Device and method for testing the amount of co2 mineralized in a saline aquifer

Abstract

The application discloses a device and a method for testing the mineralization sealing amount of CO2 in a saline aquifer, wherein a triaxial pressure chamber has a first opening and a second opening, a first valve opening is communicated with the first opening, a first tri-valve opening is communicated with a second tri-valve opening, a second valve opening is communicated with a tail liquid collecting pump, a third valve opening is communicated with the second opening, a third tri-valve opening is communicated with the tail liquid collecting pump, a first outlet is communicated with the first tri-valve opening through a first output pipeline, a second outlet is communicated with the third tri-valve opening through a second output pipeline, a first liquid output flow path is communicated with a mixing container to convey saline water into the mixing container, and a second liquid output flow path is communicated with the second valve opening, so that the testing device can be used to test the carbon fixation amount of undissolved CO2 in the saline aquifer under the buoyancy mechanism and the carbon fixation amount of dissolved CO2 in the saline aquifer under the gravity mechanism, the migration law of CO2 in the reservoir and the rock stratum carbon fixation mechanism can be conveniently analyzed, and the operation is simple and the effect is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of CO2 storage in saline aquifer, and particularly to a device and method for testing mineralization CO2 storage capacity in saline aquifer. BACKGROUND

[0002] Carbon dioxide capture and sequestration (CCS) is one of the solutions to global warming and huge energy demand, and is a very promising technology. Among many storage methods, saline aquifer storage is one of the most promising isolation methods.

[0003] In the process of CO2 storage in saline aquifer, part of CO2 is dissolved in saline after being injected into the reservoir, and moves downward due to gravity after saturation to achieve liquid phase CO2 storage. The undissolved part moves upward due to buoyancy in the form of free state to achieve gas phase CO2 storage. The existing test platform and method are difficult to answer the migration rule of different phase CO2 in the reservoir and the rock carbon fixation mechanism under different driving forces. SUMMARY

[0004] The main purpose of the present application is to provide a device and method for testing mineralization CO2 storage capacity in saline aquifer, which aims to solve the problem that the existing test platform and method are difficult to answer the migration rule of different phase CO2 in the reservoir and the rock carbon fixation mechanism under different driving forces.

[0005] To achieve the above purpose, the present application provides a device for testing mineralization CO2 storage capacity in saline aquifer, comprising:

[0006] A triaxial formation stress loading system, comprising a triaxial pressure chamber, a horizontal pressure loading system, a vertical pressure loading system, a temperature control system, a tail liquid collection pump and a plurality of three-way valves, the horizontal pressure loading system and the vertical pressure loading system are used to apply horizontal pressure and vertical pressure to the sandstone sample located in the triaxial pressure chamber, the temperature control system is used to adjust the temperature in the triaxial pressure chamber, the triaxial pressure chamber has a first opening and a second opening, the plurality of three-way valves includes a first three-way valve, a second three-way valve and a third three-way valve, a first valve port of the first three-way valve is in communication with the first opening, a first three-way port of the first three-way valve is in communication with a second three-way port of the second three-way valve, a second two-way port of the second three-way valve is in communication with the tail liquid collection pump, a third one-way port of the third three-way valve is in communication with the second opening, and a second port of the third three-way valve is in communication with the tail liquid collection pump;

[0007] The CO2-saline water mixed permeation system comprises a mixing container, the mixing container has a first outlet and a second outlet, the first outlet is connected with the first two valve ports of the first three-way valve through a first output pipeline, the first output pipeline is used for conveying liquid substances, the second outlet is connected with the third three valve ports of the third three-way valve through a second output pipeline, and the second output pipeline is used for conveying gas substances;

[0008] The CO2 gas supply system is used for conveying CO2 gas into the mixing container.

[0009] The saline water solution supply system has a first liquid output pipeline and a second liquid output pipeline, the first liquid output pipeline is connected with the mixing container to convey saline water into the mixing container, and the second liquid output pipeline is connected with the second one valve port of the second three-way valve.

[0010] Optionally, the CO2-saline water mixed permeation system further comprises a temperature adjusting assembly, the temperature adjusting assembly is installed on the mixing container, and the temperature adjusting assembly is used for adjusting the temperature of the cavity in the mixing container.

[0011] Optionally, the CO2-saline water mixed permeation system further comprises a pressure adjusting assembly, the pressure adjusting assembly is installed on the mixing container, and the pressure adjusting assembly is used for adjusting the pressure of the cavity in the mixing container.

[0012] Optionally, the first opening is located at the bottom of the triaxial pressure chamber and is connected with the bottom end surface of the rock sample in the triaxial pressure chamber, and the second opening is located at the top of the triaxial pressure chamber and is connected with the top end surface of the rock sample in the triaxial pressure chamber.

[0013] Optionally, the first opening is located at the bottom of the triaxial pressure chamber, and the second opening is located at the top of the triaxial pressure chamber.

[0014] Optionally, the CO2-saline water mixed permeation system further comprises a stirrer, and the stirrer is installed in the mixing container.

[0015] Optionally, the CO2-saline water mixed permeation system further comprises a temperature measuring element and / or a pressure sensor, and the temperature measuring element and / or the pressure sensor are installed on the mixing container.

[0016] The application further provides a test method for saline aquifer mineralization and storage of CO2, based on the test device for the amount of saline aquifer mineralization and storage of CO2 as described above, wherein the first outlet is arranged at the bottom of the mixing container, the second outlet is arranged at the top of the mixing container, the first opening of the triaxial pressure chamber is arranged below the second opening, and the test method for saline aquifer mineralization and storage of CO2 includes a test method for the amount of carbon sequestration under gravity mechanism after CO2 is saturated in the saline aquifer and / or a test method for the amount of carbon sequestration under buoyancy mechanism of the unsaturated CO2 in the saline aquifer.

[0017] The test method for the amount of carbon sequestration under gravity mechanism after CO2 is saturated in the saline aquifer includes:

[0018] The sandstone sample is loaded into the triaxial pressure chamber, and the horizontal pressure and vertical pressure are applied to the sandstone sample loaded into the triaxial pressure chamber through the horizontal pressure loading system and the vertical pressure loading system, so that the sample in the triaxial pressure chamber is under the formation stress condition.

[0019] The first one valve port and the first three valve port of the first three-way valve are turned on, the second one valve port and the second three valve port of the second three-way valve are turned on, the second liquid output flow path and the first outlet of the triaxial pressure chamber are connected, the saline water is filled into the sandstone sample, the pores of the sandstone sample are filled with saline water, and the preset pore water pressure is reached, the first one valve port and the first three valve port of the first three-way valve are closed, and the second one valve port and the second three valve port of the second three-way valve are closed.

[0020] The first one valve port and the first two valve ports of the first three-way valve are turned on, the third one valve port and the third two valve ports of the third three-way valve are turned on, the saline water saturated with dissolved CO2 in the mixing container under the first preset temperature and the first preset pressure is input from the first opening of the triaxial pressure chamber and discharged from the second opening of the triaxial pressure chamber at the first constant pressure and the first constant temperature, and is transported to the tail liquid collection pump.

[0021] The liquid in the tail liquid collection pump is collected every preset time interval, and the ion concentration of the collected liquid is detected to obtain the carbon content in the solution.

[0022] The sandstone sample is taken out of the triaxial pressure chamber, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples, so as to analyze the precipitation amount of carbonate at each part according to the SEM electron microscope scanning result, and the average value of the precipitation amount of carbonate at the three parts is taken as the evaluation result.

[0023] The test method for the amount of carbon sequestration under buoyancy mechanism of the unsaturated CO2 in the saline aquifer includes:

[0024] The sandstone sample is loaded in the triaxial pressure chamber, horizontal pressure and vertical pressure are applied to the sandstone sample loaded in the triaxial pressure chamber through the horizontal pressure loading system and the vertical pressure loading system, so that the rock sample in the triaxial pressure chamber is under the formation stress condition;

[0025] The first one valve port and the first three valve port of the first three-way valve are opened, the second one valve port and the second three valve port of the second three-way valve are opened, the second liquid output flow path and the first outlet of the triaxial pressure chamber are communicated, so that the brine is filled into the sandstone sample, the pores of the sandstone sample are filled with brine, and a preset pore water pressure is reached, the first one valve port and the first three valve port of the first three-way valve are closed, and the second one valve port and the second three valve port of the second three-way valve are closed;

[0026] The third one valve port and the third three valve port of the third three-way valve are opened, the first one valve port and the first three valve port of the first three-way valve are opened, the second two valve ports and the second three valve ports of the second three-way valve are opened, the CO2 fluid under the second preset pressure and the second preset temperature condition is transported to the second opening of the triaxial pressure chamber, is discharged through the first opening of the triaxial pressure chamber, and is transported to the tail liquid collection pump;

[0027] The liquid in the tail liquid collection pump is collected every preset time interval, and the collected liquid is subjected to ion concentration detection, and the carbon content in the solution is obtained;

[0028] The sandstone sample is taken out from the triaxial pressure chamber, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples, so that the precipitation amount of carbonate in each part is analyzed according to the SEM electron microscope scanning result, and the average value of the precipitation amount of carbonate in the three parts is taken as the evaluation result.

[0029] The technical scheme provided by the present application can selectively open the corresponding valve ports of the first three-way valve, the second three-way valve and the third three-way valve according to needs. For example, when the first one valve port and the first three valve port of the first three-way valve are opened, the second one valve port and the second three valve port of the second three-way valve are opened, the second liquid output flow path is connected with the first outlet of the triaxial pressure chamber, and the brine can be filled into the sandstone sample, so that the pores of the sandstone sample are filled with brine, and the preset pore water pressure is reached. The first one valve port and the first three valve port of the first three-way valve are closed, the second one valve port and the second three valve port of the second three-way valve are closed, the first one valve port and the first two valve port of the first three-way valve are opened, the third one valve port and the third two valve port of the third three-way valve are opened, and the brine saturated and dissolved in the mixing container under the first preset temperature and the first preset pressure is input from the first opening of the triaxial pressure chamber and discharged from the second opening of the triaxial pressure chamber at the first constant pressure and the first constant temperature, and is transported to the tail liquid collection pump. In this way, the test of the carbon sequestration amount of the dissolved CO2 in the brine layer under the gravity mechanism after saturation can be carried out. In addition, the first one valve port and the first three valve port of the first three-way valve are opened, the second one valve port and the second three valve port of the second three-way valve are opened, the second liquid output flow path is connected with the first outlet of the triaxial pressure chamber, and the brine can be filled into the sandstone sample, so that the pores of the sandstone sample are filled with brine, and the preset pore water pressure is reached. The first one valve port and the first three valve port of the first three-way valve are closed, the second one valve port and the second three valve port of the second three-way valve are closed, the third one valve port and the third three valve port of the third three-way valve are opened, the first one valve port and the first three valve port of the first three-way valve are opened, the second two valve port and the second three valve port of the second three-way valve are opened, the CO2 fluid under the second preset pressure and the second preset temperature is transported to the second opening of the triaxial pressure chamber, is discharged through the first opening of the triaxial pressure chamber, and is transported to the tail liquid collection pump. In this way, the test of the carbon sequestration amount of the undissolved CO2 in the brine layer under the buoyancy mechanism can be carried out. The test device for testing the mineralization and storage amount of CO2 in the brine layer provided by the present application can realize the test of the carbon sequestration amount of the undissolved CO2 in the brine layer under the buoyancy mechanism and the test of the carbon sequestration amount of the dissolved CO2 in the brine layer under the gravity mechanism after saturation, which is convenient for subsequent analysis of the mineral composition distribution of different phase CO2 in the rock sample under different driving forces and the carbon sequestration amount of carbonate precipitation, analysis of the migration rule of CO2 in the reservoir and the rock carbon sequestration mechanism, and simple operation and good effect. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 a schematic view of an embodiment of the test device for testing the mineralization and storage amount of CO2 in the brine layer provided by the present application;

[0031] Figure 2A flowchart of an embodiment of the method for testing the carbon sequestration amount of the dissolved CO2 in the saline aquifer under the gravity mechanism provided by the present application;

[0032] Figure 3 A flowchart of an embodiment of the method for testing the carbon sequestration amount of the undissolved CO2 in the saline aquifer under the buoyancy mechanism provided by the present application.

[0033] BRIEF DESCRIPTION OF DRAWINGS

[0034]

[0035]

[0036] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0038] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0039] In addition, if the embodiments of the present application involve descriptions of “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0040] Carbon dioxide capture and sequestration (CCS) is one of the solutions to global warming and huge energy demand, and is a very promising technology. Among many storage methods, saline aquifer storage is one of the most promising and potential isolation methods.

[0041] In the process of CO2 storage in saline aquifer, part of CO2 is dissolved in saline after being injected into the reservoir, and moves downward due to gravity after saturation to achieve liquid phase CO2 storage. The undissolved part moves upward due to buoyancy in the form of free state to achieve gas phase CO2 storage. The existing test platform and method are difficult to answer the migration rule of different phase CO2 in the reservoir under different driving forces and the carbon sequestration mechanism of the rock layer.

[0042] In view of this, the present application provides a saline aquifer mineralization CO2 storage amount testing device and method to solve the problem that the testing device of the prior art cannot carry out the penetration test of different phase CO2 storage, and it is difficult to analyze the internal mineral composition distribution of the rock sample after the penetration test of different phase CO2 and the carbon sequestration amount of carbonate precipitation. Figure 1 An embodiment of the saline aquifer mineralization CO2 storage amount testing device provided by the present application is shown in the schematic view.

[0043] Please refer to Figure 1The device 100 for testing the amount of CO2 mineralized and stored in a saline aquifer includes a triaxial formation stress loading system 1, a CO2-saline mixture permeation system 2, a CO2 gas supply system 3, and a saline solution supply system 4. The triaxial formation stress loading system 1 includes a triaxial pressure chamber 11, a horizontal pressure loading system, a vertical pressure loading system, a temperature control system, a tail liquid collection pump 12, and a plurality of three-way valves 13. The horizontal pressure loading system and the vertical pressure loading system are used to apply horizontal and vertical pressures to a sandstone sample located in the triaxial pressure chamber 11. The temperature control system is used to adjust the temperature in the triaxial pressure chamber 11. The triaxial pressure chamber 11 has a first opening 11a and a second opening 11b. The plurality of three-way valves 13 includes a first three-way valve 13a, a second three-way valve 13b, and a third three-way valve 13c. The first one-way port 131a of the first three-way valve 13a is connected to the first opening 11a. The first three-way valve 13a is connected to the second three-way valve 13b through the first three-way port 132a and the second three-way port 131b. The second two-way port 132b of the second three-way valve 13b is connected to the tail liquid collection pump 12. The third one-way port 131c of the third three-way valve 13c is connected to the second opening 11b. The third two-way port 132c of the third three-way valve 13c is connected to the tail liquid collection pump 12. The CO2-saline mixture permeation system 2 includes a mixing container 21. The mixing container 21 has a first outlet 211 and a second outlet 212. The first outlet 211 is connected to the first two-way port 133a of the first three-way valve 13a through a first output pipeline 5. The first output pipeline 5 is used to transport liquid substances. The second outlet 212 is connected to the third three-way port 133c of the third three-way valve 13c through a second output pipeline 6. The second output pipeline 6 is used to transport gaseous substances. The CO2 gas supply system 3 is used to supply CO2 gas to the mixing container 21. The saline solution supply system 4 has a first liquid output flow path 41 and a second liquid output flow path 42. The first liquid output flow path 41 is connected to the mixing container 21 to supply saline water to the mixing container 21. The second liquid output flow path 42 is connected to the second one-way port 133b of the second three-way valve 13b.

[0044] In the technical scheme, the corresponding valve ports of the first three-way valve 13a, the second three-way valve 13b and the third three-way valve 13c can be selectively opened according to needs. For example, when the first one-way valve port 131a and the first three-way valve port 132a of the first three-way valve 13a are opened, the second one-way valve port 133b and the second three-way valve port 131b of the second three-way valve 13b are opened, the second liquid output flow path 42 and the first outlet 211 of the triaxial pressure chamber 11 are communicated, the brine can be filled into the sandstone sample, the pores of the sandstone sample are filled with the brine, and a preset pore water pressure is reached. The first one-way valve port 131a and the first three-way valve port 132a of the first three-way valve 13a are closed, the second one-way valve port 133b and the second three-way valve port 131b of the second three-way valve 13b are closed, the first one-way valve port 131a and the first two-way valve port 133a of the first three-way valve 13a are opened, the third one-way valve port 131c and the third two-way valve port 132c of the third three-way valve 13c are opened, the brine saturated with dissolved CO2 in the mixing container 21 under the first preset temperature and the first preset pressure is input from the first opening 11a of the triaxial pressure chamber 11 and discharged from the second opening 11b of the triaxial pressure chamber 11 at the first constant pressure and the first constant temperature, and is transported to the tail liquid collection pump 12. In this way, the test of the carbon sequestration amount of the dissolved CO2 saturated in the brine layer under the gravity mechanism can be performed. In addition, the first one-way valve port 131a and the first three-way valve port 132a of the first three-way valve 13a are opened, the second one-way valve port 133b and the second three-way valve port 131b of the second three-way valve 13b are opened, the second liquid output flow path 42 and the first outlet 211 of the triaxial pressure chamber 1 are communicated, the brine is filled into the sandstone sample, the pores of the sandstone sample are filled with the brine, and a preset pore water pressure is reached. The first one-way valve port 131a and the first three-way valve port 132a of the first three-way valve 13a are closed, the second one-way valve port 133b and the second three-way valve port 131b of the second three-way valve 13b are closed, the third one-way valve port 131c and the third two-way valve port 132c of the third three-way valve 13c are opened, the first one-way valve port 131a and the first three-way valve port 132a of the first three-way valve 13a are opened, the second two-way valve port 132b and the second three-way valve port 131b of the second three-way valve 13b are opened, the CO2 fluid under the second preset pressure and the second preset temperature is transported to the second opening 11b of the triaxial pressure chamber 11, is discharged through the first opening 11a of the triaxial pressure chamber 11, and is transported to the tail liquid collection pump 12. In this way, the test of the carbon sequestration amount of the undissolved CO2 in the brine layer under the buoyancy mechanism can be performed. The test device 100 for testing the mineralization and sequestration amount of CO2 in the brine layer provided in the application can realize the test of the carbon sequestration amount of the undissolved CO2 in the brine layer under the buoyancy mechanism and the test of the carbon sequestration amount of the dissolved CO2 saturated in the brine layer under the gravity mechanism.It is convenient to analyze the distribution of different phase CO2 in the rock sample after the penetration test under different forces and the amount of carbonate precipitation and carbon sequestration, so as to analyze the migration rule of CO2 in the reservoir and the rock carbon sequestration mechanism, which is simple in operation and good in effect.

[0045] It should be noted that the salt water of the embodiments of the application can be a water sample taken on site, or a salt water prepared in the laboratory. The salt water generally contains NaCl and other salt components such as MgCl.

[0046] Specifically, considering that the test temperature has an impact on the storage of different phase CO2 in actual operation, the CO2-salt water mixed penetration system 2 further comprises a temperature adjusting assembly installed in the mixing container 21, which adjusts the temperature in the cavity of the mixing container 21, so that the temperature in the mixing container 21 reaches the required temperature for the test, so as to smoothly perform the test of the impact of temperature on the storage of different phase CO2, which is simple in structure, good in effect, and rich in function of the salt water layer mineralization CO2 storage amount testing device 100. In addition, adjusting the temperature in the cavity of the mixing container 21 by the temperature adjusting assembly can also change the efficiency of dissolving CO2 gas in the salt water.

[0047] Specifically, the CO2-salt water mixed penetration system 2 further comprises a pressure adjusting assembly installed in the mixing container 21, which adjusts the pressure in the cavity of the mixing container 21, so as to adjust the amount of CO2 gas dissolved in the salt water.

[0048] Specifically, the first outlet 211 is arranged at the bottom of the mixing container 21, and the second outlet 212 is arranged at the top of the mixing container 21. Due to the large density of the salt water saturated with dissolved CO2 in the mixing container 21, the salt water will sink to the bottom of the mixing container 21, and the density of the undissolved CO2 gas is small, which will exist in the upper part of the mixing container 21. Such arrangement facilitates the output of CO2 in different phases, and the structure is simple and the effect is good.

[0049] In order to accelerate the dissolution efficiency of the CO2 gas, in the embodiments of the application, the CO2-salt water mixed penetration system 2 further comprises a stirrer installed in the mixing container 21, which rotates by driving the stirrer, thereby accelerating the dissolution efficiency of the CO2 gas in the salt water.

[0050] Specifically, the CO2-saline water mixed permeation system 2 further comprises a temperature measuring device and / or a pressure sensor installed on the mixing container 21 to detect the temperature and / or pressure inside the mixing container 21 in real time, so as to adjust the temperature and pressure inside the mixing container 21 as needed, and improve the accuracy of the test.

[0051] Specifically, in the embodiment of the present application, the first opening 11a of the triaxial pressure chamber 11 is located at the bottom of the triaxial pressure chamber 11 and communicates with the bottom end surface of the rock sample in the triaxial pressure chamber 11, and the second opening 11b is located at the top of the triaxial pressure chamber 11 and communicates with the top end surface of the rock sample in the triaxial pressure chamber 11, so that the CO2 gas can enter the sandstone rock sample permeated with the saline water from top to bottom when the test of the carbon sequestration amount of the undissolved CO2 in the saline water layer under the buoyancy mechanism is performed, and the permeation path is ensured to be filled with CO2 gas, thereby achieving good effect.

[0052] Further, the CO2 gas supply system 3 further comprises a gas compression bottle 31 for storing CO2 gas, and the gas compression bottle 31 communicates with the mixing container 21 through a gas output flow path 8, so as to realize the delivery of CO2 gas to the mixing container 21, and the structure is simple.

[0053] Considering that the gas pressure in the gas compression bottle 31 is relatively large, a pressure reducing valve 7 is arranged on the gas output flow path 8, and the pressure reducing valve 7 is arranged adjacent to the gas compression bottle 31, so as to reduce the flow rate of the gas output by the gas output flow path 8, and the effect is good.

[0054] Based on the above hardware structure, the first outlet 211 is arranged at the bottom of the mixing container 21, the second outlet 212 is arranged at the top of the mixing container 21, and the first opening 11a of the triaxial pressure chamber 11 is located below the second opening 11b, and the present application provides a test method for mineralization and sequestration of CO2 in a saline water layer, which comprises a test method for carbon sequestration amount of dissolved CO2 in the saline water layer under the gravity mechanism and / or a test method for carbon sequestration amount of undissolved CO2 in the saline water layer under the buoyancy mechanism. Figure 2 The test step of the carbon sequestration amount of dissolved CO2 in the saline water layer under the gravity mechanism comprises the following steps:

[0055] In step S10a, the sandstone rock sample is loaded into the triaxial pressure chamber 11, and the horizontal pressure and vertical pressure are applied to the sandstone rock sample loaded into the triaxial pressure chamber 11 by the horizontal pressure loading system and the vertical pressure loading system, so that the rock sample in the triaxial pressure chamber 11 is under the formation stress condition.

[0056] Step S20a, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are turned on, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are turned on, so that the second liquid output flow path 42 and the first outlet 211 of the triaxial pressure chamber 11 are communicated to fill the salt water into the sandstone sample, so that the salt water fills the pores of the sandstone sample, and reaches the preset pore water pressure, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are closed, and the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are closed;

[0057] Step S30a, the first one valve port 131a and the first two valve port 133a of the first three-way valve 13a are turned on, the third one valve port 131c and the third two valve port 132c of the third three-way valve 13c are turned on, the salt water saturated with dissolved CO2 in the mixing container 21 under the condition of the first preset temperature and the first preset pressure is input from the first opening 11a of the triaxial pressure chamber 11 at a first constant pressure and a first constant temperature, and is discharged from the second opening 11b of the triaxial pressure chamber 11, and is transported to the tail liquid collection pump 12;

[0058] Step S40a, the liquid in the tail liquid collection pump 12 is collected every preset time interval, and the collected liquid is detected for ion concentration to obtain the carbon content in the solution;

[0059] Step S50a, the sandstone sample is taken out from the triaxial pressure chamber 11, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples, so as to analyze the precipitation amount of carbonate in each part according to the SEM electron microscope scanning result, and the average value of the precipitation amount of carbonate in the three parts is taken as the evaluation result.

[0060] Specifically, in the above steps, the sandstone sample is loaded into the triaxial pressure chamber 11, the sandstone sample loaded into the triaxial pressure chamber 11 is subjected to horizontal pressure and vertical pressure by the horizontal pressure loading system and the vertical pressure loading system, so that the sample in the triaxial pressure chamber 11 is under the formation stress condition, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are connected, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are connected, the second liquid output flow path 42 and the first outlet 211 of the triaxial pressure chamber 11 are connected to communicate, so that the salt water is filled into the sandstone sample, the pores of the sandstone sample are filled with salt water, and the preset pore water pressure is reached, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are closed, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are closed, the first one valve port 131a and the first two valve port 133a of the first three-way valve 13a are connected, the third one valve port 131c and the third two valve port 132c of the third three-way valve 13c are connected, the salt water saturated with CO2 dissolved in the mixing container 21 under the first preset temperature and the first preset pressure is input from the first opening 11a of the triaxial pressure chamber 11 and discharged from the second opening 11b of the triaxial pressure chamber 11 at the first constant pressure and the first constant temperature, and is transported to the tail liquid collection pump 12, the liquid in the tail liquid collection pump 12 is collected every preset time interval, and the collected liquid is subjected to ion concentration detection to obtain the carbon content in the solution, the sandstone sample is taken out from the triaxial pressure chamber 11, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples to analyze the precipitation amount of carbonate at each part according to the SEM electron microscope scanning result, the average value of the precipitation amounts of carbonate at the three parts is taken as the evaluation result, the test of the carbon sequestration amount of the salt water layer saturated with dissolved CO2 under the gravity mechanism is realized, the migration rule of CO2 in the reservoir and the rock layer carbon sequestration mechanism are analyzed, and the operation is simple.

[0061] Specifically, referring to Figure 3 , the test step of the carbon sequestration amount of the salt water layer unsaturated with dissolved CO2 under the buoyancy mechanism includes:

[0062] Step S10b, the sandstone sample is loaded into the triaxial pressure chamber 11, the sandstone sample loaded into the triaxial pressure chamber 11 is subjected to horizontal pressure and vertical pressure by the horizontal pressure loading system and the vertical pressure loading system, so that the sample in the triaxial pressure chamber 11 is under the formation stress condition;

[0063] Step S20b, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are turned on, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are turned on, so that the second liquid output flow path 42 and the first opening 11a of the triaxial pressure chamber 11 are communicated to fill the salt water into the sandstone sample, so that the salt water fills the pores of the sandstone sample, and reaches the preset pore water pressure, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are closed, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are closed;

[0064] Step S30b, the third one valve port 131c and the third three valve port 133c of the third three-way valve 13c are turned on, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are turned on, the second two valve port 132b and the second three valve port 131b of the second three-way valve 13b are turned on, the CO2 fluid under the second preset pressure and the second preset temperature condition is transported to the second opening 11b of the triaxial pressure chamber 11, and is discharged through the first opening 11a of the triaxial pressure chamber 11, and is transported to the tail liquid collection pump 12;

[0065] Step S40b, the liquid in the tail liquid collection pump 12 is collected every preset time interval, and the collected liquid is detected for ion concentration to obtain the carbon content in the solution;

[0066] Step S50b, the sandstone sample is taken out from the triaxial pressure chamber 11, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples, so as to analyze the precipitation amount of carbonate in each part according to the SEM electron microscope scanning result, and the average value of the precipitation amount of carbonate in the three parts is taken as the evaluation result.

[0067] Specifically, in the above steps, the sandstone sample is loaded in the triaxial pressure chamber 11, the sandstone sample loaded in the triaxial pressure chamber 11 is subjected to horizontal pressure and vertical pressure by the horizontal pressure loading system and the vertical pressure loading system, so that the sample in the triaxial pressure chamber 11 is under the formation stress condition, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are connected, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are connected, the second liquid output flow path 42 and the first outlet 211 of the triaxial pressure chamber are communicated to fill the brine into the sandstone sample, so that the brine fills the pores of the sandstone sample and reaches the preset pore water pressure, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are closed, the second one valve port 133b and the second three valve port 131b of the second three-way valve 13b are closed, the third one valve port 131c and the third three valve port 133c of the third three-way valve 13c are connected, the first one valve port 131a and the first three valve port 132a of the first three-way valve 13a are connected, the second two valve port 132b and the second three valve port 131b of the second three-way valve 13b are connected, the CO2 fluid under the second preset pressure and the second preset temperature condition is delivered to the second opening 11b of the triaxial pressure chamber 11, and is discharged through the first opening 11a of the triaxial pressure chamber 11 and delivered to the tail liquid collection pump 12, the liquid in the tail liquid collection pump 12 is collected every preset time interval, and the collected liquid is subjected to ion concentration detection to obtain the carbon content in the solution, the sandstone sample is taken out from the triaxial pressure chamber 11, samples are taken from the upper, middle and lower parts of the sandstone sample respectively, and SEM electron microscope scanning is performed on the samples to analyze the precipitation amount of carbonate at each part according to the SEM electron microscope scanning result, the average value of the precipitation amount of carbonate at the three parts is taken as the evaluation result, the test of the carbon sequestration amount of the undissolved CO2 in the brine layer under the buoyancy mechanism is realized, and the migration rule of CO2 in the reservoir and the rock layer carbon sequestration mechanism are analyzed, which is simple in operation and good in effect.

[0068] It should be noted that the horizontal pressure described above includes confining pressure, and the vertical pressure includes axial pressure, in order to realize the test of the carbon sequestration amount of the dissolved CO2 in the salt water layer under the gravity mechanism and the test of the carbon sequestration amount of the undissolved CO2 in the salt water layer under the buoyancy mechanism, a plurality of groups of tests are respectively performed, in the plurality of groups of tests, the axial pressure is loaded according to 70%, 80%, and 90% of the compressive strength, the confining pressure applied in different groups of tests is 10 MPa and 20 MPa respectively, the osmotic pressure difference between the upper end and the lower end in different groups of tests is 2 MPa, 5 MPa, and 8 MPa respectively, the concentration of the salt water is 0.01 mol / L, and the liquid material delivered by the first output pipeline 5 in different groups of tests is 0.01 mol / L of the salt water in which CO2 is dissolved to reach a saturated state under different pressures, and the different pressures include 2 MPa and 5 MPa pressures. Of course, in other embodiments, the axial pressure, the confining pressure, the concentration of the salt water, and the liquid material delivered by the first output pipeline 5 and the corresponding pressure can be selected as needed, and the present application does not limit this.

[0069] Specifically, in the present application, the carbon sequestration amount of the dissolved CO2 in the salt water layer after saturation under the gravity mechanism and the carbon sequestration amount of the undissolved CO2 in the salt water layer under the buoyancy mechanism, as well as the changes in mineral species, element composition ratio, structural arrangement, and surface morphology of the sandstone sample after carbon sequestration, are analyzed by electron microscope scanning and energy spectrum analysis, the dissolution of sandstone minerals and the precipitation of new minerals caused by CO2 in the salt water layer under the gravity mechanism and in the salt water layer under the buoyancy mechanism are observed, and the migration of mineral components inside the sandstone and the carbon sequestration amount under the gravity mechanism and the buoyancy mechanism are analyzed respectively. Through water quality analysis and metal cation detection, the changes in the main ion species and concentration of the pore fluid during the seepage process of different phase CO2 are analyzed, and the effect of mineralization of the reservoir rock on CO2 sequestration is studied in combination with the electron microscope scanning results, so as to find out the optimal CO2 sequestration method.

[0070] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A testing device for the amount of CO2 mineralized and sequestered in a saline aquifer, characterized in that, include: A triaxial formation stress loading system includes a triaxial pressure chamber, a horizontal pressure loading system, a vertical pressure loading system, a temperature control system, a tailings collection pump, and multiple three-way valves. The horizontal and vertical pressure loading systems are used to apply horizontal and vertical pressures, respectively, to sandstone samples located in the triaxial pressure chamber. The temperature control system is used to regulate the temperature within the triaxial pressure chamber. The triaxial pressure chamber has a first opening and a second opening. The multiple three-way valves include a first three-way valve, a second three-way valve, and a third three-way valve. The first port of the first three-way valve is connected to the first opening. The first port of the first three-way valve is connected to the second port of the second three-way valve. The second port of the second three-way valve is connected to the tailings collection pump. The third port of the third three-way valve is connected to the second opening. The third port of the third three-way valve is connected to the tailings collection pump. A CO2-saline water mixing and permeation system includes a mixing container having a first outlet and a second outlet. The first outlet is connected to the first and second valve ports of a first three-way valve via a first output pipeline, which is used to transport liquid substances. The second outlet is connected to the third and third valve ports of a third three-way valve via a second output pipeline, which is used to transport gaseous substances. A CO2 gas supply system is used to supply CO2 gas into the mixing container; A saline solution supply system has a first liquid output path and a second liquid output path. The first liquid output path is connected to the mixing container to deliver saline water into the mixing container, and the second liquid output path is connected to the second valve port of the second three-way valve. The first outlet is located at the bottom of the mixing container, and the second outlet is located at the top of the mixing container; The first opening is located at the bottom of the triaxial pressure chamber and communicates with the bottom end face of the rock sample inside the triaxial pressure chamber. The second opening is located at the top of the triaxial pressure chamber and communicates with the top end face of the rock sample inside the triaxial pressure chamber.

2. The testing device for CO2 sequestration in saline aquifers as described in claim 1, characterized in that, The CO2-saline water mixing and permeation system also includes a temperature regulating component, which is installed in the mixing container to regulate the temperature inside the mixing container.

3. The testing device for CO2 sequestration in saline aquifers as described in claim 1, characterized in that, The CO2-saline water mixing permeation system also includes a pressure regulating component installed in the mixing container, which is used to regulate the pressure inside the mixing container.

4. The testing device for CO2 sequestration in saline aquifers as described in claim 1, characterized in that, The CO2-saline water mixing permeation system also includes a stirrer installed inside the mixing container.

5. The testing device for CO2 sequestration in saline aquifers as described in claim 1, characterized in that, The CO2-saline water mixing permeation system also includes a temperature sensor and / or a pressure sensor, which are installed in the mixing container.

6. A method for testing the amount of CO2 mineralized and sequestered in a saline aquifer, comprising the apparatus for testing the amount of CO2 mineralized and sequestered in a saline aquifer as described in any one of claims 1 to 5, characterized in that, The first outlet is located at the bottom of the mixing container, the second outlet is located at the top of the mixing container, the first opening of the triaxial pressure chamber is located below the second opening, and the test method for saline aquifer mineralization and CO2 sequestration includes a test method for the amount of carbon sequestration under gravity after the saline aquifer is saturated with dissolved CO2 and / or a test method for the amount of carbon sequestration under buoyancy of undissolved CO2 in the saline aquifer. The testing steps for the amount of carbon fixed by gravity after the saline aquifer is saturated with dissolved CO2 include: Sandstone samples are loaded into a triaxial pressure chamber. Horizontal and vertical pressures are applied to the sandstone samples in the triaxial pressure chamber through a horizontal pressure loading system and a vertical pressure loading system, so that the samples in the triaxial pressure chamber are under formation stress conditions. The first valve port and the first valve port of the first three-way valve are opened, and the second valve port and the second valve port of the second three-way valve are opened, so that the second liquid output flow path and the first opening of the triaxial pressure chamber are connected to fill the sandstone sample with saline water, so that the pores of the sandstone sample are filled with saline water and the preset pore water pressure is reached. Then the first valve port and the first valve port of the first three-way valve are closed, and the second valve port and the second valve port of the second three-way valve are closed. The first valve port and the first valve port of the first three-way valve are opened, and the third valve port and the third valve port of the third three-way valve are opened. Under the conditions of the first preset temperature and the first preset pressure, the saline water saturated with dissolved CO2 in the mixing container is input from the first opening of the triaxial pressure chamber at the first constant pressure and the first constant temperature and discharged from the second opening of the triaxial pressure chamber and delivered to the tail liquid collection pump. The liquid in the tail liquid collection pump is collected at preset time intervals, and the ion concentration of the collected liquid is detected to obtain the carbon content in the solution. The sandstone sample was taken out of the triaxial pressure chamber, and samples were taken from the upper, middle and lower parts of the sandstone sample. The samples were then scanned by SEM electron microscopy to analyze the amount of carbonate precipitation in each part based on the SEM electron microscopy results. The average amount of carbonate precipitation in the three parts was taken as the evaluation result. The test steps for determining the amount of carbon sequestration by undissolved CO2 in the saline aquifer under buoyancy include: Sandstone samples are loaded into a triaxial pressure chamber. Horizontal and vertical pressures are applied to the sandstone samples in the triaxial pressure chamber through a horizontal pressure loading system and a vertical pressure loading system, so that the samples in the triaxial pressure chamber are under formation stress conditions. The first valve port and the first valve port of the first three-way valve are opened, and the second valve port and the second valve port of the second three-way valve are opened, so that the second liquid output flow path and the first opening of the triaxial pressure chamber are connected to fill the sandstone sample with saline water, so that the pores of the sandstone sample are filled with saline water and the preset pore water pressure is reached. Then the first valve port and the first valve port of the first three-way valve are closed, and the second valve port and the second valve port of the second three-way valve are closed. The third three-way valve is connected to the third first valve port and the third third valve port, the first first valve port and the first third valve port of the first three-way valve are connected, and the second second valve port and the second third valve port of the second three-way valve are connected. The CO2 fluid under the second preset pressure and the second preset temperature conditions is transported to the second opening of the triaxial pressure chamber, discharged through the first opening of the triaxial pressure chamber, and transported to the tail liquid collection pump. The liquid in the tail liquid collection pump is collected at preset time intervals, and the ion concentration of the collected liquid is detected to obtain the carbon content in the solution. The sandstone sample was removed from the triaxial pressure chamber, and samples were taken from the upper, middle and lower parts of the sandstone sample. The samples were then scanned by SEM electron microscopy to analyze the amount of carbonate precipitation in each part based on the SEM electron microscopy results. The average amount of carbonate precipitation in the three parts was taken as the evaluation result.

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