Carbon dioxide sequestration experiment simulation device and method based on in-situ conditions

Abstract

The invention discloses a carbon dioxide sequestration experiment simulation device and method based on in-situ conditions, and relates to the technical field of carbon dioxide sequestration, the device comprises a pressure container, a three-phase supply system, a load system, an acquisition system and a temperature control system, the pressure container comprises a pressure cylinder, a direction moving block and a displacement sensor; the loading system applies pressure to the rock core sample to provide stress and deformation quantity in the three-axis direction; the acquisition system comprises a nuclear magnetic data acquisition system for shooting to obtain a core sample pore structure and fluid change characteristics, and a temperature and pressure data acquisition system for acquiring pressure and temperature of CO2 injected into a core sample; the temperature control system is used for controlling the temperature when CO2 is injected into the rock core sample. According to the simulation method, the real heat-water-pressure-geomechanical conditions of the underground reservoir can be simulated, physical and chemical interaction between a two-phase or three-phase and the rock and mechanical characteristics of the rock are considered, and then research on the storage mechanism and safety of carbon dioxide geological storage is carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide storage and utilization, and more specifically, to a carbon dioxide storage experimental simulation device and method based on in-situ conditions. Background Art

[0002] Carbon Geological Storage (CGS) is a technology that injects supercritical carbon dioxide (CO2) at high pressure and permanently stores it in deep geological reservoirs to prevent it from entering the atmosphere, thereby effectively reducing CO2 emissions into the atmosphere and reducing the greenhouse effect.

[0003] However, high-pressure CO2 injected into the formation may change the rock mechanical properties and permeability of the reservoir, affect the strength, pore structure and flow characteristics of the fluid inside the rock, resulting in a decrease in the stability of the reservoir and even causing micro-vibration or leakage risks.

[0004] The invention patent with publication number CN114088684A discloses a carbon dioxide storage experimental simulation device and method, which can simulate the diffusion of carbon dioxide stored in different ways on the seabed and the hydration formation and other dynamic processes, and can also realize the leakage research of the stored carbon dioxide by temperature control. However, the above technical scheme can only simulate the process flow of carbon dioxide geological storage for a certain type of reservoir; it only considers the seepage effect (physical and chemical effect) between rocks and formation fluids (mainly formation water) under different temperature and pressure conditions, and does not consider the physical and chemical interactions between two phases (water + gas) or three phases (oil + water + gas) and rocks, and cannot evaluate the stability of rocks in CO2 storage. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a carbon dioxide storage experimental simulation device and method based on in-situ conditions, so as to solve the technical problem that the existing carbon dioxide storage simulation devices cannot consider the physical and chemical interactions between two phases (water + gas) or three phases (oil + water + gas) and rocks, and also cannot explore the sealing properties of the cap rock in carbon dioxide geological storage from the perspective of rock mechanical properties.

[0006] To achieve the above objectives, the first objective of the present invention is to provide a carbon dioxide storage experimental simulation device based on in-situ conditions, the simulation device comprising: The pressure vessel comprises a vertically arranged pressure cylinder, an X-direction moving block, a Y-direction moving block and a Z-direction moving block detachably installed in the pressure cylinder, and a displacement sensor in a core sample in the pressure cylinder, wherein the X-direction moving block, the Y-direction moving block and the Z-direction moving block are respectively used to limit the position of the core sample in corresponding directions; A three-phase supply system, comprising a water supply pipeline, an oil supply pipeline and a gas supply pipeline respectively connected to the pressure vessel; A load system, used for applying load pressure to the X-direction moving block, the Y-direction moving block and the Z-direction moving block located in the pressure cylinder, thereby providing stress and deformation in the XYZ directions to the core sample, and the deformation is measured by the displacement sensor; An acquisition system, including a nuclear magnetic data acquisition system and a temperature and pressure data acquisition system, wherein the nuclear magnetic data acquisition system is used to measure and observe the pore structure and fluid change characteristics of the core sample, and the temperature and pressure data acquisition system is used to record the pressure and temperature of CO2 injected into the core sample; The temperature control system is used to control the temperature of the core sample when CO2 is injected.

[0007] Preferably, the Z-direction moving block comprises a first Z-direction moving block located at the top end surface of the core sample, a second Z-direction moving block located at the bottom end surface of the core sample, and a third Z-direction moving block and a fourth Z-direction moving block respectively located at adjacent side surfaces of the core sample, the third Z-direction moving block and the fourth Z-direction moving block are respectively fixedly arranged between the pressure cylinder and the core sample, the first Z-direction moving block and the second Z-direction moving block are respectively embedded in the top end cover and the bottom end cover of the pressure cylinder, and are suitable for being moved along the Z-axis direction by an external force load, thereby transmitting the load to the top end and the bottom end of the core sample; The X-direction moving block and the Y-direction moving block are respectively located on other adjacent side surfaces of the core sample. The X-direction moving block is closely attached between the core sample and the side surface of the pressure cylinder, and is suitable for making a slight sliding movement along the X-direction in the horizontal plane. The Y-direction moving block is closely attached between the core sample and the side surface of the pressure cylinder, and is suitable for making a slight sliding movement along the Y-direction in the horizontal plane.

[0008] Preferably, the water supply pipeline includes a first air pump, a first water storage tank and a thermostatic valve which are connected in sequence through a first water pipe, and an end of the thermostatic valve away from the first water storage tank is connected to the interior of the core sample through the first water pipe.

[0009] Preferably, the oil supply pipeline includes a second air pump and a first oil storage tank which are connected in sequence through a first oil pipe, and one end of the first oil pipe away from the first oil storage tank is connected to the interior of the core sample.

[0010] Preferably, the gas supply pipeline includes a first gas storage tank, a first pressure regulating valve, a first switch valve, a CO2 liquid storage tank, a first speed regulating valve and a CO2 gas storage tank which are connected in sequence through an air pipe, and the air pipe is connected to the interior of the core sample away from the CO2 gas storage tank.

[0011] Preferably, it also includes a gas-liquid collection system connected to the interior of the pressure vessel, the gas-liquid collection system includes a liquid collection pipeline and a gas collection pipeline, the liquid collection pipeline includes a liquid collection pipe and a liquid collection tank, one end of the liquid collection pipe is connected to the liquid collection tank, and the other end is inserted into the core sample in the pressure vessel; the gas collection pipeline includes a gas collection pipe and a gas collection tank, one end of the gas collection pipe is connected to the gas collection tank, and the other end is inserted into the core sample in the pressure vessel.

[0012] Preferably, the load system includes an X-axis hydraulic pump, a Y-axis hydraulic pump and a Z-axis hydraulic pump, the X-axis hydraulic pump applies an X-direction load to the X-direction moving block through a first pressure sensor, the Y-axis hydraulic pump applies a Y-direction load to the Y-direction moving block through a second pressure sensor, and the Z-axis hydraulic pump applies a Z-direction load to the Z-direction moving block through a third pressure sensor.

[0013] Preferably, the temperature control system comprises a heating belt and a temperature sensor installed on the outer circumference of the pressure cylinder, the heating belt is suitable for heating and controlling the temperature of the core sample, and the temperature sensor is suitable for real-time monitoring the temperature of the core sample.

[0014] Preferably, the nuclear magnetic resonance data acquisition system includes a nuclear magnetic resonance instrument installed on the outer periphery of the pressure cylinder and a nuclear magnetic image data acquisition end electrically connected to the nuclear magnetic resonance instrument, and the nuclear magnetic image data acquisition end is suitable for collecting pore structure and fluid change characteristic data of the core sample.

[0015] Preferably, the temperature and pressure data acquisition system comprises a temperature and pressure data acquisition terminal, and the temperature and pressure data acquisition terminal is electrically connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the temperature sensor respectively.

[0016] The second object of the present invention is to provide a method for simulating a carbon dioxide storage experiment based on in-situ conditions, using the above-mentioned carbon dioxide storage experiment simulation device based on in-situ conditions, the method comprises the steps of: Step S1: preparing a core sample of a cuboid structure from a target reservoir, and measuring and recording the initial pore distribution, permeability and pore structure characteristics of the core sample; Step S2: placing the core sample and the direction moving block into a pressure cylinder, and saturating the formation fluid for a time t at a pressure exceeding 20 MPa; Step S3: applying the target reservoir pressure to the core sample in the pressure vessel through the load system, and heating the pressure cylinder to the target reservoir temperature through the temperature control system, and leaving it for a period of time to achieve pressure balance in the pressure vessel and keep it in a constant temperature and pressure state; Step S4: controlling the water supply pipeline, the oil supply pipeline and the gas supply pipeline of the three-phase supply system, so that the water, oil and gas in the water supply pipeline, the oil supply pipeline and the gas supply pipeline flow through the core sample, and increasing the load pressure of the load system at a deformation rate of 0.01-2 mm per minute, and observing and recording the relationship between the deformation and the load pressure of the core sample through the acquisition system; Step S5: When performing a carbon dioxide storage experiment, after gas or liquid is injected into the core sample, the fluid change characteristics and pore characteristics in the core sample are observed by a nuclear magnetic resonance data acquisition system; Step S6: Testing and analyzing the products of the entire experimental process through the liquid collection pipeline and the gas collection pipeline in the gas-liquid collection system.

[0017] Compared with the prior art, the present invention has the following advantages and effects: 1. The carbon dioxide storage experiment simulation device in this application is composed of a pressure vessel, a three-phase supply system, a load system, a collection system and a temperature control system. The pressure vessel is the core part of the carbon dioxide storage experiment. The pressure cylinder is designed as a square structure, which is not only convenient for loading core samples, but also used to provide an environment for the gas-water-rock interaction reaction that occurs during the carbon dioxide storage in the core sample, and also provides an environment for the core sample to be subjected to load pressure in the X, Y, and Z axis directions, ensuring the stability and consistency of the simulation experiment process; the experimental device is connected to the core sample through the water supply pipeline, the oil supply pipeline and the gas supply pipeline. It can simulate a variety of storage conditions, including pure CO2 storage, mixed CO2 storage, supercritical CO2 storage, etc. This versatility enables the device to simulate different geological conditions and storage strategies; the load system simulates the stress of actual underground core samples by applying pressure; through the nuclear magnetic resonance technology in the nuclear magnetic resonance data acquisition system, the pore structure and fluid change characteristics of the core samples can be obtained non-invasively, so as to understand the distribution and migration behavior of CO2 in the core; the temperature control system ensures that the pressure cylinder is in a constant temperature and pressure state during the experiment, simulating the actual temperature conditions of the underground reservoir and providing experimental results that are closer to reality. Therefore, the device can simulate the geological storage efficiency of carbon dioxide under different temperature and pressure conditions in different types of reservoirs (depleted oil and gas reservoirs, coal rock, shale or saline water layer, etc.); the pressure vessel can automatically expand and contract according to the size of the core sample, adapt to large-medium-small scale core column samples, and study the interaction between the core and the fluid in the geological storage process of carbon dioxide from different scales; the device can simultaneously carry out experiments involving different research directions in the geological storage process of carbon dioxide, such as geochemical tests, rock physics tests and rock mechanics tests; in addition, the device can also be applied to energy storage research, such as natural gas storage, hydrogen storage and helium storage. The device can realize multi-scenario simulation, increase the applicability and flexibility of the experimental device, and through precise control of experimental conditions and multi-directional data collection, it can provide important experimental data and theoretical support for the research of CO2 storage technology.

[0018] 2. This experimental device can simulate the real thermal-water-pressure-geomechanical conditions in deep underground reservoirs, and consider the physical and chemical interactions between two phases (water + gas) or three phases (oil + water + gas) and rocks, as well as the mechanical properties of rocks, to carry out research on the storage mechanism and storage safety of carbon dioxide geological storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of a carbon dioxide storage experiment simulation device based on in-situ conditions in an embodiment of the present invention; Figure 2 Schematic diagram of the internal structure of the pressure vessel in the embodiment of the present invention; Figure 3Schematic diagram of the bottom structure of the pressure vessel in an embodiment of the present invention; Figure 4 It is a schematic flow chart of a carbon dioxide storage experimental simulation method based on in-situ conditions in an embodiment of the present invention.

[0020] Description of reference numerals: 1- Pressure vessel; 11-pressure cylinder; 12-X direction moving block; 13-Y direction moving block; 14-Z direction moving block; 141-second Z direction moving block; 142-first Z direction moving block; 143-third Z direction moving block; 144-fourth Z direction moving block; 15-displacement sensor; 16-support frame; 2- Three-phase supply system; 21-water supply pipeline; 211-first air pump; 212-first water storage tank; 213-first water pipe; 214-thermostatic valve; 22- oil supply pipeline; 221- second air pump; 222- first oil storage tank; 223- first oil pipe; 23-gas supply pipeline; 231-first gas storage tank; 232-CO2 liquid storage tank; 233-CO2 gas storage tank; 234-first pressure regulating valve; 235-first switch valve; 236-first speed regulating valve; 3-Gas and liquid collection system; 31-liquid collecting pipeline; 311-liquid collecting pipe; 312-liquid collecting tank; 32-gas collection pipeline; 321-gas collection pipe; 322-gas collection tank; 4- Load system; 41-X-axis hydraulic pump; 411-first pressure sensor; 42-Y-axis hydraulic pump; 421-second pressure sensor; 43-Z-axis hydraulic pump; 431-third pressure sensor; 5- Collection system; 51-Nuclear magnetic resonance data acquisition system; 511-Nuclear magnetic resonance apparatus; 512-Nuclear magnetic resonance image data acquisition terminal; 52-temperature and pressure data acquisition system; 521-temperature and pressure data acquisition terminal; 6- Temperature control system; 61-heating belt; 62-temperature sensor; 7-Core samples. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "include" and "comprises" used herein should be understood as inclusive and open-ended, rather than exclusive. Specifically, when the terms "include" and "comprises" and their synonyms are used in the specification and claims, they mean including the specified features, steps or components. These terms cannot be understood to exclude the existence of other features, steps or components.

[0022] CO2 geological storage (abbreviated as "geological storage") generally refers to the injection of CO2 into geological bodies with various reservoir conditions, such as deep saline aquifers, depleted oil and gas reservoirs, deep unmineable coal seams and basalt, in order to achieve safe and effective permanent carbon fixation.

[0023] However, to safely and effectively store high-pressure CO2 permanently in deep geological reservoirs, it is necessary to have a deep understanding of the impact of CO2 injection on geological reservoirs. For example, high-pressure CO2 injected into the formation may change the rock mechanical properties and permeability of the reservoir, affect the strength and pore structure of the rock, and the flow characteristics of the fluid inside the rock, resulting in a decrease in the stability of the reservoir and even causing micro-vibration or leakage risks.

[0024] Therefore, there is an urgent need to develop laboratory equipment and corresponding methods that can simulate the CO2 injection and storage process in deep geological environments, operate under the expected in situ pressure conditions (including confining pressure and fluid pressure) and temperature conditions, and truly reproduce the temperature and pressure environment thousands of meters underground, and then systematically study the physical and chemical interactions between CO2 and rocks and formation fluids, and ultimately evaluate the safety, effectiveness and long-term stability of the CO2 storage process.

[0025] To solve the above technical problems, please refer to Figure 1-3 As shown, in one embodiment, the present invention provides a carbon dioxide storage experimental simulation device based on in-situ conditions, the carbon dioxide storage experimental simulation device comprises a pressure vessel 1, a three-phase supply system 2, a load system 4, a collection system 5 and a temperature control system 6, wherein: The pressure vessel 1 includes a vertically arranged pressure cylinder 11, a direction moving block and a displacement sensor 15 in the core sample 7 in the pressure cylinder 11. As a preferred mode of this embodiment, the pressure cylinder 11 is preferably set as a square cylinder structure, that is, the inner and outer horizontal sections of the pressure cylinder 11 are both square, and the pressure cylinder 11 is used to load the core sample 7. Exemplarily, the specifications of the core sample 7 in this embodiment are set as follows: the height is 200mm, the length and width are 50mm. The direction moving block is arranged in the pressure cylinder 11, which is used to limit the position of the core sample 7 in the corresponding direction, and the direction moving block does not seal the surrounding of the core sample 7.

[0026] The displacement sensors 15 are installed in three directions (X, Y, and Z axis directions) of the core sample 7 to record the deformation of the core sample 7 in three directions under a certain pressure. Considering the influence of the horizontality of the pressure cylinder 11 on the measurement results, in this embodiment, a plurality of support frames 16 are arranged around the bottom of the pressure cylinder 11 for leveling.

[0027] The three-phase supply system 2 includes a water supply pipeline 21, an oil supply pipeline 22 and a gas supply pipeline 23 which are respectively connected to the pressure vessel 1. Such a device can carry out a variety of simulation experiments, such as pure CO2 storage, mixed CO2 storage, supercritical CO2 storage, storage by alternating injection of water and gas, etc. In addition, CO2 oil recovery experiments can also be carried out.

[0028] The load system 4 is used to apply load pressure to the X-direction moving block 12, the Y-direction moving block 13 and the Z-direction moving block 14 located in the pressure cylinder 11, thereby providing stress and deformation in the X, Y and Z directions to the core sample 7. The deformation is measured by the displacement sensor 15 to further understand the maximum pressure that the core sample 7 can withstand, thereby evaluating the leakage of CO2.

[0029] The acquisition system 5 includes a nuclear magnetic resonance data acquisition system 51 and a temperature and pressure data acquisition system 52. The nuclear magnetic resonance data acquisition system 51 is used to obtain the pore structure and fluid change characteristics of the core sample 7 by video, and the temperature and pressure data acquisition system 52 is used to measure and record the pressure and temperature of the CO2 injected into the core sample 7.

[0030] The temperature control system 6 is used to control the temperature of the core sample 7 when CO2 is injected. The pressure cylinder 11 can be heated to the temperature of the target reservoir, and the pressure balance and constant temperature and pressure state can be achieved.

[0031] Specifically in the embodiment of the present invention, the carbon dioxide storage experimental simulation device is composed of a pressure vessel 1, a three-phase supply system 2, a load system 4, a collection system 5 and a temperature control system 6. The pressure vessel 1 is the core part of the carbon dioxide storage experiment. The pressure cylinder 11 is designed as a square structure, which is not only convenient for loading the core sample 7, but also used to provide an environment for the gas-water-rock interaction reaction that occurs during the carbon dioxide storage in the core sample 7, and also provides an environment for the core sample 7 to be subjected to load pressure in the X, Y, and Z axis directions, ensuring stability and consistency during the simulation experiment; through the connection of the water supply pipeline 21, the oil supply pipeline 22 and the gas supply pipeline 23 with the core sample 7, the experimental device can simulate a variety of sealing This versatility enables the device to simulate different geological conditions and storage strategies; the load system 4 simulates the stress on the actual underground core sample 7 by applying pressure, which is crucial for evaluating the stability of the core sample 7 and the long-term effect of CO2 storage; the nuclear magnetic resonance technology in the nuclear magnetic resonance data acquisition system 51 can be used to non-invasively obtain the pore structure and fluid change characteristics of the core sample 7, so as to understand the distribution and migration behavior of CO2 in the core; the temperature control system 6 ensures that the pressure cylinder 11 is in a constant temperature and pressure state during the experiment, simulating the actual temperature conditions of the underground reservoir and providing experimental results that are closer to reality.

[0032] Therefore, the device can simulate the geological storage efficiency of carbon dioxide under different temperature and pressure conditions in different types of reservoirs (depleted oil and gas reservoirs, coal rock, shale or saline water layer, etc.); the pressure vessel 1 can automatically expand and contract according to the size of the core sample 7, adapt to large-medium-small scale core column samples, and study the interaction between the core and the fluid in the geological storage process of carbon dioxide from different scales; the device can simultaneously carry out experiments involving different research directions in the geological storage process of carbon dioxide, such as geochemical tests, rock physics tests and rock mechanics tests; in addition, the device can also be applied to energy storage research, such as natural gas storage, hydrogen storage and helium storage. The device can realize multi-scenario simulation, increase the applicability and flexibility of the experimental device, and through precise control of experimental conditions and multi-directional data acquisition, it can provide important experimental data and theoretical support for the research of CO2 storage technology.

[0033] It should be noted that the directional moving blocks in this embodiment are all made of stainless steel, and the surface of the directional moving blocks is covered with a layer of chromium metal by electroplating to enhance its surface hardness and corrosion resistance, and is resistant to high temperature and high pressure (temperature range is -196℃~800℃, maximum pressure is 1000MPa).

[0034] In addition, the pressure vessel 1 can automatically expand and contract according to the size of the core sample 7 to adapt to large, medium and small sized core column samples, so as to study the interaction between the core sample 7 and the fluid in the carbon dioxide geological storage process from different scales.

[0035] Further, please refer to Figures 2 and 3, the Z-direction moving block 14 includes a second Z-direction moving block 141, a first Z-direction moving block 142, a third Z-direction moving block 143 and a fourth Z-direction moving block 144, wherein the first Z-direction moving block 142 is located at the top end surface of the core sample 7, the second Z-direction moving block 141 is located at the bottom end surface of the core sample 7, the third Z-direction moving block 143 and the fourth Z-direction moving block 144 are respectively located at adjacent side surfaces of the core sample 7, the third Z-direction moving block 143 and the fourth Z-direction moving block 144 are respectively fixedly arranged between the pressure cylinder 11 and the core sample 7, the first Z-direction moving block 142 and the second Z-direction moving block 141 are respectively embedded in the top end cover and the bottom end cover of the pressure cylinder 11, and are suitable for being moved along the Z-axis direction by an external force load, thereby transmitting the load to the top and bottom ends of the core sample 7; The X-direction moving block 12 and the Y-direction moving block 13 are respectively located on the other adjacent side surfaces of the core sample 7. The X-direction moving block 12 is closely attached between the side surfaces of the core sample 7 and the pressure cylinder 11, and is suitable for making a slight sliding movement along the X-direction in the horizontal plane. The Y-direction moving block 13 is closely attached between the side surfaces of the core sample 7 and the pressure cylinder 11, and is suitable for making a slight sliding movement along the Y-direction in the horizontal plane.

[0036] Therefore, in this embodiment, the directional moving blocks include an X-directional moving block 12, a Y-directional moving block 13 and a Z-directional moving block 14 that are detachably installed in the pressure cylinder 11. Preferably, the thickness of the directional moving block is set to 1 cm, the length of the directional moving block is set to 5 cm, the width of the directional moving block is set to 5 cm, the height range of the directional moving block is set to 5-20 cm, and the bottoms of the X-directional moving block 12 and the Y-directional moving block 13 form a cylindrical structure with a square cross-section to adapt to the horizontal cross-sectional shape of the pressure cylinder 11.

[0037] The Z-direction moving block 14 includes a second Z-direction moving block 141 and a first Z-direction moving block 142. The second Z-direction moving block 141 is located in the Z-direction of the pressure cylinder 11 and is close to the bottom of the core sample 7. The first Z-direction moving block 142 is located in the Z-direction of the pressure cylinder 11 and is close to the top of the core sample 7. The Z-direction moving block 14 ensures that there is no gap between the core sample 7 and the pressure cylinder 11, so that carbon dioxide can directly enter the core from the bottom of the core sample 7, and also ensures that the fluid in the core sample 7 is displaced and flows out from the top.

[0038] Further, please refer to 1, 2, and 3, the water supply pipeline 21 includes a first air pump 211, a first water storage tank 212, and a thermostatic valve 214 which are sequentially connected through a first water pipe 213, and the end of the thermostatic valve 214 away from the first water storage tank 212 is connected to the interior of the core sample 7 through the first water pipe 213.

[0039] Specifically in this embodiment, the first air pump 211 provides pressure to pump water out of the first water tank 212 and transport it to the inside of the core sample 7 through the first water pipe 213. In the experiment, the first air pump 211 can be used to simulate groundwater flow or increase water pressure to simulate water pressure under actual geological conditions; the first water tank 212 is used to store water required for the experiment. In the carbon dioxide storage experiment, the first water tank 212 can provide the water source required for the experiment and adjust the water quality to simulate different groundwater conditions; the thermostatic valve 214 is used to adjust the water temperature to simulate the temperature change under actual geological conditions. The thermostatic valve 214 can control the temperature of the water when it flows through the core sample 7, which is crucial for simulating the temperature conditions of the underground reservoir to obtain the water pressure and temperature conditions of the actual underground reservoir.

[0040] Further, please refer to 1, 2, and 3, the oil supply pipeline 22 includes a second air pump 221 and a first oil storage tank 222 which are connected in sequence through a first oil pipe 223, and one end of the first oil pipe 223 away from the first oil storage tank 222 is connected to the interior of the core sample 7.

[0041] Specifically in this embodiment, the second air pump 221 is responsible for providing pressure in the oil supply pipeline 22, extracting oil from the first oil storage tank 222 and transporting it to the interior of the core sample 7 through the first oil pipe 223; in the carbon dioxide storage experiment, the first oil storage tank 222 can provide the oil source required for the experiment, and can adjust the oil quality to simulate different reservoir conditions; the oil can be directly injected into the core sample 7 to simulate the flow of oil in the reservoir and the storage effect of carbon dioxide.

[0042] Further, referring to 1, 2, and 3, the gas supply pipeline 23 includes a first gas storage tank 231, a first pressure regulating valve 234, a first switch valve 235, a CO2 liquid storage tank 232, a first speed regulating valve 236, and a CO2 gas storage tank 233, which are sequentially connected through an air pipe, and the air pipe is connected to the interior of the core sample 7 away from the CO2 gas storage tank 233.

[0043] Specifically in this embodiment, the first gas storage tank 231 is used to store He / N2 gas to ensure a stable supply of He / N2 gas during the experiment; the first pressure regulating valve 234 is used to adjust and stabilize the gas pressure output from the first gas storage tank 231 to meet the specific pressure requirements during the experiment; the first switch valve 235 is used to control the circulation of CO2 gas, and can open or close the gas flow to facilitate experimental operation and safety management; the CO2 liquid storage tank 232 is used to store liquid CO2, and the first speed regulating valve 236 is used to adjust the flow rate of the CO2 liquid to simulate different injection conditions and experimental scenarios; the CO2 gas storage tank 233 is used to store gaseous CO2 to ensure sufficient CO2 supply during the experiment.

[0044] Therefore, through the first pressure regulating valve 234 and the first speed regulating valve 236, the experimental device can accurately control the pressure and flow rate of the CO2 gas and truly simulate the CO2 injection conditions of the underground reservoir.

[0045] Further, please refer to 1, 2, and 3. The experimental simulation device also includes a gas-liquid collection system 3 connected to the interior of the pressure vessel 1. The gas-liquid collection system 3 includes a liquid collection pipeline 31 and a gas collection pipeline 32. The liquid collection pipeline 31 includes a liquid collection pipe 311 and a liquid collection tank 312. One end of the liquid collection pipe 311 is connected to the liquid collection tank 312, and the other end is inserted into the core sample 7 in the pressure vessel 1; the gas collection pipeline 32 includes a gas collection pipe 321 and a gas collection tank 322. One end of the gas collection pipe 321 is connected to the gas collection tank 322, and the other end is inserted into the core sample 7 in the pressure vessel 1.

[0046] Thus, the gas and liquid discharged from the core sample 7 can be effectively separated through an independent gas-liquid collection pipeline, and the collected gas and liquid can be used for subsequent chemical and physical property analysis, such as CO2 concentration, solubility, pH value, etc.

[0047] Further, please refer to 1, 2, and 3, the load system 4 includes an X-axis hydraulic pump 41, a Y-axis hydraulic pump 42, and a Z-axis hydraulic pump 43. The X-axis hydraulic pump 41 applies an X-direction load to the X-direction moving block 12 via a first pressure sensor 411, the Y-axis hydraulic pump 42 applies a Y-direction load to the Y-direction moving block 13 via a second pressure sensor 421, and the Z-axis hydraulic pump 43 applies a Z-direction load to the Z-direction moving block 14 via a third pressure sensor 431.

[0048] Specifically in this embodiment, the load system 4 applies loads in different directions through X-axis, Y-axis and Z-axis hydraulic pumps and corresponding pressure sensors, wherein the X-axis hydraulic pump 41 applies an X-direction load to the X-direction moving block 12 through the first pressure sensor 411, the X-axis hydraulic pump 41 provides power, and the first pressure sensor 411 monitors and feeds back the applied pressure to ensure precise control of pressure during the experiment; the Y-axis hydraulic pump 42 applies a Y-direction load to the Y-direction moving block 13 through the second pressure sensor 421, similarly, the Y-axis hydraulic pump 42 is responsible for providing power, and the second pressure sensor 421 is responsible for monitoring pressure to achieve precise control; the Z-axis hydraulic pump 43 applies a Z-direction load to the Z-direction moving block 14 through the third pressure sensor 431, and the Z-axis hydraulic pump 43 allows pressure to be applied to the core sample 7 in the vertical direction to simulate actual underground conditions.

[0049] Therefore, the load system 4 can simulate the stresses exerted on the underground core sample 7 in the three directions of X, Y, and Z, and dynamically adjust the pressure conditions during the experiment to simulate different geological environments or sealing stages; by precisely controlling the pressure, sample damage or experimental failure caused by excessive pressure can be avoided, thereby improving the safety and stability of the experiment; the data collected in the experiment can be used to analyze the behavior of the core sample 7 under different stress conditions.

[0050] Further, as shown in FIG1 , the temperature control system 6 includes a heating belt 61 and a temperature sensor 62 installed on the outer circumference of the pressure cylinder 11 , the heating belt 61 is suitable for heating and controlling the temperature of the core sample 7 , and the temperature sensor 62 is suitable for real-time monitoring of the temperature of the core sample 7 .

[0051] Specifically in this embodiment, the temperature control and monitoring of the core sample 7 is achieved through the coordinated work of the heating belt 61 and the temperature sensor 62. The heating belt 61 is installed on the outer circumference of the pressure cylinder 11, and is used to directly heat the core sample 7 to control its temperature. This heating method is similar to the heating element of the air jacket or water jacket carbon dioxide incubator, which realizes the transfer of heat by consuming electrical energy, thereby creating the required culture environment; the temperature sensor 62 is suitable for real-time monitoring of the temperature of the core sample 7, and feeding back the detection results to the temperature control system 6.

[0052] Therefore, through the closed-loop control of the heating belt 61 and the temperature sensor 62, the temperature of the core sample 7 can be accurately controlled to truly simulate the temperature conditions of the underground reservoir and provide the necessary environment for the experiment.

[0053] Further, please refer to Figure 1, the nuclear magnetic data acquisition system 51 includes a nuclear magnetic resonance instrument 511 installed on the outer periphery of the pressure cylinder 11 and a nuclear magnetic image data acquisition terminal 512 electrically connected to the nuclear magnetic resonance instrument 511, and the nuclear magnetic image data acquisition terminal 512 is suitable for collecting pore structure and fluid change characteristic data of the core sample 7.

[0054] Specifically in this embodiment, the nuclear magnetic resonance instrument 511 is installed on the periphery of the pressure cylinder 11, and the nuclear magnetic resonance (NMR) technology is used to study the pore structure, CO2 migration characteristics and rock mechanical parameter changes. The nuclear magnetic resonance technology can provide information on reservoir properties, saturation and three-dimensional pore structure, and has obvious advantages in characterizing reservoir properties; the nuclear magnetic image data acquisition terminal 512 is suitable for collecting pore structure and fluid change characteristic data of the core sample 7. The data acquisition terminal 512 can be equipped with a high temperature and high pressure and imaging test system. For the low-pore core sample 7, the signal-to-noise ratio and sensitivity of the pore analysis are high.

[0055] Therefore, nuclear magnetic resonance technology allows for repeated non-destructive measurements of core samples 7, which can reflect the actual underground formation conditions from a macroscopic scale; nuclear magnetic resonance technology can be used for pore fluid identification, shale oil oil content evaluation, etc., to facilitate the understanding of the distribution and migration behavior of CO2 in the core.

[0056] Further, referring to FIG. 1 , the temperature and pressure data acquisition system 52 includes a temperature and pressure data acquisition terminal 521 , which is electrically connected to the first pressure sensor 411 , the second pressure sensor 421 , the third pressure sensor 431 and the temperature sensor 62 , respectively.

[0057] Specifically in this embodiment, by integrating multiple sensors and data acquisition terminals, real-time monitoring and recording of temperature and pressure data during the experiment are achieved. The first pressure sensor 411, the second pressure sensor 421, and the third pressure sensor 431 are responsible for monitoring the pressure in different directions and the temperature of the core sample 7, respectively, allowing the experimenter to adjust the experimental conditions in time and optimize the experimental process.

[0058] See also Figure 4 As shown, an embodiment of the present invention further provides a method for simulating a carbon dioxide storage experiment based on in-situ conditions, using the above-mentioned carbon dioxide storage experiment simulation device based on in-situ conditions, the method comprises the steps of: Step S1: preparing a core sample 7 of a rectangular parallelepiped structure originating from a target reservoir, and measuring and recording the initial pore distribution, permeability and pore structure characteristics of the core sample 7; In this step, the prepared core sample 7 is ground and polished according to the experimental standard to ensure that the surface of the core sample 7 is smooth and flat, and after drying for 48 hours, the core sample 7 is checked for cracks and gaps.

[0059] Step S2: placing the core sample 7 and the direction moving block into the pressure cylinder 11, and saturating the formation fluid for a time t at a pressure exceeding 20 MPa; In this step, the core sample 7 is placed in a pressure cylinder 11 and saturated with formation fluid (water, salt water or oil) for 5 days at a pressure exceeding 20 MPa.

[0060] Step S3: applying the target reservoir pressure to the core sample 7 in the pressure vessel 1 through the load system 4, and heating the pressure cylinder 11 to the temperature of the target reservoir through the temperature control system 6, and leaving it for a period of time to achieve pressure balance in the pressure vessel 1 and keep it in a constant temperature and pressure state; Step S4: Control the water supply pipeline 21, the oil supply pipeline 22 and the gas supply pipeline 23 of the three-phase supply system 2, so that the water, oil and gas in the water supply pipeline 21, the oil supply pipeline 22 and the gas supply pipeline 23 flow through the core sample 7, and increase the load pressure of the load system 4 at a deformation rate of 0.01-2 mm per minute, and observe and record the relationship between the deformation and load pressure of the core sample 7 through the acquisition system 5; In this step, the suction / liquid pump and the switch valve at the gas tank containing gas / liquid CO2 or other gas are turned on to allow it to flow through the entire core sample 7, and the load pressure is increased at a deformation rate of 0.01-2 mm per minute, and the acquisition system 5 is used to record and observe the relationship between the deformation and the load pressure.

[0061] Step S5: During the carbon dioxide storage experiment, after the gas or liquid is injected into the core sample 7, the fluid change characteristics and pore characteristics in the core sample 7 are observed by the nuclear magnetic data acquisition system 51; In this step, when conducting the carbon dioxide storage experiment, the nuclear magnetic resonance instrument 511 is used to observe the fluid change characteristics and pore characteristics in the core sample 7 after the gas or liquid is injected into the core sample 7.

[0062] Step S6: Testing and analyzing the products of the entire experimental process through the liquid collection pipeline 31 and the gas collection pipeline 32 in the gas-liquid collection system 3.

[0063] Therefore, this method simulates the CO2 injection and storage process in deep geological environment, systematically studies the physical and chemical interactions between CO2 and rocks and formation fluids, evaluates the safety, effectiveness and long-term stability of the CO2 storage process, and combines numerical simulation to optimize the CO2 injection strategy, improve storage efficiency and reduce risks.

[0064] In addition, the experimental method provided by the present invention can simulate the real thermal-water-pressure-geomechanical conditions in deep underground reservoirs, and consider the physical and chemical interactions between two phases (water + gas) or three phases (oil + water + gas) and rocks, as well as the mechanical properties of rocks, to carry out research on the storage mechanism and storage safety of carbon dioxide geological storage.

[0065] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A carbon dioxide storage experimental simulation device based on in-situ conditions, used to simulate the internal process of carbon dioxide storage in a core sample, wherein the core sample is set as a square column structure, characterized in that: include: The pressure vessel comprises a vertically arranged pressure cylinder, an X-direction moving block, a Y-direction moving block and a Z-direction moving block detachably installed in the pressure cylinder, and a displacement sensor in a core sample in the pressure cylinder, wherein the X-direction moving block, the Y-direction moving block and the Z-direction moving block are respectively used to limit the position of the core sample in corresponding directions; A three-phase supply system, comprising a water supply pipeline, an oil supply pipeline and a gas supply pipeline respectively connected to the pressure vessel; A load system, used for applying load pressure to the X-direction moving block, the Y-direction moving block and the Z-direction moving block located in the pressure cylinder, thereby providing stress and deformation in the XYZ directions to the core sample, and the deformation is measured by the displacement sensor; An acquisition system, including a nuclear magnetic data acquisition system and a temperature and pressure data acquisition system, wherein the nuclear magnetic data acquisition system is used to measure and observe the pore structure and fluid change characteristics of the core sample, and the temperature and pressure data acquisition system is used to record the pressure and temperature of CO2 injected into the core sample; The temperature control system is used to control the temperature of the core sample when CO2 is injected.

2. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 1 is characterized in that: The Z-direction moving block comprises a first Z-direction moving block located at the top end surface of the core sample, a second Z-direction moving block located at the bottom end surface of the core sample, and a third Z-direction moving block and a fourth Z-direction moving block respectively located at adjacent side surfaces of the core sample, the third Z-direction moving block and the fourth Z-direction moving block are respectively fixedly arranged between the pressure cylinder and the core sample, the first Z-direction moving block and the second Z-direction moving block are respectively embedded in the top end cover and the bottom end cover of the pressure cylinder, and are suitable for being moved along the Z-axis direction by an external force load, thereby transmitting the load to the top end and the bottom end of the core sample; The X-direction moving block and the Y-direction moving block are respectively located on other adjacent side surfaces of the core sample. The X-direction moving block is closely attached between the core sample and the side surface of the pressure cylinder, and is suitable for making a slight sliding movement along the X-direction in the horizontal plane. The Y-direction moving block is closely attached between the core sample and the side surface of the pressure cylinder, and is suitable for making a slight sliding movement along the Y-direction in the horizontal plane.

3. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 1 is characterized in that: The water supply pipeline includes a first air pump, a first water storage tank and a temperature regulating valve which are connected in sequence through a first water pipe, and one end of the temperature regulating valve away from the first water storage tank is connected to the interior of the core sample through the first water pipe.

4. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 1 is characterized in that: The oil supply pipeline includes a second air pump and a first oil storage tank which are connected in sequence through a first oil pipe, and one end of the first oil pipe away from the first oil storage tank is connected to the interior of the core sample.

5. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 1 is characterized in that: The gas supply pipeline includes a first gas storage tank, a first pressure regulating valve, a first switch valve, a CO2 liquid storage tank, a first speed regulating valve and a CO2 gas storage tank which are connected in sequence through an air pipe, and the air pipe is connected to the interior of the core sample away from the CO2 gas storage tank.

6. The carbon dioxide storage experimental simulation device based on in-situ conditions according to any one of claims 1 to 5, characterized in that: It also includes a gas-liquid collection system connected to the interior of the pressure vessel, the gas-liquid collection system includes a liquid collection pipeline and a gas collection pipeline, the liquid collection pipeline includes a liquid collection pipe and a liquid collection tank, one end of the liquid collection pipe is connected to the liquid collection tank, and the other end is inserted into the core sample in the pressure vessel; the gas collection pipeline includes a gas collection pipe and a gas collection tank, one end of the gas collection pipe is connected to the gas collection tank, and the other end is inserted into the core sample in the pressure vessel.

7. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 6 is characterized in that: The load system includes an X-axis hydraulic pump, a Y-axis hydraulic pump and a Z-axis hydraulic pump. The X-axis hydraulic pump applies an X-direction load to the X-direction moving block through a first pressure sensor, the Y-axis hydraulic pump applies a Y-direction load to the Y-direction moving block through a second pressure sensor, and the Z-axis hydraulic pump applies a Z-direction load to the Z-direction moving block through a third pressure sensor.

8. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 7 is characterized in that: The temperature control system comprises a heating belt and a temperature sensor installed on the outer circumference of the pressure cylinder. The heating belt is suitable for heating and controlling the temperature of the core sample, and the temperature sensor is suitable for real-time monitoring the temperature of the core sample.

9. The carbon dioxide storage experimental simulation device based on in-situ conditions according to claim 8, characterized in that: The nuclear magnetic data acquisition system comprises a nuclear magnetic resonance instrument installed on the outer periphery of the pressure cylinder and a nuclear magnetic image data acquisition terminal electrically connected to the nuclear magnetic resonance instrument, wherein the nuclear magnetic image data acquisition terminal is suitable for acquiring pore structure and fluid change characteristic data of the core sample; The temperature and pressure data acquisition system includes a temperature and pressure data acquisition terminal, which is electrically connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the temperature sensor respectively.

10. A method for simulating an experimental storage of carbon dioxide under in-situ conditions, using the experimental simulation device for simulating an experimental storage of carbon dioxide under in-situ conditions as claimed in any one of claims 1 to 9, characterized in that: The method comprises the steps of: Step S1: preparing a core sample of a cuboid structure from a target reservoir, and measuring and recording the initial pore distribution, permeability and pore structure characteristics of the core sample; step S2: placing the core sample and the directional moving block into a pressure cylinder, and saturating the formation fluid for time t at a pressure exceeding 20 MPa; Step S3: applying the target reservoir pressure to the core sample in the pressure vessel through the load system, and heating the pressure cylinder to the target reservoir temperature through the temperature control system, and leaving it for a period of time to achieve pressure balance in the pressure vessel and keep it in a constant temperature and pressure state; Step S4: controlling the water supply pipeline, the oil supply pipeline and the gas supply pipeline of the three-phase supply system, so that the water, oil and gas in the water supply pipeline, the oil supply pipeline and the gas supply pipeline flow through the core sample, and increasing the load pressure of the load system at a deformation rate of 0.01-2 mm per minute, and observing and recording the relationship between the deformation and the load pressure of the core sample through the acquisition system; Step S5: When performing a carbon dioxide storage experiment, after gas or liquid is injected into the core sample, the fluid change characteristics and pore characteristics in the core sample are observed by a nuclear magnetic resonance data acquisition system; step S6: The products of the entire experimental process are tested and analyzed through the liquid collection pipeline and gas collection pipeline in the gas-liquid collection system.

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