Aviation or semi-aviation geophysical exploration CO2 monitoring system and method based on unmanned aerial vehicle

Abstract

The invention discloses an aerial or semi-aerial geophysical exploration CO2 monitoring system and method based on an unmanned aerial vehicle. A carbon dioxide gas sensor, an aerial three-component electromagnetic field sensor and an aerial horizontal controllable electromagnetic field transmitting coil are mounted at the lowest part of the unmanned aerial vehicle; the optical fiber CO2 modulation and demodulation instrument, the controllable electromagnetic source transmitter and the three-component electromagnetic field data acquisition instrument are carried in the unmanned aerial vehicle, and the electromagnetic field transmitting coil or the rectangular current source transmitting antenna and the controllable current transmitting source are laid around a CO2 injection well on the ground. The method comprises the following steps of: performing long-term safety monitoring on the migration of underground supercritical CO2 by using the CO2 concentration in equal-elevation air acquired at different stages and the processing result of real-time or time-shifting aviation or semi-aviation three-dimensional controllable source electromagnetic data; the geological disaster that the supercritical CO2 is leaked to the ground along the well wall of the injection well or the monitoring well or a shallow surface fault or a crack activated by the high-pressure supercritical CO2 injected underground is prevented.

Description

Technical Field

[0001] The present invention relates to the field of underground geochemistry and electromagnetic exploration technology, and more specifically, to an aerial or semi-aerial geochemical CO2 monitoring system and a monitoring method based on an unmanned aerial vehicle. Background Art

[0002] CCS, or Carbon Dioxide Capture and Storage, is a technology used to mitigate climate change and reduce carbon dioxide emissions. Its prototype is the technology of using carbon dioxide to drive oil to improve oil recovery that emerged in the United States in the 1970s; the three key elements of CCS are the capture, transportation and geological storage of carbon dioxide. CCUS, or Carbon Dioxide Capture, Utilization and Storage, is a concept proposed by my country based on its own conditions, which adds the link of carbon dioxide utilization on the basis of CCS. Definition of CCS and CCUS Carbon Capture and Storage (CCS) technology refers to the process of separating carbon dioxide from industrial or related emission sources, transporting it to a storage site, and isolating it from the atmosphere for a long time; this technology is considered to be the most economical and feasible way to reduce greenhouse gas emissions and slow global warming on a large scale in the future. CCUS stands for Carbon Capture, Utilization and Storage, which refers to carbon capture, storage and reuse technology; Carbon dioxide (CO2) capture, utilization and storage (CCUS) refers to the process of separating CO2 from industrial processes, energy utilization or the atmosphere, and directly utilizing or injecting it into the formation to achieve permanent CO2 emission reduction. As one of the key technologies for addressing global climate change, CCUS aims to capture CO2 from the source, purify it and then recycle it, or store it underground, thereby balancing the negative impact of CO2 on the climate.

[0003] Carbon Capture, Utilization and Storage (CCUS) technology is a new development trend of CCS technology, which is to capture and purify the carbon dioxide emitted in the production process, and then put it into the new production process for recycling or storage; this technology has the synergy of achieving large-scale greenhouse gas emission reduction and low-carbon utilization of fossil energy, and is one of the important technical options for coping with global warming in the future. CCS technology mainly consists of four links: capture, transportation, geological storage and monitoring, and use for increased oil recovery (EOR / EGR). The fourth link is an optional link with potential benefits.

[0004] Through the implementation of a large number of CCS and CCUS projects, millions or tens of millions of tons or even hundreds of millions of tons of high-pressure supercritical carbon dioxide have been injected underground; because the ratio of carbon dioxide is greater than that of oxygen, if the carbon dioxide injected underground leaks to the ground through the wall of the injection well or monitoring well or the shallow fault or fracture zone activated by the underground high-pressure carbon dioxide, it will cause huge geological disasters and cause immeasurable losses to life and property in the carbon dioxide leakage area. Therefore, we need to deploy real-time and long-term effective monitoring systems on the ground and underground of CCS and CCUS projects to monitor the leakage of underground carbon dioxide to the ground in real time. Once carbon dioxide leaks on the surface, early warning information will be issued in time, and the emergency response mechanism will be activated. Necessary engineering and technical means will be taken to block the carbon dioxide leakage channel, evacuate the people in and near the leakage area, and try to avoid the occurrence of major geological disasters.

[0005] At present, there are carbon dioxide gas monitoring sensors installed on the ground and wellheads of CCS and CCUS work areas for real-time monitoring and early warning, but this method is only passive monitoring. When there is no carbon dioxide leakage on the ground or underground, it is impossible to know or monitor the migration status of underground high-pressure carbon dioxide in advance. In addition, the ground three-dimensional time-lapse seismic (four-dimensional seismic) or time-lapse three-dimensional vertical seismic profile (4D-VSP) exploration technology is used to monitor the migration of deep underground carbon dioxide; because the density of supercritical carbon dioxide reaches 0.7, which is not much different from the density of pore water in deep underground formations, the elastic parameters in the deep underground reservoir change little after the supercritical carbon dioxide in the underground reservoir displaces the pore water, and the data collected by the ground three-dimensional time-lapse seismic (four-dimensional seismic) or time-lapse three-dimensional vertical seismic profile (4D-VSP) also change little; considering the acquisition error of time-lapse seismic data on the ground or in the well, the error in the data processing process, the reliability of the time-lapse seismic data processing results is greatly reduced, so it is difficult for the ground or underground time-lapse seismic data to accurately monitor the migration and occurrence status of the carbon dioxide front in the deep underground reservoir. Summary of the invention

[0006] The purpose of the present invention is to provide a CO2 monitoring system and a monitoring method for aerial or semi-aerial comprehensive geophysical exploration based on unmanned aerial vehicles, using the real-time or time-lapse aerial CO2 concentrations at equal altitudes collected at different stages and the processing results of aerial or semi-aerial controlled source three-component electromagnetic field data to evaluate in real time the efficiency of high-pressure supercritical CO2 injection into underground reservoirs, and to conduct real-time and long-term safety monitoring of the migration of underground high-pressure supercritical CO2, so as to prevent supercritical carbon dioxide from leaking to the ground along the well wall of the injection well or monitoring well or through shallow surface faults or cracks activated by the high-pressure supercritical CO2 injected into the ground.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] In the first aspect, the present application provides a CO2 monitoring system for aerial or semi-aerial integrated geophysical exploration based on drones, including a drone, a carbon dioxide gas sensor mounted at the bottom of the drone, an aerial three-component electromagnetic field sensor mounted above the carbon dioxide gas sensor, an aerial horizontal controllable electromagnetic field transmitting coil mounted above the aerial three-component electromagnetic field sensor, an optical fiber CO2 modem instrument, a controllable electromagnetic source transmitter and a three-component electromagnetic field data acquisition instrument are carried inside the drone, and also includes a large-diameter high-power electromagnetic field transmitting coil or a long-length high-power rectangular current source transmitting antenna laid around a high-pressure supercritical CO2 injection well on the ground, and a ground high-power controllable current transmitting source;

[0009] The carbon dioxide gas sensor may be a chemical CO2 sensor or an optical fiber CO2 sensor;

[0010] The aerial three-component electromagnetic field sensor is a three-component magnetic field and three-component electric field sensor composed of three mutually orthogonal magnetic field sensors and a six-sided cubic electrode plate;

[0011] The three mutually orthogonal magnetic field sensors may be fluxgate magnetic field sensors, induction coil induction magnetic field sensors, or optical fiber magnetic field sensors;

[0012] The three-component electric field sensor is composed of six-sided cubic electrode plates, and each pair of parallel corresponding electrode plates of the six-sided cubic electrode plates is a capacitive electric field sensor in this direction;

[0013] The aerial horizontal controllable electromagnetic field transmitting coils are three mutually orthogonal electromagnetic field transmitting coils mounted directly below the UAV, with a diameter between 1 meter and 5 meters.

[0014] The diameter of the large-diameter high-power electromagnetic field transmitting coil laid around the ground CO2 injection well is between 1 km and 5 km, and the transmitting coil is connected to the ground high-power controllable current transmitting source;

[0015] The long, high-power rectangular current source transmitting antenna laid around the ground CO2 injection well has a side length between 1 km and 5 km, a ground high-power controllable current transmitting source is connected in the middle of each side, and grounded copper power supply electrode rods are provided at both ends of each side;

[0016] The drone is equipped with an operation control computer system, and before the construction work, the drone's flight line track coordinates, track elevation, track spacing, flight speed and other control information are input;

[0017] The drone is internally installed with a data acquisition control computer system, which is respectively connected to an optical fiber CO2 modem, a controllable electromagnetic source transmitter, and a three-component electromagnetic field data acquisition instrument;

[0018] The carbon dioxide gas sensor mounted at the bottom of the drone is connected to the airborne optical fiber CO2 modulation and demodulation instrument through an optoelectronic composite cable;

[0019] The aerial three-component electromagnetic field sensor mounted below the UAV is connected to the onboard data acquisition control computer system via a cable;

[0020] The aerial horizontal controllable electromagnetic field transmitting coil mounted below the UAV is connected to the onboard controllable electromagnetic source transmitter via a cable;

[0021] The monitoring method of the aerial or semi-aerial geophysical and chemical CO2 monitoring system based on UAV includes the following specific steps:

[0022] (1) Before injecting high-pressure supercritical CO2 into the ground, an aerial or semi-aerial geophysical and geochemical exploration baseline data measurement based on drones is carried out in the monitoring construction area around the high-pressure supercritical CO2 injection well on the ground to establish a baseline model of surface CO2 concentration distribution data (baseline model) and a baseline model of resistivity distribution in underground rock formations in three-dimensional space (baseline model);

[0023] (2) Before construction work, the UAV system’s flight control functions must be self-checked;

[0024] (3) Then, self-check all onboard data acquisition control computer systems, fiber optic CO2 modem instruments, controllable electromagnetic source transmitters, and three-component electromagnetic field data acquisition instruments;

[0025] (4) Then, the carbon dioxide gas sensor, the three-component electromagnetic field sensor in the air, and the horizontal controllable electromagnetic field transmitting coil in the air mounted on the drone are self-checked;

[0026] (5) Input the UAV with the flight line track coordinates, track elevation, track spacing, flight speed and other control information required for monitoring the construction work area;

[0027] (6) When the UAV flies to the pre-set survey line position of the monitoring construction work area, start the onboard data acquisition control computer system, optical fiber CO2 modem instrument, controllable electromagnetic source transmitter, three-component electromagnetic field data acquisition instrument, carbon dioxide gas sensor, aerial three-component electromagnetic field sensor and aerial horizontal controllable electromagnetic field transmitting coil;

[0028] (7) Various sensors mounted below the drone collect high-pressure supercritical CO2 concentration data along the survey line in the monitoring construction area around the ground high-pressure supercritical CO2 injection well according to the pre-designed flight survey line track coordinates, track elevation, track spacing, flight speed and other parameters, and simultaneously collect aerial three-component electromagnetic field data excited by the aerial horizontal controllable electromagnetic field transmitting coil;

[0029] (8) After the collection of aviation high-pressure supercritical CO2 concentration data and aviation three-component electromagnetic field data in the construction work area is completed, the airborne controllable electromagnetic source transmitter is turned off, and the ground high-power controllable current transmitting source is started to transmit alternating current to the ground large-diameter high-power electromagnetic field transmitting coil or long-length high-power rectangular current source transmitting antenna;

[0030] (9) The various sensors mounted below the drone again collect high-pressure supercritical CO2 concentration data in the monitoring construction area around the ground high-pressure supercritical CO2 injection well along the survey line in accordance with the pre-designed flight survey line track coordinates, track elevation, track spacing, flight speed and other parameters, and simultaneously collect semi-aerial three-component electromagnetic field data excited underground by the ground large-diameter high-power electromagnetic field transmitting coil or the long-length high-power rectangular current source transmitting antenna;

[0031] (10) performing data preprocessing such as elevation correction and velocity correction of the CO2 sensor on the CO2 concentration data in the air collected twice in the monitoring construction work area around the ground high-pressure supercritical CO2 injection well, and then performing linear or nonlinear two-dimensional interpolation processing, and finally generating a distribution map of CO2 concentration in the air at the same elevation from the ground within the monitoring construction work area around the ground high-pressure supercritical CO2 injection well;

[0032] (11) performing data preprocessing such as elevation correction, velocity correction and denoising of the aerial three-component electromagnetic field sensor on the aerial three-component electromagnetic field data collected in step (7), and then performing inversion processing on the three-dimensional aerial three-component electromagnetic field data to obtain the distribution of resistivity anomalies in the shallow strata below the ground surface in three-dimensional space;

[0033] (12) performing data preprocessing such as elevation correction, velocity correction and denoising of the airborne three-component electromagnetic field sensor on the semi-aerial three-component electromagnetic field data collected in step (9), and then performing inversion processing on the semi-aerial three-dimensional three-component electromagnetic field data to obtain the distribution of resistivity in the deeper strata below the ground surface in three-dimensional space;

[0034] (13) performing data fusion processing on the resistivity data of the shallow and deeper underground strata obtained in step (11) and step (12) to establish an accurate distribution of the resistivity of the shallow and deeper underground strata in three-dimensional space;

[0035] (14) after injecting high-pressure supercritical CO2 into the ground, periodically repeating the operations and data processing of steps (2) to (13) to obtain a distribution map of CO2 concentration in the air at an altitude equal to the ground within the monitoring construction work area after injecting high-pressure supercritical CO2 into the ground and a distribution of resistivity in a deeper stratum below the ground in three-dimensional space;

[0036] (15) performing differential processing on the CO2 concentration distribution data in the air at an altitude equal to the ground obtained in step (14) after each injection of high-pressure supercritical CO2 into the ground and the CO2 concentration distribution data in the air at an altitude equal to the ground measured in step (10) when the high-pressure supercritical CO2 is not injected into the ground;

[0037] (16) performing differential processing on the resistivity distribution data in the three-dimensional space of the shallow and deeper strata below the ground surface obtained in step (13) after each injection of high-pressure supercritical CO2 into the ground and the resistivity distribution data in the three-dimensional space of the shallow and deeper strata measured when the high-pressure supercritical CO2 is not injected into the ground;

[0038] (17) Analyze and study the high-pressure supercritical CO2 concentration differential data obtained in step (15). When the differential data of the CO2 concentration distribution in the air at the ground level or other elevations are abnormal, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground.

[0039] (18) Analyzing and studying the resistivity differential data of the shallow and deeper underground strata obtained in step (16); when an abnormal body of the resistivity differential data distribution of the shallow and deeper underground strata appears, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground;

[0040] (19) When the projections of the abnormal differential data areas appearing in step (17) and step (18) on the ground surface basically overlap, it can be basically determined that the high-pressure supercritical CO2 injected into the well may have migrated and leaked to the ground. It is necessary to immediately send a warning message to the high-pressure supercritical CO2 injection party that the high-pressure supercritical CO2 may have migrated and leaked to the ground, and the party must pay attention to it immediately and adopt corresponding technical responses and safety precautions.

[0041] Compared with the prior art, the present invention has at least the following beneficial effects:

[0042] In the present invention, a drone is used to carry out rapid aerial or semi-aerial geophysical and geochemical surveying and controlled source electromagnetic surveying in a monitoring area around a well for injecting high-pressure supercritical CO2 into the ground, to measure or monitor in real time the distribution of air CO2 concentration at equal elevations on the ground before and after the high-pressure supercritical CO2 is injected into the underground well and the change of resistivity distribution in the reservoir over time, to monitor and judge the migration and occurrence state of the supercritical CO2 front injected into the underground reservoir in the underground reservoir; wherein, the processing results of real-time or aerial or semi-aerial time-shifted controlled source electromagnetic data collected at different stages are used to evaluate in real time the efficiency of injecting ultra-high-pressure critical CO2 into the underground reservoir, and to carry out long-term safety monitoring of the migration of underground high-pressure supercritical CO2, so as to prevent the high-pressure supercritical CO2 from leaking to the ground along the well wall of the injection well or the monitoring well or the shallow surface faults or cracks activated by the high-pressure supercritical carbon dioxide injected into the ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0044] Figure 1 It is a structural schematic diagram of an aerial or semi-aerial geochemical CO2 monitoring system based on a drone in an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the construction site deployment of an aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on a drone in an embodiment of the present invention.

[0046] Marks and corresponding parts names in the attached drawings:

[0047] 1. Unmanned aerial vehicle; 2. Carbon dioxide gas sensor; 3. Three-component electromagnetic field sensor in the air; 4. Horizontal controllable electromagnetic field transmitting coil in the air; 5. Optical fiber CO2 modulation and demodulation instrument; 6. Controllable electromagnetic source transmitter; 7. Three-component electromagnetic field data acquisition instrument; 8. Large diameter and high power electromagnetic field transmitting coil; 9. Long length and high power rectangular current source transmitting antenna; 10. Ground high power controllable current transmitting source; 11. Copper power supply electrode rod; 12. High current power supply wire; 13. Data acquisition control computer system; 31. Magnetic field sensor; 32. Six-sided cubic electrode plate. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0051] In the description of the embodiments of the present invention, it should be noted that if the terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0052] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0053] In the description of the embodiments of the present invention, "plurality" means at least 2.

[0054] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] Embodiment 1:

[0056] like Figure 1 and Figure 2As shown, this embodiment provides an aerial or semi-aerial geophysical CO2 monitoring system based on a drone, including a drone 1, a carbon dioxide gas sensor 2 mounted at the bottom of the drone 1, an aerial three-component electromagnetic field sensor 3 mounted above the carbon dioxide gas sensor 2, an aerial horizontal controllable electromagnetic field transmitting coil 4 mounted above the aerial three-component electromagnetic field sensor 3, an optical fiber CO2 modem instrument 5, a controllable electromagnetic source transmitter 6 and a three-component electromagnetic field data acquisition instrument 7 carried inside the drone, and also includes a large-diameter high-power electromagnetic field transmitting coil 8 or a long-length high-power rectangular current source transmitting antenna 9 laid around the ground high-pressure supercritical CO2 injection well, and a ground high-power controllable current transmitting source 10 ( Figure 2 );

[0057] The carbon dioxide gas sensor 2 may be a chemical CO2 sensor or an optical fiber CO2 sensor;

[0058] The three-component electromagnetic field sensor 3 is a three-component magnetic field and three-component electric field sensor composed of three mutually orthogonal magnetic field sensors 31 and a six-sided cubic electrode plate 32 ( Figure 1 );

[0059] The three mutually orthogonal magnetic field sensors 31 may be fluxgate magnetic field sensors, induction coil induction magnetic field sensors, or optical fiber magnetic field sensors;

[0060] The three-component electric field sensor is composed of six-sided cubic electrode plates 32, and each pair of parallel corresponding electrode plates of the six-sided cubic electrode plates 32 is a capacitive electric field sensor in this direction ( Figure 1 );

[0061] The aerial horizontal controllable electromagnetic field transmitting coils 4 are three mutually orthogonal electromagnetic field transmitting coils mounted directly below the UAV, with a diameter between 1 meter and 5 meters.

[0062] like Figure 2 As shown, the diameter of the large-diameter high-power electromagnetic field transmitting coil 8 laid around the ground CO2 injection well is between 1 km and 5 km, and the transmitting coil 8 is connected to the ground high-power controllable current transmitting source 10;

[0063] The long and high-power rectangular current source transmitting antenna 9 laid around the ground CO2 injection well has a side length between 1 km and 5 km, a ground high-power controllable current transmitting source 10 is connected in the middle of each side, and a grounded copper power supply electrode rod 11 is provided at both ends of each side;

[0064] The drone 1 is internally installed with a data acquisition control computer system 13, and before construction work, the drone 1 is input with control information such as flight line track coordinates, track elevation, track spacing, flight speed, etc.;

[0065] The drone 1 is internally installed with a data acquisition control computer system 13, which is respectively connected to the optical fiber CO2 modem instrument 5, the controllable electromagnetic source transmitter 6 and the three-component electromagnetic field data acquisition instrument 7;

[0066] The carbon dioxide gas sensor 2 mounted at the bottom of the drone 1 is connected to the onboard optical fiber CO2 modem instrument 5 via an optoelectronic composite cable;

[0067] The aerial three-component electromagnetic field sensor 3 mounted below the UAV 1 is connected to the onboard data acquisition control computer system 13 via a cable;

[0068] The aerial horizontal controllable electromagnetic field transmitting coil 4 mounted below the UAV 1 is connected to the onboard controllable electromagnetic source transmitter 6 via a cable;

[0069] The monitoring method of the aerial or semi-aerial geophysical and chemical CO2 monitoring system based on UAV includes the following specific steps:

[0070] (a) Before injecting high-pressure supercritical CO2 underground, an aerial or semi-aerial geophysical and geochemical exploration baseline data measurement based on drones is carried out in the monitoring construction area around the high-pressure supercritical CO2 injection well on the ground to establish a baseline model of surface CO2 concentration distribution data (baseline model) and a baseline model of resistivity distribution in underground rock formations in three-dimensional space (baseline model);

[0071] (b) Before the construction work, the flight control functions of the UAV 1 system shall be self-checked;

[0072] (c) then self-checking all onboard data acquisition control computer systems 13, optical fiber CO2 modem instruments 5, controllable electromagnetic source transmitters 6, and three-component electromagnetic field data acquisition instruments 7;

[0073] (d) then performing a self-check on the carbon dioxide gas sensor 2, the aerial three-component electromagnetic field sensor 3, and the aerial horizontal controllable electromagnetic field transmitting coil 4 mounted on the drone 1;

[0074] (e) inputting control information such as flight line track coordinates, track elevation, track spacing, flight speed, etc. required for monitoring the construction work area into the UAV 1;

[0075] (f) When the UAV 1 flies to the pre-set survey line position of the monitoring construction work area, the airborne data acquisition control computer system 13, the optical fiber CO2 modem instrument 5, the controllable electromagnetic source transmitter 6, the three-component electromagnetic field data acquisition instrument 7, the carbon dioxide gas sensor 2, the aerial three-component electromagnetic field sensor 3 and the aerial horizontal controllable electromagnetic field transmitting coil 4 are started;

[0076] (g) Various sensors mounted below the drone 1 collect high-pressure supercritical CO2 concentration data in the monitoring construction area around the ground high-pressure supercritical CO2 injection well along the survey line in accordance with pre-designed flight survey line track coordinates, track elevation, track spacing, flight speed and other parameters, and simultaneously collect aerial three-component electromagnetic field data excited by the aerial horizontal controllable electromagnetic field transmitting coil 4;

[0077] (h) After the collection of aviation high-pressure supercritical CO2 concentration data and aviation three-component electromagnetic field data in the construction work area is completed, the airborne controllable electromagnetic source transmitter 6 is turned off, and the ground high-power controllable current transmitting source 10 is started to transmit alternating current to the ground large-diameter high-power electromagnetic field transmitting coil 8 or the long-length high-power rectangular current source transmitting antenna 9;

[0078] (i) The various sensors mounted below the drone 1 again collect high-pressure supercritical CO2 concentration data in the monitoring construction area around the ground high-pressure supercritical CO2 injection well along the survey line in accordance with the pre-designed flight survey line track coordinates, track elevation, track spacing, flight speed and other parameters, and simultaneously collect semi-aerial three-component electromagnetic field data excited underground by the ground large-diameter high-power electromagnetic field transmitting coil 8 or the long-length high-power rectangular current source transmitting antenna 9;

[0079] (j) performing data preprocessing such as elevation correction and velocity correction of the CO2 sensor on the CO2 concentration data in the air collected twice in the monitoring construction work area around the ground high-pressure supercritical CO2 injection well, and then performing linear or nonlinear two-dimensional interpolation processing, and finally generating a distribution map of CO2 concentration in the air at the same elevation from the ground within the monitoring construction work area around the ground high-pressure supercritical CO2 injection well;

[0080] (k) performing data preprocessing such as elevation correction, velocity correction and noise removal by the aerial three-component electromagnetic field sensor 3 on the aerial three-component electromagnetic field data collected in step (g), and then performing inversion processing on the three-dimensional aerial three-component electromagnetic field data to obtain the distribution of resistivity anomalies in the shallow strata below the ground surface in three-dimensional space;

[0081] (l) performing data preprocessing such as elevation correction, velocity correction and noise removal by the aerial three-component electromagnetic field sensor 3 on the semi-aerial three-component electromagnetic field data collected in step (i), and then performing inversion processing on the semi-aerial three-dimensional three-component electromagnetic field data to obtain the distribution of resistivity in the deeper strata below the ground surface in three-dimensional space;

[0082] (m) performing data fusion processing on the resistivity data of the shallow and deeper underground strata obtained in step (k) and step (l) to establish an accurate distribution of the resistivity of the shallow and deeper underground strata in three-dimensional space;

[0083] (n) after injecting high-pressure supercritical CO2 into the ground, periodically repeating the operations and data processing of steps (b) to (m) to obtain a distribution map of CO2 concentration in the air at an equal height from the ground within the monitoring construction work area after injecting high-pressure supercritical CO2 into the ground and a distribution of resistivity in deeper strata below the ground in three-dimensional space;

[0084] (o) performing differential processing on the CO2 concentration distribution data in the air at an altitude equal to the ground obtained in step (n) after each injection of high-pressure supercritical CO2 into the ground and the CO2 concentration distribution data in the air at an altitude equal to the ground measured in step (j) when the high-pressure supercritical CO2 is not injected into the ground;

[0085] (p) performing differential processing on the resistivity distribution data in the three-dimensional space of the shallow and deeper strata below the ground surface obtained in step (m) after each injection of high-pressure supercritical CO2 into the ground and the resistivity distribution data in the three-dimensional space of the shallow and deeper strata measured when the high-pressure supercritical CO2 is not injected into the ground;

[0086] (q) analyzing and studying the high-pressure supercritical CO2 concentration difference data obtained in step (o) and step (p); when the differential data of the CO2 concentration distribution in the air at the ground level or the like is abnormal, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground;

[0087] (r) analyzing and studying the resistivity differential data of the shallow and deeper underground strata obtained in step (o) and step (p); when an abnormal body of the resistivity differential data distribution of the shallow and deeper underground strata appears, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground;

[0088] (s) When the projections of the differential data anomaly areas appearing in step (q) and step (r) on the ground surface are basically overlapped, the saturation occurrence state and front migration change state of the high-pressure supercritical CO2 injected into the well in the three-dimensional space of the underground reservoir can be judged respectively, and the saturation occurrence judgment results and front migration judgment results can be obtained respectively, so as to realize the real-time monitoring of the high-pressure supercritical CO2 injected into the underground reservoir and prevent the occurrence of geological disasters caused by the underground CO2 leaking to the ground. At this time, it can be basically judged that the high-pressure supercritical CO2 has migrated and leaked to the ground, and it is necessary to immediately send an early warning information to the high-pressure supercritical CO2 injection party that the high-pressure supercritical CO2 may have migrated and leaked to the ground, urging the construction party to conduct on-site investigations and test and monitor the ground CO2 concentration in a timely manner, and adopt corresponding technical correspondence and safety precautions to prevent the occurrence of geological disasters caused by the leakage of CO2 to the ground.

[0089] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on drones, characterized by: The invention comprises an unmanned aerial vehicle (1), a carbon dioxide gas sensor (2) mounted at the bottom of the unmanned aerial vehicle (1), an aerial three-component electromagnetic field sensor (3) mounted above the carbon dioxide gas sensor (2), an aerial horizontal controllable electromagnetic field transmitting coil (4) mounted above the aerial three-component electromagnetic field sensor (3), an optical fiber CO2 modulation and demodulation instrument (5), a controllable electromagnetic source transmitter (6) and a three-component electromagnetic field data acquisition instrument (7) carried inside the unmanned aerial vehicle (1), and also comprises a large-diameter high-power electromagnetic field transmitting coil (8) or a long-length high-power rectangular current source transmitting antenna (9) laid around a ground high-pressure supercritical CO2 injection well, and a ground high-power controllable current transmitting source (10); The carbon dioxide gas sensor (2) is an optical fiber CO2 sensor or a chemical CO2 sensor; The aerial three-component electromagnetic field sensor (3) is a three-component magnetic field sensor composed of three mutually orthogonal magnetic field sensors (31) and a three-component electric field sensor composed of a six-sided cubic electrode plate (32); The three mutually orthogonal magnetic field sensors (31) are fluxgate magnetic field sensors, or induction coil induction magnetic field sensors, or optical pump magnetic field sensors, or superconducting magnetic field sensors, or optical fiber magnetic field sensors; The three-component electric field sensor is composed of six-sided cubic electrode plates (32), and each pair of parallel corresponding electrode plates of the six-sided cubic electrode plates (32) is a capacitive electric field sensor in this direction; The aerial horizontal controllable electromagnetic field transmitting coil (4) is a horizontal controllable electromagnetic field transmitting coil mounted directly below the drone, and has a diameter between 1 meter and 5 meters.

2. UAV-based aerial or semi-aerial geophysical and geochemical CO2 monitoring system, characterized by: The large-diameter high-power electromagnetic field transmitting coil (8) laid on the ground has a diameter between 1 km and 5 km, and the large-diameter high-power electromagnetic field transmitting coil (8) is connected to a ground high-power controllable current transmitting source (10).

3. UAV-based aerial or semi-aerial geophysical and geochemical CO2 monitoring system, characterized by: The long current power supply wire (12) on each side of the long-length high-power rectangular current source transmitting antenna (9) laid on the ground is between 1 km and 5 km long, a ground high-power controllable current transmitting source (10) is connected in the middle of each side of the long current power supply wire (12), and grounded copper power supply electrode rods (11) are provided at both ends of each side of the long current power supply wire (12).

4. The unmanned aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on claim 1 is characterized in that: The drone (1) is internally installed with a data acquisition control computer system (13), and before construction work, the flight line track coordinates, track elevation, track spacing, and flight speed control information of the drone (1) are input.

5. The unmanned aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on a drone according to claim 4, characterized in that: The drone (1) is internally installed with a data acquisition control computer system (13), which is respectively connected to an optical fiber CO2 modulation and demodulation instrument (5), a controllable electromagnetic source transmitter (6), and a three-component electromagnetic field data acquisition instrument (7).

6. The unmanned aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on claim 1, characterized in that: The optical fiber or chemical carbon dioxide gas sensor (2) mounted at the bottom of the drone (1) is connected to the onboard optical fiber CO2 modulation and demodulation instrument (5) via a photoelectric composite cable.

7. The unmanned aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on claim 1, characterized in that: An aerial three-component electromagnetic field sensor (3) mounted below the unmanned aerial vehicle (1) is connected to a data acquisition control computer system (13) via an optoelectronic composite cable.

8. The unmanned aerial or semi-aerial geophysical and geochemical CO2 monitoring system based on claim 1, characterized in that: The aerial horizontal controllable electromagnetic field transmitting coil (4) mounted below the unmanned aerial vehicle (1) is connected to a controllable electromagnetic source transmitter (6) via an optoelectronic composite cable.

9. A method for monitoring CO2 by aerial or semi-aerial geophysical exploration based on drones, applied to the aerial or semi-aerial geophysical exploration CO2 monitoring system based on drones as claimed in any one of claims 1 to 8, characterized in that: The specific steps include: (a) Before injecting high-pressure supercritical CO2 into the ground, an aerial or semi-aerial geophysical and geochemical exploration baseline data measurement based on drones is carried out in the monitoring construction area around the high-pressure supercritical CO2 injection well on the ground to establish a baseline model of surface CO2 concentration distribution data and a baseline model of the resistivity distribution in underground rock formations in three-dimensional space; (b) Before construction work, the UAV (1) system itself should be self-checked for various flight control functions; (c) then self-checking all onboard data acquisition control computer systems (13), optical fiber CO2 modem instruments (5), controllable electromagnetic source transmitters (6), and three-component electromagnetic field data acquisition instruments (7); (d) then performing a self-inspection on the carbon dioxide gas sensor (2), the aerial three-component electromagnetic field sensor (3), and the aerial horizontal controllable electromagnetic field transmitting coil (4) mounted below the drone (1); (e) inputting the flight line track coordinates, track elevation, track spacing, and flight speed control information required for monitoring the construction work area into the UAV (1); (f) When the UAV (1) flies to a pre-set survey line position in the monitoring construction work area, the airborne data acquisition control computer system (13), the optical fiber CO2 modulation and demodulation instrument (5), the controllable electromagnetic source transmitter (6), the three-component electromagnetic field data acquisition instrument (7), the carbon dioxide gas sensor (2), the airborne three-component electromagnetic field sensor (3) and the airborne horizontal controllable electromagnetic field transmitting coil (4) are started; (g) the various sensors mounted below the drone (1) collect the CO2 concentration data in the air along the survey line in the monitoring construction area around the ground high-pressure supercritical CO2 injection well according to the pre-designed flight survey line track coordinates, track elevation, track spacing, and flight speed parameters, and simultaneously collect the aerial three-component electromagnetic field data excited by the aerial horizontal controllable electromagnetic field transmitting coil (4); (h) After the collection of the aerial CO2 concentration data and the aerial three-component electromagnetic field data in the construction work area is completed, the onboard controllable electromagnetic source transmitter (6) is turned off, and the ground-based high-power controllable current transmitting source (10) is started to transmit alternating current to the ground-based large-diameter high-power electromagnetic field transmitting coil (8) or the long-length high-power rectangular current source transmitting antenna (9); (i) the various sensors mounted below the drone (1) again collect the CO2 concentration data in the air along the survey line in the monitoring construction area around the ground high-pressure supercritical CO2 injection well according to the pre-designed flight survey line track coordinates, track elevation, track spacing, and flight speed parameters, and simultaneously collect the semi-aerial three-component electromagnetic field data excited underground by the ground large-diameter high-power electromagnetic field transmitting coil (8) or the long-length high-power rectangular current source transmitting antenna (9); (j) performing a data preprocessing of the CO2 sensor elevation correction and the drone (1) flight speed correction on the CO2 concentration data in the air collected twice in the monitoring construction work area around the ground high-pressure supercritical CO2 injection well, and then performing a linear or nonlinear two-dimensional interpolation process, and finally generating a distribution map of the CO2 concentration in the air at the same elevation from the ground within the monitoring construction work area around the ground high-pressure supercritical CO2 injection well; (k) performing elevation correction, attitude correction, flight speed correction, inclination and azimuth rotation and denoising data preprocessing of the aerial three-component electromagnetic field sensor (3) on the aerial three-component electromagnetic field data collected in step (g), and then performing inversion processing on the three-dimensional aerial three-component electromagnetic field data to obtain the distribution of resistivity anomalies in shallow strata below the ground surface in three-dimensional space; (l) performing elevation correction, attitude correction, flight speed, inclination and azimuth rotation correction and denoising data preprocessing of the airborne three-component electromagnetic field sensor (3) on the semi-aerial three-component electromagnetic field data collected in step (i), and then performing inversion processing on the semi-aerial three-dimensional three-component electromagnetic field data to obtain the resistivity distribution in the deeper strata below the ground surface in three-dimensional space; (m) performing data fusion processing on the resistivity data of the shallow and deeper underground strata obtained in step (k) and step (l) to establish an accurate distribution of the resistivity of the shallow and deeper underground strata in three-dimensional space; (n) after injecting high-pressure supercritical CO2 into the ground, periodically repeating the construction operation flow and data processing work of step (b) to step (m), obtaining a distribution map of CO2 concentration in the air at an altitude equal to the ground within the monitoring construction operation area after injecting high-pressure supercritical CO2 into the ground, and a distribution of resistivity in three-dimensional space from below the ground surface to deeper strata; (o) performing differential processing on the CO2 concentration distribution data in the air at an altitude equal to the ground obtained in step (n) after each injection of high-pressure supercritical CO2 into the ground and the CO2 concentration distribution data in the air at an altitude equal to the ground measured in step (j) when the high-pressure supercritical CO2 is not injected into the ground; (p) performing differential processing on the resistivity distribution data in the three-dimensional space of the shallow and deeper strata below the ground surface obtained in step (m) after each injection of high-pressure supercritical CO2 into the ground and the resistivity distribution data in the three-dimensional space of the shallow and deeper strata measured when the high-pressure supercritical CO2 is not injected into the ground; (q) analyzing and studying the high-pressure supercritical CO2 concentration difference data obtained in step (o) and step (p); when the differential data of the CO2 concentration distribution in the air at the ground level or the like is abnormal, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground; (r) analyzing and studying the resistivity differential data of the shallow and deeper underground strata obtained in step (o) and step (p); when an abnormal body of the resistivity differential data distribution of the shallow and deeper underground strata appears, it indicates that the high-pressure supercritical CO2 injected into the well may have the risk of migration and leakage to the ground; (s) When the projections of the abnormal areas of the differential data appearing in step (q) and step (r) on the ground surface basically overlap, it can be basically determined that the high-pressure supercritical CO2 injected into the well may have migrated and leaked to the ground, and it is necessary to immediately send a warning message to the high-pressure supercritical CO2 injection operator that the high-pressure supercritical CO2 may have migrated and leaked to the ground, and the operator must pay attention to it immediately and adopt corresponding technical responses and safety precautions.

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