A natural gas hydrate formation evolution simulation device and control method thereof

Abstract

The present application discloses a natural gas hydrate formation evolution simulation device and a control method thereof, and relates to the field of geophysical technology. The simulation device comprises: a fault-controlled anticline formation simulation system, a variable-volume low-temperature water bath circulation system, a hydrate evolution dynamic monitoring system, a data transmission control system, a hydraulic water tank module and a gas source supply module; through the simulation device, the present application realizes accurate simulation of the dynamic evolution process of hydrates under the control of structural factors, especially under different spatial and temporal configuration combinations of the closure overflow point position and the stable domain, as well as real-time monitoring and recording; the present application effectively overcomes the limitations of existing simulation technologies in structural design and function realization, and provides simulation devices and technical support for deepening the characteristics and enrichment laws of structurally controlled hydrate accumulation.

Description

Technical Field

[0001] The present application relates to the field of geophysical technology, and in particular to a natural gas hydrate formation and evolution simulation device and a control method thereof. Background Art

[0002] Structural traps often constitute favorable areas for natural gas accumulation, providing gas sources for the formation of hydrates. The size of the structural trap controls the scale of the natural gas reservoir that can be accommodated. In theory, as long as the natural gas in the structural trap is located in the hydrate stability domain, it is possible to fully combine with liquid water and transform into natural gas hydrates. With the continuous supply and accumulation of natural gas in the structural trap and the cyclic evolution of the hydrate reservoir, the saturation of hydrates is getting higher and higher, and eventually becomes an ideal exploration and development target. In a certain sense, the effective trap range restricts the scale of hydrate reservoir development and the hydrate saturation.

[0003] Under geological conditions, affected by fault activity and the morphology of the structural trap itself, there are usually overflow points in structural traps, that is, after natural gas accumulates to a certain extent in the trap, it will overflow along the overflow point to the outside of the trap, and cannot continue to form stable accumulation. The spatial configuration combination relationship between the position of the trap overflow point and the bottom depth of the hydrate stability domain is an important condition that restricts the scale of structural hydrate reservoirs and the saturation of the ore body. Designing relevant structural trap simulation experimental equipment and conducting experimental research has theoretical significance and practical value for revealing the formation and evolution mechanism of structurally controlled high-saturation hydrate reservoirs, clarifying the spatial distribution laws of hydrates and free gas, and serving the scientific and efficient exploration of hydrates. The existing technology mainly synthesizes high-saturation natural gas hydrates artificially through simulation experiments. The geological models based on them are mostly horizontal and the sedimentary reservoir conditions are homogeneous, which makes it impossible to accurately reveal the formation and evolution process of natural gas hydrates. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to propose a natural gas hydrate formation and evolution simulation device and a control method thereof, so as to accurately reveal the formation and evolution process of natural gas hydrates.

[0005] To achieve the above-mentioned purpose, one aspect of the embodiment of the present application proposes a natural gas hydrate formation evolution simulation device, the simulation device comprising a fault-controlled anticline formation simulation system, a variable volume low-temperature water bath circulation system, a hydrate evolution dynamic monitoring system, a data transmission control system, a hydraulic water tank module and a gas source supply module;

[0006] Wherein, the fault-controlled anticline formation simulation system is arranged in the hydraulic water tank module; the fault-controlled anticline formation simulation system is connected to the circulation loop formed by the variable volume low temperature water bath circulation system;

[0007] The fault-controlled anticline formation simulation system is filled with quartz sand or ceramsite, and the fault-controlled anticline formation simulation system is used to simulate structural traps and overflow points of the structural traps;

[0008] The variable volume low temperature water bath circulation system is used to generate constant pressure and constant temperature circulating fluids with different pressures and temperatures in the circulation loop;

[0009] The hydrate evolution dynamic monitoring system is used to collect feedback information from the fault-controlled anticline formation simulation system;

[0010] The data transmission control system is used to start and control the simulation device, dynamically record the feedback information collected by the hydrate evolution dynamic monitoring system, and dynamically analyze the feedback information;

[0011] The gas source supply module is used to supply gas to the fault-controlled anticline formation simulation system.

[0012] In some embodiments, the fault-controlled anticline formation simulation system includes an independent and detachable combined fault simulation structure and an anticline sedimentary formation simulation structure;

[0013] The sidewall of the fracture simulation structure is provided with a plurality of card slots, and the anticline sedimentary stratum simulation structure is provided with a plurality of card plates; the card slots at any position can be engaged with the card plates at any position, so that the fracture simulation structure and the anticline sedimentary stratum simulation structure are connected, thereby simulating different structural traps and the overflow points at different positions;

[0014] The fracture simulation structure and the anticline sedimentary stratum simulation structure are both filled with the quartz sand or the ceramsite;

[0015] A gas injection hole is arranged at the bottom of the anticline sedimentary stratum simulation structure, and the gas injection hole is connected to the gas source supply module through a gas transmission conduit.

[0016] In some embodiments, the fracture simulation structure and the anticline sedimentary stratum simulation structure are both configured as multi-layer substructures, and permeable baffles are provided between each layer of the substructures;

[0017] The interior of each layer of the substructure of the fracture simulation structure and the anticline sedimentary stratum simulation structure is filled with the quartz sand or ceramsite of different particle sizes.

[0018] In some embodiments, the particle size of the quartz sand or the ceramsite filled in the fracture simulation structure is larger than the particle size of the quartz sand or the ceramsite filled in the anticline sedimentary stratum simulation structure.

[0019] In some embodiments, the variable volume low temperature water bath circulation system comprises a water bath circulation chamber, a temperature and pressure controller, a circulation pump and a water tank; the water tank is filled with a refrigerant;

[0020] Wherein, the water bath circulation chamber, the temperature and pressure controller, the circulation pump and the water tank are cyclically connected in sequence through a fluid pipeline to form the circulation loop;

[0021] The water bath circulation jacket is wrapped around the periphery of the fault-controlled anticline formation simulation system in the form of a jacket, so that the refrigerant in the water bath circulation jacket interacts with the fault-controlled anticline formation simulation system;

[0022] The temperature and pressure controller is used to adjust the temperature and pressure of the refrigerant in the circulation loop;

[0023] The circulating pump is used to drive the refrigerant to flow.

[0024] In some embodiments, the hydrate evolution dynamic monitoring system includes a resistivity sensor, an acoustic wave velocity sensor, and a shear strength sensor;

[0025] Wherein, each of the sensors is provided with a plurality of sensor signal receiving points at different vertical positions;

[0026] The hydrate evolution dynamic monitoring system is placed in a hole opened at the top of the fault-controlled anticline formation simulation system and then inserted into the quartz sand or the ceramsite;

[0027] The resistivity sensor, the acoustic wave velocity sensor and the shear strength sensor are respectively used to collect the resistivity, acoustic wave velocity and shear strength of natural gas hydrates in different spatial positions and different reservoir sections as the feedback information.

[0028] In some embodiments, the data transmission control system is respectively connected to the fault-controlled anticline formation simulation system, the variable volume low-temperature water bath circulation system and the hydrate evolution dynamic monitoring system;

[0029] The data transmission control system is used to control the variable volume low temperature water bath circulation system to inject water into the hydraulic water tank module until the pressure in the fault control anticline formation simulation system reaches a preset starting pressure;

[0030] The data transmission control system is used to control the speed and flux of gas supply from the gas source supply module to the fault-controlled anticline formation simulation system according to a preset gas flow rate.

[0031] In some embodiments, the hydraulic water tank module is a sealed reaction device made of stainless steel;

[0032] Wherein, a water injection port is provided on the top of the hydraulic water tank module, and the water injection port is connected to the water pressure control device;

[0033] The hydraulic water tank module is connected to the fluid pipeline of the variable capacity low temperature water bath circulation system; the fluid pipeline is connected to a hydraulic pump and a pressure control valve; the pressure control valve is connected to the data transmission control system;

[0034] The hydraulic pump is used to provide power for the flow transmission of simulated seawater;

[0035] The pressure control valve is used to adjust the water injection speed and cross-sectional flow rate.

[0036] In some embodiments, the simulation device further comprises an image recording module;

[0037] The image recording module is used to record images of the formation process of natural gas hydrate in the simulation device.

[0038] To achieve the above object, another aspect of the embodiment of the present application provides a control method, which is used to control a natural gas hydrate formation and evolution simulation device as described above, and the control method comprises the following steps:

[0039] Set the starting pressure of the hydraulic tank module;

[0040] Set the gas supply speed and flux of the gas source supply module;

[0041] starting the simulation device according to the starting pressure, the gas supply speed and the flux;

[0042] Obtain feedback information collected by the data transmission control system;

[0043] The formation and evolution of natural gas hydrates are simulated according to the feedback information.

[0044] The embodiments of the present application include at least the following beneficial effects:

[0045] Through the fault-controlled anticline formation simulation system, variable-volume low-temperature water bath circulation system, hydrate evolution dynamic monitoring system, data transmission control system, hydraulic water tank module and gas source supply module of the simulation device, the present application realizes accurate simulation of the dynamic evolution process of hydrates under the control of structural factors, especially under different spatial and temporal configuration combinations of the closure overflow point position and the stability domain, as well as real-time monitoring and recording; the present application effectively overcomes the limitations of existing simulation technologies in structural design and function realization, and provides simulation devices and technical support for deepening the characteristics and enrichment laws of structurally controlled hydrate accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 A schematic diagram of the structure of a fault-controlled, closed-type high-saturation natural gas hydrate formation and evolution simulation device provided in an embodiment of the present application;

[0048] Figure 2 A schematic diagram of the structure of the fault-controlled anticline formation simulation system combination provided in an embodiment of the present application;

[0049] Figure 3 A decomposition diagram of the fault-controlled anticline formation simulation system provided in an embodiment of the present application;

[0050] Figure 4 A schematic diagram of the structure of a variable volume low temperature water bath circulation system provided in an embodiment of the present application;

[0051] Figure 5 A schematic diagram of the structure of a hydrate evolution dynamic monitoring system provided in an embodiment of the present application;

[0052] Figure 6 A schematic diagram of hydrate phase equilibrium simulation under different structural trap conditions provided in the embodiments of the present application;

[0053] Figure 7 A schematic diagram of the prediction of the spatial distribution characteristics of hydrates and free gas in different simulation experiment scenarios provided in the embodiments of the present application;

[0054] Figure 8 A schematic diagram of natural gas accumulation distribution and gas overflow characteristics of different structural trap types provided in the embodiments of the present application;

[0055] Fig. 9 A flow chart of a control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0057] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0058] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0060] Before describing the embodiments of the present application in detail, some nouns and terms involved in the embodiments of the present application are first described. The nouns and terms involved in the embodiments of the present application are subject to the following interpretations:

[0061] Hydrate: A mineral crystal formed by the combination of water molecules and gas molecules under low temperature and high pressure conditions. It is often found in marine environments or tundra zones on land and is a potential, clean energy source with huge energy. Hydrate in this application refers specifically to methane hydrate in the marine environment.

[0062] Hydrate stability domain: Hydrates can only form under certain specific "low temperature and high pressure" conditions. Beyond the corresponding temperature or pressure range, hydrates cannot form, or the formed hydrates will decompose. The physical space range where hydrates are stably aggregated under specific temperature and pressure conditions is called the hydrate stability domain. In the case of marine natural gas hydrates, the top boundary of the hydrate stability domain is usually the seabed, and the bottom boundary depth of the hydrate stability domain is often determined by the intersection of the hydrate phase equilibrium curve and the geothermal gradient line. The bottom boundary depth of the hydrate stability domain is a key factor in controlling the maximum distribution range of hydrate deposits and the scale of the ore body.

[0063] Hydrate saturation: Hydrate formation will occupy the pore space of the sediment, and the ratio of the volume of hydrate formed to the volume of the pore space of the sediment is the hydrate saturation. Theoretically, as long as there is sufficient supply of methane gas and liquid water, and within the hydrate stability domain, methane gas can be converted into methane hydrate. With the continuous supply of methane gas, the hydrate saturation continues to increase. On the contrary, if there is a lack of gas supply or the gas cannot be stably aggregated, hydrate deposits cannot be formed even within the hydrate stability domain. Generally, the larger the scale of the ore body and the higher the saturation of the hydrate deposit, the more potential it has for commercial exploration and development.

[0064] Hydrate acoustic-electric response: refers to the geophysical record that reflects the distribution characteristics of hydrates in the reservoir through acoustic or electrical signals. In hydrate exploration practice, the distribution law of hydrates in the reservoir is often reflected based on geophysical information such as reservoir resistivity, acoustic velocity, and shear strength. Generally, higher hydrate saturation corresponds to greater reservoir resistivity, acoustic velocity, and shear strength. Gas layers usually have higher resistivity, but relatively lower acoustic velocity and shear strength.

[0065] Fault: refers to the geological phenomenon that sedimentary strata break due to stress and undergo significant relative displacement along the fracture surface. Faults vary in size, with large ones extending hundreds of kilometers along the strike and small ones only tens of centimeters.

[0066] Diversion channel: In geological environments, deep strata are often destroyed due to tectonic activities and overpressure in the strata, forming a series of channels. Formation fluids often migrate and gather along these channels to shallow layers. Faults are usually the most common type of fluid diversion channel in geological environments.

[0067] Structural trap: refers to a special stratigraphic structure in which the sedimentary reservoir is bent and deformed and tilted toward the surrounding area under the action of tectonic activities. Under geological conditions, oil and natural gas often accumulate stably in structural traps to form oil or natural gas reservoirs.

[0068] Trap overflow point: The position where the structural trap can accommodate the maximum amount of natural gas. If the position is lower than this point, the natural gas will overflow from this position and migrate to the updip direction of the reservoir, and gas accumulation will no longer continue.

[0069] Trap closure height: refers to the vertical distance between the highest point of the trap and the trap overflow point, which is the maximum height that the structural trap can accommodate the natural gas reservoir.

[0070] Marine natural gas hydrate resources are an important new type of mineral resources with huge resource potential. Natural gas hydrates are mainly distributed in terrestrial permafrost zones and deep-sea slope environments worldwide, and their distribution is closely related to formation temperature and pressure conditions. Hydrates in nature are mostly distributed in mud or muddy silt hydrate reservoirs with a water depth of more than 1000m, which are typical deep-sea sediment-controlled hydrate reservoirs. Hydrate ore bodies mostly exist in the form of "low saturation" (saturation is usually less than 10%) and do not have significant commercial exploration and development value. However, with the continuous deepening of hydrate exploration, more and more high-saturation hydrate reservoirs (saturation is usually above 50%, up to 90%) have been discovered, and these high-saturation hydrate reservoirs often show significant structural control characteristics and have the potential for exploration and development.

[0071] Structural traps often constitute favorable areas for natural gas accumulation, providing gas sources for the formation of hydrates. The size of the structural trap controls the scale of the natural gas reservoir that can be accommodated. In theory, as long as the natural gas in the structural trap is located in the hydrate stability domain, it is possible to fully combine with liquid water and transform into natural gas hydrates. With the continuous supply and accumulation of natural gas in the structural trap and the cyclic evolution of the hydrate reservoir, the saturation of hydrates is getting higher and higher, and eventually becomes an ideal exploration and development target. In a certain sense, the effective trap range restricts the scale of hydrate reservoir development and the hydrate saturation.

[0072] Under geological conditions, affected by fault activity and the morphology of the structural trap itself, there are usually overflow points in structural traps, that is, after natural gas accumulates to a certain extent in the trap, it will overflow along the overflow point to the outside of the trap, and cannot continue to form stable accumulation. The spatial configuration combination relationship between the location of the trap overflow point and the bottom depth of the hydrate stability domain is an important condition that restricts the scale of structural hydrate reservoirs and the saturation of ore bodies. Designing relevant structural trap simulation experimental devices and conducting experimental research has theoretical significance and practical value for revealing the formation and evolution mechanism of structurally controlled high-saturation hydrate reservoirs, clarifying the spatial distribution law of hydrates and free gas, and serving the scientific and efficient exploration of hydrates.

[0073] Existing technical solutions mainly use simulation experiments to artificially synthesize high-saturation natural gas hydrates. The geological models they are based on are mostly horizontal and the sedimentary reservoir conditions are homogeneous. They do not fully consider the gas migration and accumulation characteristics and the formation and evolution of hydrate reservoirs under different structural forms or structural conditions. There is still a lack of effective experimental simulation devices and experimental methods for the distribution, ore body scale and saturation dynamic evolution process of hydrates under structural closures with obvious overflow points and temporal and spatial changes in stable domains.

[0074] CN204389257U discloses a device for generating a high-saturation methane hydrate sediment sample for a triaxial compression experiment, which mainly includes a mold, a piston, a thermocouple, a data acquisition system, a computer control system, a clamp, a heat exchanger, a gas storage tank circuit, a methane gas charging circuit, a vacuum circuit, a pressure detection circuit, an exhaust gas collection circuit, an exhaust pipeline, and an exhaust gas pressure control pipeline. The device can simulate the generation of a high-saturation methane hydrate sediment sample in a laboratory environment and provide raw materials for a methane hydrate sediment mechanical property test experiment.

[0075] CN101376853B discloses a method and device for simulating the gas hydrate accumulation process under one-dimensional conditions. The experimental gas is introduced into the inner chamber of the reactor, and the gas is made to flow from bottom to top through the porous medium filling area to generate hydrates. The hydrate formation rate is determined by measuring the flow change of the gas in the porous medium during the seepage process, and the process of hydrate from nucleation induction, gradual formation to accumulation is simulated.

[0076] CN113391050B discloses an experimental device and method for stratified simulation of hydrate accumulation process. It includes a liquid injection system, a gas injection system, an accumulation system, a gas-liquid separation system, a vacuum system and a data acquisition system, which can simulate the upward migration of gas to the hydrate layer and the formation process of the hydrate reservoir. The experimental device can collect parameters such as temperature, pressure, resistivity, etc. of the hydrate layer and the free gas layer.

[0077] CN114459961B discloses a physical simulation device and experimental method for natural gas hydrate migration and accumulation, which includes an experimental box, a pressure control mechanism, a movable baffle, a power drive rod, a fluid filling mechanism, etc. The experimental box is artificially controlled to simulate the structural deformation and fluid filling of the formation, so as to simulate the deep gas-bearing fluid activity and the natural gas hydrate migration and accumulation process under confining pressure and complex geological conditions.

[0078] As mentioned above, structural conditions are key factors affecting hydrate accumulation, especially the accumulation of high-saturation hydrates. The location of structural traps and trap overflow points is an important variable affecting the scale of free gas reservoirs. Its spatial matching relationship with the hydrate stability domain is a decisive factor in determining the scale of hydrate ore bodies and hydrate saturation. Existing experimental simulation devices and technical methods are mostly designed based on simple sedimentary geological models (i.e., geological models are mostly horizontal sedimentary strata, reservoir conditions are homogeneous, and there are no significant lithological changes), and do not fully consider the formation and evolution characteristics of hydrate reservoirs under the influence of structural conditions. In particular, when the trap overflow point and the range of the hydrate stability domain change due to tectonic activities, there is still a lack of effective experimental simulation devices and experimental methods for the spatial distribution of hydrates, the scale of ore bodies and the dynamic evolution of saturation. This restricts the understanding of the formation laws of hydrates that are widely distributed in nature.

[0079] In summary, the existing simulation devices mainly simulate the hydrate formation process at the laboratory scale, and have certain limitations in "simulation device structure design", "realization of spatial matching function of structural closure and stable domain" and "dynamic monitoring of hydrate evolution process". The specific manifestations are as follows: First, the existing experimental simulation devices are usually designed as single-layer or multi-layer horizontal structures, and the lithology filling in the same layer does not change, and the reservoir is homogeneous, which cannot meet the simulation of sedimentary reservoir characteristics under real marine geological conditions, especially in complex sedimentary environments (that is, when the lithology of sediments changes rhythmically); second, the existing experimental simulation devices do not fully consider the control of structural factors on gas migration and hydrate formation, or only simulate gas migration and hydrate formation by designing simple structural forms such as paleo-uplifts, structural faults or monocline formations. There is a lack of effective simulation methods for the hydrate accumulation process under the control of complex structural patterns with closure overflow points. Third, the existing experimental simulation devices do not fully consider the changes in geological conditions (such as changes in the morphology of structural closures and the location of overflow points caused by geological activities) and the resulting changes in the spatiotemporal coupling with the hydrate stability domain, and there is a lack of effective monitoring methods for the distribution and dynamic evolution of hydrates under this tectonic action.

[0080] This application is based on the needs of hydrate exploration practice, closely combined with actual geological conditions, and focuses on the formation mechanism of structurally controlled high-saturation hydrate reservoirs. In the process of hydrate accumulation simulation research, the "structural closure" element in traditional petroleum geology is introduced, and the system modular design scheme is used to innovatively design the "fault-controlled anticline formation simulation system", "variable volume low-temperature water bath circulation system", "hydrate evolution dynamic monitoring system" and "data transmission control system". Through experimental simulation, real-time monitoring and recording of the dynamic evolution process of hydrates under structural conditions, especially under different spatial and temporal configuration combinations of closure overflow point locations and stable domains, is achieved. The limitations of existing hydrate accumulation simulation devices and technologies in structural design and function realization are effectively overcome, and simulation experimental devices and technical support are provided for deepening the structurally controlled hydrate aggregation process and the formation evolution mechanism of high-saturation hydrates.

[0081] The embodiment of the present application provides a natural gas hydrate formation evolution simulation device, the simulation device comprising a fault-controlled anticline formation simulation system, a variable volume low-temperature water bath circulation system, a hydrate evolution dynamic monitoring system, a data transmission control system, a hydraulic water tank module and a gas source supply module;

[0082] Wherein, the fault-controlled anticline formation simulation system is arranged in the hydraulic water tank module; the fault-controlled anticline formation simulation system is connected to the circulation loop formed by the variable volume low temperature water bath circulation system;

[0083] The fault-controlled anticline formation simulation system is filled with quartz sand or ceramsite, and the fault-controlled anticline formation simulation system is used to simulate structural traps and overflow points of the structural traps;

[0084] The variable volume low temperature water bath circulation system is used to generate constant pressure and constant temperature circulating fluids with different pressures and temperatures in the circulation loop;

[0085] The hydrate evolution dynamic monitoring system is used to collect feedback information from the fault-controlled anticline formation simulation system;

[0086] The data transmission control system is used to start and control the simulation device, dynamically record the feedback information collected by the hydrate evolution dynamic monitoring system, and dynamically analyze the feedback information;

[0087] The gas source supply module is used to supply gas to the fault-controlled anticline formation simulation system.

[0088] Furthermore, the fault-controlled anticline stratum simulation system comprises an independent and detachable combined fault simulation structure and an anticline sedimentary stratum simulation structure;

[0089] The sidewall of the fracture simulation structure is provided with a plurality of card slots, and the anticline sedimentary stratum simulation structure is provided with a plurality of card plates; the card slots at any position can be engaged with the card plates at any position, so that the fracture simulation structure and the anticline sedimentary stratum simulation structure are connected, thereby simulating different structural traps and the overflow points at different positions;

[0090] The fracture simulation structure and the anticline sedimentary stratum simulation structure are both filled with the quartz sand or the ceramsite;

[0091] A gas injection hole is arranged at the bottom of the anticline sedimentary stratum simulation structure, and the gas injection hole is connected to the gas source supply module through a gas transmission conduit.

[0092] As a more specific implementation, the fracture simulation structure and the anticline sedimentary stratum simulation structure are both configured as multi-layer substructures, and permeable baffles are provided between each layer of the substructures;

[0093] The interior of each layer of the substructure of the fracture simulation structure and the anticline sedimentary stratum simulation structure is filled with the quartz sand or ceramsite of different particle sizes.

[0094] As another more specific embodiment, the particle size of the quartz sand or the ceramsite filled in the fracture simulation structure is larger than the particle size of the quartz sand or the ceramsite filled in the anticline sedimentary stratum simulation structure.

[0095] In some optional embodiments, the variable volume low temperature water bath circulation system comprises a water bath circulation chamber, a temperature and pressure controller, a circulation pump and a water tank; the water tank is filled with a refrigerant;

[0096] Wherein, the water bath circulation chamber, the temperature and pressure controller, the circulation pump and the water tank are cyclically connected in sequence through a fluid pipeline to form the circulation loop;

[0097] The water bath circulation jacket is wrapped around the periphery of the fault-controlled anticline formation simulation system in the form of a jacket, so that the refrigerant in the water bath circulation jacket interacts with the fault-controlled anticline formation simulation system;

[0098] The temperature and pressure controller is used to adjust the temperature and pressure of the refrigerant in the circulation loop;

[0099] The circulating pump is used to drive the refrigerant to flow.

[0100] In some optional embodiments, the hydrate evolution dynamic monitoring system includes a resistivity sensor, an acoustic wave velocity sensor, and a shear strength sensor;

[0101] Wherein, each of the sensors is provided with a plurality of sensor signal receiving points at different vertical positions;

[0102] The hydrate evolution dynamic monitoring system is placed in a hole opened at the top of the fault-controlled anticline formation simulation system and then inserted into the quartz sand or the ceramsite;

[0103] The resistivity sensor, the acoustic wave velocity sensor and the shear strength sensor are respectively used to collect the resistivity, acoustic wave velocity and shear strength of natural gas hydrates in different spatial positions and different reservoir sections as the feedback information.

[0104] Further, the data transmission control system is respectively connected with the fault-controlled anticline formation simulation system, the variable volume low-temperature water bath circulation system and the hydrate evolution dynamic monitoring system;

[0105] The data transmission control system is used to control the variable volume low temperature water bath circulation system to inject water into the hydraulic water tank module until the pressure in the fault control anticline formation simulation system reaches a preset starting pressure;

[0106] The data transmission control system is used to control the speed and flux of gas supply from the gas source supply module to the fault-controlled anticline formation simulation system according to a preset gas flow rate.

[0107] Furthermore, the hydraulic water tank module is a sealed reaction device made of stainless steel;

[0108] Wherein, a water injection port is provided on the top of the hydraulic water tank module, and the water injection port is connected to the water pressure control device;

[0109] The hydraulic water tank module is connected to the fluid pipeline of the variable capacity low temperature water bath circulation system; the fluid pipeline is connected to a hydraulic pump and a pressure control valve; the pressure control valve is connected to the data transmission control system;

[0110] The hydraulic pump is used to provide power for the flow transmission of simulated seawater;

[0111] The pressure control valve is used to adjust the water injection speed and cross-sectional flow rate.

[0112] Optionally, the simulation device further includes an image recording module;

[0113] The image recording module is used to record images of the formation process of natural gas hydrate in the simulation device.

[0114] Next, the solution of the embodiment of the present application will be introduced and explained in detail with reference to specific application examples.

[0115] The simulation device and control method focus on the influence of fault-controlled structural closures on gas migration and hydrate accumulation under real geological conditions. Through the simulation device and variable conditions of this embodiment, the distribution and formation evolution of high-saturation hydrates in the closure overflow point and stable domain under different spatial configuration combinations are simulated.

[0116] Reference Figure 1 This embodiment provides a fault-controlled closed type high-saturation natural gas hydrate formation evolution simulation device, which adopts a system modular design scheme, including: a fault-controlled anticline formation simulation system, a variable-volume low-temperature water bath circulation system, a hydrate evolution dynamic monitoring system, and a data transmission control system; in addition, the simulation device also includes a hydraulic water tank module (used to inject water into the simulation reaction system and increase the simulation system pressure to approximately simulate the real marine environment formation pressure); a gas source supply module (used to provide gas supply to the simulation reaction system to promote the formation of hydrates in the simulation system) and an image recording module (used to collect video image data of the gas filling and hydrate formation evolution process in the simulation reaction system) and other auxiliary device structures.

[0117] The following is a specific description:

[0118] Fault-controlled anticline formation simulation system: The fault-controlled anticline formation simulation system is the core structure of the entire simulation experiment device and an important space carrier for the simulation experiment. The material of the fault-controlled anticline formation simulation system is selected from organic glass with high compressive strength, which has the characteristics of withstanding high pressure above 15Mpa and can meet the test simulation conditions of deep-water marine environment.

[0119] The fault-controlled anticline stratigraphic simulation system specifically includes a fault simulation structure and anticline sedimentary stratigraphic simulation structure (refer to Figure 2 ). The fracture simulation structure and the anticline sedimentary stratum simulation structure are independent and can be freely disassembled and combined. The side wall of the fracture simulation structure is provided with a card slot, and the anticline sedimentary stratum simulation structure is provided with a card plate. As needed, a plurality of card slots can be provided on the side wall of the fracture simulation structure, and a plurality of card plate positions can be provided in the anticline sedimentary stratum simulation structure accordingly, so as to realize the combination and matching of the fracture simulation structure and the anticline sedimentary stratum simulation structure at any position. In the embodiment, by changing the spatial configuration combination relationship between the fracture simulation structure and the anticline sedimentary stratum simulation structure, the spatial position of the simulated structural closure overflow point can be effectively controlled and experimentally simulated (refer to Figure 3 ).

[0120] According to the needs, the fracture simulation structure and the anticline sedimentary stratum simulation structure can be set into a multi-layer structure, and each layer can be separated by a permeable baffle. During the simulation experiment, each layer of the fracture simulation structure and the anticline sedimentary stratum simulation structure can be filled with quartz sand particles or ceramsite of different particle sizes (grain size) to simulate the rhythmic changes of sedimentary lithology and particle size in the real marine environment and the changes in permeability at different positions of the fracture system.

[0121] In a specific embodiment, the particle size of quartz sand or expanded clay filled in the fault simulation structure is slightly coarser than that of the anticline sedimentary stratum simulation structure, ensuring that the fault simulation structure has better permeability, so that when the gas continuously filled in the structural trap reaches the connection position between the fault simulation structure and the anticline sedimentary stratum simulation structure (i.e., the trap overflow point position of the fault-controlled anticline stratum simulation system), the gas escapes along the upward direction of the fault simulation structure and cannot continue to gather.

[0122] A gas injection hole is opened at the bottom of the anticline sedimentary formation simulation structure, and the gas injection hole is connected to the gas cylinder through a gas pipe, so as to simulate the process of gas migration and accumulation in the reservoir in the form of leakage or diffusion under the action of buoyancy in the real formation environment. In some embodiments, the gas in the gas cylinder is mainly methane gas, and it can also contain a small amount of ethane, propane and other gases according to experimental needs. The gas pipe is connected to the control valve and the gas flowmeter, and inserted into the bottom hole of the anticline sedimentary formation simulation structure to provide simulated gas supply. The control valve is connected to the data transmission control system to realize the automatic opening and closing of the valve and the effective control of the gas flow ( Figure 1 Line ②).

[0123] During the simulation experiment, the fault-controlled anticline formation simulation system (i.e., the fault simulation structure and the anticline-type sedimentary formation simulation structure) was filled with water-moistened quartz sand or expanded clay and placed in a hydraulic water tank module. By injecting water into the hydraulic water tank module to increase the pressure, the entire reaction system was placed in a certain pressure state to simulate the geological fluid characteristics of fine-grained sedimentary reservoirs in a real deep-water marine environment.

[0124] Variable volume low temperature water bath circulation system: The variable volume low temperature water bath circulation system includes a water bath circulation chamber, a refrigerant, a temperature and pressure controller and a circulation pump, which are connected together through fluid pipelines to form a water bath circulation loop (refer to Figure 4 ).

[0125] As the main structure of the system, during the implementation of the simulation experiment, the water bath circulation chamber is wrapped around the periphery of the fault-controlled anticline formation simulation system in the form of a "clamp".

[0126] The water bath circulation chamber adopts a cavity structure design. According to needs, it can also be designed as a variable volume type with free expansion and contraction of the system structure, so as to form autonomous control over the temperature and pressure space range of the simulated sedimentary strata, and realize effective simulation of the dynamic migration of the hydrate stability domain space caused by changes in geological conditions.

[0127] The cryogenic fluid containing coolant circulates inside the water bath circulation chamber to achieve constant pressure low temperature water bath control of the simulation system. The variable volume low temperature water bath circulation system temperature and pressure controller is connected to the data transmission control system ( Figure 1 Line ③) realizes the effective control of the temperature and pressure conditions of the water bath system during the simulation experiment, and plays a role in simulating the spatial distribution of the stable domain of natural gas hydrates.

[0128] Hydrate evolution dynamic monitoring system: The hydrate evolution dynamic monitoring system is essentially a series of sensor combinations including resistivity sensors, acoustic wave velocity sensors, and shear strength sensors. The sensor is protected by a high-pressure cladding structure (refer to Figure 5 ). According to the needs, each sensor series is equipped with multiple sensor signal receiving points at different vertical positions (i.e., upper, middle, and lower positions) to realize the real-time monitoring and recording of the acoustic and electrical parameter information of the hydrate reservoir at different spatial positions of the simulated structure of the anticline sedimentary formation.

[0129] During the simulation experiment, the hydrate evolution dynamic monitoring system was placed from the reserved hole at the top of the anticline sedimentary formation simulation structure and inserted into the simulated quartz sand.

[0130] The top sensor combination of the hydrate evolution dynamic monitoring system is connected to the data transmission control system ( Figure 1 Line ④), along with the filling of underlying gas in the experimental simulation system and the formation of hydrates in the structural trap, the key acoustic and electrical parameter information such as resistivity, acoustic wave velocity and shear strength of hydrates in different spatial positions and different reservoir sections in the fault-controlled anticline formation simulation system can be recorded and transmitted back.

[0131] As needed, a data analysis and processing program is preset in the data transmission control system. By identifying the measured acoustic and electrical signals of the hydrate layer such as resistivity, acoustic wave velocity, shear strength, and extracting data information, the system program automatically generates a hydrate saturation function curve and records the dynamic evolution of hydrate saturation over time, thereby realizing real-time dynamic recording of the spatiotemporal distribution and evolution law of the hydrate-free gas system in the simulation device.

[0132] Data transmission control system: mainly realizes instrument and equipment connection, software and hardware system coordination, signal command transmission feedback, and real-time dynamic display of data information. The data transmission control system is connected to the fault control anticline formation simulation system, variable volume low temperature water bath circulation system and hydrate evolution dynamic monitoring system respectively, and completes the automatic start-up control of the experimental simulation system and the real-time feedback and dynamic analysis of data information.

[0133] In the specific implementation process, by setting the starting pressure of the simulation experiment in the data transmission control system (such as setting the starting pressure of the simulation system experiment to 15Mpa to simulate the 1500m ocean deep water conditions), that is, continuously injecting water into the hydraulic water tank module through system control, the pressure in the reaction system increases to the preset value, and then the water injection stops and the simulation experiment program is automatically started.

[0134] In the specific implementation process, the gas flow rate is set in the data transmission control system to achieve effective control of the speed and flux of gas injection into the simulated structure of the anticline sedimentary formation.

[0135] The hydraulic water tank module is a sealed high-pressure reaction device made of stainless steel throughout. A water injection port is set on the top of the hydraulic water tank module and is connected to the water pressure control device. During the simulation experiment, the control pressure of the hydraulic water tank module is not less than 15Mpa to simulate the real deep-water marine sedimentation environment. The hydraulic water tank module is connected to the water injection pipeline to inject water into the simulation device system when conducting the simulation experiment. A hydraulic pump and a pressure control valve are connected to the water injection pipeline. The hydraulic pump provides power for the flow transmission of simulated seawater; the pressure control valve realizes the adjustment of the water injection speed and cross-sectional flow rate. The pressure control valve is connected to the data transmission control system ( Figure 1 Line ①) realizes real-time control and dynamic display of the system pressure in the reaction system during the simulation experiment.

[0136] The image recording module (such as a video camera, a camera) is connected to the data transmission control system ( Figure 1 Line ⑤) realizes the real-time display and storage of video or image information to record the entire simulation experiment process of hydrate formation evolution.

[0137] Traditional hydrate geological accumulation theory and simulation experimental design rarely consider the influence of structural factors on the hydrate accumulation process and enrichment law. However, with the continuous deepening of hydrate exploration, more and more high-saturation hydrate reservoirs show significant influence of structural factors, but there is currently a lack of necessary functional experimental equipment to simulate the evolution law of structurally controlled hydrate accumulation.

[0138] Specifically, this application is closely integrated with hydrate exploration practice, focusing on the problem of structurally controlled hydrate accumulation mechanism. In the process of designing the hydrate accumulation simulation device, the "structural closure" element in traditional petroleum geology is introduced, and an innovative fault-controlled anticline formation simulation system is designed, in which the fracture simulation structure and the anticline sedimentary formation simulation structure are independent of each other and can be freely disassembled and combined. By changing the spatial configuration combination relationship and sedimentary filling lithology of the fracture simulation structure and the anticline sedimentary formation simulation structure, an effective simulation of the structural trap and the location of the trap overflow point is formed. In addition, by designing a variable-volume hydrate stability domain simulation system, the autonomous adjustment of the hydrate stability domain simulation space and the multi-scenario dynamic matching with the spatial location of the structural trap overflow point are realized (refer to Figure 6 and Figure 7 ), to effectively simulate the spatiotemporal evolution of structurally trapped hydrate reservoirs. For example, Figure 8 The following is a schematic diagram of the natural gas accumulation distribution and gas overflow characteristics of different structural trap types; Figure 8 a is a schematic diagram of a fault-controlled anticline trap. Figure 8 Figure b is a schematic diagram of anticline trap.

[0139] In summary, the simulation experiment system has practical significance for revealing the formation mechanism of structurally controlled high-saturation hydrate reservoirs and serving hydrate exploration deployment. The fault-controlled anticline formation simulation system and the variable-volume low-temperature water bath circulation system of the simulation device in this embodiment are important device structure carriers for realizing the structure-controlled hydrate simulation reaction and hydrate dynamic evolution functions.

[0140] The beneficial effects of this embodiment are as follows:

[0141] Most existing technical solutions artificially synthesize natural gas hydrates through simulation experiments. The geological models they are based on do not fully consider the impact of structural factors on the formation and evolution of hydrate reservoirs. For structural patterns with closed overflow points, there is still a lack of effective experimental simulation devices and technical methods for the dynamic evolution of hydrate formation and saturation under the conditions of spatial changes in the stable domain.

[0142] This embodiment focuses on the formation and evolution process of structurally controlled high-saturation natural gas hydrates, and innovatively designs simulation tool structures such as "fault-controlled anticline formation simulation system", "variable volume low-temperature water bath circulation system", and "hydrate evolution dynamic monitoring system" to achieve real-time monitoring and recording of the dynamic evolution process of hydrates under the control of structural factors, especially the location of the closure overflow point and the combination of different time and space configurations of the stable domain. This application effectively overcomes the limitations of existing simulation technology in structural design and function realization, and provides simulation devices and technical support for deepening the characteristics and enrichment laws of structurally controlled hydrate accumulation.

[0143] Specifically, this embodiment has comparative advantages over the prior art in the following three aspects. Advantage 1: "Systematic". That is, this embodiment adopts a system modular design, and each module (operation system) has a relatively independent physical space and functional area. As a whole system, during the experimental simulation process, each module cooperates closely, and through the two-way collaborative control between software and hardware, the unification of the sending of operation instructions and the return of observation data is realized, and the full process automation control such as the triggering of hydrate experimental conditions, the occurrence of simulated reactions, real-time data collection, and comprehensive dynamic analysis is completed. Advantage 2: "Flexibility". As the core structure of the entire simulation experimental device, the fault-controlled anticline formation simulation system realizes the integrated design of the fault simulation structure and the anticline sedimentary formation simulation structure, while maintaining the relative independence of the functions of each structure. Through the convenient design of the card slot and card plate structure and the change of the sediment lithology (i.e., the filling quartz sand grain size) in different simulated geological units, the effective simulation of the structural closure at different overflow point positions in multiple scenarios is realized, which is generally convenient and flexible. Advantage 3: "Intelligence". This application designs a dynamic monitoring system for hydrate evolution. When the simulated experimental reaction occurs, the monitored acoustic and electrical parameter information of the simulated reservoir, such as resistivity, acoustic wave velocity, shear strength and other measured data, can be fed back to the data transmission control system in real time. The system program automatically generates a hydrate saturation function curve to record the dynamic evolution of hydrate saturation over time. At the same time, combined with the video and image information recorded in real time by the camera (camera), a multi-dimensional (dynamic video, node image, function curve, data parameter) comprehensive display of the spatiotemporal distribution and evolution law of the hydrate-free gas system in the simulation device is realized.

[0144] In addition, this embodiment also provides an alternative solution:

[0145] This embodiment aims to simulate the distribution and dynamic evolution of high-saturation hydrates under structural conditions by controlling the spatial configuration combination relationship between the position of the overflow point of the trap and the bottom boundary of the hydrate stability domain (or the closure height of the trap and the thickness of the hydrate stability domain) on the basis of designing a geological model of a structural trap. This embodiment takes the "fault-controlled anticline trap" as an example to carry out simulation device design and simulation experiments, and realizes effective simulation of the spatial position of the overflow point of the structural trap by changing the spatial configuration combination relationship between the fault simulation structure and the anticline sedimentary stratum simulation structure.

[0146] In addition to the "fault-controlled anticline trap" involved in this embodiment, this embodiment can also use other structural types of traps, such as the overflow point of the "anticline trap" and the hydrate formation and evolution simulation device under its control. In other words, the "anticline trap" only changes in the structural style and the morphology of the simulation device. Its essence is still to simulate the enrichment law and dynamic evolution process of hydrates by controlling the spatial configuration combination relationship between the "overflow point" of the trap and the bottom boundary of the hydrate stability domain. Therefore, simple changes in the structure and morphology of the simulation device are all within the scope of the solution of this embodiment.

[0147] Reference Fig. 9 The embodiment of the present application further provides a control method, which can control a natural gas hydrate formation evolution simulation device of the present application, and the control method includes the following steps S901~S905:

[0148] S901: Setting the starting pressure of the hydraulic water tank module;

[0149] S902: Setting the gas supply speed and flux of the gas source supply module;

[0150] S903: starting the simulation device according to the starting pressure, the gas supply speed and the flux;

[0151] S904: Acquire feedback information collected by the data transmission control system;

[0152] S905: Simulating the formation and evolution of natural gas hydrate according to the feedback information.

[0153] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0154] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0155] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0156] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0157] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0158] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0159] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0160] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0161] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0162] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A natural gas hydrate formation evolution simulation device, characterized in that: The simulation device includes a fault-controlled anticline formation simulation system, a variable-volume low-temperature water bath circulation system, a hydrate evolution dynamic monitoring system, a data transmission control system, a hydraulic water tank module and a gas source supply module; Wherein, the fault-controlled anticline formation simulation system is arranged in the hydraulic water tank module; the fault-controlled anticline formation simulation system is connected to the circulation loop formed by the variable volume low temperature water bath circulation system; The fault-controlled anticline formation simulation system is filled with quartz sand or ceramsite, and the fault-controlled anticline formation simulation system is used to simulate structural traps and overflow points of the structural traps; The variable volume low temperature water bath circulation system is used to generate constant pressure and constant temperature circulating fluids with different pressures and temperatures in the circulation loop; The hydrate evolution dynamic monitoring system is used to collect feedback information from the fault-controlled anticline formation simulation system; The data transmission control system is used to start and control the simulation device, dynamically record the feedback information collected by the hydrate evolution dynamic monitoring system, and dynamically analyze the feedback information; The gas source supply module is used to supply gas to the fault-controlled anticline formation simulation system; The fault-controlled anticline stratum simulation system comprises an independent and detachable combined fault simulation structure and an anticline sedimentary stratum simulation structure; The sidewall of the fracture simulation structure is provided with a plurality of card slots, and the anticline sedimentary stratum simulation structure is provided with a plurality of card plates; the card slots at any position can be engaged with the card plates at any position, so that the fracture simulation structure and the anticline sedimentary stratum simulation structure are connected, thereby simulating different structural traps and the overflow points at different positions; The fracture simulation structure and the anticline sedimentary stratum simulation structure are both filled with the quartz sand or the ceramsite; A gas injection hole is provided at the bottom of the anticline sedimentary stratum simulation structure, and the gas injection hole is connected to the gas source supply module through a gas transmission conduit; The variable volume low temperature water bath circulation system comprises a water bath circulation chamber, a temperature and pressure controller, a circulation pump and a water tank; the water tank is filled with a refrigerant; Wherein, the water bath circulation chamber, the temperature and pressure controller, the circulation pump and the water tank are cyclically connected in sequence through a fluid pipeline to form the circulation loop; The water bath circulation jacket is wrapped around the periphery of the fault-controlled anticline formation simulation system in the form of a jacket, so that the refrigerant in the water bath circulation jacket interacts with the fault-controlled anticline formation simulation system; The temperature and pressure controller is used to adjust the temperature and pressure of the refrigerant in the circulation loop; The circulating pump is used to drive the refrigerant to flow.

2. A natural gas hydrate formation evolution simulation device according to claim 1, characterized in that: The fracture simulation structure and the anticline sedimentary stratum simulation structure are both configured as multi-layer substructures, and permeable baffles are provided between the substructures at each layer; The interior of each layer of the substructure of the fracture simulation structure and the anticline sedimentary stratum simulation structure is filled with the quartz sand or ceramsite of different particle sizes.

3. A natural gas hydrate formation evolution simulation device according to claim 1, characterized in that: The particle size of the quartz sand or the ceramsite filled in the fracture simulation structure is larger than the particle size of the quartz sand or the ceramsite filled in the anticline sedimentary stratum simulation structure.

4. A natural gas hydrate formation and evolution simulation device according to claim 1, characterized in that: The hydrate evolution dynamic monitoring system includes a resistivity sensor, an acoustic wave velocity sensor and a shear strength sensor; Wherein, each of the sensors is provided with a plurality of sensor signal receiving points at different vertical positions; The hydrate evolution dynamic monitoring system is placed in a hole opened at the top of the fault-controlled anticline formation simulation system and then inserted into the quartz sand or the ceramsite; The resistivity sensor, the acoustic wave velocity sensor and the shear strength sensor are respectively used to collect the resistivity, acoustic wave velocity and shear strength of natural gas hydrates in different spatial positions and different reservoir sections as the feedback information.

5. The natural gas hydrate formation and evolution simulation device according to claim 1, characterized in that: The data transmission control system is respectively connected with the fault-controlled anticline formation simulation system, the variable volume low-temperature water bath circulation system and the hydrate evolution dynamic monitoring system; The data transmission control system is used to control the variable volume low temperature water bath circulation system to inject water into the hydraulic water tank module until the pressure in the fault control anticline formation simulation system reaches a preset starting pressure; The data transmission control system is used to control the speed and flux of gas supply from the gas source supply module to the fault-controlled anticline formation simulation system according to a preset gas flow rate.

6. A natural gas hydrate formation evolution simulation device according to claim 1, characterized in that: The hydraulic water tank module is a sealed reaction device made of stainless steel; Wherein, a water injection port is provided on the top of the hydraulic water tank module, and the water injection port is connected to the water pressure control device; The hydraulic water tank module is connected to the fluid pipeline of the variable capacity low temperature water bath circulation system; the fluid pipeline is connected to a hydraulic pump and a pressure control valve; the pressure control valve is connected to the data transmission control system; The hydraulic pump is used to provide power for the flow transmission of simulated seawater; The pressure control valve is used to adjust the water injection speed and cross-sectional flow rate.

7. A natural gas hydrate formation and evolution simulation device according to any one of claims 1 to 6, characterized in that: The simulation device also includes an image recording module; The image recording module is used to record images of the formation process of natural gas hydrate in the simulation device.

8. A control method, characterized in that: The control method is used to control a natural gas hydrate formation and evolution simulation device according to any one of claims 1 to 7, and the control method comprises the following steps: Set the starting pressure of the hydraulic tank module; Set the gas supply speed and flux of the gas source supply module; starting the simulation device according to the starting pressure, the gas supply speed and the flux; Obtain feedback information collected by the data transmission control system; The formation and evolution of natural gas hydrates are simulated according to the feedback information.

Images