CO2-water-rock dynamic reaction simulation device and experiment method

Abstract

The invention discloses a CO2-water-rock dynamic reaction simulation device and an experiment method, and relates to the technical field of geochemical water-rock reaction, the simulation device comprises a gas-liquid internal circulation system, a CO2 input and monitoring system, a temperature control system, a pressure control system and a pH monitoring system; wherein the gas-liquid internal circulation system comprises a core holder and a circulating pump, the core holder is used for fixing a sample and applying confining pressure to the sample, and the gas-liquid internal circulation system can realize continuous fluid-solid coupling physical simulation under a high-pressure condition and continuously monitor environmental pH and circulating confining pressure at the same time; the CO2 input and monitoring system can accurately measure the CO2 injection and discharge amount, and the CO2 geological storage amount in the CO2-water-rock dynamic reaction process and the rock permeability before and after the reaction are obtained. The high-temperature and high-pressure environment of the reservoir under the in-situ condition is simulated in a laboratory, the geochemical response of the CO2-water-rock system and the permeability evolution characteristic of the sample are monitored at the same time, and guidance is provided for improving the existing CO2 enhanced oil and gas exploitation and CO2 geological storage technology.

Description

Technical Field

[0001] The present invention relates to the technical field of geochemical water-rock reaction, and in particular to a CO 2 -Water-rock dynamic reaction simulation device and experimental method. Background Art

[0002] CCUS (Carbon Capture, Utilization and Storage) technology is one of the key technologies to address global climate change. 2 Geological storage is an important part of CCUS technology. 2 - The characteristic of water-rock reaction is CO 2 Effective means to enhance unconventional oil and gas production. Related results help to clarify CO 2 Geological storage caprock leakage and crack leakage mechanism, for oil and gas reservoir CO 2 Provide guidance for storage safety evaluation.

[0003] In the CO 2 When geological storage is in operation, fluctuations in hydrodynamic conditions, temperature and pressure conditions can cause CO 2 A certain amount of fluidity is generated inside the reservoir, and CO 2 -water-rock is mainly a dynamic reaction process. Existing engineering cases have confirmed that CO 2 Mixing with water and injecting it can greatly increase the CO 2 Storage efficiency, such as the world’s largest CO 2 Mineralization Engineering - CarbFix Project in Iceland uses two wells to combine water and CO 2 After being fully mixed, it is injected into the target layer. This solution can 2 The storage efficiency is increased to more than 95% (reference: DOI: 10.1126 / science.1250828). However, the experimental device used in the current technical solution is mainly the first-generation static reactor (such as CN215375410U), which can only control CO 2 During the injection process, it is impossible to guarantee the CO 2 Continuous flow under pressure gradient, simulated CO 2 -The water-rock reaction environment does not match the actual injection conditions. In addition, the existing simulation device can only meet the test of rock particles and cannot apply confining pressure to the sample, which will cause the simulation environment to be inconsistent with the reservoir conditions, resulting in the experimental conclusion being out of touch with reality; on the other hand, the existing simulation method is limited to qualitative water-rock reaction and lacks the ability to simulate CO2 during the reaction cycle. 2 Real-time monitoring of important geological parameters such as geological storage capacity and rock permeability.2 Frontier technology of geological storage engineering, through innovative means to improve the existing experimental system, to form a CO 2 -Water-rock dynamic reaction simulation device and experimental method are necessary. Summary of the invention

[0004] The object of the present invention is to provide a CO 2 -Water-rock dynamic reaction simulation device and experimental method are used to solve the above technical problems existing in the prior art.

[0005] To achieve the above object, in one aspect, the present invention provides a CO 2 -Water-rock dynamic reaction simulation device, including:

[0006] The gas-liquid internal circulation system includes a circulation pump, a core holder, and a confining pressure pump; the core holder is connected to the confining pressure pump to fix the sample and apply confining pressure to the sample;

[0007] CO 2 Input and monitoring systems, including CO 2 A gas cylinder, a heated gas storage tank and a gas flow meter, wherein the gas flow meter is provided before and after the gas-liquid internal circulation system, and is used to measure the CO before the reaction. 2 Injection volume and CO after reaction 2 Exhaust volume, the heated gas tank is connected to CO 2 gas cylinders and core holders;

[0008] A temperature control system comprises a constant temperature box, wherein the gas-liquid internal circulation system is arranged in the constant temperature box;

[0009] Pressure control system, including the CO 2 A booster pump between the gas cylinder and the heated gas storage tank, an air compressor connected to the booster pump, and a plurality of pressure sensors located on the circulation pipeline.

[0010] The above technical solution of the present invention aims to provide a CO 2 -Water-rock dynamic reaction simulation device, which can simulate the high temperature and high pressure environment of the reservoir under in-situ conditions in the laboratory, and realize CO 2 - Monitoring the permeability evolution characteristics of samples while monitoring the water-rock geochemical response, in order to improve the existing CO 2 Enhanced Oil and Gas Recovery and CO 2 Provide guidance on geological storage technology.

[0011] Optionally, the core holder is also connected to N 2 Gas cylinder, N 2 The gas cylinder is used to N the core holder 2 Purge.

[0012] Optionally, the CO 2 -The water-rock dynamic reaction simulation device also includes a pH monitoring system, which includes a pH controller built into the constant temperature box, and the pH controller is used to regularly monitor the pH value of the solution in the reaction process.

[0013] Optionally, the pressure sensor comprises pressure sensor 1 and pressure sensor 2 arranged on the air inlet pipeline and air outlet pipeline of the core clamp; temperature sensor 1 and temperature sensor 2 are also respectively arranged on the inlet and outlet pipelines of the core clamp.

[0014] Optionally, the outlet pipeline of the core holder is connected to a back-pressure pump, a back-pressure valve is provided between the back-pressure pump and the core holder, and the back-pressure valve pipeline is connected to a gas-liquid separation system.

[0015] Optionally, the gas-liquid separation system includes a gas-liquid separator, a container connected to the liquid outlet end of the gas-liquid separator, and a gas flow meter connected to the gas outlet end of the gas-liquid separator. The container is placed on an electronic balance, and a desiccant and an exhaust valve are arranged on the exhaust pipe at the front end of the gas flow meter.

[0016] Optionally, a back-pressure buffer is provided between the back-pressure pump and the back-pressure valve.

[0017] In another aspect of the present invention, a CO 2 -Water-rock dynamic reaction experimental method for CO 2 Determination of geological storage capacity, use of any of the above CO 2 -Water-rock dynamic reaction simulation device, comprising the following steps:

[0018] S101, preparing blocky rocks into columnar samples with a diameter of 2.5 cm and a length of 5 cm, and subjecting the samples to water saturation treatment;

[0019] S102, weighing the water-saturated sample, placing it in a core holder, applying confining pressure, and turning on a constant temperature box to keep it constant at a set value;

[0020] S103, using N 2 Replace and discharge the residual air in the gas-liquid internal circulation system, and inject deionized water to discharge the internal N 2 , record the water injection volume, and then inject CO 2 Drain part of the water in the gas-liquid circulation system, close the water outlet valve when the residual water reaches the set value, and record the CO 2 Injection volume and residual water volume;

[0021] S104, turning on the air compressor and the booster pump to pressurize the gas-liquid internal circulation system, and closing the booster and air intake valves after the pressure reaches the set value;

[0022] S105, open the system valve and set the circulation pump flow rate to 0~30mL / min for internal circulation CO 2 -Water-rock dynamic reaction experiment, recording the system pressure change data over time;

[0023] S106. During the experiment, the pH value of the circulation system is measured regularly to monitor the internal solution water chemical environment in real time;

[0024] S107, after the experiment, the CO in the circulation system 2 The gas is discharged through the flow meter and mixed with CO 2 Injection rate analysis, CO 2 The total storage volume is expressed as:

[0025]

[0026] Where: N is CO 2 Total storage volume, n 1 For CO 2 Injection volume, n 2 For CO 2 Discharge volume;

[0027] CO 2 The expression of solubility is:

[0028]

[0029] Among them, n d For CO 2 Dissolved amount, k CO2 The amount of substance CO 2 Dissolved amount, m w is the water content, M w is the molar mass of water;

[0030] Since most oil and gas reservoirs are low-porosity and low-permeability rocks, CO 2 After injection, the content of physical storage states such as free and adsorbed is relatively small, so it can be considered that the dissolved and mineralized states are the main sources of CO during the experiment. 2 Main storage forms. Combined with the previous CO 2 Calculation conclusion of total storage and dissolved amount, CO 2 Mineralization amount m The expression is:

[0031] .

[0032] In another aspect of the present invention, a CO 2 - Water-rock dynamic reaction experimental method for permeability determination, using any of the above-mentioned CO 2-Water-rock dynamic reaction simulation device, comprising the following steps:

[0033] S201, placing the sample in a core holder, turning on a constant temperature box, and keeping it constant at a set value;

[0034] S202, draining the moisture in the core holder, introducing the gas to be tested and draining the residual gas;

[0035] S203, increasing the pressure in the core holder to a measured value, and recording the pressure and gas flow rate at the inlet and outlet;

[0036] S204. Calculate the permeability of the sample according to the sample size, inlet and outlet pressures and gas flow rate. The calculation formula is:

[0037]

[0038] Where K is the permeability, P 0 is atmospheric pressure, Q is the gas flow rate during the seepage process, μ is the gas viscosity, L is the length of the cylindrical sample, A is the bottom area of ​​the cylindrical sample, P 1 is the inlet pressure.

[0039] The present invention discloses the following technical effects:

[0040] The device and method of the present invention can realize the columnar or granular CO 2 -Water-rock dynamic reaction simulation experiment, and CO can be realized without frequent sampling 2 Real-time monitoring of geological storage volume and permeability; columnar and granular samples can be compared with CO 2 Simulation experiments on geochemical behavior can solve the problem of limited sample specifications applicable to existing experimental devices; CO 2 - Water-rock dynamic reaction experiment and monitoring of permeability change characteristics before and after solve the problem of single function of existing experimental devices; it also solves the problem that existing experimental devices cannot guarantee CO 2 The effective contact between fluid and water and rock samples can reflect the CO 2 Flow processes in an in situ reservoir after injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 The CO provided by the present invention 2- A schematic diagram of a water-rock dynamic reaction simulation device;

[0043] Figure 2 It is a schematic diagram of the structure of the gas-liquid internal circulation system in the device of the present invention;

[0044] In the figure: 1, N 2 Gas cylinder; 2. CO 2 Gas cylinder; 3. CO 2 Gas inlet; 4. Booster pump; 5. Solenoid valve; 6. Air compressor; 8. Heated gas storage tank; 9. Pressure regulating valve; 10. Gas flow meter 1; 11. Confining pressure pump; 12. Booster pump; 13. Pressure sensor 3; 14. Core holder; 15. Temperature sensor 1; 16. Pressure sensor 1; 17. Temperature sensor 2; 18. Pressure sensor 2; 19. Circulation pump; 20. Constant temperature box; 21. Back pressure valve; 22. Back pressure buffer; 23. Back pressure pump; 24. Gas-liquid separator; 25. Electronic balance; 26. Desiccant; 27. Gas flow meter 2; 100, N 2 Gas inlet valve; 101, valve one; 102, valve two; 103, valve three; 104, valve four; 105, valve five; 106, valve six; 107, valve seven; 108, valve eight; 109, valve nine; 110, valve ten; 111, valve eleven; 112, valve twelve; 113, valve thirteen; 114, valve fourteen; 115, valve fifteen; 116, valve sixteen; 117, valve seventeen; 201, pressure regulating meter one; 202, pressure regulating meter two; 203, pressure regulating meter three; 204, pressure regulating meter four; 205, pH controller; 206, back pressure regulating meter. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0046] Currently, CO 2 -The study of water-rock reaction is mainly carried out using static high-pressure reactors. The simulation experimental device cannot truly reduce the CO under actual conditions. 2 The fluid environment generated after injection cannot guarantee the validity and authenticity of the experiment. In addition, the existing analysis method cannot use the built-in functional modules of the device to monitor the CO 2 The geological storage volume and sample permeability data, and the analysis methods supporting the simulation experiment are relatively simple.

[0047] How to truly restore CO through technical means 2-The dynamic reaction process of water-rock and periodic monitoring of rock and solution samples during the experimental period are key technical issues that need to be solved in this field.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] Example 1

[0050] Reference Figure 1 and Figure 2 As shown, Example 1 of the present invention provides a CO 2 -Water-rock dynamic reaction simulation device, including gas-liquid internal circulation system, CO 2 Input and monitoring system, temperature control system, pressure control system, pH monitoring system.

[0051] The gas-liquid internal circulation system includes a circulation pump 19, a core clamp 14, a pressure sensor 16, a pressure sensor 2 18, a temperature sensor 15, and a temperature sensor 2 17; wherein the circulation pump 19 is also connected to the confining pressure pump 11 and the booster pump 12, and a pressure sensor 3 13 is provided on the circulation pipeline between the circulation pump 19 and the confining pressure pump 11, and the pressure condition that the circulation pump 19 can meet is 0~20MPa, and the flow rate can be set to 0~30mL / min; the core clamp 14 is used to fix the sample and apply confining pressure to the sample to simulate the formation environment, and the confining pressure range that can be met is 0~30MPa; the pressure sensor is used to measure the inlet and outlet pressures of the clamp.

[0052] The CO 2 The input and monitoring system includes a gas flow meter, a heated gas storage tank 8 and a plurality of pressure sensors; a gas flow meter is provided before and after the gas-liquid internal circulation system, including a gas flow meter 10 and a gas flow meter 27, which are used to measure the CO before the reaction. 2 Injection volume and CO after reaction 2 The heated gas tank 8 is connected to CO 2 The gas cylinder 2 and the core holder 14 are mainly used to inject CO 2 The gas is preheated and pressurized to ensure the stable injection state; the pressure sensor is used to measure CO 2 The pressure of the gas cylinder 2 and the heated gas storage tank 8.

[0053] The temperature control system includes a thermostat 20, which is an electric thermostat located outside the internal circulation system and is used to keep the temperature of the gas-liquid internal circulation system constant, and can meet the temperature condition of 0~100°C.

[0054] The pressure control system mainly includes a booster pump 4, an air compressor 6 and a plurality of pressure sensors; the booster pump 4 is located in the CO 2 The rear of gas cylinder 2 is used to transfer CO 2 CO released from cylinder 2 2 Injected into the gas storage tank, the pressure condition that can be met is 0~30MPa; the air compressor 6 is connected to the booster pump 4, which can be CO 2 The injection process provides power; the pressure sensor is used to measure the gas pressure at the outlet of the booster pump 4.

[0055] The pH monitoring system mainly includes a pH controller 205, which is built into the thermostat 20 and is used to regularly monitor the pH of the solution during the reaction process to ensure that the CO 2 -The water-rock reaction continues.

[0056] like Figure 1 As shown, the gas-liquid internal circulation system is connected to the CO 2 Gas cylinder 2, where CO 2 The circulation pipeline from the gas cylinder 2 to the core holder 14 is provided with: CO 2 Gas inlet 3, pressure regulating meter 202, valve 101, booster pump 4, valve 3 103, heated gas storage tank 8, valve 5 105, pressure regulating valve 9, pressure regulating meter 3 203, valve 6 106, gas flow meter 10, valve 7 107, valve 110. The booster pump 4 is provided with valve 2 102 at the front end, which is a pipeline vent valve, the heated gas storage tank 8 is provided with valve 4 104 at the front end, which is a gas storage tank vent valve, a solenoid valve 5 is provided between the heated gas storage tank 8 and the air compressor 6, and the heated gas storage tank 8 is also connected to pressure regulating meter 4 204.

[0057] The gas-liquid internal circulation system is connected to N 2 Cylinder 1, from N 2 The gas pipeline from the gas cylinder 1 to the core holder 14 is provided with: a pressure regulator 201, N 2 Gas inlet valve 100.

[0058] A valve 111 and a valve 12 112 are provided between the core clamp 14 and the circulation pump 19, a valve 15 115 is further provided at the rear end of the core clamp 14, and the valve 15 115 is a pipeline vent valve, a valve 16 116 is provided on the pipeline between the core clamp 14 and the back pressure valve 21, a valve 9 109 is provided between the core clamp 14 and the confining pressure pump 11, a valve 8 108 is provided between the core clamp 14 and the booster pump 12, and a valve 17 117 is provided between the core clamp 14 and the pH controller 205, and the valve 17 117 is a water intake valve.

[0059] A valve thirteen 113, a back pressure buffer 22, and a back pressure valve 21 are sequentially arranged on the back pressure pipeline between the back pressure pump 23 and the gas-liquid internal circulation system. A back pressure regulating gauge 206 is also arranged at the front end of the back pressure pump 23. The back pressure valve 21 is connected to the gas-liquid separator 24 through an exhaust pipeline. A container (such as a beaker) is placed at the liquid discharge end of the gas-liquid separator 24 for receiving the liquid. The container is placed on an electronic balance 25. The gas discharge end of the gas-liquid separator 24 is connected to the desiccant 26 through a valve fourteen 114 (exhaust valve). The dry gas treated by the desiccant 26 is discharged through a gas flow meter two 27.

[0060] Example 2

[0061] Embodiment 2 of the present invention provides a CO 2 -Water-rock dynamic reaction experimental method for CO 2 Determination of geological storage capacity, this method uses the CO 2 -Water-rock dynamic reaction simulation device, comprising the following steps:

[0062] S101, preparing blocky rocks into columnar samples with a diameter of 2.5 cm and a length of 5 cm, and subjecting the samples to water saturation treatment;

[0063] In some embodiments, the block rock is directly prepared into a columnar sample with a diameter of 2.5 cm and a length of 5 cm, and then the water-saturated columnar sample is weighed and directly subjected to CO 2 - Water-rock reaction experiments;

[0064] In other embodiments, the block rock is prepared into particles with a particle size of 50-500 μm, and then saturated with water. The saturated granular sample is placed in a CO2-resistant container with a diameter of 2.5 cm and a length of 5 cm. 2 The two ends of the rubber sleeve are sealed and then molded to obtain a columnar sample, which can be used for the next CO 2 -Water-rock reaction experiment.

[0065] S102, weighing the water-saturated sample, placing it in the core holder 14, applying confining pressure, and turning on the thermostat 20 to keep it constant at a set value;

[0066] In a specific embodiment, before inserting the sample, first check whether there is system pressure in the pipeline, and confirm the pressure of the system by turning on the power supply. If there is pressure in the pipeline, release the pressure first;

[0067] After confirming the system pressure, open the inlet and outlet ends of the core holder 14, load the sample and dummy core, and tighten the inlet and outlet plugs;

[0068] Check whether the digital display is normal, turn on the computer, and start the operating software.

[0069] Close all valves, adjust the pressure regulating valve 9 to the closed state, and then install and open the corresponding valves in sequence when operating.

[0070] In a specific embodiment, step S102 includes: opening valve nine 109, adjusting the pressure of the core clamp 14 by starting the confining pressure pump 11, the confining pressure pump 11 can be automatically controlled or manually controlled, if the initial test pressure is low, directly increase the pressure to the test pressure; if the initial test pressure is high, it can be pressurized to 5Mpa first, and at the same time, the internal circulation is pressurized to keep the confining pressure 2MPa higher than the internal pressure.

[0071] In a specific embodiment, the adjustment of the initial pressure value includes: opening the gas cylinder, opening valve one 101 and valve three 103 at the same time, pressing the boost start button on the control panel, increasing the pressure in the heated gas storage tank 8 to 20 MPa, closing valve three 103, opening valve five 105, and adjusting the output pressure to the test initial pressure through the pressure regulating valve 9.

[0072] S103, using N 2 Replace and discharge the residual air in the gas-liquid internal circulation system, and inject deionized water to discharge the internal N 2 , record the water injection volume, and then inject CO 2 Drain part of the water in the gas-liquid circulation system, close the water outlet valve when the residual water reaches the set value, and record the CO 2 Injection volume and residual water volume;

[0073] In one embodiment, turn on N 2 Gas inlet valve 100, valve 10 110, keep valve 111 112 closed, introduce nitrogen, open valve 15 115, use nitrogen to purge the pipeline, where N 2 Gas cylinder 1 contains high-purity nitrogen;

[0074] Then, close N 2 Gas inlet valve 100, open valve eight 108 and valve eleven 111, start the booster pump 12 to inject experimental water into the pipeline to displace nitrogen in the pipeline and the sample, open the outlet of valve fifteen 115 to collect liquid in a beaker, stop water injection after nitrogen is fully discharged, and record the water injection volume;

[0075] S104, turning on the air compressor 6 and the booster pump 4 to boost the pressure of the gas-liquid internal circulation system, and closing the booster and air intake valves after the pressure reaches the set value;

[0076] Specifically, valve eight 108 and valve fifteen 115 are closed, valve six 106, valve seven 107, valve eleven 111, and valve twelve 112 are opened, and CO is injected into the core holder 14 according to the preset pressure of the experiment. 2 , after reaching the expected pressure, close valve twelve 112;

[0077] S105, open the system valve, turn on the circulation pump 19, set the constant flow rate within the range of 0~30mL / min, and perform internal circulation CO 2 -Water-rock dynamic reaction experiment, recording the system pressure change data over time;

[0078] S106, during the experiment, the pH value of the circulation system is regularly measured through the water intake valve (valve seventeen 117), and at the same time, the pH controller 205 is used to monitor the internal solution water chemical environment in real time;

[0079] S107, after the experiment, the CO in the circulation system 2 The gas is discharged through the flow meter and mixed with CO 2 Injection rate analysis, CO 2 The total storage volume is expressed as:

[0080]

[0081] Where: N is CO 2 Total storage volume, n 1 For CO 2 Injection volume, n 2 For CO 2 Discharge volume;

[0082] CO 2 The expression of solubility is:

[0083]

[0084] Among them, n d For CO 2 Dissolved amount, k CO2 The amount of substance CO 2 Dissolved amount, m w is the water content, M w is the molar mass of water;

[0085] Since most oil and gas reservoirs are low-porosity and low-permeability rocks, CO 2 After injection, the content of physical storage states such as free and adsorbed is relatively small, so it can be considered that the dissolved and mineralized states are the main sources of CO during the experiment. 2 Main storage forms; combined with previous CO 2 The calculation conclusion of the total storage amount and dissolved amount is obtained. 2 Mineralization amount m The expression is:

[0086]

[0087] Among them, n m For CO 2Mineralization amount, w 0 is the weight of the dry sample before the experiment, w 1 This is the weight of the dried sample after the experiment.

[0088] In a specific embodiment, at the end of the experiment, a back-pressure pump 23 is used to increase the back pressure to the experimental pressure, and valve sixteen 116 is opened to release the gas-liquid mixture in the pump and the pipeline into the gas-liquid separator 24 through the back-pressure valve 21. Valve fourteen 114 is opened to measure the gas volume by gas flow meter two 27 and the liquid volume by electronic balance 25 respectively. The gas can be collected by using a gas collecting bag at the outlet of gas flow meter two 27. After the experiment, the confining pressure is slowly reduced according to the internal pressure. After the pressure is released, the inlet and outlet ends are disassembled and the sample is taken out.

[0089] Example 3

[0090] Embodiment 3 of the present invention provides another CO 2 - Water-rock dynamic reaction experimental method, used for permeability determination, this method uses CO 2 -Water-rock dynamic reaction simulation device, comprising the following steps:

[0091] S201, placing the sample in the core holder 14, turning on the thermostat 20, and keeping it constant at a set value;

[0092] S202, draining the water in the core holder 14, introducing the gas to be tested and draining the residual gas;

[0093] S203, increasing the pressure in the core holder 14 to a measured value, and recording the pressure and gas flow rate at the inlet and outlet;

[0094] S204. Calculate the permeability of the sample according to the sample size, inlet and outlet pressures and gas flow rate. The calculation formula is:

[0095]

[0096] Where K is the permeability, P 0 is atmospheric pressure, Q is the gas flow rate during the seepage process, μ is the gas viscosity, L is the length of the cylindrical sample, A is the bottom area of ​​the cylindrical sample, P 1 is the inlet pressure.

[0097] Specifically, in a specific embodiment, the CO of Example 1 is used 2 -Water-rock dynamic reaction simulation device, including the following operating steps:

[0098] Turn on the power supply and observe whether there is any residual pressure in the pipeline. If there is pressure, release it through the vent valve. Unscrew the plug at the outlet of the core holder 14, load the sample, and tighten the plug. Close all valves and open the thermostat 20;

[0099] First, open valve nine 109, and use the confining pressure pump 11 to inject the confining pressure liquid. If the test pressure is low, it can be directly pressurized to the test pressure. If the test pressure is high, it is first pressurized to 5MPa;

[0100] Connect N 2 Place gas cylinder 1 at the gas inlet, open valve 1 101 and valve 3 103, use booster pump 4 to increase the pressure to 20 MPa, open valve 5 105, adjust pressure regulating valve 9 to the experimental pressure, open valve 6 106, valve 7 107, valve 10 110, valve 13 113, valve 16 116, use back pressure pump 23 to increase the back pressure to the set pressure, and open valve 16 116;

[0101] The permeability of the sample is calculated using the software on the computer and the collected temperature and pressure data;

[0102] After the experiment, the confining pressure was slowly reduced according to the internal pressure. After the pressure was released, the inlet and outlet ends were disassembled and the samples were taken out.

[0103] Compared with the prior art, the present invention at least discloses the following beneficial effects:

[0104] The present invention can realize columnar or granular CO by setting up a gas-liquid internal circulation system. 2 -Water-rock dynamic reaction simulation experiment; and, CO can be realized without frequent sampling 2 The experimental device of the present invention can monitor the geological storage volume and permeability in real time. 2 The simulation experiment of geochemical behavior can solve the problem of limited sample specifications applicable to existing experimental equipment and carry out CO 2 -Water-rock dynamic reaction experiment and monitoring of permeability change characteristics before and after solve the problem of single function of existing experimental devices. The present invention also solves the problem that existing experimental devices cannot guarantee CO 2 The effective contact between fluid and water and rock samples can reflect the CO 2 Flow processes in an in situ reservoir after injection.

[0105] Compared with the experimental devices and methods in the prior art, the present invention can ensure that CO 2 After injection, it can be fully dissolved and its reaction continuity can be guaranteed. 2 Continuous flow throughout the system to simulate high pressure CO in the field 2 Injection into the environment can ensure CO 2 The solution is complete and the chemical reaction continues.

[0106] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0107] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0108] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A CO2-water-rock dynamic reaction simulation device, characterized in that: include: The gas-liquid internal circulation system comprises a circulation pump (19), a core holder (14), and a confining pressure pump (11); the core holder (14) is connected to the confining pressure pump (11) and is used to fix the sample and apply confining pressure to the sample; The CO2 input and monitoring system comprises a CO2 gas cylinder (2), a heated gas storage tank (8) and a gas flow meter. The gas flow meter is provided before and after the gas-liquid internal circulation system, and is used to measure the CO2 injection amount before the reaction and the CO2 discharge amount after the reaction. The heated gas storage tank (8) is connected to the CO2 gas cylinder (2) and the core holder (14), and is used to preheat the CO2 in the CO2 gas cylinder (2) and then inject it into the gas-liquid internal circulation system; A temperature control system, comprising a constant temperature box (20), wherein the gas-liquid internal circulation system is arranged in the constant temperature box (20); A pressure control system comprises a booster pump (4) arranged between a CO2 gas cylinder (2) and a heated gas storage tank (8), an air compressor (6) connected to the booster pump (4), and a plurality of pressure sensors located on a circulation pipeline.

2. The CO2-water-rock dynamic reaction simulation device according to claim 1, characterized in that: The core holder (14) is also connected to a N2 gas cylinder (1), and the N2 gas cylinder (1) is used to purge the core holder (14) with N2.

3. The CO2-water-rock dynamic reaction simulation device according to claim 1, characterized in that: It also includes a pH monitoring system, which includes a pH controller (205) built into the constant temperature box (20), and the pH controller (205) is used to regularly monitor the pH value of the solution in the reaction process.

4. The CO2-water-rock dynamic reaction simulation device according to claim 1, characterized in that: The pressure sensor comprises a first pressure sensor (16) and a second pressure sensor (18) which are arranged on the air inlet pipeline and the air outlet pipeline of the core holder (14); a first temperature sensor (15) and a second temperature sensor (17) are also arranged on the inlet pipeline and the outlet pipeline of the core holder (14), respectively.

5. The CO2-water-rock dynamic reaction simulation device according to claim 1, characterized in that: The outlet pipeline of the core holder (14) is connected to a back-pressure pump (23), a back-pressure valve (21) is provided between the back-pressure pump (23) and the core holder (14), and the pipeline of the back-pressure valve (21) is connected to a gas-liquid separation system.

6. The CO2-water-rock dynamic reaction simulation device according to claim 5, characterized in that: The gas-liquid separation system comprises a gas-liquid separator (24), a container connected to a liquid outlet end of the gas-liquid separator (24), and a gas flow meter (27) connected to a gas outlet end of the gas-liquid separator, wherein the container is placed on an electronic balance (25), and a desiccant (26) and an exhaust valve are arranged on an exhaust pipeline at the front end of the gas flow meter (27).

7. The CO2-water-rock dynamic reaction simulation device according to claim 5, characterized in that: A back-pressure buffer (22) is provided between the back-pressure pump (23) and the back-pressure valve (21).

8. A CO2-water-rock dynamic reaction experimental method for determining the amount of CO2 geological storage, characterized in that: The CO2-water-rock dynamic reaction simulation device according to any one of claims 1 to 7 comprises the following steps: S101, preparing blocky rocks into columnar samples with a diameter of 2.5 cm and a length of 5 cm, and subjecting the samples to water saturation treatment; S102, weighing the water-saturated sample, placing it in a core holder (14), applying confining pressure, and turning on a constant temperature box (20) to keep it constant at a set value; S103, using N2 to replace and discharge the residual air in the gas-liquid internal circulation system, injecting deionized water to discharge the internal N2, recording the water injection volume, and then injecting CO2 to discharge part of the water in the gas-liquid internal circulation system, closing the water outlet valve after the residual water reaches the set value, and recording the CO2 injection volume and the residual water volume; S104, turning on the air compressor (6) and the booster pump (4) to pressurize the gas-liquid internal circulation system, and closing the booster valve and the air intake valve after the pressure reaches a set value; S105, opening the system valve, setting the circulation pump (19) flow rate to 0-30 mL / min to conduct an internal circulation CO2-water-rock dynamic reaction experiment, and recording the system pressure change data over time; S106. During the experiment, the pH value of the circulation system is measured regularly to monitor the internal solution water chemical environment in real time; S107. After the experiment, the CO2 in the circulation system is discharged through the flow meter and analyzed with the CO2 injection amount. The total CO2 storage amount is expressed as: Where: N is the total CO2 storage capacity, n1 is the CO2 injection capacity, and n2 is the CO2 discharge capacity; The expression of dissolved CO2 is: Among them, n d is the amount of dissolved CO2, k CO2 The amount of dissolved CO2 per unit substance, m w is the water content, M w is the molar mass of water; Combined with the previous calculation conclusions on the total amount of CO2 stored and dissolved, the CO2 mineralization amount n is obtained. m The expression is: 。 9. A CO2-water-rock dynamic reaction experimental method for permeability determination, characterized in that: The CO2-water-rock dynamic reaction simulation device according to any one of claims 1 to 7 comprises the following steps: S201, placing the sample in a core holder (14), turning on a constant temperature box (20) to keep it constant at a set value; S202, draining the moisture in the core holder (14), introducing the gas to be tested and draining the residual gas; S203, increasing the pressure in the core holder (14) to a measured value, and recording the pressure and gas flow rate at the inlet and outlet; S204. Calculate the permeability of the sample according to the sample size, inlet and outlet pressures and gas flow rate. The calculation formula is: Where K is the permeability, P0 is the atmospheric pressure, Q is the gas flow rate during the seepage process, μ is the gas viscosity, L is the length of the cylindrical sample, A is the bottom area of ​​the cylindrical sample, and P1 is the inlet pressure.

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