Method for evaluating influence of carbon sequestration project carbon dioxide leakage on groundwater environment

Abstract

The application discloses a kind of carbon sequestration engineering carbon dioxide leakage influence evaluation method to groundwater environment, comprising: determining monitoring area;Determine monitoring point;Determine background value data and monitoring baseline;Carrying out CO2-H2O reaction experiment, obtain the influence mechanism of CO2 leakage to different medium, and screen out sensitive monitoring index;Screen out actual monitoring index, find the type of each actual monitoring index Adapted monitoring equipment;For the monitoring point, the type and specification of the monitoring equipment used are specified;After injecting CO2, monitoring equipment is laid out at each monitoring point.The monitoring data obtained by the monitoring equipment is compared with the monitoring baseline to determine whether CO2 leakage occurs and the impact of CO2 leakage on the groundwater environment.The present application can provide a true and objective evaluation of whether CO2 leakage occurs and the impact of leaked CO2 on the groundwater environment in the carbon sequestration project implementation area.

Description

TECHNICAL FIELD

[0001] The present application relates to a groundwater environmental impact assessment method, in particular to a method for assessing the impact of carbon dioxide leakage on the groundwater environment in a carbon sequestration project. BACKGROUND

[0002] With the proposal of the "double carbon" goal, carbon sequestration projects have been widely carried out. Carbon sequestration refers to a technology that captures carbon and safely stores it instead of directly releasing CO2 into the atmosphere, which can reduce the concentration of carbon dioxide in the atmosphere and effectively address the problem of global climate change. However, CO2 may be accompanied by geological activities such as the development of deep coal or oil and gas resources, poor sealing of abandoned wellbores, or natural earthquakes (extremely low probability) during large-scale injection, which can cause the cap rock to crack, thereby increasing the risk of CO2 leakage from underground storage. Once CO2 leaks into the recharge layer of underground fresh water, it will contaminate the groundwater, and when the contaminated groundwater reaches the surface, it will harm the soil environment and ecosystem, and endanger human health and safety. Therefore, monitoring whether CO2 injected into a carbon sequestration project leaks and whether the leaked CO2 has an impact on the groundwater environment is a key step in carbon sequestration projects. Currently, the traditional approach is to install monitoring equipment in the carbon sequestration project area to monitor whether CO2 leaks and the impact of the leaked CO2 on the groundwater environment. However, from actual implementation, it can be found that there are many types of monitoring equipment, and it is difficult to choose suitable monitoring equipment for the characteristics of the carbon sequestration project area. In addition, the traditional approach is to send samples collected by monitoring equipment back to the laboratory for monitoring, which often has a large difference from the actual situation due to changes in the monitoring environment, and cannot truly reflect the actual situation of the carbon sequestration project area. Therefore, it is urgent to design a technical solution that can truly reflect whether CO2 leaks and the impact on the groundwater environment. SUMMARY

[0003] The present application aims to provide a carbon sequestration project carbon dioxide leakage impact on groundwater environment evaluation method, which can give a true and objective evaluation of whether CO2 leaks and the impact of the leaked CO2 on the groundwater environment in the carbon sequestration project area.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0005] A carbon sequestration project carbon dioxide leakage impact on groundwater environment evaluation method, comprising the steps of:

[0006] 1) according to the site condition and geological condition of the carbon sequestration project implementation area, a monitoring area is determined, wherein the monitoring area is located in the carbon sequestration project implementation area, the monitoring area comprises a core area and an extension area, the core area is located in the extension area, and the area of the extension area is much larger than the area of the core area;

[0007] 2) in the monitoring area, a risk point investigation is carried out, potential CO2 leakage risk points are determined as monitoring points based on geological data, geophysical prospecting data, drilling data, logging data and rock water sample test data, and in combination with the actual situation of field exploration;

[0008] 3) in the monitoring area, the background value data representing the groundwater quality of the carbon sequestration project implementation area is determined through on-site water quality rapid detection, on-site simple experimental test and laboratory water quality full analysis test, so as to determine the monitoring baseline for comparison with the monitoring data obtained after CO2 injection;

[0009] 4) through the CO2-H2O reaction experiment of the corresponding formation water, deionized water and simulated formation water composition preparation liquid that can be obtained in the monitoring area by an experimental device, the influence degree of CO2 on different media under different monitoring indexes is known, the influence mechanism of CO2 leakage on different media is obtained, and then sensitive monitoring indexes are screened from all the monitoring indexes affecting the groundwater environment;

[0010] 5) in combination with the site condition and geological condition of the monitoring area, actual monitoring indexes suitable for the monitoring area are screened from all the sensitive monitoring indexes, and a type-adapted monitoring device is found for each actual monitoring index;

[0011] 6) according to the site condition and geological condition of the monitoring point, the type and specification of the monitoring device used for monitoring each actual monitoring index corresponding to the monitoring point are determined for each monitoring point, wherein a dangerous threshold of CO2 leakage and an upper limit value corresponding to each actual monitoring index are set, when the dangerous threshold or the upper limit value is exceeded, it indicates that harm will be caused to the human body, so as to issue a harm warning and persuade personnel to move away;

[0012] 7) after CO2 is injected into the carbon sequestration project implementation area, the corresponding monitoring device is arranged at each monitoring point, and each monitoring device communicates with the monitoring center through the Internet of Things, wherein the monitoring data obtained by the monitoring device is compared with the monitoring baseline to determine whether CO2 leakage occurs and the influence of CO2 leakage on the groundwater environment, so as to objectively evaluate the influence of CO2 leakage on the groundwater environment in the monitoring area in real time.

[0013] The advantages of the present application are:

[0014] The application provides a way for making a real, objective and real-time evaluation on the influence of carbon sequestration project carbon dioxide leakage on groundwater environment, focuses on that the evaluation result can reflect the objective situation and is real-time. Specifically, the application considers the influence mechanism of CO2 leakage on groundwater environment, screens sensitive monitoring indexes from the influence factors of water quality, physicochemical parameters, water chemical components, harmful elements, gas phase components and the like of groundwater through CO2-H2O reaction experiment, and further optimizes actual monitoring indexes by considering the applicability of the monitoring area, selects the most suitable monitoring equipment based on the actual monitoring indexes to perform real-time monitoring on the monitoring points, and builds a monitoring and early warning platform based on the Internet of Things, thereby providing favorable guarantee for timely evaluating the influence of CO2 leakage on groundwater environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a composition schematic diagram of the experimental device used in the method of the application. DETAILED DESCRIPTION

[0016] The application provides a carbon sequestration project carbon dioxide leakage influence evaluation method on groundwater environment, specifically including the following steps:

[0017] 1) determining a monitoring area according to the site condition, geological condition and the like of the carbon sequestration project implementation area, wherein the monitoring area is located in the carbon sequestration project implementation area, the monitoring area includes a core area and an extension area, the core area is located in the extension area, and the area of the extension area is much larger than that of the core area;

[0018] 2) carrying out risk point investigation in the monitoring area, determining potential CO2 leakage risk points as monitoring points based on the collection and analysis of geological data, geophysical prospecting data, drilling data, well logging data and rock water sample test data, and combining the actual situation of field exploration;

[0019] 3) carrying out groundwater environment investigation and monitoring in the monitoring area, determining background value data representing the groundwater quality of the carbon sequestration project implementation area through on-site water quality rapid detection, on-site simple experiment test and laboratory water quality full analysis test, so as to determine a monitoring baseline for comparison with monitoring data obtained after CO2 injection;

[0020] 4) carrying out CO2-H2O reaction experiment on corresponding formation water (or groundwater) in the monitoring area, deionized water and simulated formation water composition preparation liquid that can be obtained in the monitoring area through an experimental device, obtaining the influence degree of CO2 on different media under different monitoring indexes, obtaining the influence mechanism of CO2 leakage on different media, and further screening sensitive monitoring indexes from all monitoring indexes influencing the groundwater environment;

[0021] 5) Based on the statistical analysis of the monitoring technology method of the sensitivity index, the adaptability of the sensitivity index and the instrument equipment is researched, the actual monitoring index suitable for the monitoring area is selected from all the sensitive monitoring indexes combined with the site conditions, geological conditions and the like of the monitoring area, and the type-adapted monitoring equipment is found for each actual monitoring index;

[0022] 6) According to the site conditions, geological conditions and the like of the monitoring point, the type and specification of the monitoring equipment used for monitoring each actual monitoring index corresponding to the monitoring point are determined for each monitoring point, wherein, the relevant standard specifications (mainly for the Technical Guidelines for Monitoring of Carbon Dioxide Geological Sequestration and the Technical Specifications for Quantification and Verification of Greenhouse Gas Emission Reduction of Carbon Capture Utilization and Sequestration Project) are referred to, and the CO2 leakage danger threshold and the upper limit value corresponding to each actual monitoring index are set according to the carbon sequestration project and the site conditions, when the danger threshold or the upper limit value is exceeded, it indicates that the human body will be harmed, thereby issuing a harm warning to persuade personnel to move away;

[0023] 7) After CO2 is injected into the carbon sequestration project implementation area, the corresponding monitoring equipment is arranged at each monitoring point, and each monitoring equipment communicates with the monitoring center through the Internet of Things, wherein, the monitoring data obtained by the monitoring equipment is compared with the monitoring baseline to determine whether CO2 leakage occurs and the influence of CO2 leakage on the groundwater environment (here, the determination of CO2 leakage and its influence on the groundwater environment is given according to the CO2-H2O reaction experiment in step 4), so as to objectively evaluate the influence of CO2 leakage on the groundwater environment in the monitoring area in real time.

[0024] In the present application, the site conditions are, for example, whether the development of deep coal or oil and gas resources is involved, whether there is an abandoned well shaft, and the like, and the geological conditions are, for example, whether there are developed fractures and faults, whether natural earthquakes are easy to cause, and the like. Determining a reasonable range of the monitoring area in the carbon sequestration project implementation area is a well-known technology in the art, and the characteristics of CO2 migration in the underground and the like can be reflected from the site conditions, geological conditions and the like, and then used for planning the monitoring area. In addition, in addition to considering the site conditions, geological conditions and the like, the range of the monitoring area can also be reasonably designed in combination with engineering practical experience.

[0025] In actual implementation, the size of the core area and the extension area should be reasonably designed according to the carbon sequestration project implementation area and actual requirements, and generally, the core area and the extension area are designed as circular or square regions, for example, the core area is a square region of 1kmx1km, and the extension area is a square region of 10kmx10km, which is not limited.

[0026] In the present application, the investigation of the risk points in the monitoring area is usually based on the indexes of geological risk, engineering risk, environmental risk and health risk, of course, not limited to. And the potential CO2 leakage risk points should be based on the existing geological data, geophysical data, drilling data, logging data and rock water sample test data, and the actual situation of field exploration, focusing on the geological risk and environmental risk to check and evaluate each risk point, so as to select a part of the risk points as monitoring points. The determination process of the risk points and the monitoring points is the well-known technology in the art, which should be reasonably designed and adjusted according to the actual situation, and will not be described here in detail.

[0027] In practice, the stratum injected with CO2 can be in deep layer, buffer layer, middle-shallow layer, near-surface layer, etc., not limited to.

[0028] In step 3), the background value data is the underground water data obtained for the monitoring area before CO2 injection, such as PH value, conductivity, temperature, dissolved oxygen, etc., and the background value data is measured through the wellbore.

[0029] In actual implementation, for different types of underground water data, choose one from the methods of field water quality rapid test, field simple experimental test and laboratory water quality full analysis test, etc., which are all the conventional methods in the art, not limited to. The field simple experimental test is, for example, the test of HCO3 - , CO3 2- , CO2 and other variable components.

[0030] In the present application, the background value data is used as the reference for comparison, for example, higher than the reference by a certain degree, it is determined that CO2 leakage has occurred.

[0031] In practice, the wellbore can be the existing injection well, monitoring well, abandoned well modification, etc., or the field drilling dedicated monitoring well (recommended).

[0032] In step 4), for example, Figure 1The experimental device includes four full-sealed pressure-resistant organic glass covers arranged side by side, three of which are used as formation comparison covers 10, and the remaining one is used as a pure gas comparison cover 20. The bottoms of the formation comparison covers 10 are respectively connected with the outlets of a gas-liquid mixing device 50 via injection pipes 60, and control valves 61 are arranged on the injection pipes 60. The control valves 61 are used for controlling the gas-liquid mixture entering the formation comparison covers 10. The inlets of the gas-liquid mixing devices 50 are divided into two paths. One path is connected with a plunger pump 42 via a gas supply pipe 40, and an air inlet valve 43 is arranged on the gas supply pipe 40 connected with the inlets of the gas-liquid mixing devices 50. The other path is connected with a liquid supply device (not shown in the figure) via a liquid supply pipe 30, and a liquid injection valve 31 is arranged on the liquid supply pipe 30 connected with the inlets of the gas-liquid mixing devices 50. The liquid injection valve 31 is used for controlling the passage of brine. The bottom of the pure gas comparison cover 20 is connected with the plunger pump 42 via the gas supply pipe 40, and the air inlet valve 43 is arranged on the gas supply pipe 40 connected with the bottom of the pure gas comparison cover 20. The above-mentioned air inlet valves 43 are used for controlling the conduction of carbon dioxide gas. The plunger pump 42 is connected with a carbon dioxide gas source tank 41, which is used for providing carbon dioxide gas. The tops of the formation comparison covers 10 and the pure gas comparison cover 20 are provided with sealable liquid inlets 90. The formation comparison covers 10 and the pure gas comparison cover 20 are provided with sampling pipes 70 and gas outlet pipes 80. Sampling valves 71 are arranged on the sampling pipes 70, which are used for starting and stopping the sampling process. Sampling bottles 72 are oppositely arranged at the outlets of the sampling pipes 70. Gas outlet valves 81 are arranged on the gas outlet pipes 80, which are used for starting and stopping the gas discharge process to adjust the pressure in the covers. The formation comparison covers 10 and the pure gas comparison cover 20 are installed with sensors for monitoring corresponding monitoring indexes. Different sensors correspond to different monitoring indexes, such as pH value sensors for monitoring pH values, etc. Among them, the three formation comparison covers 10 are respectively used for containing formation water, prepared liquid simulating the composition of formation water, and deionized water (distilled water). The pure gas comparison cover 20 is used for containing deionized water (distilled water). The liquid supply pipe 30 is used for injecting brine reflecting the situation of formation water when CO2 leaks. The gas supply pipe 40 is used for injecting CO2 gas. The plunger pump 42 is used for controlling the flow rate and flow of CO2 injection. The gas-liquid mixing device 50 is used for controlling the mixing ratio of brine and CO2 gas, which can be 2:1, 1:1 or 1:2, etc., without limitation. The gas-liquid mixing device 50 is a conventional device.

[0033] Further, in step 4), at the set reaction time point (such as 0 hours, 1 hour, 4 hours, 24 hours, 48 hours, etc.) after the injection of the salt water and the carbon dioxide gas into each formation contrast cover 10 and the injection of the carbon dioxide gas into the pure gas contrast cover 20, sampling is performed through the sampling valve 71 and full analysis testing is performed to obtain the influence degree of CO2 on the formation water, the prepared liquid and the deionized water under different monitoring indexes, so as to obtain the influence mechanism of the CO2 leakage on different media, so as to screen a plurality of monitoring indexes from all the monitoring indexes affecting the underground water environment as sensitive monitoring indexes. The pure gas contrast cover 20 is used to compare the reaction occurred in the formation contrast cover 10 containing the deionized water, and only the pure CO2 reacts with the deionized water (distilled water) in the pure gas contrast cover 20, the reaction element is single, and the pure gas contrast cover 20 is suitable as a control, and the formation contrast cover 10 is used to simulate the reaction scene of the CO2 carrying the salt water and different media in the formation.

[0034] Specifically, the experimental process is as follows: Figure 1 The formation water, the prepared liquid prepared according to the predetermined proportion for simulating the composition of the formation water, and the deionized water are respectively filled into the three formation contrast covers 10 from the liquid inlet 90, and the deionized water is filled into the pure gas contrast cover 20 from the sealable liquid inlet 90, and then the liquid inlet 90 is sealed. The gas-liquid mixing ratio of the gas-liquid mixing device 50 is adjusted, and then the salt water and the carbon dioxide gas are injected into each formation contrast cover 10, and the carbon dioxide gas is injected into the pure gas contrast cover 20, and then sampling is performed through the sampling valve 71 at the set reaction time point (such as 0h, 1h, 4h, 24h, 48h, etc.) to perform full analysis testing to obtain the influence of CO2 on the formation water, the prepared liquid and the deionized water under different monitoring indexes (such as pH value, oxidation-reduction potential, total dissolved solids, etc.). During the whole process, the pure gas contrast cover 20 is used to compare the reaction occurred in the formation contrast cover 10 containing the deionized water. Thus, the influence mechanism of the leaked CO2 on different media can be obtained. The sensors of different types installed on the formation contrast cover 10 and the pure gas contrast cover 20 respectively monitor the corresponding monitoring indexes, and feed back the monitoring results to the control device (including the processor).

[0035] Then, different gas-liquid mixing ratios (such as gas-liquid ratio 2:1, 1:1, 1:2, etc.) are set, and the above process is repeated for multiple times, so that the control device screens a plurality of sensitive monitoring indexes from all the monitoring indexes affecting the underground water environment as sensitive monitoring indexes based on the obtained monitoring results.

[0036] In actual implementation, the influence on the underground water is generally reflected from the monitoring indexes such as water quality, physicochemical parameters, water chemical components, harmful elements, gas phase components, etc., and then sensitive monitoring indexes are screened from these monitoring indexes.

[0037] Here, the sensitive monitoring index refers to an index that can sensitively reflect the monitoring result from a certain angle. The angle can be that the monitoring data changes significantly, the monitoring data feedback is rapid, the medium impact is outstanding, and it is not disturbed by drift, etc. In short, the sensitive monitoring index should be able to quickly, intuitively and accurately reflect the impact on the groundwater.

[0038] In practice, how to prepare the prepared liquid is a well-known technology. Moreover, the process of comparing and analyzing the influence degree and mechanism of CO2 on different media, which is not mentioned in the above experimental process, is a well-known technology in the art. The comparison and analysis process of different media is slightly different, which is not described in detail here.

[0039] In practice, the experimental device can perform multiple batches of experiments, and the experimental results are used for real-time comparison to intuitively observe the influence degree of CO2 on different media under different monitoring indexes, so as to obtain the influence mechanism of CO2 leakage on different media, and to accurately screen out sensitive monitoring indexes.

[0040] Here, different media refer to the media involved in formation water, prepared liquid and deionized water, and the influence mechanism of CO2 leakage on different media refers to the influence mode or way of carbon dioxide gas on various media contained in the formation.

[0041] In actual implementation, in step 4), when no wellbore, wellhead or the like is found in the monitoring area to obtain real formation water, the water quality (such as salinity, ions, etc.) indicators of the formation water in the monitoring area are found out by collecting literature and other materials, and a prepared liquid for simulating the actual situation of the formation water is artificially prepared, wherein one of the formation comparison covers 10 is empty, and the above CO2-H2O reaction experiment is performed through the other two formation comparison covers 10 and one pure gas comparison cover 20.

[0042] In step 5), the selection of actual monitoring indexes from sensitive monitoring indexes should consider whether they can be implemented in the monitoring area, whether monitoring equipment and environmental factors suitable for the actual monitoring indexes can be found, etc.

[0043] In actual implementation, some actual monitoring indexes can be directly measured by monitoring equipment, such as pH value, conductivity, TDS in water, oxidation-reduction potential, carbon dioxide concentration in water, etc. Another part of the actual monitoring indexes that cannot be directly obtained by the monitoring equipment is obtained by sampling through the monitoring equipment and then testing and analyzing in the laboratory, such as physicochemical parameters, water chemical components, gas phase components, and toxicological indexes.

[0044] In step 7), the monitoring center builds a monitoring and early warning platform, which can include efficient storage of monitoring data, processing and analysis of monitoring data, trend analysis and prediction, and API interaction service business, wherein the monitoring devices in the core area are monitored online, and the monitoring devices in the extended area are supplemented by manual inspection in addition to online monitoring.

[0045] The advantages of the present application are:

[0046] The present application provides a way for real, objective and real-time evaluation of the influence of carbon sequestration engineering carbon dioxide leakage on groundwater environment, and the evaluation result can truly reflect the objective situation and is real-time. Specifically, the present application considers the influence mechanism of CO2 leakage on groundwater environment, selects sensitive monitoring indexes through CO2-H2O reaction experiments from the influence factors of water quality, physicochemical parameters, water chemical components, harmful elements and gas phase components of groundwater, and further optimizes the actual monitoring indexes by considering the applicability of the monitoring area, selects the most suitable monitoring equipment based on the actual monitoring indexes to monitor the monitoring points in real time, and builds a monitoring and early warning platform based on the Internet of Things, which provides a favorable guarantee for timely evaluation of the influence of CO2 leakage on groundwater environment.

[0047] The above is the preferred embodiment of the present application and the technical principle used thereby, and for those skilled in the art, any equivalent transformation, simple replacement and the like based on the technical solution of the present application without departing from the spirit and scope of the present application shall belong to the protection scope of the present application.

Claims

1. A method for assessing the environmental impact of carbon dioxide leakage from a carbon sequestration project on groundwater, characterized in that, Including the following steps: 1) Based on the site conditions and geological conditions of the carbon sequestration project implementation area, the monitoring area is determined, wherein the monitoring area is located within the carbon sequestration project implementation area, the monitoring area includes a core area and an extension area, the core area is located within the extension area and the area of ​​the extension area is much larger than the area of ​​the core area; 2) Conduct risk point investigations within the monitoring area. Based on geological data, geophysical data, drilling data, well logging data, and rock water sample test data, and in conjunction with the actual situation of field exploration, identify potential CO2 leakage risk points as monitoring points. 3) Within the monitoring area, background values ​​representing the groundwater quality of the carbon sequestration project implementation area are determined through on-site rapid water quality testing, on-site simple experimental testing, and laboratory full water quality analysis testing, thereby determining a monitoring baseline for comparison with the monitoring data obtained after CO2 injection; 4) Using an experimental device, CO2-H2O reaction experiments were conducted on the prepared solutions of formation water, deionized water, and simulated formation water components that could be obtained in the monitoring area. The degree of influence of CO2 on different media under different monitoring indicators was obtained, the mechanism of CO2 leakage on different media was obtained, and then sensitive monitoring indicators were screened from all the monitoring indicators that affect the groundwater environment. 5) Based on the site conditions and geological conditions of the monitoring area, select the actual monitoring indicators suitable for the monitoring area from all the sensitive monitoring indicators, and find the appropriate monitoring equipment for each actual monitoring indicator. 6) Based on the site conditions and geological conditions of the monitoring points, specify the model and specifications of the monitoring equipment used to monitor each of the actual monitoring indicators corresponding to the monitoring point for each monitoring point. In this case, set the danger threshold for CO2 leakage and the upper limit value corresponding to each of the actual monitoring indicators. When the danger threshold or the upper limit value is exceeded, it indicates that it will cause harm to the human body, thereby issuing a hazard alarm and advising people to move away. 7) After CO2 is injected into the carbon sequestration project implementation area, corresponding monitoring equipment is deployed at each monitoring point. Each monitoring equipment communicates with the monitoring center through the Internet of Things. The monitoring data obtained by the monitoring equipment is compared with the monitoring baseline to determine whether CO2 leakage has occurred and the impact of CO2 leakage on the groundwater environment, so as to objectively evaluate the impact of CO2 leakage on the groundwater environment in the monitoring area in real time.

2. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 1, characterized in that, In step 3), the background value data is groundwater data obtained for the monitoring area before CO2 injection, and the background value data is measured through a well.

3. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 1, characterized in that, In step 4), the experimental apparatus includes four fully sealed, pressure-resistant plexiglass covers arranged side-by-side. Three of these covers serve as formation comparison covers, and the remaining cover serves as a pure gas comparison cover. The bottom of each formation comparison cover is connected to the outlet of a gas-liquid mixing device via an injection pipe. Each injection pipe is equipped with a control valve. The inlet of each gas-liquid mixing device is divided into two paths: one path connects to a plunger pump via a gas supply pipe, and the gas supply pipe connected to the inlet of each gas-liquid mixing device is equipped with an inlet valve; the other path connects to a liquid supply device via a liquid supply pipe, and the liquid supply pipe connected to the inlet of each gas-liquid mixing device is equipped with a liquid injection valve. The bottom of the pure gas comparison cover is connected to the plunger pump via a gas supply pipe, and the gas supply pipe connected to the bottom of the pure gas comparison cover is equipped with the inlet valve. The plunger pump and the gas-liquid mixing device are connected to a gas-liquid mixing device. A carbon source tank is connected. The top of the formation comparison hood and the pure gas comparison hood are equipped with a sealable liquid inlet. The formation comparison hood and the pure gas comparison hood are equipped with a sampling tube and a gas outlet tube. The sampling tube is equipped with a sampling valve. A sampling bottle is placed opposite each other at the outlet of the sampling tube. The gas outlet tube is equipped with a gas outlet valve. The formation comparison hood and the pure gas comparison hood are equipped with sensors for monitoring the corresponding monitoring indicators. The three formation comparison hoods are respectively used to hold formation water, a preparation solution simulating the composition of formation water, and deionized water. The pure gas comparison hood is used to hold deionized water. The liquid supply tube is used to inject brine. The gas supply tube is used to inject CO2 gas. The plunger pump is used to control the flow rate and volume of carbon dioxide injection. The gas-liquid mixing device is used to control the mixing ratio of brine and CO2 gas.

4. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 3, characterized in that, In step 4), samples are taken at predetermined reaction time points after the injection of brine and carbon dioxide gas into each of the formation comparison hoods and the injection of carbon dioxide gas into the pure gas comparison hood, and then subjected to full analysis tests to obtain the degree of influence of CO2 on formation water, prepared solution and deionized water under different monitoring indicators. This yields the mechanism of CO2 leakage on different media, which is used to screen out several monitoring indicators from all the monitoring indicators affecting the groundwater environment as the sensitive monitoring indicators. The pure gas comparison hood is used to compare the reaction with the formation comparison hood containing deionized water.

5. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 4, characterized in that, In step 4), when no wellbore can be found in the monitoring area to obtain formation water, the water quality indicators of the formation water in the monitoring area are determined by collecting data, and a preparation solution is artificially prepared to simulate the actual situation of the formation water. In this case, one of the formation comparison hoods is empty, and the CO2-H2O reaction experiment is carried out by the other two formation comparison hoods and one pure gas comparison hood.

6. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 1, characterized in that, In step 5), the actual monitoring indicators are selected from the sensitive monitoring indicators based on whether they can be implemented in the monitoring area and whether monitoring equipment and environmental factors suitable for the actual monitoring indicators can be found.

7. The method for assessing the impact of carbon dioxide leakage from carbon sequestration projects on groundwater environment as described in claim 1, characterized in that, Some of the actual monitoring indicators are directly measured by the monitoring equipment, while others, which cannot be directly obtained by the monitoring equipment, are obtained by sampling through the monitoring equipment and then testing and analyzing them in the laboratory.

8. The method for assessing the environmental impact of carbon dioxide leakage from carbon sequestration projects on groundwater as described in claim 1, characterized in that, In step 7), the monitoring center constructs a monitoring and early warning platform. The monitoring and early warning platform includes efficient storage of monitoring data, processing and analysis of monitoring data, trend analysis and prediction, and API interaction services. The monitoring equipment in the core area adopts online monitoring, while the monitoring equipment in the outer area adopts online monitoring and is supplemented by manual inspection.

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