Ore prospecting method and system based on air-ground-well three-dimensional geophysical exploration

Abstract

The invention discloses a prospecting method and system based on air-ground-well three-dimensional geophysical exploration, and relates to the field of geological mineral exploration. The method comprises the specific steps that large-area high-resolution aviation gravity and magnetic detection is carried out according to existing geological data of a research area, aviation gravity and magnetic data are acquired, and a prospecting prospective area is delineated; in the prospecting distant view area, ground gravity and magnetic measurement is carried out, ground measurement data are obtained, the ground measurement data are processed and explained, aeronautical geophysical prospecting abnormity is verified, the occurrence state of an ore body is preliminarily deduced, and a prospecting target area is delineated; in the prospecting target area, drilling verification holes are formed, logging is carried out, drilling information is obtained, and air-ground-well joint inversion is carried out based on the aviation gravity and magnetic data, the ground measurement data and the drilling data; and carrying out constrained three-dimensional geophysical-geological modeling based on an inversion result, and predicting the position, the form and the scale of mineral resources in the research area. According to the method, fine exploration of mineral resources is realized by fully utilizing the characteristics of air-ground-well three-dimensional geophysical data.

Description

Technical Field

[0001] The present invention relates to the technical field of geological mineral exploration, and in particular to a prospecting method and system based on air-ground-well three-dimensional geophysical detection. Background Art

[0002] Mineral resources are an important material basis for economic and social development. With the exploitation and consumption of mineral resources, open-pit mines and shallow mineral resources are gradually facing depletion. The huge demand for resources makes the research on deep geological prospecting of great significance, especially geophysical exploration technology. However, prospecting and exploration are faced with more complex prospecting conditions and exploration technology limitations. Traditional geophysical prospecting methods often use a single detection method, such as ground geophysical detection or underground geophysical detection. Although these methods can provide information about mineral resources to a certain extent, they have limitations. A single detection method can only provide local geophysical information, and it is difficult to fully understand the geological structure and mineral distribution of the mining area. In order to overcome the limitations of traditional prospecting methods, it is necessary to comprehensively utilize air, ground and underground geophysical detection methods to form a three-dimensional detection system. Summary of the invention

[0003] The purpose of the present invention is to provide a prospecting method and system based on air-ground-well three-dimensional geophysical detection to solve the problems raised in the background technology and make full use of the characteristics of air-ground-well three-dimensional geophysical data to realize the detailed exploration of mineral resources.

[0004] To achieve the above object, the present invention provides the following solutions: On the one hand, a prospecting method based on air-ground-well three-dimensional geophysical detection is provided, and the specific steps include the following:

[0005] Carry out large-scale high-resolution airborne gravity and magnetic surveys based on the existing geological data in the study area, obtain airborne gravity and magnetic data, and delineate prospecting areas;

[0006] In the prospecting area, carry out ground gravity and magnetic surveys, obtain ground survey data, process and interpret the ground survey data, verify the aerogeophysical anomalies, preliminarily infer the occurrence state of the ore body, and delineate the prospecting target area;

[0007] Arrange drilling verification holes and well logging in the prospecting target area to obtain drilling information, and carry out joint inversion of air-ground-well based on multivariate information based on the aerogravimetric and magnetic data, the ground measurement data, and the drilling data;

[0008] Based on the joint inversion results, constrained three-dimensional geophysical-geological modeling is carried out to predict the location, morphology and scale of mineral resources in the study area.

[0009] Preferably, the existing geological data includes mineral data, geophysical data, and drilling data.

[0010] Preferably, the specific steps of delineating the prospecting area according to the acquired aerogravimetric data are:

[0011] Processing and calculating the aerogravimetric and magnetic data to obtain a ΔT contour line map and an ASM contour line map;

[0012] Classifying and screening the aeromagnetic anomalies according to the ΔT contour plane map and the ASM contour plane map, and respectively delineating a first area where the ASM is greater than a first threshold value and a second area where the ΔT maximum value is greater than a second threshold value and the ASM is greater than a third threshold value;

[0013] The first area and the second area are used as the prospecting areas.

[0014] Preferably, the process of obtaining the ΔT contour line plane map is as follows:

[0015] Performing diurnal variation correction, height correction and gradient correction on the total magnetic field T in the horizontal gradient direction of the aerogravimetric and magnetic data to obtain the magnetic anomaly ΔT before leveling;

[0016] The magnetic anomaly ΔT before leveling is subjected to trend approximation leveling and low-pass filtering processing, and finally the ΔT magnetic anomaly data is obtained, the ΔT magnetic anomaly data is gridded, the GRD grid data is generated, and the ΔT contour line plane map is drawn.

[0017] Preferably, an air-ground-well joint inversion based on fuzzy C-means clustering is performed according to the aerial gravity and magnetic data, the ground measurement data and the drilling data.

[0018] Preferably, the specific steps of the air-ground-well joint inversion are:

[0019] Step 1: Establish an initial model using smooth inversion;

[0020] Step 2: Calculate the cluster center and membership degree of the initial model, set the fuzzy factor, the number of cluster centers and the priori cluster center, and initialize the regularization factor;

[0021] Step 3, calculating the residual density using focusing inversion according to the cluster center and the degree of membership;

[0022] Step 4: updating the cluster center and the degree of membership, and then updating the residual density;

[0023] Step 5: Determine whether to stop iteration. If the root mean square error between the observed data and the predicted data is less than the preset threshold, stop iteration and exit. Otherwise, return to step 2 until the iteration stop condition is met.

[0024] Preferably, the method further includes narrowing the scope of the prospecting target area, determining the polarization space, drilling in the polarization space, and arranging drilling verification holes and logging.

[0025] Preferably, the step of determining the polarization space is:

[0026] The mapping coordinates of the prospecting target area are converted based on the coordinate system used by the map coordinates;

[0027] Calculating the coordinate average of the converted drawing coordinates and map coordinates;

[0028] The polarization space is marked in the network map according to the coordinate average value.

[0029] On the other hand, a prospecting system based on air-ground-well three-dimensional geophysical detection is provided, including an airborne gravity and magnetic measurement module, a ground gravity and magnetic measurement module, a well gravity and magnetic measurement module, and an inversion module; wherein,

[0030] The aerial gravity and magnetic measurement module is used to carry out large-scale high-resolution aerial gravity and magnetic detection based on the existing geological data in the study area, obtain aerial gravity and magnetic data, and delineate prospecting areas;

[0031] The ground gravity and magnetic measurement module is used to carry out ground gravity and magnetic measurement in the prospecting area, obtain ground measurement data, process and interpret the ground measurement data, verify the aerogeophysical anomalies, preliminarily infer the occurrence state of the ore body, and delineate the prospecting target area;

[0032] The in-well gravity and magnetic measurement module is used to arrange drilling verification holes and well logging in the prospecting target area, obtain drilling information, and carry out air-ground-well joint inversion based on multivariate information based on the aerial gravity and magnetic data, the ground measurement data, and the drilling data;

[0033] The inversion module is used to perform constrained three-dimensional geophysical-geological modeling based on the joint inversion results to predict the location, shape and scale of mineral resources in the study area.

[0034] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0035] 1. Improve the efficiency of mineral exploration: Through coordinated detection in the air, on the ground and underground, a large amount of geophysical data can be obtained in a shorter time, thus improving the efficiency of mineral exploration.

[0036] 2. Enhance the accuracy of mineral exploration: Different geophysical detection methods can detect mineral resources from different angles and depths, verify each other, and enhance the accuracy of mineral exploration.

[0037] 3. Expand the scope of mineral exploration: The air-ground-well three-dimensional geophysical exploration method can cover a wide area from the air to deep underground, expanding the scope of mineral exploration.

[0038] 4. Reduce the cost of mineral exploration: Compared with a single geophysical detection method, the air-ground-well three-dimensional geophysical detection method can reduce repeated detection and blind detection, and reduce the cost of mineral exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 is a flow chart of the method of the present invention;

[0041] Figure 2 It is a system structure diagram of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0043] The purpose of the present invention is to provide a prospecting method based on air-ground-well three-dimensional geophysical detection, such as Figure 1 As shown, the specific steps include the following:

[0044] S1. Carry out large-scale high-resolution airborne gravity and magnetic surveys based on the existing geological data in the study area, obtain airborne gravity and magnetic data, and delineate prospecting areas;

[0045] S2. Carry out ground gravity and magnetic surveys in prospecting areas, obtain ground survey data, process and interpret ground survey data, verify aerogeophysical anomalies, preliminarily infer the occurrence state of ore bodies, and delineate prospecting target areas;

[0046] S3. Arrange drilling verification holes and well logging in the prospecting target area to obtain drilling information, and carry out joint inversion of air-ground wells based on multivariate information based on aerial gravity and magnetic data, ground measurement data, and the drilling data;

[0047] S4. Perform constrained three-dimensional geophysical-geological modeling based on the joint inversion results to predict the location, morphology and scale of mineral resources in the study area.

[0048] Furthermore, in step S1, the existing geological data of the study area includes mineral data, geophysical data, and drilling data.

[0049] Furthermore, the specific steps of delineating the prospecting area according to the acquired aerogravimetric data in step S1 are as follows:

[0050] S11. Process and calculate the aerogravimetric and magnetic data to obtain a ΔT contour map and an ASM contour map;

[0051] S12, classifying and screening the aeromagnetic anomalies according to the ΔT contour plane map and the ASM contour plane map, and respectively delineating a first area where the ASM is greater than a first threshold value and a second area where the ΔT maximum value is greater than a second threshold value and the ASM is greater than a third threshold value;

[0052] S13. Use the first area and the second area as prospecting areas.

[0053] Furthermore, in step S11, the process of obtaining the ΔT contour plane map is as follows:

[0054] S111, performing diurnal variation correction, height correction and gradient correction on the total magnetic field T in the horizontal gradient direction of the aerogravimetric and magnetic data to obtain the magnetic anomaly ΔT before leveling;

[0055] S112, the magnetic anomaly ΔT before leveling is subjected to trend approximation leveling and low-pass filtering, and finally the ΔT magnetic anomaly data is obtained, the ΔT magnetic anomaly data is gridded, the GRD grid data is generated, and the ΔT contour line plane map is drawn.

[0056] Furthermore, it also includes using an aerial or satellite-borne hyperspectral imager on the basis of step S1 to obtain hyperspectral image data of the study area, and using deep learning algorithms, such as convolutional neural networks (CNN), to classify, identify and detect anomalies in the hyperspectral data, so as to further verify the prospecting prospecting area delineated by the aerial gravity and magnetic method.

[0057] The spectral resolution of hyperspectral image data can reach the nanometer level, which can capture extremely subtle spectral differences. The AI ​​model is trained to identify specific spectral absorption or reflection features associated with a certain mineral, so as to quickly locate areas where the mineral may exist in the image. Compared with traditional ground survey methods, this method based on remote sensing hyperspectral and AI can cover a large area in a short time, improve the efficiency of prospecting, reduce costs, and also discover some potential mineralization information that is difficult to detect on the ground.

[0058] Furthermore, step S3 further includes narrowing the scope of the prospecting target area, determining the polarization space, drilling in the polarization space, arranging drilling verification holes and logging. Specifically, the steps for determining the polarization space are: converting the drawing coordinates of the prospecting target area based on the coordinate system used by the map coordinates; calculating the coordinate averages of the converted drawing coordinates and map coordinates; and marking the polarization space in the network map according to the coordinate average.

[0059] In the process of prospecting, according to the geological design and engineering requirements, appropriate drilling equipment and technology are selected to carry out vertical or horizontal well drilling construction. During the drilling process, parameters such as well inclination and well depth must be strictly controlled to ensure the quality of drilling. The drilled cores and cuttings are systematically sampled and analyzed, including petrological identification, chemical analysis, mineralogical analysis, etc., to determine information such as rock type, mineral composition, and grade changes, providing a basis for mineral resource evaluation. Various logging instruments are lowered into the well to measure different physical parameters, such as resistivity, density, sonic velocity, natural gamma, etc., and to draw logging curves. Through the comprehensive interpretation of the logging curves, the boundaries between the mineral layer and the non-mineral layer are identified, and the physical characteristics and change laws of the mineral layer are analyzed.

[0060] Vertical wells are the most common well type. By drilling vertically downward from the ground, physical data such as cores and cuttings at different depths can be obtained for direct geological observation and analysis. At the same time, geophysical logging, such as resistivity logging and natural gamma logging, can also be performed in the well to obtain information on the physical properties of the strata around the well wall and further determine the location, thickness and grade of the ore layer.

[0061] Horizontal well exploration: Under certain specific geological conditions and prospecting targets, horizontal wells have unique advantages. They can be drilled along the direction of the ore layer or potential ore layer, revealing the ore layer to a greater extent, improving the control of the ore layer and the accuracy of resource reserve estimation, and are particularly suitable for the exploration of complex ore bodies such as thin ore layers and lens-shaped ore layers.

[0062] Furthermore, in step S3, according to the aerial gravity and magnetic data, the ground measurement data, and the drilling data, the air-ground-well joint inversion based on fuzzy C-means clustering is performed, and the specific steps are as follows:

[0063] S31, establishing an initial model using smooth inversion;

[0064] S32, calculating the cluster center and membership degree of the initial model, setting the fuzzy factor, the number of cluster centers and the priori cluster center, and initializing the regularization factor;

[0065] S33, calculating the residual density using focusing inversion according to the cluster center and the membership degree;

[0066] S34, updating the cluster center and the degree of membership, and then updating the residual density;

[0067] S35, determine whether to stop iteration. If the root mean square error between the observed data and the predicted data is less than a preset threshold, stop iteration and exit. Otherwise, return to S32 until the iteration stop condition is met.

[0068] On the other hand, a prospecting system based on air-ground-well three-dimensional geophysical detection is provided, such as Figure 2 As shown, it includes an airborne electromagnetic measurement module, a ground electromagnetic measurement module, a well electromagnetic measurement module, and an inversion module; wherein,

[0069] The airborne gravity and magnetic measurement module is used to carry out large-scale high-resolution airborne gravity and magnetic detection based on the existing geological data in the study area, obtain airborne gravity and magnetic data, and delineate prospecting areas;

[0070] The ground gravity and magnetic measurement module is used to carry out ground gravity and magnetic measurements in prospecting areas, obtain ground measurement data, process and interpret ground measurement data, verify aeroponic anomalies, preliminarily infer the occurrence state of ore bodies, and delineate prospecting target areas;

[0071] The well gravity and magnetic measurement module is used to arrange drilling verification holes and well logging in the prospecting target area, obtain drilling information, and carry out joint inversion of air-ground and well based on multi-information based on aerial gravity and magnetic data, ground measurement data, and drilling data;

[0072] The inversion module is used to perform constrained three-dimensional geophysical-geological modeling based on the joint inversion results to predict the location, morphology and scale of mineral resources in the study area.

[0073] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A prospecting method based on air-ground-well three-dimensional geophysical detection, characterized in that: The specific steps include the following: Carry out large-scale high-resolution airborne gravity and magnetic surveys based on the existing geological data in the study area, obtain airborne gravity and magnetic data, and delineate prospecting areas; In the prospecting area, carry out ground gravity and magnetic surveys, obtain ground survey data, process and interpret the ground survey data, verify the aerogeophysical anomalies, preliminarily infer the occurrence state of the ore body, and delineate the prospecting target area; Arrange drilling verification holes and well logging in the prospecting target area to obtain drilling information, and carry out joint inversion of air-ground-well based on multivariate information based on the aerogravimetric and magnetic data, the ground measurement data, and the drilling data; Based on the joint inversion results, constrained three-dimensional geophysical-geological modeling is carried out to predict the location, morphology and scale of mineral resources in the study area.

2. A prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 1, characterized in that: The existing geological data include mineral data, geophysical data, and drilling data.

3. The prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 1 is characterized in that: The specific steps for delineating the prospecting area according to the acquired aeromagnetic and magnetic data are as follows: Processing and calculating the aerogravimetric and magnetic data to obtain a ΔT contour line map and an ASM contour line map; Classifying and screening the aeromagnetic anomalies according to the ΔT contour plane map and the ASM contour plane map, and respectively delineating a first area where the ASM is greater than a first threshold value and a second area where the ΔT maximum value is greater than a second threshold value and the ASM is greater than a third threshold value; The first area and the second area are used as the prospecting areas.

4. A prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 3, characterized in that: The process of obtaining the ΔT contour plane map is as follows: Performing diurnal variation correction, height correction and gradient correction on the total magnetic field T in the horizontal gradient direction of the aerogravimetric and magnetic data to obtain the magnetic anomaly ΔT before leveling; The magnetic anomaly ΔT before leveling is subjected to trend approximation leveling and low-pass filtering processing, and finally the ΔT magnetic anomaly data is obtained, the ΔT magnetic anomaly data is gridded, the GRD grid data is generated, and the ΔT contour line plane map is drawn.

5. The prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 1 is characterized in that: According to the aerial gravity and magnetic data, the ground measurement data and the drilling data, a joint inversion of air-ground wells based on fuzzy C-means clustering is performed.

6. A prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 5, characterized in that: The specific steps of the joint inversion of the air-ground well are as follows: Step 1: Establish an initial model using smooth inversion; Step 2: Calculate the cluster center and membership degree of the initial model, set the fuzzy factor, the number of cluster centers and the priori cluster center, and initialize the regularization factor; Step 3, calculating the residual density using focusing inversion according to the cluster center and the degree of membership; Step 4: updating the cluster center and the degree of membership, and then updating the residual density; Step 5: Determine whether to stop iteration. If the root mean square error between the observed data and the predicted data is less than the preset threshold, stop iteration and exit. Otherwise, return to step 2 until the iteration stop condition is met.

7. The prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 1 is characterized in that: It also includes further narrowing the scope of the prospecting target area, determining the polarization space, drilling in the polarization space, arranging drilling verification holes and logging.

8. A prospecting method based on air-ground-well three-dimensional geophysical detection according to claim 7, characterized in that: The steps of determining the polarization space are: The mapping coordinates of the prospecting target area are converted based on the coordinate system used by the map coordinates; Calculating the coordinate average of the converted drawing coordinates and map coordinates; The polarization space is marked in the network map according to the coordinate average value.

9. A prospecting system based on air-ground-well three-dimensional geophysical detection, characterized in that: It includes airborne gravity and magnetic measurement module, ground gravity and magnetic measurement module, well gravity and magnetic measurement module, and inversion module; among them, The aerial gravity and magnetic measurement module is used to carry out large-scale high-resolution aerial gravity and magnetic detection based on the existing geological data in the study area, obtain aerial gravity and magnetic data, and delineate prospecting areas; The ground gravity and magnetic measurement module is used to carry out ground gravity and magnetic measurement in the prospecting area, obtain ground measurement data, process and interpret the ground measurement data, verify the aerogeophysical anomalies, preliminarily infer the occurrence state of the ore body, and delineate the prospecting target area; The in-well gravity and magnetic measurement module is used to arrange drilling verification holes and well logging in the prospecting target area, obtain drilling information, and carry out air-ground-well joint inversion based on multivariate information based on the aerial gravity and magnetic data, the ground measurement data, and the drilling data; The inversion module is used to perform constrained three-dimensional geophysical-geological modeling based on the joint inversion results to predict the location, shape and scale of mineral resources in the study area.

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