A method and system for full-cycle safety monitoring of CO2 storage

Abstract

The application provides a kind of sealing CO2 whole cycle safety monitoring method and system, comprising: the geological structure of CO2 to be sealed and its surrounding certain range are determined as monitoring area;Microseismic sensor is arranged on the boundary of monitoring area through drilling;Microseismic monitoring data analysis system is started before the implementation of sealing CO2, receives the microseismic signal in monitoring area, judges the influence of drilling disturbance on monitoring area;In the process of injecting CO2 into geological structure, the safety of injection process is judged by the position of microseismic signal, and the injection process is adjusted according to the judgment result;After the end of carbon injection into geological structure, the injection hole is sealed, and continuous microseismic monitoring is continued, the influence of CO2 injection process on monitoring area is judged by microseismic signal, and the safety of sealing area is identified.The application realizes the whole cycle safety monitoring of geological structure sealing CO2 engineering structure, and effectively guarantees the safety of CO2 sealing engineering of geological structure.

Description

Technical Field

[0001] This invention relates to the field of CO2 storage safety monitoring technology, and for example to a method and system for full-cycle safety monitoring of CO2 storage. Background Technology

[0002] Geological sequestration is a typical negative carbon emission technology. Supercritical CO2 is injected into geological structures such as permafrost, oil and gas fields, saline aquifers, or unminable coal seams through pipelines, which can form long-term or permanent CO2 sequestration. Therefore, this method is considered the primary choice for CO2 sequestration.

[0003] The safety of CO2 sequestration in geological structures, such as permafrost, is mainly affected by factors such as the structure of the sequestered geological body, geological hazards, and engineering disturbances. Currently, the main monitoring targets of carbon sequestration safety monitoring methods are CO2 or certain environmental effects caused by CO2 leakage, and most of them are biased towards environmental monitoring, lacking attention to the safety of the sequestered geological body itself. Summary of the Invention

[0004] This invention provides a method and system for monitoring the safety of CO2 storage throughout its entire lifecycle, used to monitor the safety of CO2 storage in geological structures throughout its entire lifecycle. The technical solution is as follows:

[0005] On the one hand, a method for monitoring the safety of CO2 storage throughout its entire lifecycle is provided, including:

[0006] S1. The geological structure to be sealed with CO2 and a certain area around it are defined as the monitoring area;

[0007] S2. Microseismic sensors are installed by drilling holes on the boundary of the monitoring area;

[0008] S3. Before implementing CO2 sealing in the geological structure, activate the microseismic monitoring data analysis system to receive microseismic signals within the monitoring area and determine the impact of borehole disturbance on the monitoring area.

[0009] S4. During the process of injecting CO2 into the geological structure, the safety of the injection process is determined by the location of the microseismic signal, and the carbon injection process is adjusted according to the determination result.

[0010] S5. After the carbon injection of the geological structure is completed, the carbon injection hole is sealed and continuous microseismic monitoring is continued. The impact of the CO2 injection process on the monitoring area is judged by the microseismic signal, and the safety of the sealed area is identified.

[0011] Optionally, in step S5, the safety of the sealed area is assessed. If a dangerous situation occurs, the leak or impending leak area is sealed according to the assessment result. After the sealing is completed, the sealing effect is verified by micro-vibration monitoring to determine whether the sealing has been restored to stability.

[0012] Optionally, the step of arranging microseismic sensors by drilling holes at the boundary of the monitoring area specifically includes:

[0013] Holes were drilled in the five directions of the monitoring area: top, front, back, left, and right. A total of 13 microseismic sensors were arranged at the boundary centers and nodes in the five directions.

[0014] Optionally, before implementing CO2 sealing in the geological structure, step S3 activates the microseismic monitoring data analysis system to receive microseismic signals within the monitoring area and determine the impact of borehole disturbance on the monitoring area, specifically including:

[0015] Before implementing CO2 sealing in the geological structure, the microseismic monitoring data analysis system is activated to receive microseismic signals within the monitoring area, locate the microseismic signals, and count their number.

[0016] If energy is continuously generated greater than 10 4 If the micro-vibration signal of J is generated, the area near the location where the micro-vibration signal is generated is affected by the drilling disturbance, and carbon injection is temporarily suspended at this time.

[0017] If the microseismic signal energy is greater than 10 4 If the number of microseismic signals J remains at 0 for a continuous period of time, it indicates that the monitored area is stabilizing and CO2 sealing of the geological structure can begin.

[0018] Optionally, in step S4, during the CO2 injection into the geological structure, the safety of the injection process is determined by the location of microseismic signals, and adjustments are made to the carbon injection process based on the determination result. Specifically, this includes:

[0019] If the micro-vibration signal appears at the designed carbon injection hole, it indicates that the injection process is normal and injection can continue.

[0020] If the location of the microseismic signal deviates from the designed carbon injection borehole but remains within the geological structure where CO2 is sealed, it indicates the presence of a void around the carbon injection site. Continuous monitoring is necessary. If the microseismic signal remains within the geological structure where CO2 is sealed and its energy is less than 10... 4 J indicates that the carbon injection process is normal and no adjustment is needed;

[0021] If the location of the microseismic signal exceeds the geological structure containing CO2, and the energy is greater than 10... 4J indicates that structural damage occurred during the carbon injection process, requiring the carbon injection to be stopped and repairs carried out.

[0022] Optionally, the criteria for determining the security of the sealed area in S5 include:

[0023] If the energy generated is greater than 10 4 The microseismic signal of J indicates that a rupture has occurred, and the location where the microseismic signal appears is the location where the rupture has occurred, and the direction of rupture transfer is the direction of crack propagation;

[0024] If the direction of rupture and transfer is concentrated within the geological structure containing CO2 and does not extend to the edge of the structure, it indicates that there is no risk of CO2 leakage.

[0025] If the rupture shifts towards the edge of the geological structure containing CO2 or beyond the structure, it indicates that a CO2 leak is imminent or a CO2 leak has already occurred, and measures need to be taken to contain it.

[0026] Optionally, the step of verifying the leak-sealing effect through microseismic monitoring and determining whether the sealing has returned to stability specifically includes:

[0027] If the energy of the generated microseismic signal is greater than 10 4 J indicates that the sealing effect is not good, and the sealing process should continue until the microseismic signal energy is below 10. 4 When there is no micro-vibration signal (J), it indicates that the leak has been stabilized and the CO2 sequestration has returned to stability.

[0028] On the other hand, a full-cycle safety monitoring system for CO2 storage is provided, including: geological structure, storage area, monitoring area, microseismic sensor, borehole, cable, surface monitoring room and microseismic monitoring data analysis system;

[0029] The geological structure is used for CO2 sequestration, wherein the geological structure for CO2 sequestration constitutes the sequestration area;

[0030] The monitoring area includes the geological structure to be sealed CO2 and a certain range around it;

[0031] The microseismic sensor is arranged on the boundary of the monitoring area through the borehole and connected to the microseismic monitoring host in the well monitoring room through the cable;

[0032] Before implementing CO2 sealing in the geological structure, the microseismic monitoring data analysis system is activated. The microseismic monitoring host receives microseismic signals within the monitoring area, and the microseismic monitoring data analysis system determines the impact of borehole disturbance on the monitoring area.

[0033] During the CO2 injection process into the geological structure, the microseismic monitoring data analysis system determines the safety of the injection process by the location of the microseismic signals and adjusts the carbon injection process according to the determination results.

[0034] After carbon injection into the geological structure is completed, the carbon injection holes are sealed. The microseismic monitoring system continues to perform continuous microseismic monitoring. The microseismic monitoring data analysis system uses microseismic signals to determine the impact of the CO2 injection process on the monitored area and assesses the safety of the sealed area.

[0035] Optionally, the microseismic monitoring data analysis system uses microseismic signals to determine the impact of the CO2 injection process on the monitoring area, identifies the safety of the sealed area, and if a dangerous situation occurs, it seals the leak area or the area about to leak based on the identification results. After the sealing is completed, the sealing effect is verified by microseismic monitoring to determine whether the sealed area has returned to stability.

[0036] Optionally, before implementing CO2 sealing in the geological structure, the microseismic monitoring data analysis system is activated, and the microseismic monitoring host receives microseismic signals in the monitoring area, locates the microseismic signals, and counts them.

[0037] If energy is continuously generated greater than 10 4 If the micro-vibration signal of J is generated, the area near the location where the micro-vibration signal is generated is affected by the drilling disturbance, and carbon injection is temporarily suspended at this time.

[0038] If the microseismic signal energy is greater than 10 4 If the number of microseismic signals J remains at 0 for a continuous period of time, it indicates that the monitored area is stabilizing and CO2 sealing of the geological structure can begin.

[0039] Optionally, during the CO2 injection into the geological structure, the microseismic monitoring data analysis system determines the safety of the injection process based on the location of microseismic signals, and adjusts the carbon injection process according to the determination result, specifically including:

[0040] If the micro-vibration signal appears at the designed carbon injection hole, it indicates that the injection process is normal and injection can continue.

[0041] If the location of the microseismic signal deviates from the designed carbon injection borehole but remains within the geological structure where CO2 is sealed, it indicates the presence of a void around the carbon injection site. Continuous monitoring is necessary. If the microseismic signal remains within the geological structure where CO2 is sealed and its energy is less than 10... 4 J indicates that the carbon injection process is normal and no adjustment is needed;

[0042] If the location of the microseismic signal exceeds the geological structure containing CO2, and the energy is greater than 10...4 J indicates that structural damage occurred during the carbon injection process, requiring the carbon injection to be stopped and repairs carried out.

[0043] Optionally, after carbon injection into the geological structure is completed, the carbon injection holes are sealed, and the microseismic monitoring system continues continuous microseismic monitoring. The microseismic monitoring data analysis system uses microseismic signals to determine the impact of the CO2 injection process on the monitored area, and the criteria for assessing the safety of the sealed area include:

[0044] If the energy generated is greater than 10 4 The microseismic signal of J indicates that a rupture has occurred, and the location where the microseismic signal appears is the location where the rupture has occurred, and the direction of rupture transfer is the direction of crack propagation;

[0045] If the direction of rupture and transfer is concentrated within the geological structure containing CO2 and does not extend to the edge of the structure, it indicates that there is no risk of CO2 leakage.

[0046] If the direction of the rupture shifts to the edge of the geological structure containing CO2 or beyond the structure, it indicates that a CO2 leak is imminent or a CO2 leak has already occurred, and measures need to be taken to seal it.

[0047] Optionally, the monitoring system verifies the leak-sealing effect through microseismic monitoring to determine whether the sealing has returned to stability, specifically including:

[0048] If the energy of the generated microseismic signal is greater than 10 4 J indicates that the sealing effect is not good, and the sealing process should continue until the microseismic signal energy is below 10. 4 When there is no micro-vibration signal (J), it indicates that the leak has been stabilized and the CO2 sequestration has returned to stability.

[0049] The above technical solution has at least the following advantages compared with the existing technology:

[0050] This invention utilizes microseismic monitoring technology to provide a method and system for full-cycle safety monitoring of CO2 storage in geological structures, such as permafrost. Microseismic sensors are deployed through boreholes along the monitoring area boundary to perform steps including borehole disturbance monitoring before carbon injection, monitoring during the carbon injection process, safety monitoring of the storage area after carbon injection, hazard identification, and verification of mitigation effectiveness. This enables full-cycle safety monitoring of CO2 storage engineering structures in geological structures and verification of the effectiveness of leak-stopping and mitigation measures after a leakage accident. Overall, the large-scale application of this invention can generate significant safety and economic benefits.

[0051] The main advantages of this invention are also reflected in:

[0052] 1. This invention utilizes micro-vibration technology to monitor borehole disturbance before carbon injection, monitor the carbon injection process, monitor the safety of the carbon-sealed area after carbon injection, identify hazards, and verify the effectiveness of hazard mitigation. It requires only one construction operation and has real-time monitoring capabilities, significantly reducing labor costs and providing convenience and speed. It achieves the goal of safety monitoring of the entire service life of the geological structure for CO2 storage engineering.

[0053] 2. This invention uses microseismic technology to monitor the safety of the sealed geological body itself, enabling early identification of hazards. This avoids the limitations of existing carbon sequestration safety monitoring methods, which mainly monitor CO2 or the environmental effects caused by CO2 leakage, and are mostly biased towards environmental monitoring, thus better ensuring safety.

[0054] 3. This invention monitors the microseismic signals after leak sealing to verify the effectiveness of the emergency response and determine whether carbon sequestration has returned to stability, thereby further improving the safety of CO2 sequestration in geological structures, such as permafrost. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 A flowchart of a method for full-cycle safety monitoring of sealed CO2 provided by an embodiment of the present invention;

[0057] Figure 2 Flowchart of another method for full-cycle safety monitoring of sealed CO2 provided by an embodiment of the present invention;

[0058] Figure 3 Flowchart of another method for full-cycle safety monitoring of sealed CO2 provided by an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of a full-cycle safety monitoring system for CO2 storage provided in an embodiment of the present invention.

[0060] Explanation of reference numerals in the attached figures:

[0061] 1. Geological structures, such as permafrost; 2. Monitoring area; 3. Sequestration area (permafrost structures for CO2 sequestration); 4. Microseismic sensors; 5. Boreholes; 6. Cables; 7. Microseismic monitoring data analysis system; 8. On-site monitoring room. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0063] like Figure 1 As shown, this embodiment of the invention provides a method for full-cycle safety monitoring of sealed CO2, including:

[0064] S1. The geological structure to be sealed with CO2 and a certain area around it are defined as the monitoring area;

[0065] S2. Microseismic sensors are installed by drilling holes on the boundary of the monitoring area;

[0066] S3. Before implementing CO2 sealing in the geological structure, activate the microseismic monitoring data analysis system to receive microseismic signals within the monitoring area and determine the impact of borehole disturbance on the monitoring area.

[0067] S4. During the process of injecting CO2 into the geological structure, the safety of the injection process is determined by the location of the microseismic signal, and the carbon injection process is adjusted according to the determination result.

[0068] S5. After the carbon injection of the geological structure is completed, the carbon injection hole is sealed and continuous microseismic monitoring is continued. The impact of the CO2 injection process on the monitoring area is judged by the microseismic signal, and the safety of the sealed area is identified.

[0069] First Embodiment

[0070] This invention provides a method and system for full-cycle safety monitoring of CO2 sequestration in geological structures, such as permafrost, to address the problem that most current carbon sequestration safety monitoring methods focus on environmental monitoring and lack monitoring of the safety of the sequestrated geological body itself. The basic principle of the microseismic monitoring technology used in this invention is to collect and acquire seismic wave signals (i.e., microseismic signals) emitted by rock mass failure or rock fracturing through sensors. By processing and analyzing the microseismic signals, information such as the location, magnitude, and energy of rock mass fracturing is obtained. This invention, by monitoring the location and energy of microseismic signals generated in the monitoring area before and after CO2 sequestration, determines the rock mass fracturing situation in the monitoring area, thereby determining the safety of the carbon injection process and achieving the goal of full-cycle safety monitoring of CO2 sequestration.

[0071] The execution flowchart of this method is as follows: Figure 2As shown, it includes the following steps:

[0072] S1: First, the monitoring area is defined as the frozen soil structure to be sealed with CO2 and the range extending 100m outward from its six boundaries in the upper, lower, front, back, left, and right directions.

[0073] The 100m range mentioned is just an example; the specific range can be determined as needed.

[0074] S2: Microseismic sensors are installed through boreholes at the boundary of the monitoring area, and the sensors are connected to the microseismic monitoring host in the monitoring room above the well via cables;

[0075] S3: Before implementing CO2 sealing in the permafrost layer, activate the microseismic monitoring system (specifically, a microseismic monitoring data analysis system) to receive microseismic signals within the monitoring area and determine the impact of borehole disturbance on the monitoring area;

[0076] The geological structure in this embodiment of the invention is specifically a permafrost layer, but it can also be other geological structures such as oil and gas fields, saline aquifers, or unminable coal seams.

[0077] S4: During the CO2 injection into the permafrost layer, the safety of the injection process is determined by the location of the microseismic signal, and the carbon injection process is adjusted according to the judgment result;

[0078] S5: After carbon injection into the frozen soil, the injection holes are sealed and continuous microseismic monitoring continues. The microseismic signals are used to determine the impact of the CO2 injection process on the monitoring area and to assess the safety of the sealed area.

[0079] The structure of the permafrost layer that seals CO2 constitutes the sealing area.

[0080] S6: If a dangerous situation occurs, the leak or impending leak area will be sealed off based on the assessment results;

[0081] S7: After the sealing is completed, the sealing effect is verified by microseismic monitoring to determine whether the sealing has returned to stability.

[0082] In summary, this invention utilizes microseismic monitoring technology to provide a method and system for full-cycle safety monitoring of geological structures, such as CO2 storage in permafrost. By deploying microseismic sensors through boreholes along the monitoring area boundary, the system performs steps including borehole disturbance monitoring before carbon injection, monitoring during the carbon injection process, safety monitoring of the storage area after carbon injection, hazard identification, and verification of mitigation effectiveness. This enables full-cycle safety monitoring of CO2 storage engineering structures in permafrost and verification of the effectiveness of leak-stopping and mitigation measures after a leakage accident.

[0083] Second Embodiment

[0084] Please see Figure 3 and Figure 4 This invention provides a method and system for full-cycle safety monitoring of CO2 storage in geological structures, such as permafrost, applicable to the field of CO2 storage safety monitoring in permafrost. The execution flow of this method is as follows: Figure 3 As shown, it includes the following steps:

[0085] Before sealing CO2 in the permafrost layer 1, the monitoring area 2 is determined based on the sealing area 3, and the drilling depth and radius are determined. A total of 13 microseismic sensors 4 are arranged through drilling 5 on the boundary of the monitoring area 2. A microseismic monitoring room 8 is built on the ground, and the microseismic sensors 4 are connected to the microseismic monitoring data analysis system 7 through cables 6.

[0086] Before implementing CO2 sealing in the permafrost layer 1, the microseismic monitoring data analysis system 7 was activated to receive microseismic signals within the monitoring area 2. The location and number of microseismic signals were then determined to assess the impact of borehole 5 disturbance on the monitoring area 2. If the energy generated continuously exceeds 10... 4 The microseismic signal J indicates that the area near the location where the microseismic signal was generated is affected by the disturbance from borehole 5; carbon injection will not be performed at this time. If the microseismic signal energy is greater than 10... 4 If the number of J signals remains at 0 for a continuous period of time, such as 24 hours, it indicates that monitoring area 2 is stabilizing and CO2 sealing in the permafrost layer 1 can begin.

[0087] Microseismic signals monitored during drilling: mainly collected microseismic signals generated by rock mass cracking caused by stress changes in the monitoring area (mainly around the borehole) before and after drilling, in order to determine the impact of borehole disturbance on the monitoring area. Carbon injection operation was carried out after the signal tended to stabilize.

[0088] During the CO2 injection into the permafrost layer 1, the microseismic monitoring data analysis system 7 is activated. The location of the microseismic signals is used to determine the safety of the injection process, and adjustments are made to the carbon injection process based on the results. If the microseismic signal appears at the designed carbon injection hole, it indicates that the injection process is normal and can continue. If the location of the microseismic signal deviates from the designed carbon injection hole but is within the geological structure 3 where CO2 is stored, it indicates that there is a void around the carbon injection location. Continuous monitoring is then conducted. If the microseismic signal remains within the geological structure 3 where CO2 is stored and the energy is less than 10... 4 J indicates that the carbon injection process is normal and no adjustment is needed; if the location of the microseismic signal deviates from the designed carbon injection hole, but the process is normal within the CO2-sealing permafrost structure, no adjustment is required. If the location of the microseismic signal exceeds the range of the CO2-sealing permafrost structure and the energy is greater than 10... 4 J indicates that the carbon injection process caused damage to structure 3, and carbon injection needs to be stopped and repaired.

[0089] After carbon injection into the frozen soil layer 1, the injection holes were sealed, and continuous microseismic monitoring continued. The microseismic signals were used to assess the impact of the CO2 injection process on monitoring area 2 and to evaluate the safety of the sealed area 3. If the generated energy exceeds 10... 4 If the microseismic signal of J indicates a rupture, the location of the signal is the location of the rupture, and the direction of rupture transfer is the direction of crack propagation. If the direction of rupture transfer is concentrated inside the permafrost structure 3 containing CO2 and does not transfer to the edge area of ​​the structure 3, it indicates that there is no risk of CO2 leakage. If the direction of rupture transfer transfers to the edge area of ​​the permafrost structure 3 containing CO2 or exceeds the structure 3, it indicates that CO2 leakage is about to occur or a CO2 leakage accident has occurred, and measures need to be taken to seal it.

[0090] If a dangerous situation occurs, the leak or impending leak will be sealed off based on the assessment results.

[0091] After the sealing is completed, microseismic monitoring is used to verify the sealing effect and determine whether the sealing has returned to stability. If the generated microseismic signal energy is greater than 10... 4 J indicates that the sealing effect is not good, and the sealing process should continue until the microseismic signal energy is below 10. 4 When there is no micro-vibration signal (J), it indicates that the leak has been stabilized and the CO2 sequestration has returned to stability.

[0092] Microseismic signals monitored after carbon injection and borehole sealing: The main focus is on collecting microseismic signals from the bottom of the carbon injection borehole and inside the structure. During the carbon injection process and after borehole sealing, the geological structure rock mass will experience certain vibrations or even cracks due to corresponding internal factors (carbon injection) and external disturbances (earthquakes, excavation, rock mass rheology, etc.). At this time, microseismic signals will be collected. If the detected microseismic signals do not extend to the edge or outside of the sealed structure, it indicates that there is no risk of CO2 leakage. If the signals extend to the edge or outside of the sealed structure, it indicates that CO2 leakage is about to occur or a CO2 leakage accident has already occurred.

[0093] The microseismic signals monitored in this embodiment of the invention originate from the vibration and cracking of the rock mass. This embodiment of the invention does not investigate how the vibration and cracking of the rock mass are caused, because regardless of the cause, when the damage to the rock mass extends beyond the edge of the sealed structure, it will lead to CO2 leakage.

[0094] The CO2 storage state addressed in this invention is not limited to liquid supercritical CO2; it is also applicable to the storage of solid CO2 forms such as CO2 hydrates and complexes. Liquid storage does not require an empty space, while solid CO2 compounds are generally placed within an empty space inside the storage structure, and the method described in this application can still be used for monitoring.

[0095] like Figure 4As shown, this embodiment of the invention also provides a full-cycle safety monitoring system for CO2 storage, including: a geological structure 1, a storage area 3, a monitoring area 2, a microseismic sensor 4, a borehole 5, a cable 6, a surface monitoring room 8, and a microseismic monitoring data analysis system 7;

[0096] The geological structure 1 is used for CO2 sequestration, wherein the geological structure for CO2 sequestration constitutes the sequestration area 3;

[0097] The monitoring area 2 includes the geological structure to be sealed CO2 and a certain range around it;

[0098] The microseismic sensor 4 is arranged on the boundary of the monitoring area 2 through the borehole 5 and is connected to the microseismic monitoring host in the well monitoring room 8 through the cable 6.

[0099] Before implementing CO2 sealing in the geological structure 1, the microseismic monitoring data analysis system 7 is activated. The microseismic monitoring host receives microseismic signals within the monitoring area, and the microseismic monitoring data analysis system 7 determines the impact of borehole disturbance on the monitoring area 2.

[0100] During the process of injecting CO2 into the geological structure 1, the microseismic monitoring data analysis system 7 determines the safety of the injection process by the location of the microseismic signals, and adjusts the carbon injection process according to the judgment results;

[0101] After carbon injection into the geological structure is completed, the carbon injection holes are sealed. The microseismic monitoring system continues to perform continuous microseismic monitoring. The microseismic monitoring data analysis system 7 uses microseismic signals to determine the impact of the CO2 injection process on the monitoring area and assesses the safety of the sealed area.

[0102] Optionally, the microseismic monitoring data analysis system uses microseismic signals to determine the impact of the CO2 injection process on the monitoring area, identifies the safety of the sealed area, and if a dangerous situation occurs, it seals the leak area or the area about to leak based on the identification results. After the sealing is completed, the sealing effect is verified by microseismic monitoring to determine whether the sealed area has returned to stability.

[0103] Optionally, before implementing CO2 sealing in the geological structure, the microseismic monitoring data analysis system is activated, and the microseismic monitoring host receives microseismic signals in the monitoring area, locates the microseismic signals, and counts them.

[0104] If energy is continuously generated greater than 10 4 If the micro-vibration signal of J is generated, the area near the location where the micro-vibration signal is generated is affected by the drilling disturbance, and carbon injection is temporarily suspended at this time.

[0105] If the microseismic signal energy is greater than 104 If the number of microseismic signals J remains at 0 for a continuous period of time, it indicates that the monitored area is stabilizing and CO2 sealing of the geological structure can begin.

[0106] Optionally, during the CO2 injection into the geological structure, the microseismic monitoring data analysis system determines the safety of the injection process based on the location of microseismic signals, and adjusts the carbon injection process according to the determination result, specifically including:

[0107] If the micro-vibration signal appears at the designed carbon injection hole, it indicates that the injection process is normal and injection can continue.

[0108] If the location of the microseismic signal deviates from the designed carbon injection borehole but remains within the geological structure where CO2 is sealed, it indicates the presence of a void around the carbon injection site. Continuous monitoring is necessary. If the microseismic signal remains within the geological structure where CO2 is sealed and its energy is less than 10... 4 J indicates that the carbon injection process is normal and no adjustment is needed;

[0109] If the location of the microseismic signal exceeds the geological structure containing CO2, and the energy is greater than 10... 4 J indicates that structural damage occurred during the carbon injection process, requiring the carbon injection to be stopped and repairs carried out.

[0110] Optionally, after carbon injection into the geological structure is completed, the carbon injection holes are sealed, and the microseismic monitoring system continues continuous microseismic monitoring. The microseismic monitoring data analysis system uses microseismic signals to determine the impact of the CO2 injection process on the monitored area, and the criteria for assessing the safety of the sealed area include:

[0111] If the energy generated is greater than 10 4 The microseismic signal of J indicates that a rupture has occurred, and the location where the microseismic signal appears is the location where the rupture has occurred, and the direction of rupture transfer is the direction of crack propagation;

[0112] If the direction of rupture and transfer is concentrated within the geological structure containing CO2 and does not extend to the edge of the structure, it indicates that there is no risk of CO2 leakage.

[0113] If the direction of the rupture shifts to the edge of the geological structure containing CO2 or beyond the structure, it indicates that a CO2 leak is imminent or a CO2 leak has already occurred, and measures need to be taken to seal it.

[0114] Optionally, the monitoring system verifies the leak-sealing effect through microseismic monitoring to determine whether the sealing has returned to stability, specifically including:

[0115] If the energy of the generated microseismic signal is greater than 10 4J indicates that the sealing effect is not good, and the sealing process should continue until the microseismic signal energy is below 10. 4 When there is no micro-vibration signal (J), it indicates that the leak has been stabilized and the CO2 sequestration has returned to stability.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring the safety of the whole cycle of CO2 sequestration, characterized in that, The method comprises the following steps: S1. Determine a geological structure body to be sealed with CO2 and a certain range around the geological structure body as a monitoring area; S2. Arrange microseismic sensors on the boundary of the monitoring area through drilling; The step of arranging microseismic sensors on the boundary of the monitoring area through drilling specifically comprises the following steps: Drill holes in the upper, front, rear, left and right directions of the monitoring area, and arrange a total of 13 microseismic sensors on the boundary centers and nodes of the upper, front, rear, left and right directions; S3. Start a microseismic monitoring data analysis system before the geological structure body is used to seal CO2, receive microseismic signals in the monitoring area, and judge the influence of drilling disturbance on the monitoring area; The step of starting the microseismic monitoring data analysis system before the geological structure body is used to seal CO2, receiving microseismic signals in the monitoring area, and judging the influence of drilling disturbance on the monitoring area specifically comprises the following steps: Start the microseismic monitoring data analysis system before the geological structure body is used to seal CO2, receive microseismic signals in the monitoring area, and position and count the number of microseismic signals; If the microseismic signal of J continuously generates energy greater than 10 4 If the microseismic signal of J continuously generates energy greater than 10 If the microseismic signal of J continuously generates energy greater than 10 If the microseismic signal energy is greater than 10 4 If the number of microseismic signals of J remains 0 for a continuous period of time, it indicates that the monitoring area tends to be stable, and the geological structure begins to store CO2. S4. In the process of injecting CO2 into the geological structure body, judge the safety of the injection process through the position of the microseismic signal, and adjust the carbon injection process according to the judgment result; The step of judging the safety of the injection process through the position of the microseismic signal in the process of injecting CO2 into the geological structure body, and adjusting the carbon injection process according to the judgment result specifically comprises the following steps: If the position of the microseismic signal appears at the designed carbon injection hole, it indicates that the injection process is normal and the injection can continue; If the position of the microseismic signal deviates from the designed carbon injection hole, but is within the range of the geological structure for storing CO2, it indicates that there is a void around the carbon injection position, and continuous monitoring is performed. If the microseismic signal is always within the range of the geological structure for storing CO2, and the energy is less than 10 4 J, it indicates that the carbon injection process is normal, and no adjustment is needed. If the position of the microseismic signal exceeds the range of the geological structure body storing CO2 and the energy is greater than 10 4 J, it indicates that the structure body is damaged during the carbon injection process, and the carbon injection needs to be stopped and the maintenance needs to be carried out. S5. After the carbon injection of the geological structure body is completed, seal the carbon injection hole, and continue the microseismic continuous monitoring, judge the influence of the CO2 injection process on the monitoring area through the microseismic signal, and identify the safety of the sealing area; The criteria for identifying the safety of the sealing area in the step S5 comprise: If the generated energy is greater than 10 4 If the microseismic signal of J is generated, it indicates that a crack is generated, and the position where the microseismic signal appears is the position where the crack appears, and the direction where the crack transfers is the direction where the crack expands. If the directions of the fracture transfer are all concentrated in the geological structure body for sealing CO2, and are not transferred to the edge area of the structure body, it indicates that there is no risk of CO2 leakage; If the directions of the fracture transfer are transferred to the edge area of the geological structure body for sealing CO2 or beyond the structure body, it indicates that CO2 leakage or CO2 leakage accident will occur, and measures need to be taken to seal off; In the step S5 of identifying the safety of the sealing area, if a dangerous situation occurs, sealing is performed in the leakage area or the area about to leak according to the identification result, after the sealing is completed, the sealing stability is judged through the leakage effect test of the microseismic monitoring; The step of judging whether the sealing is restored to be stable through the leakage effect test of the microseismic monitoring specifically comprises the following steps: If the microseismic signal energy is greater than 10 4 J, it indicates that the plugging effect is poor, and the plugging continues until the microseismic signal energy is less than 10 4 J or there is no microseismic signal, indicating that the plugging is stable, and the CO2 storage is restored to stability.

2. A CO2 sequestration full-cycle safety monitoring system, characterized by, The method according to claim 1 comprises a geological structure body, a sealing area, a monitoring area, a microseismic sensor, a drill hole, a cable, a wellhead monitoring room and a microseismic monitoring data analysis system; The geological structure body is used to seal CO2, wherein the geological structure body for sealing CO2 constitutes the sealing area; The monitoring area comprises a geological structure body to be sealed with CO2 and a certain range around the geological structure body. The microseismic sensor is arranged on the boundary of the monitoring area through the borehole and is connected with the microseismic monitoring host in the wellhead monitoring room through the cable; Before the geological structure body is used to store CO2, the microseismic monitoring data analysis system is started, the microseismic monitoring host receives the microseismic signals in the monitoring area, and the microseismic monitoring data analysis system judges the influence of the borehole disturbance on the monitoring area; During the process of injecting CO2 into the geological structure body, the microseismic monitoring data analysis system judges the safety of the injection process through the position of the microseismic signals, and adjusts the carbon injection process according to the judgment result; After the carbon injection into the geological structure body is completed, the injection hole is sealed, the microseismic monitoring data analysis system continues to perform the microseismic continuous monitoring, the microseismic monitoring data analysis system judges the influence of the CO2 injection process on the monitoring area through the microseismic signals, and judges the safety of the storage area.

3. The system of claim 2, wherein, The microseismic monitoring data analysis system judges the influence of the CO2 injection process on the monitoring area through the microseismic signals, judges the safety of the storage area, if a dangerous situation occurs, the sealing is performed in the leakage area or the area about to leak according to the judgment result, after the sealing is completed, the plugging effect is tested through the microseismic monitoring, and whether the storage is restored to be stable is judged.

4. The system of claim 3, wherein, Before the geological structure body is used to store CO2, the microseismic monitoring data analysis system is started, the microseismic monitoring host receives the microseismic signals in the monitoring area, and the microseismic signals are positioned and counted. If the microseismic signal of J continues to generate energy greater than 10 4 If the microseismic signal of J continues to generate energy greater than 10 If the microseismic signal of J continues to generate energy greater than 10 If the microseismic signal energy is greater than 10 4 If the number of microseismic signals of J remains 0 for a continuous period of time, it indicates that the monitoring area tends to be stable, and the geological structure begins to store CO2.

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