Carbon dioxide mineralization sequestration simulation system and method

Abstract

The application discloses a carbon dioxide mineralization sealing simulation system and method, and belongs to the technical field of carbon dioxide mineralization sealing simulation. The carbon dioxide mineralization sealing simulation system comprises a fracturing injection device, a carbon dioxide injection device, a plurality of clamping devices and a plurality of well pipes. The clamping device is provided with a medium inlet and a sample cavity, and the sample cavities of at least two clamping devices are different in size. One clamping device corresponds to at least one well pipe, the injection inlet of the well pipe is communicated with the medium inlet, and at least a part of the well pipe is embedded in a rock sample to be tested. The fracturing injection device and the carbon dioxide injection device are connected with the injection inlet, so that the fracturing injection device is used for injecting fracturing fluid into the well pipe, and the carbon dioxide injection device is used for injecting carbon dioxide into the well pipe. The carbon dioxide mineralization sealing simulation system of the embodiment of the application can simulate the crack initiation and expansion of the rock sample under different fracturing process technical parameters and the influence law of the crack initiation and expansion on the mineralization sealing efficiency, thereby providing a theoretical basis and data support for the optimization selection of the fracturing process parameters in the field construction.

Description

Technical Field

[0001] This invention relates to the technical field of carbon dioxide mineralization and storage, and specifically to a carbon dioxide mineralization and storage simulation system and method. Background Technology

[0002] Carbon dioxide sequestration utilizes basic rock layers such as basalt to preserve carbon dioxide. Carbon dioxide is injected into the basalt layer, and the carbon dioxide reacts chemically with the basalt to form relatively stable carbonate minerals, thereby achieving permanent carbon dioxide sequestration.

[0003] Before injecting carbon dioxide into basalt formations, fracturing fluid can be used to create microfractures in the basalt formation to increase the efficiency of the carbon dioxide mineralization reaction rate, thereby improving mineralization storage efficiency. However, there is a lack of systematic research methods on how to optimize fracturing process parameters (such as fracturing fluid flow rate, fracturing fluid type, and well placement) to most effectively improve mineralization efficiency. Therefore, an experimental system is needed to simulate and study the formation fracture initiation and propagation under different fracturing processes, as well as the formation rock sample and carbon dioxide mineralization storage efficiency, thereby providing theoretical basis and data support for optimizing fracturing processes in field operations. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a carbon dioxide mineralization storage simulation system, which can simulate the fracture initiation and propagation of experimental rock samples under different fracturing process parameters, and the influence of these parameters on mineralization storage efficiency. Analyzing the experimental results can provide theoretical basis and data support for the optimization of fracturing process parameters in field construction.

[0006] The carbon dioxide mineralization and storage simulation system of this invention includes a fracturing injection device, a carbon dioxide injection device, multiple clamping devices, and multiple well pipes. Each clamping device has a medium inlet and a sample cavity for placing a rock sample to be tested. The sample cavities of at least two clamping devices have different sizes. Each clamping device corresponds to at least one well pipe, which has an injection port communicating with the medium inlet. At least a portion of the well pipe is embedded in the rock sample to be tested. The fracturing injection device is connected to the injection port to inject fracturing fluid into the well pipe to fracture the rock sample. The carbon dioxide injection device is connected to the injection port to inject carbon dioxide into the well pipe.

[0007] In some embodiments, at least one of the clamping devices is a first clamping device, the well pipe corresponding to the first clamping device is a first well pipe, the number of first well pipes is multiple, and at least two of the first well pipes have different well placement methods, so as to use multiple first well pipes to simulate the fracturing of the rock sample to be tested under different well placement methods.

[0008] In some embodiments, the first well casing includes a straight section, at least a portion of which is used to embed the rock sample to be tested, and one end of the straight section has the injection port; or

[0009] The first well casing includes a first section and a second section, which are connected to each other. The extension direction of the first section intersects the extension direction of the second section, and the injection port is located at the end of the first section away from the second section; or

[0010] The first well casing includes a first section, a second section, and multiple branch sections. The extension direction of the first section intersects with and is connected to the extension direction of the second section. The multiple branch sections are arranged at intervals along the extension direction of the second section and are all connected to the second section.

[0011] In some embodiments, the first clamping device includes a plurality of clamping plates that form a first sample cavity, at least two of the clamping plates being detachably connected, and the first sample cavity forming the sample cavity of the first clamping device.

[0012] In some embodiments, the first clamping device further includes an elastic layer disposed in the first sample cavity, the elastic layer forming a wrapping cavity for placing the rock sample to be tested, and the well casing passing through the elastic layer.

[0013] In some embodiments, the first sample cavity is rectangular, with a length of 1cm to 500cm, a width of 1cm to 500cm, and a height of 1cm to 500cm.

[0014] In some embodiments, at least one of the clamping devices is a second clamping device, the second clamping device having a second sample cavity, the second sample cavity forming the sample cavity of the second clamping device; the second sample cavity is cylindrical, the diameter of the second sample cavity is 1cm to 20cm, and the axial length of the second sample cavity is greater than or equal to 2.5 times the diameter of the second sample cavity.

[0015] In some embodiments, the simulation system further includes a reaction vessel having a fluid inlet and a reaction chamber for containing the rock sample to be tested, the fluid inlet being connected to the carbon dioxide injection device to inject carbon dioxide into the reaction vessel using the carbon dioxide injection device.

[0016] In some embodiments, the clamping device has a medium outlet, and the simulation system further includes a confining pressure device and a backpressure device. The confining pressure device is connected to the sample chamber to apply confining pressure to the rock sample to be tested in the sample chamber, and the backpressure device is connected to the medium outlet to maintain the pressure at the medium outlet.

[0017] The carbon dioxide mineralization and storage simulation method of this invention employs the carbon dioxide mineralization and storage simulation system described in any of the above embodiments, and the simulation method includes:

[0018] Obtain the first characteristic information and rock sample type of the rock sample to be tested, and select a clamping device that matches the rock sample to be tested in the preset carbon dioxide mineralization and storage simulation system according to the rock sample type.

[0019] Based on the carbon dioxide mineralization and storage simulation system and the controlled variable method, a simulation comparison experiment was conducted on the rock sample to be tested to obtain multiple target rock samples obtained from the simulation comparison experiment under different variables.

[0020] Based on a preset rock sample feature detection method, feature detection is performed on the target rock sample to obtain the second feature information corresponding to any target rock sample, and the first feature information and the second feature information are compared and analyzed.

[0021] The carbon dioxide mineralization and storage simulation method of this invention involves, before the experiment begins, performing feature detection on the rock sample to be tested based on a preset rock sample feature detection method to obtain the first feature information of the rock sample. Based on the controlled variable method, after the experiment, multiple target rock samples after fracturing and mineralization under different variables can be obtained. Detecting the target rock samples using the preset rock sample feature detection method can obtain the second feature information of multiple target rock samples. Comparing the first and second feature information of the same rock sample can reveal the changes in the rock sample before and after the experiment. Comparing the second feature information of multiple target rock samples obtained under different fracturing fluid types, different fracturing fluid discharge rates, or different well placement methods can reveal the influence of different fracturing fluid types, different fracturing fluid discharge rates, and different well placement methods on the fracturing effect and mineralization and storage efficiency of the rock sample. This provides a theoretical basis and data support for the optimized selection of fracturing fluid discharge rate, fracturing fluid type, and well placement method in field operations. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the first clamping device of a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0024] Figure 3 It is along Figure 2 Sectional view of AA.

[0025] Figure 4 This is a schematic diagram of the first well casing simulating a vertical well in a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the first well casing simulating a horizontal well in a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the first well casing simulating a branch well in a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the structure of the second clamping device of a carbon dioxide mineralization and storage simulation system according to an embodiment of the present invention.

[0029] Figure label:

[0030] 100. Simulation system;

[0031] 1. Fracturing injection unit; 11. Fracturing injection pump; 12. Intermediate vessel;

[0032] 2. Carbon dioxide injection device; 21. Carbon dioxide storage cylinder; 22. Booster pump; 23. Control valve; 24. Vacuum pump;

[0033] 3. First clamping device; 31. Clamping plate; 311. First sample chamber; 32. Elastic layer; 321. Encapsulation cavity; 33. Medium inlet; 34. Medium outlet;

[0034] 4. Second clamping device; 41. Clamping body; 411. Second sample chamber; 42. Rubber sleeve;

[0035] 51. First well casing; 511. Vertical well casing; 512. Horizontal well casing; 513. Branch well casing; 52. Second well casing;

[0036] 6. Confining pressure pump;

[0037] 7. Back pressure device; 71. Back pressure pump; 72. Back pressure container; 73. Back pressure valve;

[0038] 81. Gas-liquid separator; 82. Dryer; 83. Gas mass flow meter;

[0039] 9. Reactor; 91. Drain pipe; 92. Drain valve. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] like Figure 1 As shown, the carbon dioxide mineralization and storage simulation system 100 of this embodiment includes a fracturing injection device 1, a carbon dioxide injection device 2, multiple clamping devices, and multiple well pipes. The clamping device has a medium inlet 33 and a sample cavity for placing the rock sample to be tested. The sample cavities of at least two clamping devices have different sizes. Each clamping device corresponds to at least one well pipe. The well pipe has an injection port that communicates with the medium inlet 33. At least a portion of the well pipe is embedded in the rock sample to be tested. The fracturing injection device 1 is connected to the injection port to inject fracturing fluid into the well pipe to fracture the rock sample to be tested. The carbon dioxide injection device 2 is connected to the injection port to inject carbon dioxide into the well pipe.

[0042] The carbon dioxide mineralization storage simulation system 100 of this invention can place multiple different types of rock samples to be tested using sample cavities of different sizes, and simultaneously perform fracturing and mineralization experiments on multiple different types of rock samples.

[0043] Before the experiment began, the rock sample to be tested was subjected to feature detection based on the preset rock sample feature detection method to obtain the first feature information of the rock sample to be tested.

[0044] First, a fracturing experiment is conducted. Fracturing fluid is injected into the well casing using fracturing injection device 1 to achieve fracturing of the rock sample to be tested. Based on the controlled variable method, multiple sets of experiments can be conducted, using fracturing fluid type, fracturing fluid discharge rate, and well casing layout as variables to simulate the fracture initiation and propagation of the rock sample under different fracturing fluid types, different fracturing fluid discharge rates, and different well casing layouts, and obtain multiple fracturing rock samples. Then, a mineralization experiment is conducted on any fracturing rock sample. Carbon dioxide is injected into the fracturing rock sample, and carbon dioxide, water, and rock undergo a chemical reaction to achieve carbon dioxide mineralization, sealing the carbon dioxide within the rock sample. After the mineralization experiment is completed, multiple mineralized rock samples are obtained.

[0045] Using the mineralized rock samples obtained after the mineralization experiment as target rock samples, and based on the aforementioned pre-defined rock sample feature detection method, feature detection of the target rock samples can obtain the corresponding second feature information. By comparing the first and second feature information of the same rock sample, the changes of the rock sample before and after the experiment can be obtained. By comparing the second feature information of multiple target rock samples obtained under different fracturing fluid types, different fracturing fluid discharge rates, or different well placement methods, the influence of different fracturing fluid types, different fracturing fluid discharge rates, and different well placement methods on the fracturing effect and mineralization storage efficiency of the rock samples can be obtained. This provides a theoretical basis and data support for the optimization selection of fracturing fluid discharge rate, fracturing fluid type, and well placement method in field construction.

[0046] In other embodiments, the fractured rock sample obtained after the fracturing experiment can be used as the target rock sample to obtain the changes in the rock sample before and after fracturing. Then, the fractured rock sample can be put back into the sample chamber to continue the mineralization experiment.

[0047] Among them, rock samples can be directly extracted from rock strata (such as basalt strata) in carbon dioxide storage sites, or artificially created rock samples with similar composition to the rock strata.

[0048] Optionally, the variables in the controlled variable method include rock sample type, temperature, confining pressure, mineralization reaction time, fracturing fluid injection pressure, fracturing fluid discharge rate, fracturing fluid type, and well placement method. Rock sample types include basalt, peridotite, serpentine, etc.

[0049] Optionally, the fracturing fluid type includes carbon dioxide fracturing fluid, hydraulic fracturing fluid, etc. In the fracturing experiment, different types of fracturing fluids are selected for comparative experiments to study the fracturing effect of different types of fracturing fluids on rock samples.

[0050] Optionally, a mineralization reaction promoter can be added to the fracturing fluid to promote the mineralization reaction rate; wherein, the type and dosage of the mineralization reaction promoter can also be used as variables in the controlled variable method.

[0051] Optionally, the preset rock sample characteristic detection methods include various mineral analysis methods, such as XRD analysis, scanning electron microscopy, CT detection, and gravimetric analysis. XRD analysis can detect the mineral composition of the rock sample, scanning electron microscopy can detect the pore structure, CT detection can detect fractures and mineral composition, and gravimetric analysis can measure the weight of the rock sample and evaluate the mineralization effect by observing the weight change before and after a certain period of mineralization.

[0052] Correspondingly, the first characteristic information includes various information about the rock sample to be tested, such as mineral composition information, porosity information, fracture information, and weight information; the second characteristic information includes various information about the target rock sample, such as mineral composition information, porosity information, fracture information, and weight information.

[0053] As an example, such as Figure 1 As shown, the medium inlet 33 of the clamping device is connected to an inlet pipe. The fracturing injection device 1 includes a fracturing injection pump 11 and an intermediate container 12. The fracturing injection pump 11 and the intermediate container 12 are connected by a pipe, and the intermediate container 12 is connected to the inlet pipe by a pipe. The inlet of the fracturing injection pump 11 is used to connect to the fracturing fluid storage tank. The fracturing injection pump 11 is used to inject the fracturing fluid in the fracturing fluid storage tank into the intermediate container 12, and then inject it into the well pipe through the medium inlet 33 to fracture the rock sample to be tested, forming multiple micro-fractures in the rock sample to be tested.

[0054] The carbon dioxide injection device 2 includes a carbon dioxide storage cylinder 21, a booster pump 22, and a control valve 23. The carbon dioxide storage cylinder 21, the booster pump 22, and the control valve 23 are connected in sequence and connected to the inlet pipe. The booster pump 22 can pressurize the carbon dioxide in the carbon dioxide storage cylinder 21 and then inject it into the well pipe, so that the carbon dioxide reacts chemically with the rock sample.

[0055] In this process, after fracturing the rock sample, the microfractures in the sample contain water. Then, carbon dioxide is injected, and the carbon dioxide, water, and rock sample can undergo a chemical reaction. If a mineralization experiment is to be performed directly on the rock sample, carbon dioxide is injected directly into the sample through the well casing, allowing the carbon dioxide to penetrate into the pores of the sample and react. In this case, water needs to be injected into the sample in a certain proportion to create conditions for the reaction between carbon dioxide and rock sample.

[0056] In some embodiments, such as Figures 1 to 3 As shown, at least one clamping device is a first clamping device 3, and the well pipe corresponding to the first clamping device 3 is a first well pipe 51. There are multiple first well pipes 51, and at least two first well pipes 51 have different well layout methods so as to use multiple first well pipes 51 to simulate the fracturing of the test rock sample under different well layout methods.

[0057] In some embodiments, such as Figures 4 to 6As shown, the first well pipe 51 includes a straight pipe section, at least a portion of which is used to embed the rock sample to be tested, and one end of the straight pipe section has an injection port; or, the first well pipe 51 includes a first pipe section and a second pipe section, the first pipe section and the second pipe section are connected to each other, the extension direction of the first pipe section intersects the extension direction of the second pipe section, and the end of the first pipe section away from the second pipe section has an injection port; or, the first well pipe 51 includes a first segment, a second segment and multiple branch segments, the extension direction of the first segment intersects the extension direction of the second segment and is connected to each other, and the multiple branch segments are arranged at intervals along the extension direction of the second segment and are all connected to the second segment.

[0058] It is known that well placement methods include vertical wells, horizontal wells, and multi-branch wells.

[0059] The first well casing 51 of the three well placement methods described above is embedded into three rock samples respectively to form three experimental rock samples with different well placement methods. This is applicable to the first clamping device 3. The first clamping device 3 is used to perform fracturing experiments and / or mineralization experiments on the three experimental rock samples respectively to obtain three target rock samples. The three target rock samples are tested according to the preset rock sample characteristic detection method to obtain the fracturing effect and sealing effect of different well placement methods on the rock samples, thereby providing theoretical basis and data support for the optimization selection of well placement methods in field construction.

[0060] It should be noted that rock samples used to simulate both vertical and horizontal well layouts need to undergo fracturing and mineralization experiments in sequence, while rock samples used to simulate multi-branch wells only undergo mineralization experiments and not fracturing experiments.

[0061] like Figure 3 and Figure 4 As shown, the first well pipe 51 is a vertical well pipe 511 used to simulate a vertical well. The vertical well pipe 511 includes a straight pipe section, which is inserted into the rock sample to be tested. One end of the straight pipe section is located in the middle of the rock sample to be tested, and the other end extends out of the rock sample to be tested and is connected to the medium inlet 33 of the first clamping device 3. The fracturing fluid and carbon dioxide can be injected into the first well pipe 51 through the medium inlet 33 to conduct fracturing and mineralization experiments on the rock sample to be tested.

[0062] like Figure 5 As shown, the first well pipe 51 is a horizontal well pipe 512, used to simulate a horizontal well. The horizontal well pipe 512 includes a first pipe section and a second pipe section. The first pipe section and the second pipe section are perpendicular to each other. The second pipe section is arranged in the middle of the rock sample to be tested. The end of the first pipe section away from the second pipe section extends out of the rock sample to be tested and is connected to the medium inlet 33 of the first clamping device 3. The fracturing fluid and carbon dioxide can be injected into the second pipe section through the medium inlet 33 to carry out fracturing and mineralization experiments on the rock sample to be tested.

[0063] like Figure 6 As shown, the first well pipe 51 is a branch well pipe 513, used to simulate a branch well. The branch well pipe 513 includes a first section, a second section, and multiple branch sections. The first section and the second section are perpendicular to each other. The second section is arranged in the middle of the rock sample to be tested, and multiple branch sections are symmetrically arranged on both sides of the second section. The end of the first section away from the second section extends out of the rock sample to be tested and is connected to the medium inlet 33 of the first clamping device 3. Carbon dioxide can be injected into multiple branch sections through the medium inlet 33 to carry out mineralization experiments on the rock sample to be tested.

[0064] In some embodiments, the first clamping device 3 includes a plurality of clamping plates 31, which form a first sample cavity 311. At least two clamping plates 31 are detachably connected, and the first sample cavity 311 forms the sample cavity of the first clamping device 3.

[0065] In some embodiments, the first clamping device 3 further includes an elastic layer 32, which is disposed in the first sample cavity 311 and forms a wrapping cavity 321 for placing the rock sample to be tested, through which the well pipe passes.

[0066] In some embodiments, the first sample cavity 311 is rectangular in shape, with a length of 1cm to 500cm, a width of 1cm to 500cm, and a height of 1cm to 500cm.

[0067] Optionally, the elastic layer 32 is made of an elastic stretching material, such as rubber.

[0068] As an example, such as Figure 1 and Figure 3 As shown, multiple clamping plates 31 are detachably connected by bolts, forming a cubic first sample cavity 311. The length, width, and height of the first sample cavity 311 are all 30cm, which is suitable for fracturing and mineralization experiments on rock samples with a length, width, and height of 28cm. The elastic layer 32 is generally cubic and matches the size of the first sample cavity 311. There is a gap between the elastic layer 32 and the cavity wall of the first sample cavity 311 to allow space for the size changes of the rock sample during fracturing and mineralization.

[0069] like Figure 3As shown, the two clamping plates 31 have through holes. One of the clamping plates 31 has a through hole that forms the medium inlet 33 of the first clamping device 3. The medium inlet 33 is connected to the injection port of the first well pipe 51 to inject fracturing fluid and carbon dioxide. The other clamping plate 31 has a through hole that forms the medium outlet 34 of the first clamping device 3. After the carbon dioxide reacts fully with the rock sample, the remaining carbon dioxide seeps out of the outside of the rock sample and is discharged through the medium outlet 34. By measuring the amount of carbon dioxide injected and discharged, the amount of carbon dioxide used for mineralization can be obtained.

[0070] In addition, the reaction liquid inside the first clamping device 3 can be sampled during the mineralization experiment using the medium outlet 34 to obtain the reaction status of the rock sample inside the first clamping device.

[0071] The first clamping device 3 of this invention is suitable for conducting experiments on large-sized rock samples, so as to use the first well pipe 51 to simulate different well layout methods in the rock sample and study the influence of different well layout methods on fracturing efficiency, mineralization efficiency, etc.

[0072] In some embodiments, at least one clamping device is a second clamping device 4, the second clamping device 4 having a second sample cavity 411, the second sample cavity 411 forming the sample cavity of the second clamping device 4; the second sample cavity 411 is cylindrical, the diameter of the second sample cavity 411 is 1cm to 20cm, and the axial length of the second sample cavity is greater than or equal to 2.5 times the diameter of the second sample cavity.

[0073] As an example, such as Figure 7 As shown, the second clamping device 4 is a core holder, which includes a clamping body 41 and a rubber sleeve 42. The clamping body 41 has the aforementioned second sample cavity 411, and the rubber sleeve 42 is disposed inside the second sample cavity 411. The rock sample to be tested is placed inside the rubber sleeve 42. The medium inlet 33 and the medium outlet 34 are respectively arranged at both ends of the rubber sleeve 42. This core holder is suitable for fracturing and mineralization experiments on rock samples with a diameter of 38 mm and an axial length of 100 mm. The well pipe corresponding to the second clamping device 4 is a second well pipe 52. The second well pipe 52 is straight and extends along the axial direction of the second sample cavity 411. The second well pipe 52 is inserted into the rock sample, with one end extending to the middle of the axial length of the rock sample, and the other end extending out of the rock sample and connected to the medium inlet 33 of the second clamping device 4.

[0074] Based on the controlled variable method, by changing the type and flow rate of fracturing fluid, fracturing and mineralization experiments were conducted on multiple rock samples. This yielded target rock samples with different fracturing fluid types and flow rates, allowing us to obtain the effects of fracturing fluid type and flow rate on the fracturing effect and mineralization reaction rate of the rock samples. This provides a theoretical basis and data support for the optimal selection of fracturing fluid flow rate and type in field operations.

[0075] In addition, in other embodiments, when using the second clamping device 4 to conduct experiments, the variable based on the control variable method can also be the rock sample crack type, which includes simple cracks and complex cracks. In this case, the rock sample can be pre-fractured by a fracturing device to form two rock samples with simple cracks and complex cracks respectively. Then, the two rock samples are respectively used to conduct mineralization experiments using the second clamping device 4, thereby obtaining the influence of the rock sample crack type on the mineralization experiment.

[0076] In some embodiments, the clamping device has a medium outlet 34, and the simulation system 100 further includes a confining pressure device and a back pressure device 7. The confining pressure device is connected to the sample chamber to apply confining pressure to the rock sample to be tested in the sample chamber, and the back pressure device 7 is connected to the medium outlet 34 to maintain the pressure of the medium outlet 34.

[0077] As an example, such as Figure 1 As shown, the confining pressure device includes a confining pressure pump 6, which is connected to the confining pressure chamber of the clamping device. The confining pressure pump 6 can be used to apply confining pressure to the rock sample to be tested, simulating the formation pressure borne by the rock sample. The confining pressure device is also connected to the confining pressure chambers of the first clamping device 3 and the second clamping device 4, so that confining pressure can be applied to the rock samples in the first clamping device 3 and the second clamping device 4 at the same time.

[0078] The back pressure device 7 includes a back pressure pump 71, a back pressure container 72, and a back pressure valve 73. The back pressure pump 71, the back pressure container 72, and the back pressure valve 73 are connected in sequence and connected to the medium outlet 34 of the clamping device. The opening pressure threshold of the back pressure valve is manually adjusted by a manual pump, thereby controlling the outlet pressure of the clamping device and simulating the outlet boundary pressure conditions of the underground reservoir.

[0079] The medium outlet 34 of the clamping device is also connected in sequence to a gas-liquid separator 81, a dryer 82, and a gas mass flow meter 83. The gas-liquid separator 81 and the dryer 82 can be used to dry the carbon dioxide discharged from the medium outlet 34. The gas mass flow meter 83 can be used to measure the amount of carbon dioxide discharged. In addition, a gas mass flow meter 83 can be installed at the medium inlet 33 of the clamping device to measure the amount of carbon dioxide injected into the clamping device. The amount of carbon dioxide used for the carbon dioxide mineralization reaction, i.e., the amount of carbon dioxide stored, is calculated by the difference between the amount of carbon dioxide injected and the amount of carbon dioxide discharged.

[0080] In addition, the gas-liquid separator 81 can be used to sample the reaction liquid in the clamping device during the mineralization reaction to obtain the reaction status of the rock sample in the clamping device. After the sampling is completed, if the pressure in the clamping device decreases, it is necessary to replenish the liquid in the clamping device to ensure the normal progress of the mineralization experiment.

[0081] like Figure 3As shown, the gap between the elastic layer 32 of the first clamping device 3 and the cavity wall of the first sample chamber 311 forms its confining pressure cavity; the medium outlet 34 of the first clamping device 3 is connected to the enclosing cavity 321 formed by the elastic layer 32, and carbon dioxide seeps into the cracks and pores inside the rock sample through the first well pipe 51, reacts fully with the rock sample, and excess carbon dioxide seeps out to the outside of the rock sample and is discharged through the medium outlet 34. Figure 7 As shown, the gap between the inner lining of the second clamping device 4 and the cavity wall of the second sample cavity 411 forms its confining pressure cavity; the medium outlet 34 of the first clamping device 3 is arranged opposite to the medium inlet 33, and carbon dioxide enters the internal fracture of the rock sample through the second well pipe 52 to fully react, and excess carbon dioxide is discharged through the medium outlet 34.

[0082] Optionally, the variables in the controlled variable method may also include confining pressure.

[0083] In some embodiments, the simulation system 100 further includes a reaction vessel 9 having a fluid inlet and a reaction chamber for containing the rock sample to be tested. The fluid inlet is connected to a carbon dioxide injection device 2 to inject carbon dioxide into the reaction vessel 9 using the carbon dioxide injection device 2.

[0084] Therefore, the simulation system 100 can simultaneously conduct fracturing, mineralization, and soaking experiments for carbon dioxide mineralization and storage, providing theoretical basis and data support for improving mineralization efficiency in on-site construction.

[0085] Based on the controlled variable method, the rock sample can be immersed in the reaction vessel 9 for an experiment.

[0086] The variable in the controlled variable method is the soaking time. When multiple preset soaking times are reached, the rock sample is taken out and tested based on a preset rock sample characteristic detection method. This allows us to obtain the change law of the reaction rate of carbon dioxide, water and rock sample over time.

[0087] The variable in the controlled variable method is the rock sample fracture type, which includes simple fractures and complex fractures. The rock sample is pre-fracturing using a fracturing device to form two rock samples with simple and complex fractures. The two rock samples are then placed in a reaction vessel for immersion experiments. After the experiment, the two immersed rock samples are tested according to a preset rock sample characteristic detection method to obtain the influence of rock sample fractures on the reaction rate.

[0088] The variable in the controlled variable method is the perforation pattern within the rock sample. This perforation pattern is similar to the well pipe arrangement in the first clamping device mentioned above. Vertical holes, horizontal holes, and multi-branch holes are respectively opened in the three rock samples to simulate vertical wells, horizontal wells, and multi-branch wells. The three rock samples are placed in the reaction vessel for immersion experiments. After the experiment, the three immersed rock samples are tested according to the preset rock sample characteristic detection method to obtain the influence law of the perforation pattern on the reaction rate.

[0089] Specifically, such as Figure 1 As shown, the reaction vessel 9 also has a liquid injection port; the rock sample to be tested is placed in the reaction chamber, and water and carbon dioxide are injected into the reaction chamber in a certain proportion to conduct an immersion test on the rock sample, so that the carbon dioxide reacts with the rock sample to carry out a mineralization reaction; wherein, the pressure of the reaction chamber can be controlled by injecting carbon dioxide to meet the pressure conditions of the immersion test; when injecting water into the reaction chamber, a certain proportion of chemical reagents can also be added to accelerate the reaction rate.

[0090] like Figure 1 As shown, the reactor 9 also has a drain port, which is connected to a drain pipe 91. A drain valve 92 is connected to the drain pipe 91, and the drain valve 92 is used to control the opening and closing of the drain pipe 91. During the soaking experiment, the liquid in the reactor 9 can be sampled at regular intervals to obtain the reaction status and reaction law of the rock sample in the reactor 9.

[0091] like Figure 1 As shown, the carbon dioxide injection device 2 also includes a vacuum pump 24 and a one-way valve 25. The media inlets of the first clamping device 3 and the second clamping device 4 are both connected to the vacuum pump 24, and the fluid inlet of the reaction vessel 9 is also connected to the vacuum pump 24. Therefore, before the experiment begins, the vacuum pump 24 is used to evacuate the first clamping device 3, the second clamping device 4, and the reaction vessel 9, and then the experiment is conducted. This prevents air in each device from affecting the experiment and improves the accuracy of the experimental data. The one-way valve 25 is used to prevent backflow of fluid within the device.

[0092] The carbon dioxide mineralization and storage simulation system 100 of this invention also requires a temperature control device when conducting fracturing experiments, mineralization experiments, and immersion experiments. The temperature control device has a temperature range of room temperature to 200°C, so as to control the experimental temperature of the first clamping device 3, the second clamping device 4, and the reaction vessel 9 to simulate the formation temperature. The temperature control device is a technology well known to those skilled in the art and will not be described in detail here.

[0093] The carbon dioxide mineralization and sequestration simulation method of this invention employs the carbon dioxide mineralization and sequestration simulation system 100 in any of the above embodiments, and the simulation method includes:

[0094] Obtain the first characteristic information and rock sample type of the rock sample to be tested, and select a clamping device that matches the rock sample to be tested in the preset carbon dioxide mineralization and storage simulation system 100 according to the rock sample type.

[0095] Based on the carbon dioxide mineralization and storage simulation system 100 and the controlled variable method, a simulation comparison experiment was conducted on the rock samples to be tested, and multiple target rock samples were obtained from the simulation comparison experiment under different variables.

[0096] Based on a preset rock sample feature detection method, feature detection is performed on the target rock sample to obtain the second feature information corresponding to any target rock sample, and the first feature information and the second feature information are compared and analyzed.

[0097] Optionally, the variables in the controlled variable method include fracturing fluid type, fracturing fluid discharge rate, and well casing placement method.

[0098] In the carbon dioxide mineralization and storage simulation experiment method of this invention, before the experiment begins, the rock sample to be tested is subjected to feature detection based on a preset rock sample feature detection method to obtain the first feature information of the rock sample to be tested.

[0099] Based on the controlled variable method, after the experiment, multiple target rock samples after fracturing and mineralization under different variables can be obtained. By detecting the target rock samples using a preset rock sample feature detection method, the second feature information of multiple target rock samples can be obtained. By comparing the first and second feature information of the same rock sample, the changes of the rock sample before and after the experiment can be obtained. By comparing the second feature information of multiple target rock samples obtained under different fracturing fluid types, different fracturing fluid discharge rates, or different well placement methods, the influence of different fracturing fluid types, different fracturing fluid discharge rates, and different well placement methods on the fracturing effect and mineralization preservation efficiency of the rock samples can be obtained. This provides a theoretical basis and data support for the optimization selection of fracturing fluid discharge rate, fracturing fluid type, and well placement method in field construction.

[0100] like Figure 1 As shown, the medium inlet and medium outlet of the first clamping device 3 and the second clamping device 4 are both equipped with switching valves, which are used to control the opening and closing of the corresponding medium inlet and medium outlet.

[0101] Taking the simulation method of the second clamping device 4 as an example, it includes the following steps:

[0102] The rock sample to be tested is loaded into the second sample cavity 411 of the second clamping device 4, so that the well pipe inserted in the rock sample is aligned and connected with the medium inlet.

[0103] Vacuum pump 24 is used to evacuate the second sample chamber 411;

[0104] The opening pressure threshold of the back pressure valve 73 is adjusted using the back pressure pump 71;

[0105] Fracturing fluid is injected into the well casing of the rock sample to be tested using the fracturing injection pump 12 to achieve fracturing of the rock sample and form micro-fractures inside the rock sample.

[0106] Carbon dioxide is injected into the well pipe of the rock sample to be tested using carbon dioxide injection pump 22. Then the switch valves at the medium inlet and medium outlet of the second clamping device 4 are closed to create a mineralization reaction environment for carbon dioxide and rock sample. Carbon dioxide seeps into the micro-fractures and reacts with the rock sample.

[0107] During the mineralization reaction, the medium outlet of the second clamping device 4 can be opened by the corresponding switch valve to sample the contents of the second clamping device 4 to obtain information on the carbon dioxide mineralization reaction.

[0108] After the mineralization reaction reaches the preset time, the liquid in the second clamping device is discharged and tested, the rock sample is taken out, and the rock sample is tested based on the preset rock sample characteristic detection method.

[0109] It is understood that the above description of the carbon dioxide mineralization and storage simulation system 100 also applies to this carbon dioxide mineralization and storage simulation method, and will not be repeated here.

[0110] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0112] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0113] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0114] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0115] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A carbon dioxide mineralization and storage simulation system, characterized in that, include: Multiple clamping devices, each having a medium inlet and a sample cavity for placing a rock sample to be tested, wherein the sample cavities of at least two of the clamping devices are of different sizes; Multiple well casings, one of the clamping devices corresponding to at least one well casing, the well casing having an injection port communicating with the medium inlet, and at least a portion of the well casing being embedded in the rock sample to be tested; A fracturing injection device is connected to the injection port to inject fracturing fluid into the well casing to fracture the rock sample to be tested. A carbon dioxide injection device, connected to the injection port, for injecting carbon dioxide into the well casing using the carbon dioxide injection device.

2. The carbon dioxide mineralization and storage simulation system according to claim 1, characterized in that, At least one of the clamping devices is a first clamping device, and the well pipe corresponding to the first clamping device is a first well pipe. There are multiple first well pipes, and at least two of the first well pipes have different well placement methods, so as to use multiple first well pipes to simulate the fracturing of the rock sample to be tested under different well placement methods.

3. The carbon dioxide mineralization and storage simulation system according to claim 2, characterized in that, The first well casing includes a straight section, at least a portion of which is used to embed the rock sample to be tested, and one end of the straight section has the injection port; or The first well casing includes a first section and a second section, which are connected to each other. The extension direction of the first section intersects the extension direction of the second section, and the injection port is located at the end of the first section away from the second section; or The first well casing includes a first section, a second section, and multiple branch sections. The extension direction of the first section intersects with and is connected to the extension direction of the second section. The multiple branch sections are arranged at intervals along the extension direction of the second section and are all connected to the second section.

4. The carbon dioxide mineralization and storage simulation system according to claim 2, characterized in that, The first clamping device includes a plurality of clamping plates, which form a first sample cavity. At least two of the clamping plates are detachably connected, and the first sample cavity forms the sample cavity of the first clamping device.

5. The carbon dioxide mineralization and storage simulation system according to claim 4, characterized in that, The first clamping device further includes an elastic layer disposed in the first sample cavity, the elastic layer forming a wrapping cavity for placing the rock sample to be tested, and the well pipe passing through the elastic layer.

6. The carbon dioxide mineralization and storage simulation system according to claim 4, characterized in that, The first sample chamber is rectangular in shape, with a length of 1cm to 500cm, a width of 1cm to 500cm, and a height of 1cm to 500cm.

7. The carbon dioxide mineralization and storage simulation system according to claim 1, characterized in that, At least one of the clamping devices is a second clamping device, the second clamping device having a second sample cavity, the second sample cavity forming the sample cavity of the second clamping device; The second sample chamber is cylindrical, with a diameter of 1cm to 20cm, and an axial length greater than or equal to 2.5 times the diameter of the second sample chamber.

8. The carbon dioxide mineralization and storage simulation system according to claim 1, characterized in that, The simulation system also includes a reaction vessel having a fluid inlet and a reaction chamber for containing the rock sample to be tested. The fluid inlet is connected to the carbon dioxide injection device to inject carbon dioxide into the reaction vessel using the carbon dioxide injection device.

9. The carbon dioxide mineralization and storage simulation system according to any one of claims 1-8, characterized in that, The clamping device has a medium outlet, and the simulation system further includes a confining pressure device and a back pressure device. The confining pressure device is connected to the sample chamber to apply confining pressure to the rock sample to be tested in the sample chamber. The back pressure device is connected to the medium outlet to maintain the pressure at the medium outlet.

10. A method for simulating carbon dioxide mineralization and storage, characterized in that, The carbon dioxide mineralization and storage simulation system according to any one of claims 1-9, wherein the simulation method comprises the following steps: Obtain the first characteristic information and rock sample type of the rock sample to be tested, and select a clamping device that matches the rock sample to be tested in the preset carbon dioxide mineralization and storage simulation system according to the rock sample type. Based on the carbon dioxide mineralization and storage simulation system and the controlled variable method, a simulation comparison experiment was conducted on the rock sample to be tested to obtain multiple target rock samples obtained from the simulation comparison experiment under different variables. Based on a preset rock sample feature detection method, feature detection is performed on the target rock sample to obtain the second feature information corresponding to any target rock sample, and the first feature information and the second feature information are compared and analyzed.

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