Safety assessment method for carbon storage sites based on carbon dioxide plume monitoring

Abstract

The present invention discloses a carbon storage site safety assessment method based on carbon dioxide plume monitoring, comprising: real-time acquisition of monitoring data from various areas within the carbon storage site; storing the monitoring data in a monitoring database; comparing migration velocity data when the fluctuation amplitude of a type of monitoring data obtained at the current monitoring moment exceeds a threshold compared with the same type of monitoring data at the previous monitoring moment; if the migration velocity data are the same, determining whether most of the other types of monitoring data have not experienced significant fluctuations; if it is determined that most of the other types of monitoring data have experienced significant fluctuations and the migration velocity data obtained in the previous step are different, it is considered that the site may be abnormal and the next step is entered; obtaining the permeability, porosity, and fracture pressure data of the corresponding area at the current monitoring moment, and determining whether they are within the normal range; if they are not within the normal range, it is considered that the site has a safety hazard and an alarm is issued. The present invention can quickly and timely make an accurate assessment of site safety, has low energy consumption, and is suitable for promotion.

Description

Technical Field

[0001] The present invention relates to a carbon sequestration site safety assessment method based on carbon dioxide plume monitoring, belonging to the technical field of carbon sequestration site safety assessment. Background Art

[0002] Carbon dioxide sequestration is an important technology that captures CO2 emitted by industrial industries and stores it in geological structures for a long time to reduce atmospheric greenhouse gas concentrations and mitigate climate change. It can not only directly reduce carbon emissions from fossil energy and industrial processes, but also provide an emission reduction path for high-emission industries (such as steel, cement, etc.) before renewable energy is completely replaced.

[0003] In practical implementation, after CO2 injection and storage, long-term safety assessment and monitoring of the carbon storage site are necessary to ensure storage effectiveness, prevent leakage risks, and estimate environmental impacts. Existing safety assessment methods involve deploying sensors at the site to monitor various geological parameters, including pressure, microseismic waves, temperature and humidity, permeability, porosity, fracture pressure, and reservoir geochemical parameters (such as major ions, pH, alkalinity, stable isotopes, and gas composition of underground fluid samples). Real-time data collection from these sensors enables real-time monitoring of the site and thus an assessment of its safety. While practical implementation demonstrates that this approach is simple and reliable, it has the following drawbacks: First, the large number of sensors required, the need for simultaneous monitoring, and the high frequency of data transmission, necessitates significant energy consumption. Second, a safety assessment requires complex computational analysis of the monitoring data from each sensor, a cumbersome process that hinders prompt and timely assessments. Summary of the Invention

[0004] The purpose of the present invention is to provide a carbon storage site safety assessment method based on carbon dioxide plume monitoring, which can quickly and timely make an accurate assessment of the safety of the carbon storage site, has low energy consumption, is economical and environmentally friendly, and is suitable for promotion.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A carbon storage site safety assessment method based on carbon dioxide plume monitoring comprises the following steps:

[0007] 1) acquiring real-time monitoring data for each area within the carbon storage site, the monitoring data comprising spatial distribution data and migration velocity data of the carbon dioxide plume, as well as pressure data, microseismic wave data, humidity data, and temperature data, wherein the carbon storage site is divided into the plurality of areas;

[0008] 2) storing the monitoring data obtained for each of the areas into a monitoring database according to monitoring time, wherein the monitoring data obtained at each monitoring time is recorded in units of the area and arranged in chronological order of the monitoring times;

[0009] 3) When the fluctuation range of a type of monitoring data obtained at the current monitoring time exceeds the threshold compared with the monitoring data of the same type obtained at the previous monitoring time, the migration speed data obtained at the current monitoring time and the previous monitoring time are compared. If the migration speed data obtained at the current monitoring time and the previous monitoring time are different, it is considered that there may be an anomaly and the process proceeds to step 5. Otherwise, the process proceeds to step 4.

[0010] 4) If more than 80% of the other types of monitoring data obtained at the current monitoring moment and the previous monitoring moment fluctuate by less than 10%, the monitoring data whose fluctuation amplitude exceeds the threshold in step 3) is eliminated, and the monitoring data other than the eliminated monitoring data at the current monitoring moment is considered normal, stored in the monitoring database, and the process returns to step 1). Otherwise, it is considered that there may be an abnormality, and the process proceeds to step 5).

[0011] 5) Obtain the permeability, porosity, and fracture pressure data obtained at the current monitoring time for the area corresponding to the monitoring data whose fluctuation amplitude exceeds the threshold;

[0012] 6) If the permeability, porosity, and fracture pressure data are all outside the normal range, the carbon storage site is deemed to have a safety hazard and an alarm is issued; otherwise, the carbon storage site is deemed to be safe;

[0013] 7) The evaluation is completed.

[0014] The advantages of the present invention are:

[0015] 1. The present invention introduces the monitoring of carbon dioxide plume information, which can promptly detect abnormal geological migration in carbon storage sites. It also greatly reduces the types of sensors used, reduces the number of sensors, avoids high-frequency data transmission from a large number of sensors, greatly reduces energy consumption, improves feasibility and reduces costs.

[0016] 2. The present invention does not require complex calculations and analyses of the monitoring data obtained by each sensor, which greatly simplifies the safety assessment process and enables the safety assessment results to be produced quickly, promptly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an implementation flow chart of the carbon storage site safety assessment method based on carbon dioxide plume monitoring of the present invention.

[0018] Figure 2 This is an example of a monitoring data list stored in the monitoring database. DETAILED DESCRIPTION

[0019] like Figure 1 The present invention proposes a carbon storage site safety assessment method based on carbon dioxide plume monitoring, comprising the following steps:

[0020] 1) Real-time monitoring data for each area within the carbon storage site, including the spatial distribution and migration velocity of the carbon dioxide plume, as well as pressure, microseismic wave, humidity, and temperature data. The carbon storage site is divided into several areas;

[0021] 2) To improve data processing efficiency and facilitate subsequent comparison, the monitoring data obtained for each region is stored in a monitoring database according to the monitoring time (for example, monitoring once every 20 seconds). The monitoring data obtained at each monitoring time is recorded in units of regions and the monitoring data are arranged in the order of the monitoring time;

[0022] 3) When the fluctuation range of a type of monitoring data obtained at the current monitoring time exceeds the threshold compared with the monitoring data of the same type obtained at the previous monitoring time, the migration velocity data obtained at the current monitoring time and the previous monitoring time are compared. If the migration velocity data obtained at the current monitoring time and the previous monitoring time are different, it is considered that there may be an anomaly and the process proceeds to step 5. Conversely, if the migration velocity data obtained at the current monitoring time and the previous monitoring time are the same, the process proceeds to step 4.

[0023] 4) If more than 80% of the other types of monitoring data obtained at the current monitoring moment and the previous monitoring moment fluctuate by less than 10%, the monitoring data with fluctuations exceeding the threshold in step 3) are eliminated, and the monitoring data other than the eliminated monitoring data at the current monitoring moment are considered normal, stored in the monitoring database, and the process returns to step 1). Otherwise, it is considered that there may be an anomaly, and the process proceeds to step 5).

[0024] 5) Obtain the permeability, porosity, and fracture pressure data obtained at the current monitoring time for the area corresponding to the monitoring data whose fluctuation amplitude exceeds the threshold;

[0025] 6) If the permeability, porosity, and fracture pressure data are all outside the normal range, the carbon storage site is considered to have a safety hazard and an alarm is issued; otherwise, the carbon storage site is considered safe;

[0026] 7) The evaluation is completed.

[0027] In actual implementation, the present invention further includes completing the deployment of various types of sensors in various areas of the carbon storage site before step 1).

[0028] In step 1), pressure data, microseismic wave data, humidity data, temperature data, spatial distribution data and migration velocity data of the carbon dioxide plume are obtained respectively through a pressure sensor, a microseismic wave detector, a humidity sensor, a temperature sensor, a distributed acoustic sensor and a gas chromatograph. Among them, the migration velocity data of the carbon dioxide plume is obtained by injecting a tracer into the carbon storage site before or during the injection of carbon dioxide, and then tracking the tracer by a gas chromatograph.

[0029] For step 2), the monitoring data in the monitoring database can be stored in the form of a list, such as Figure 2 In the example shown, the monitoring data of each area is stored independently, and the monitoring data of each area is arranged in chronological order according to the monitoring time.

[0030] For the same type of sensor, at least one is deployed in each area. When multiple sensors of the same type are deployed in an area, the sensors are evenly distributed in the area, and the average of the monitoring data obtained by each sensor is used as the monitoring data of this type in this area.

[0031] In the present invention, various types of sensors are deployed within each area of ​​a carbon storage site to monitor various types of monitoring data. If multiple sensors of the same type are deployed within a single area, for example, if each area is equipped with three pressure sensors, then for any given area, all three pressure sensors are evenly distributed, and the average of the pressure data acquired by the three pressure sensors at the same monitoring time is used as the pressure data for that area at that monitoring time.

[0032] In the present invention, pressure data, microseismic wave data, humidity data, temperature data, spatial distribution data of carbon dioxide plumes, and migration velocity data are six different types of monitoring data.

[0033] In this invention, the monitoring database not only compares pre- and post-monitoring data, facilitating the rapid identification of abnormal data, but also provides a complete record of monitoring data at the carbon storage site. In the event of a carbon dioxide leak, historical data can be quickly traced to identify the cause. Furthermore, it provides data support for subsequent optimization of carbon storage site construction.

[0034] In actual design, the above threshold is designed to be 10%-20%.

[0035] In step 3), when judging the fluctuation amplitude of the same type of monitoring data monitored at the current monitoring moment and the previous monitoring moment, the threshold value should be reasonably designed according to the type of monitoring data. For example, when judging pressure data, the threshold value can be set to 15%, that is, it should be judged whether the fluctuation of the pressure data obtained at the current monitoring moment exceeds 15% of the pressure data obtained at the previous monitoring moment. For another example, when judging temperature data, the threshold value can be set to 20%, that is, it should be judged whether the fluctuation of the temperature data obtained at the current monitoring moment exceeds 20% of the temperature data obtained at the previous monitoring moment.

[0036] The prerequisite for executing step 4) is that if the fluctuation range of the same type of monitoring data obtained between the current and previous monitoring times exceeds the threshold, but the migration speed data remains unchanged, then step 4) must be further executed to determine the fluctuation range of other monitoring data. In step 4), the current and previous monitoring times are compared to determine whether 80% of the other types of monitoring data have fluctuated by less than 10%. If so, the current monitoring is considered normal, and only the monitoring data with a fluctuation range exceeding the threshold needs to be eliminated.

[0037] In actual implementation, when a certain type of monitoring data changes significantly, if the geological conditions of the carbon storage site have really changed, it is very likely to affect the storage of carbon dioxide, then it will inevitably cause other types of monitoring data to change synchronously. However, if only this type of monitoring data changes significantly, and other types of monitoring data do not change synchronously, it is very likely that the sensor used to monitor this type of monitoring data has a fault or error. Therefore, it is necessary to eliminate abnormal data in this case.

[0038] In the present invention, the key to determining whether the geological conditions of the carbon storage site have changed is the migration rate of the carbon dioxide plume. This is because once the geological conditions of the carbon storage site have changed in a way that affects carbon dioxide sequestration, the migration rate of the carbon dioxide plume will inevitably change, and the change will be obvious and last for a long time. Therefore, monitoring whether the migration rate has changed is of primary importance. By monitoring whether the migration rate data has changed, it is possible to more quickly and accurately determine whether the geological conditions have changed.

[0039] In other words, given that CO2 plumes persist throughout the storage process, this invention innovatively incorporates CO2 plume monitoring. By monitoring plume stability, changes in site geology can be inferred. This approach not only significantly reduces the number of sensors but also ensures the accuracy and timeliness of safety assessments. Furthermore, long-term monitoring of CO2 plume information allows for accurate assessment of the stability of the carbon storage site during operation and prevents CO2 leakage from polluting the surrounding ecosystem and atmosphere.

[0040] Carbon dioxide plume monitoring is crucial in carbon storage technology. By tracking the migration and distribution of CO2 underground in real time, it ensures the safety and effectiveness of storage. Data from CO2 plume monitoring can be used to promptly detect CO2 leakage risks, preventing them from contaminating groundwater or escaping to the atmosphere, thereby ensuring environmental safety.

[0041] In step 3), the monitoring data with fluctuation amplitude exceeding the threshold is eliminated by replacing it with the same type of monitoring data at the previous monitoring moment, so as to eliminate abnormal data.

[0042] Regarding step 5), in carbon dioxide geological storage projects, real-time collection of geological parameters such as permeability, porosity, and fracture pressure is a key link in ensuring the safety of carbon storage. Among them: permeability determines the migration ability of CO2 in the reservoir. High permeability means a greater risk of carbon dioxide leakage; porosity is used to measure the storage capacity of carbon dioxide in rocks. The greater the porosity, the greater the carbon storage capacity, which means a greater risk of carbon dioxide leakage; fracture pressure is used to reflect the maximum pressure that the caprock of the carbon storage site can withstand. If the fracture pressure exceeds the predetermined value, it indicates the presence of cracks in the caprock, which means there is a risk of carbon dioxide leakage.

[0043] In step 6), if the carbon storage site is considered to have a safety hazard, the geological bodies within the screening area that can be repaired will be repaired (such as cracks in the building layer caused by natural geological movement). Otherwise, no intervention will be made. The area corresponding to the monitoring data with a fluctuation amplitude exceeding the threshold will be used as the screening area.

[0044] In actual implementation, the repair can be carried out by remotely controlling robots. The repair materials are produced outside the site, transported to the site, and then the robots are controlled to repair the cracks on the inner wall.

[0045] The advantages of the present invention are:

[0046] 1. The present invention introduces the monitoring of carbon dioxide plume information, which can promptly detect abnormal geological migration in carbon storage sites. It also greatly reduces the types of sensors used, reduces the number of sensors, avoids high-frequency data transmission from a large number of sensors, greatly reduces energy consumption, improves feasibility and reduces costs.

[0047] 2. The present invention does not require complex calculations and analyses of the monitoring data obtained by each sensor, which greatly simplifies the safety assessment process and enables the safety assessment results to be produced quickly, promptly and accurately.

[0048] The above are preferred embodiments of the present invention and the technical principles used therein. For those skilled in the art, any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, are within the scope of protection of the present invention.

Claims

1. A carbon storage site safety assessment method based on carbon dioxide plume monitoring, characterized in that: Including steps: 1) acquiring real-time monitoring data for each area within the carbon storage site, the monitoring data comprising spatial distribution data and migration velocity data of the carbon dioxide plume, as well as pressure data, microseismic wave data, humidity data, and temperature data, wherein the carbon storage site is divided into the plurality of areas; 2) storing the monitoring data obtained for each of the areas into a monitoring database according to monitoring time, wherein the monitoring data obtained at each monitoring time is recorded in units of the area and arranged in chronological order of the monitoring times; 3) When the fluctuation range of a type of monitoring data obtained at the current monitoring time exceeds the threshold compared with the monitoring data of the same type obtained at the previous monitoring time, the migration speed data obtained at the current monitoring time and the previous monitoring time are compared. If the migration speed data obtained at the current monitoring time and the previous monitoring time are different, it is considered that there may be an anomaly and the process proceeds to step 5. Otherwise, the process proceeds to step 4. 4) If more than 80% of the other types of monitoring data obtained at the current monitoring moment and the previous monitoring moment fluctuate by less than 10%, the monitoring data whose fluctuation amplitude exceeds the threshold in step 3) is eliminated, and the monitoring data other than the eliminated monitoring data at the current monitoring moment is considered normal, stored in the monitoring database, and the process returns to step 1). Otherwise, it is considered that there may be an abnormality, and the process proceeds to step 5). 5) Obtain the permeability, porosity, and fracture pressure data obtained at the current monitoring time for the area corresponding to the monitoring data whose fluctuation amplitude exceeds the threshold; 6) If the permeability, porosity, and fracture pressure data are all outside the normal range, the carbon storage site is deemed to have a safety hazard and an alarm is issued; otherwise, the carbon storage site is deemed to be safe; 7) End of evaluation; Wherein, in the step 4), the elimination process of the monitoring data with a fluctuation amplitude exceeding a threshold is to replace it with the same type of monitoring data at the previous monitoring moment, and the threshold is 10%-20%.

2. The carbon storage site safety assessment method based on carbon dioxide plume monitoring according to claim 1, characterized in that: In step 1), the pressure data, the microseismic wave data, the humidity data, the temperature data, the spatial distribution data of the carbon dioxide plume, and the migration velocity data are respectively obtained by a pressure sensor, a microseismic wave detector, a humidity sensor, a temperature sensor, a distributed acoustic sensor, and a gas chromatograph. The migration velocity data of the carbon dioxide plume is obtained by injecting a tracer into the carbon sequestration site before or during the injection of carbon dioxide, and then tracking the tracer by the gas chromatograph.

3. The carbon storage site safety assessment method based on carbon dioxide plume monitoring according to claim 2, characterized in that: For sensors of the same type, at least one is deployed in each of the areas, wherein: when multiple sensors of the same type are deployed in an area, each sensor is evenly distributed in the area, and the average of the monitoring data obtained by each sensor is used as the monitoring data of this type in the area.

4. The carbon storage site safety assessment method based on carbon dioxide plume monitoring according to claim 1, characterized in that: In step 6), if the carbon storage site is considered to have a safety hazard, the geological bodies that can be repaired in the screening area are repaired, otherwise no intervention is performed, wherein the area corresponding to the monitoring data with a fluctuation amplitude exceeding the threshold is used as the screening area.

5. The carbon storage site safety assessment method based on carbon dioxide plume monitoring according to claim 4, characterized in that: The repair is carried out by remotely controlling a robot. The repair materials are produced outside the site and transported to the site, where the robot is controlled to repair the inner wall cracks.

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