is arranged between the oil storage tank and the water storage tank, and the thermal insulation partition floats up and down with the change of the volume of the oil storage tank; the thermal insulation partition is a multi-layer composite structure, including an active heating layer on the side close to the oil storage tank and a phase change material layer on the side close to the water storage tank. When the oil temperature is lower than a preset value, the active heating layer is controlled to start to directionally heat the crude oil in the oil storage tank, and the heat dissipated by the active heating layer to the side of the water storage tank is stored in the phase change material layer, so as to avoid the heat from escaping to the external water body. The phase change material layer releases the latent heat of phase change when impacted by the external low-temperature water body to buffer the external low temperature. The oil and liquid storage tank body is fixedly connected to the seabed through a mooring system. A multi-type sensor system is used to monitor the attitude, stress and strain, oil temperature and leakage state of the oil and liquid storage tank body in real time.

[0007] In the second aspect of the present invention, an underwater oil storage method using the deep-sea underwater suspended oil and liquid storage device includes: In the initial state, there is no oil in the flexible storage bladder, the water storage tank is filled with seawater, and the thermal insulation partition is close to the top of the oil storage tank. When storing oil, the crude oil is injected into the flexible storage bladder through the inlet / outlet oil pipe. The increased volume of the oil storage tank pushes the thermal insulation partition down, and the seawater in the water storage tank is discharged. The load adjustment system pumps in seawater to keep the total mass constant. When discharging oil, seawater enters the water storage tank to push the thermal insulation partition up, squeezing the flexible storage bladder to discharge oil, and the load adjustment system discharges seawater to keep the total mass constant. When the oil temperature is lower than the preset value, the active heating layer of the thermal insulation partition is controlled to start to directionally heat the crude oil in the oil storage tank, and the heat dissipated by the active heating layer to the side of the water storage tank is stored in the phase change material layer of the thermal insulation partition, so as to avoid the heat from escaping to the external water body. The phase change material layer releases the latent heat of phase change when impacted by the external low-temperature water body to buffer the external low temperature.

[0008] The present invention has the following beneficial effects: The present invention proposes a deep - sea underwater suspended oil and liquid storage device. Through the design of a layered oil and liquid storage tank body and the dynamic adjustment of net buoyancy by a load - adjusting system, the design difficulty and maintenance cost of the mooring system are significantly reduced. The flexible storage bladder and movable composite thermal insulation partition structure design are adopted, integrating an active heating layer for directional heating of highly viscous crude oil and a phase - change material layer for buffering the external low - temperature impact, effectively solving the problems of oil storage tank deformation and thermal insulation in the deep - water high - pressure environment, and having mechanical strength, energy efficiency and extreme - environment adaptability. It is equipped with multiple types of sensor systems to monitor the tank body attitude, stress and strain, oil temperature and leakage status in real time. Further, a digital twin monitoring system is constructed to realize risk early warning and operation and maintenance decision - making support through load inversion and near - real - time mechanical simulation, ensuring the safe operation of the device and extending its service life. The overall solution of the present invention does not require pre - treatment of the seabed foundation, has the advantages of strong mobility, low construction cost, reusability, etc., is compatible with the existing technology system, and provides a reliable technical path for the efficient, safe and economic storage, transportation and large - scale commercial development of deep - sea oil and gas resources.

[0009] Other beneficial effects in the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a general installation schematic diagram of the underwater oil storage equipment according to the embodiment of the present invention.

[0011] Figure 2 It is a structural schematic diagram of the underwater oil storage equipment according to the embodiment of the present invention.

[0012] Figure 3 It is a structural schematic diagram of the thermal insulation partition according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] The following makes a detailed description of the embodiments of the present invention. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its applications.

[0014] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the connection can be for a fixing function or for a coupling or communicating function.

[0015] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0016] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0017] In view of the deficiencies of traditional floating storage and offloading units (FSO), the present invention proposes a deep - sea underwater suspended oil and liquid storage device that can replace FSO. This device can effectively solve problems such as the deformation of the oil storage tank, the heat preservation of highly viscous oil, and the mooring stability in the deep - water high - pressure environment, realizing the economic, efficient, and safe storage and transportation of oil and liquid in the complex deep - sea environment, and providing reliable technical support for deep - sea oil and gas development.

[0018] Refer to Figure 1 and Figure 2, an embodiment of the present invention provides a deep - sea underwater suspended oil and liquid storage device, including an oil and liquid storage tank body 1, the inner cavity of which is divided into a ballast tank 2, an oil storage tank 3 and a water storage tank 4 from top to bottom, where: The ballast tank 2 is internally provided with a ballast system 5 for adjusting the overall net buoyancy through seawater inlet / outlet; The ballast tank 2 and the oil storage tank 3 can be separated by a fixed partition 6; The oil storage tank 3 includes a flexible storage bladder 7 for accommodating oil; A movable thermal insulation partition 8 is arranged between the oil storage tank 3 and the water storage tank 4, and the thermal insulation partition 8 floats up and down with the change of the volume of the oil storage tank 3 (the thermal insulation partition 8 does not need to be strictly sealed, but the radius is adapted to the inner diameter of the storage tank, and it is preferably as close as possible to the inner diameter of the storage tank); The thermal insulation partition 8 is a multi - layer composite structure, including an active heating layer on the side close to the oil storage tank 3 and a phase - change material layer on the side close to the water storage tank 4. When the oil temperature is lower than a preset value, the active heating layer is controlled to start to directionally heat the crude oil in the oil storage tank 3, and the heat transferred by the active heating layer to the side of the water storage tank 4 is stored in the phase - change material layer to avoid heat dissipation to the external water body. The phase - change material layer releases latent heat of phase change when impacted by the external low - temperature water body to buffer the external low temperature; The oil and liquid storage tank body 1 is anchored to the seabed through a mooring system. This oil and liquid storage device is also provided with a multi - type sensor system for real - time monitoring of the attitude, stress and strain, oil temperature and leakage state of the oil and liquid storage tank body 1.

[0019] In some embodiments, the ballast system 5 includes a ballast tank inlet / drain pipe 12, which is connected to external seawater to eliminate the water pressure difference and keeps the total mass of the device constant by pumping seawater.

[0020] In some embodiments, the thermal insulation partition 8 includes a rigid plate 81, an active heating layer 82, a first flexible heat - insulation layer 83, a phase - change material layer 84 and a second flexible heat - insulation layer 85 from top to bottom.

[0021] In some embodiments, the outer shell of the oil and liquid storage tank body 1 is a steel - plate concrete composite structure, including inner and outer steel plates, core concrete, shear connectors arranged at the steel - concrete interface and steel webs connecting the inner and outer steel plates.

[0022] In some embodiments, the sensor system includes: an IMU attitude sensor 16 and a water pressure gauge 17, which are arranged at the top of the tank body to monitor the attitude and water pressure; an optical fiber sensor 18, which is arranged in the middle of the tank body to monitor the stress and strain; an inlet / outlet water flow velocity sensor 19 arranged on the water storage tank inlet / drain pipe 15 and an inlet / outlet oil flow velocity sensor 20 arranged on the inlet / outlet oil pipe 13; an oil leakage monitoring sensor 21, a temperature sensor 22 and a flexible sensor 23, which respectively monitor the leakage, oil temperature and deformation of the flexible storage bladder 7 in the oil storage tank 3.

[0023] In some embodiments, the inlet / outlet oil pipe 13 is installed on the central axis of the tank body through a guiding mechanism 14, can be adjusted up and down along the axial direction, and is communicated with the flexible storage bladder 7.

[0024] In some embodiments, the mooring system includes a quick release 9, a mooring cable 10, and a gravity anchor 11. The two ends of the mooring cable 10 are respectively connected to the quick release 9 and the gravity anchor 11. The quick release 9 is arranged on the oil and liquid storage tank body 1 for emergency disconnection.

[0025] In some embodiments, the deep-sea underwater suspended oil and liquid storage device further includes a digital twin monitoring system, which inversely calculates the load based on sensor data and nearly real-time simulates the structural mechanics behavior. The digital twin monitoring system includes: a load inversion algorithm for inversely calculating the global load of the tank body based on sensor data; a nearly real-time mechanics simulation algorithm for evaluating the mechanics behavior of the tank body, the fatigue fracture of the flexible storage bladder 7, and the wear of the pipeline.

[0026] An embodiment of the present invention further provides an underwater oil storage method using the deep-sea underwater suspended oil and liquid storage device of any one of the foregoing embodiments, including: In the initial state, there is no oil liquid in the flexible storage bladder 7, the water storage tank 4 is filled with seawater, and the thermal insulation partition 8 is close to the top of the oil storage tank 3. When storing oil, the crude oil is injected into the flexible storage bladder 7 through the inlet / outlet oil pipe. The increased volume of the oil storage tank 3 pushes the thermal insulation partition 8 downward, and the seawater in the water storage tank 4 is discharged. The load adjustment system 5 pumps in seawater to keep the total mass constant. When discharging oil, seawater enters the water storage tank 4, pushes the thermal insulation partition 8 upward, squeezes the flexible storage bladder 7 to discharge oil, and the load adjustment system 5 discharges seawater to keep the total mass constant. When the oil temperature is lower than the preset value, the active heating layer of the thermal insulation partition 8 is controlled to start to directionally heat the crude oil in the oil storage tank 3, and the heat dissipated to the water storage tank 4 side by the active heating layer is stored in the phase change material layer of the thermal insulation partition 8 to avoid heat dissipation to the external water body. The phase change material layer releases the latent heat of phase change when impacted by the external low-temperature water body to buffer the external low temperature.

[0027] In some embodiments, the underwater oil storage method further includes: real-time monitoring of the tank body state through a sensor system, including the attitude, stress and strain, oil temperature, and leakage state of the oil and liquid storage tank body; according to the tank body state data real-time monitored by the sensor system, the following operations are synchronously executed through the digital twin monitoring system: inversely calculating the global load distribution of the oil and liquid storage tank body 1 based on the load inversion algorithm; evaluating the stress and strain behavior of the tank body shell, the fatigue fracture risk of the flexible storage bladder 7, and the wear condition of the inlet / outlet oil pipe 13 through the nearly real-time mechanics simulation algorithm; generating maintenance decision suggestions or risk warnings in combination with the simulation results to ensure the safe operation of the device.

[0028] The innovative design of the present invention solves the problems of deformation of the oil storage tank, high pour point oil heat preservation, and mooring stability in the deep - water high - pressure environment. It has the characteristics of low construction cost, strong environmental adaptability, and high - efficiency operation and maintenance, and is suitable for the safe storage and transportation of deep - sea oil and gas resources.

[0029] The following further describes specific embodiments of the present invention and their working principles.

[0030] As Figure 1 and Figure 2 shown, a deep - sea underwater suspended oil and liquid storage device includes: an oil and liquid storage tank body 1. The inner cavity of the oil and liquid storage tank body 1 is respectively set as a ballast tank 2, an oil storage tank 3, and a water storage tank 4 from top to bottom. The positions of the ballast tank 2, the oil storage tank 3, and the water storage tank 4 can be adjusted according to specific requirements. Among them, a ballast system 5 is installed in the ballast tank 2. The ballast tank 2 and the oil storage tank 3 are separated by a fixed partition 6. The oil storage tank 3 is composed of a flexible storage bladder 7. Between the oil storage tank 3 and the water storage tank 4 is a heat - preservation partition 8, and the heat - preservation partition 8 moves up and down with the floating of the water layer.

[0031] It is recommended that the outer shell of the oil and liquid storage tank body 1 adopt a composite material shell structure, and it can also adopt a pure steel structure or a concrete structure. Taking the composite material shell structure as an example, the outer shell structure of the storage device is a composite material shell structure, specifically adopting a steel - plate concrete composite structure. The typical structure is inner and outer steel plates, core concrete, shear connectors arranged at the steel - concrete interface, and steel webs connecting the inner and outer steel plates.

[0032] Both the outer shell of the oil and liquid storage tank body 1 and the fixed partition 6 are made of composite materials and have the function of heat preservation. The heat - preservation partition 8 is composed of a phase - change heat - preservation material and has an active heating system, which can actively heat the crude oil. Specifically, the composite material is a multi - layer composite structure, including an outer protective layer, an intermediate core heat - preservation interlayer, and a transition layer; specifically, as Figure 3 shown, the heat - preservation partition 8 is a multi - layer composite structure, which is successively a rigid plate 81, an active heating layer 82, a first flexible heat - insulation layer 83, a phase - change material layer 84, and a second flexible heat - insulation layer 85 from top to bottom.

[0033] A quick release device 9 is arranged on the oil and liquid storage tank body 1. The quick release device 9 is connected to a mooring cable 10, and the mooring cable is connected to a gravity anchor 11 on the seabed.

[0034] The load adjustment tank 2 is provided with an inlet / outlet water pipe 12 to connect the seawater inside the load adjustment tank 2 with the seawater outside, so that there is no water pressure difference between the inside and outside of the load adjustment tank. The inlet / outlet oil pipe 13 is installed at the position of the central axis of the tank of the oil and liquid storage tank body 1 through a guiding mechanism 14, and the inlet / outlet oil pipe 13 can be adjusted up and down along the central axis of the tank. The lower part of the water storage tank 4 is provided with an inlet / outlet water pipe 15, and the water storage tank 4 is connected with the seawater outside through the inlet / outlet water pipe 15, and there is no water pressure difference between the inside and outside of the water storage tank 4.

[0035] An IMU attitude sensor 16 and a water pressure gauge 17 are arranged on the top of the oil and liquid storage tank body 1 to monitor the attitude of the oil and liquid storage tank body 1 and the water pressure at the top of the oil and liquid storage tank body 1. An optical fiber sensor 18 is arranged in the middle of the outer shell of the oil and liquid storage tank body 1 to monitor the stress and strain of the oil and liquid storage tank body 1. An inlet / outlet water flow velocity sensor 19 is arranged in the inlet / outlet water pipe 15 to detect the flow rate and velocity of the water entering / leaving the water storage tank 4. An inlet / outlet oil flow velocity sensor 20 is arranged in the inlet / outlet oil pipe 13 to monitor the flow rate and velocity of the crude oil entering / leaving the flexible storage bag 7. An oil leakage monitoring sensor 21 is arranged on the fixed partition plate 6 to monitor whether the flexible storage bag 7 leaks oil. A temperature sensor 22 is arranged on the outside of the flexible storage bag 7 to monitor the crude oil temperature in real time. A flexible sensor 23 is arranged on the outside of the flexible storage bag 7 to monitor the deformation of the flexible storage bag 7.

[0036] The oil and liquid storage tank body is equipped with a monitoring system. Based on the concept of digital twin, it mainly includes a composite material shell load inversion algorithm part and a global structure near-real-time mechanical simulation algorithm, which are jointly installed in the monitoring terminal 24. The load inversion algorithm can perform high-precision inversion of the global load of the outer shell of the oil and liquid storage tank body 1 based on the sensor; the global structure near-real-time mechanical simulation algorithm can perform near-real-time simulation and evaluation of the mechanical behavior and effects of the outer shell of the oil and liquid storage tank body 1, the fatigue and fracture effects of the flexible storage bag 7, and the blockage overpressure and pipeline inner wall wear conditions of the inlet / outlet oil pipe 13 based on the sensor data.

[0037] Both the load adjustment tank and the water storage tank are connected with the seawater outside, and there is no water pressure difference between the inside and outside. The load adjustment system ensures that the underwater net buoyancy of the oil and liquid storage device remains unchanged by operating the inlet / outlet water according to the working state of the oil and liquid storage device.

[0038] The thermal insulation layer has good thermal insulation performance, and the thermal insulation partition 8 has an active heating system. Specifically, the composite material is a multi-layer composite structure, including an outer protective layer, an intermediate core thermal insulation layer, and a transition layer; specifically, the thermal insulation partition 8 is a multi-layer composite structure, which is successively a rigid plate, an active heating layer, a first flexible heat insulation layer, a phase change material layer, and a second flexible heat insulation layer from top to bottom.

[0039] The outer shell of the oil and liquid storage tank body 1 is preferably made of a composite material shell structure, or can also be made of a pure steel structure or a concrete structure. Taking the composite material shell structure as an example, the outer shell structure of the oil and liquid storage device is a composite material shell structure, specifically a steel plate - concrete composite structure. The typical composition includes inner and outer steel plates, core concrete, shear connectors arranged at the steel - concrete interface, and steel webs connecting the inner and outer steel plates.

[0040] Each of the sensors can detect in real time the deformation magnitudes of the flexible storage bladder and the oil and liquid storage tank body of the oil and liquid storage device, the temperature of the crude oil, and whether there is oil leakage in the oil storage tank, ensuring the normal operation of the deep - sea underwater suspended oil and liquid storage device.

[0041] The digital twin system can invert the external shell load of the oil and liquid storage tank body 1 in an extremely short time, simulate the non - linear strain behavior and effects of the external shell, evaluate the attitude, behavior, non - linear fatigue, and crack conditions of the flexible storage bladder 7, and quickly simulate the wear conditions of the inlet / outlet pipe 13 caused by over - pressure leakage and erosion by sand and gravel in the oil liquid.

[0042] An underwater oil storage method using the deep - sea underwater suspended oil and liquid storage device of the foregoing embodiment specifically includes the following operation process: State 1: When the oil storage amount in the flexible storage bladder 7 is zero, the space in the oil storage tank 3 is compressed, and the heat - insulating partition 8 is close to the upper fixed partition 6. At this time, the water storage tank 4 is filled with seawater.

[0043] State 2: When crude oil starts to enter the flexible storage bladder 7 from the inlet / outlet pipe 13, the volume of the oil storage tank 3 increases gradually as the volume of crude oil in the flexible storage bladder 7 increases, and the heat - insulating partition 8 moves downward. The seawater in the water storage tank 4 is discharged into the external seawater of the oil and liquid storage tank body 1 through the inlet / outlet water pipe 15. At this time, the load - adjusting system 5 pumps seawater into the load - adjusting system 5 to keep the overall total mass of the oil and liquid storage tank body 1 unchanged when crude oil enters the flexible storage bladder 7. When the volume of crude oil in the flexible storage bladder 7 reaches the designed volume, the oil inlet stops.

[0044] State 3: When crude oil starts to be discharged from the flexible storage bladder 7 through the inlet / outlet pipe 13, the external seawater of the oil and liquid storage tank body 1 enters the water storage tank 4 through the inlet / outlet water pipe 15. The heat - insulating partition 8 moves upward under the action of seawater, and the volume in the oil storage tank 3 gradually decreases. The rising of seawater inside the water storage tank 4 provides pressure for the crude oil to be discharged from the flexible storage bladder 7, enabling the crude oil to be spontaneously discharged from the flexible storage bladder 7. At this time, the load - adjusting system 5 discharges seawater from the load - adjusting tank 2 to keep the overall mass of the oil and liquid storage tank body 1 unchanged when crude oil is discharged from the flexible storage bladder 7.

[0045] State Four: When the temperature of the crude oil drops close to the wax precipitation temperature, the thermal insulation partition 8 actively heats up to keep the crude oil in a flowing state. When the oil temperature is lower than the preset wax precipitation temperature, the active heating layer of the thermal insulation partition 8 is turned on, and heat is transferred to the oil storage and liquid storage side through the rigid plate to heat the crude oil. At the same time, on the other side of the active heating layer, the heat flow passes through the first flexible heat insulation layer, the phase change material layer, and the second flexible heat insulation layer, and the heat is stored in the phase change material layer to prevent the heat from dissipating to the external water body; the phase change material layer releases the latent heat of phase change when impacted by the external low-temperature water body and delays the temperature transfer.

[0046] State Five: When the crude oil starts to enter or be discharged from the flexible storage bladder 7 through the inlet / outlet oil pipe 13, the flow rate and velocity sensor 20 monitors the flow rate and velocity of the crude oil entering and leaving the flexible storage bladder 7 in real time. At the same time, the flexible sensor 23 monitors the deformation of the flexible storage bladder 7 in real time; the oil leakage monitoring sensor 21 monitors whether the flexible storage bladder 7 leaks oil in real time; the temperature sensor 22 monitors the crude oil temperature in real time.

[0047] Compared with the prior art, the present invention has the following remarkable advantages: 1. The present invention designs a deep-sea underwater suspended oil and liquid storage device. Compared with the gravity-based bottom-mounted oil storage device, this deep-sea underwater suspended oil and liquid storage device has low construction costs, good mobility, can be applied to the deep sea, and does not require prior treatment of the seabed foundation before installation and deployment.

[0048] 2. Compared with the existing underwater suspended oil storage devices, the present invention configures a load adjustment system to keep the overall underwater net buoyancy unchanged in any state, reducing the design difficulty and construction cost of the mooring system.

[0049] 3. The present invention not only has good heat insulation performance but also has an active heating function to prevent high pour point crude oil from solidifying and ensure production efficiency. By designing a multi-layer thermal insulation partition structure based on the combination of active heating and phase change materials, the synergistic heat insulation effect of dynamic temperature control of the oil and liquid storage tank and passive buffering of external low temperature is realized, while taking into account mechanical strength, energy efficiency and extreme environment adaptability.

[0050] 4. In the present invention, each sensor can monitor the deformation of the flexible storage bladder body, the stress and strain of the outer shell of the oil and liquid storage tank body, the temperature of the crude oil, and whether the oil storage tank leaks in real time, ensuring the normal operation of this deep-sea underwater suspended oil and liquid storage device.

[0051] 5. In the present invention, the digital twin monitoring system can perform local analysis and remote monitoring based on sensor data to evaluate the mechanical effects of the main parts of the overall oil and liquid storage device. It is fast and accurate, and can assist the equipment autonomy and operation and maintenance personnel in remote decision-making assistance and risk assessment, achieving extended service life, reduced risk, and ultimately cost reduction and efficiency increase.

[0052] 6. The tank shell of the present invention preferably adopts a composite material shell structure, taking into account the requirements of the floating system, significantly improving the bearing capacity and durability, and effectively reducing the construction cost.

[0053] 7. The solution provided by the present invention is applicable as an oil and liquid storage device during the development of deep - sea and ultra - deep - sea oil and gas fields, and can be well combined with the existing technology system, providing an effective route for cost reduction and efficiency improvement for the large - scale commercial development of deep - sea and ultra - deep - sea oil and gas.

[0054] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several alternatives or modifications can be made to these described embodiments, and these alternative or modified forms should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description with reference to terms such as "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of protection of the patent application.

Claims

1. A deep - sea underwater suspended oil and liquid storage device, characterized in that, Comprising: An oil and liquid storage tank, the inner cavity of which is divided into a ballast tank, an oil storage tank and a water storage tank from top to bottom, wherein: The ballast tank is internally provided with a ballast system for adjusting the overall net buoyancy through a seawater inlet / outlet regulating device; The oil storage tank includes a flexible storage bladder for containing oil; A movable thermal insulation partition is arranged between the oil storage tank and the water storage tank, and the thermal insulation partition floats up and down as the volume of the oil storage tank changes; The thermal insulation partition is a multi-layer composite structure, including an active heating layer on the side close to the oil storage tank and a phase change material layer on the side close to the water storage tank. When the oil temperature is lower than a preset value, the active heating layer is controlled to start to directionally heat the crude oil in the oil storage tank, and the heat dissipated by the active heating layer to the side of the water storage tank is stored in the phase change material layer to avoid heat dissipation to the external water body. The phase change material layer releases latent heat of phase change when impacted by the external low-temperature water body to buffer the external low temperature; The oil and liquid storage tank is fixedly connected to the seabed through a mooring system; A multi-type sensor system for real-time monitoring of the attitude, stress and strain, oil temperature and leakage state of the oil and liquid storage tank.

2. The deep-sea underwater suspended oil and liquid storage device according to claim 1, wherein The ballast system includes a ballast tank inlet / outlet water pipe, which is communicated with the external seawater to eliminate the water pressure difference and keeps the total mass of the device constant by pumping seawater.

3. The deep-sea underwater suspended oil and liquid storage device according to claim 1 or 2, wherein The thermal insulation partition includes a rigid plate, an active heating layer, a first flexible heat insulation layer, a phase change material layer and a second flexible heat insulation layer from top to bottom.

4. The deep-sea underwater suspended oil and liquid storage device according to any one of claims 1 to 2, wherein The outer shell of the oil and liquid storage tank is a steel plate-concrete composite structure, including inner and outer steel plates, core concrete, shear connectors arranged at the steel-concrete interface and steel webs connecting the inner and outer steel plates.

5. The deep-sea underwater suspended oil and liquid storage device according to any one of claims 1 to 2, wherein The sensor system includes: An IMU attitude sensor and a water pressure gauge, which are arranged at the top of the tank to monitor the attitude and water pressure; An optical fiber sensor, which is arranged in the middle of the tank to monitor the stress and strain; Flow rate and velocity sensors, which are arranged on the inlet / outlet oil pipes and the water storage tank inlet / outlet water pipes; An oil leakage monitoring sensor, a temperature sensor and a flexible sensor, which respectively monitor the oil leakage of the oil storage tank, the oil temperature and the deformation of the flexible storage bladder.

6. The deep-sea underwater suspended oil and liquid storage device according to claim 5, wherein The inlet / outlet oil pipes are installed on the central axis of the tank through a guiding mechanism, can be adjusted up and down along the axial direction, and are communicated with the flexible storage bladder.

7. The deep-sea underwater suspended oil and liquid storage device according to any one of claims 1 to 2, wherein The mooring system includes a quick release device, a mooring cable and a gravity anchor. The two ends of the mooring cable are respectively connected to the quick release device and the gravity anchor, and the quick release device is arranged on the oil and liquid storage tank for emergency disconnection.

8. The deep seawater underwater suspended oil and liquid storage device according to any one of claims 1 to 2, characterized in that, It further includes a digital twin monitoring system for inversely calculating the load based on the sensor data and nearly real-time simulating the structural mechanics behavior; The digital twin monitoring system includes: A load inversion algorithm for inversing the global load of the tank body based on sensor data; A near-real-time mechanical simulation algorithm for evaluating the mechanical behavior of the tank body, the fatigue fracture of the flexible bladder, and the wear of the pipeline.

9. An underwater oil storage method using the deep seawater underwater suspended oil and liquid storage device according to any one of claims 1 to 8, characterized in that, It includes: In the initial state, there is no oil in the flexible bladder, the water storage tank is full of seawater, and the heat insulation partition is close to the top of the oil storage tank; When storing oil, the crude oil is injected into the flexible bladder through the inlet / outlet pipeline. The increased volume of the oil storage tank pushes the heat insulation partition down, and the seawater in the water storage tank is discharged. The load adjustment system pumps in seawater to keep the total mass constant; When discharging oil, seawater enters the water storage tank, pushing the heat insulation partition up, squeezing the flexible bladder to discharge oil, and the load adjustment system discharges seawater to keep the total mass constant; When the oil temperature is lower than the preset value, the active heating layer of the heat insulation partition is controlled to start to directionally heat the crude oil in the oil storage tank, and the heat dissipated by the active heating layer to the side of the water storage tank is stored in the phase change material layer of the heat insulation partition to avoid heat dissipation to the external water body. The phase change material layer releases the latent heat of phase change when impacted by the external low-temperature water body to buffer the external low temperature.

10. The method according to claim 9, characterized in that, It also includes: Real-time monitoring of the tank body state through the sensor system, including the attitude, stress and strain, oil temperature, and leakage state of the oil and liquid storage tank body; According to the tank body state data real-time monitored by the sensor system, the following operations are synchronously performed through the digital twin monitoring system: Inverting the global load distribution of the oil and liquid storage tank body based on the load inversion algorithm; Evaluating the stress and strain behavior of the tank body shell, the fatigue fracture risk of the flexible bladder, and the wear condition of the inlet / outlet pipeline through the near-real-time mechanical simulation algorithm; Generating maintenance decision suggestions or risk warnings based on the simulation results to ensure the safe operation of the device.

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