Method for inferring a cover fault in a sedimentary basin

Abstract

The present application relates to a kind of sedimentary basin cover layer fracture inference method, comprising: a. collect the aerial uranium data of sedimentary basin area, form the basis database, collect the geological data of sedimentary basin area, understand the distribution characteristics of regional fault structure;B. the average value and standard deviation of the content of aerial uranium in sedimentary basin area are counted, determine the weak anomaly extraction benchmark background threshold and the minimum amplitude of abnormality of aerial uranium content;C. according to weak uranium anomaly extraction threshold, weak uranium anomaly is extracted according to survey line by survey line, and weak uranium anomaly database is formed;D. the weak uranium anomaly information is discriminated, and interference anomaly information is removed, according to the distribution characteristics of known fault structure, identify and extract fault structure weak uranium anomaly information;E. according to the extracted fault structure weak uranium anomaly information, the weak anomaly of aerial uranium is connected in line for continuous and consistent extension direction, and the distribution of sedimentary basin cover layer fault structure is obtained.The present application can quickly and low cost infer the cover layer fracture of sedimentary basin.

Description

Technical Field

[0001] This invention relates to a method for inferring geological faults, specifically a method for inferring faults in the caprock of sedimentary basins. Background Technology

[0002] The supply of sandstone-type uranium resources is crucial for ensuring a sustainable uranium supply. However, the exploration of sandstone-type uranium deposits is difficult, making it challenging to guarantee a continuous increase in uranium supply. Basin caprock faults are key to controlling sandstone-type uranium mineralization. The commonly used exploration method is seismic exploration, but its high cost and low efficiency limit exploration to the periphery of known mining areas, severely hindering the progress of uranium resource exploration and utilization and ensuring a secure supply. Conducting rapid extraction studies of basin caprock faults can help quickly delineate prospective areas and guide further drilling deployments. Since uranium decay products can migrate and enrich upwards along basin caprock faults, weak uranium anomalies can be generated. High-precision aerial uranium scattering data can be used to infer some basin caprock fault structures, providing a rapid and efficient method for finding concealed sandstone-type uranium resources. Summary of the Invention

[0003] The purpose of this invention is to provide a method for inferring faults in the caprock of sedimentary basins, so as to solve the problems of high cost and low efficiency of existing methods for exploring faults in the caprock of basins.

[0004] The present invention is implemented as follows: a method for inferring faults in the caprock of a sedimentary basin, comprising the following steps.

[0005] a. Collect aerial uranium release data from sedimentary basins to form a basic database, and at the same time collect geological data from sedimentary basins to gain a general understanding of the distribution characteristics of regional fault structures.

[0006] b. Statistically analyze the average and standard deviation of uranium content from aerial venting in the sedimentary basin area, and determine the baseline background threshold and minimum amplitude for weak anomalies in uranium content from aerial venting.

[0007] c. Based on the uranium content of aerial radio waves, weak uranium anomalies are extracted from each radio wave line according to the weak uranium anomaly extraction threshold, forming a weak uranium anomaly database.

[0008] d. The extracted weak uranium anomaly information is screened, interfering anomaly information is removed, and weak uranium anomaly information of the fracture structure is identified and extracted based on the known distribution characteristics of the fracture structure.

[0009] e. Based on the extracted weak uranium anomaly information of the fracture structure, connect the continuous weak uranium anomalies of air-released uranium with consistent extension direction to obtain the distribution of fracture structures in the caprock of the sedimentary basin.

[0010] For the method for inferring faults in the caprock of sedimentary basins of the present invention, in step a, the basic database includes aerial uranium content data with survey line number, point number, coordinates, and elevation.

[0011] For the sedimentary basin cap fracture inference method of the present invention, in step b, the baseline background value is taken as 1 / 5 of the average value of the whole area, the minimum amplitude of the anomaly is taken as 2σ, and σ is the standard deviation of the uranium content released by air in the sedimentary basin area.

[0012] In the sedimentary basin cap fracture inference method of the present invention, in step c, the aerial uranium content data is anomaly identified and extracted line by line according to the survey line. For the local maximum value that is greater than the baseline background value, it is determined whether the difference between the local maximum value and the adjacent local minimum value is greater than the minimum amplitude of the anomaly. If the difference is greater than the minimum amplitude of the anomaly, the corresponding coordinates and the anomalous amplitude of the aerial uranium are extracted to form a weak anomaly database of aerial uranium content.

[0013] For the sedimentary basin caprock fault inference method of the present invention, in step d, weak uranium anomaly data are projected onto the aerial uranium scattering planar map to remove lithological and human interference anomalies, which are manifested as anomalies in blocky concentrated distribution areas or single-point anomalies; then, based on the known fault distribution characteristics, anomalies with anomalies on continuous survey lines and whose distribution direction is roughly consistent with the known fault distribution direction are retained, and the corresponding anomaly coordinates and amplitudes are extracted to form a weak uranium scattering anomaly database of basin caprock fault structures.

[0014] In the sedimentary basin caprock fault inference method of the present invention, in step e, the weak anomaly of airborne uranium emission from the fault structure is projected onto the airborne uranium emission planar map, and the continuous weak anomalies of airborne uranium emission with the same extension direction are connected to form the distribution of the sedimentary basin caprock fault structure, thus forming the basin caprock fault structure distribution map.

[0015] This invention provides a rapid method for inferring and interpreting basin caprock faults without conducting large-scale, high-cost seismic exploration. Since uranium decay products can migrate and enrich upwards along basin caprock faults, forming weak uranium anomalies, this invention utilizes this principle to extract weak uranium anomalies from aerial uranium data. Then, based on the distribution of these anomalies and the known fault distribution characteristics, partial basin caprock fault structures can be inferred. This allows for rapid and low-cost inference of sedimentary basin caprock faults, providing a fast and efficient method for later searching for concealed sandstone-type uranium resources. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for inferring faults in the caprock of a sedimentary basin according to the present invention.

[0017] Figure 2 This is an example diagram illustrating the inference of caprock fractures in a sedimentary basin region based on the present invention. Detailed Implementation

[0018] like Figure 1 , Figure 2As shown, the present invention is a method for inferring faults in the caprock of sedimentary basins, which specifically includes the following steps.

[0019] a. Collect aerial uranium release data from sedimentary basins to form a basic database, and at the same time collect geological data from sedimentary basins to gain a general understanding of the distribution characteristics of regional fault structures.

[0020] b. Statistically analyze the average and standard deviation of uranium content from aerial venting in the sedimentary basin area, and determine the baseline background threshold and minimum amplitude for weak anomalies in uranium content from aerial venting.

[0021] c. Based on the uranium content of aerial radio waves, weak uranium anomalies are extracted from each radio wave line according to the weak uranium anomaly extraction threshold, forming a weak uranium anomaly database.

[0022] d. The extracted weak uranium anomaly information is screened, interfering anomaly information is removed, and weak uranium anomaly information of the fracture structure is identified and extracted based on the known distribution characteristics of the fracture structure.

[0023] e. Based on the extracted weak uranium anomaly information of the fracture structure, connect the continuous weak uranium anomalies of air-released uranium with consistent extension direction to obtain the distribution of fracture structures in the caprock of the sedimentary basin.

[0024] For the method for inferring faults in the caprock of sedimentary basins of the present invention, in step a, the basic database includes aerial uranium content data with survey line number, point number, coordinates, and elevation.

[0025] After collecting high-precision aerial uranium data from the sedimentary basin area, the data was processed to form a basic database of aerial uranium content with survey line numbers, point numbers, coordinates, and elevations, laying the foundation for subsequent statistical analysis. At the same time, geological map data of the study area was collected to gain a general understanding of the regional fault structure distribution characteristics, providing a reference for the subsequent identification of weak anomalies in aerial uranium from faults.

[0026] For the sedimentary basin cap fracture inference method of the present invention, in step b, the baseline background value is taken as 1 / 5 of the average value of the whole area, the minimum amplitude of the anomaly is taken as 2σ, and σ is the standard deviation of the uranium content released by air in the sedimentary basin area.

[0027] Statistical analysis was performed on the aerial uranium content data in the basic database to obtain the average value and standard deviation σ of the aerial uranium content in the sedimentary basin area. Then, the baseline background threshold and minimum amplitude of weak anomaly extraction of aerial uranium content were determined. The baseline background value was taken as 1 / 5 of the average value of the whole area, and the minimum amplitude of the anomaly was taken as 2σ.

[0028] In the sedimentary basin cap fracture inference method of the present invention, in step c, the aerial uranium content data is anomaly identified and extracted line by line according to the survey line. For the local maximum value that is greater than the baseline background value, it is determined whether the difference between the local maximum value and the adjacent local minimum value is greater than the minimum amplitude of the anomaly. If the difference is greater than the minimum amplitude of the anomaly, the corresponding coordinates and the anomalous amplitude of the aerial uranium are extracted to form a weak anomaly database of aerial uranium content.

[0029] In the sedimentary basin cap fault inference method of the present invention, in step d, weak uranium anomaly data are projected onto the aerial uranium planar map to remove lithological and human interference anomalies. Lithological and human interference anomalies are manifested as anomalies in blocky concentrated distribution areas or single-point anomalies, wherein there are no anomalies in adjacent survey lines of single-point anomalies.

[0030] Since uranium decay products can migrate and accumulate upward along the faults in the basin caprock, they can form weak uranium anomalies. Therefore, weak uranium anomalies are distributed along the direction of the faults. Conversely, if a series of weak uranium anomalies are identified, the direction of the fault structure in the basin caprock can be inferred from the connection of the weak uranium anomalies.

[0031] Based on the known fault distribution characteristics, anomalies with continuous anomalies on adjacent survey lines and whose distribution direction is roughly consistent with the known fault distribution direction are retained. The corresponding anomaly coordinates and amplitudes are extracted to form a weak anomaly database of uranium ionization from the air in the basin caprock fault structure.

[0032] In the sedimentary basin caprock fault inference method of the present invention, in step e, the weak anomaly of the fault structure is projected onto the uranium ionization plane map, and the weak anomalies of the uranium ionization that are continuous and have the same extension direction are connected to form the inferred distribution of the sedimentary basin caprock fault structure, thereby forming a distribution map of the basin caprock fault structure.

[0033] After obtaining the distribution map of the fault structure in the basin caprock, combined with the geological data in the area, a foundation was laid for the comprehensive study and prospect delineation of sandstone-type uranium deposits in the area.

[0034] This invention provides a rapid method for inferring and interpreting basin caprock faults without conducting large-scale, high-cost seismic exploration. The invention utilizes the principle that uranium decay products migrate upwards and enrich along basin caprock faults, forming weak uranium anomalies. Weak uranium anomalies are extracted from aerial uranium data. Then, based on the distribution of these anomalies and the known fault distribution characteristics, a connection line for the aerial uranium anomalies can be obtained. This connection line is the inferred fault structure of the basin caprock. This allows for rapid and low-cost inference of sedimentary basin caprock faults, providing a fast and efficient method for later searching for concealed sandstone-type uranium resources.

Claims

1. A method for inferring faults in the caprock of a sedimentary basin, characterized in that, Includes the following steps: a. Collect aerial uranium release data from sedimentary basins to form a basic database, and at the same time collect geological data from sedimentary basins to understand the distribution characteristics of regional fault structures; b. Statistically analyze the average and standard deviation of uranium content from aerial venting in the sedimentary basin area, and determine the baseline background threshold and minimum amplitude of weak anomalies in uranium content from aerial venting; c. Based on the weak uranium anomaly extraction threshold, weak uranium anomalies are extracted from each survey line according to the uranium content of aerial radio, forming a weak uranium anomaly database. d. The extracted weak uranium anomaly information is screened, interfering anomaly information is removed, and weak uranium anomaly information of the fracture structure is identified and extracted based on the known distribution characteristics of the fracture structure. e. Based on the extracted weak uranium anomaly information of the fracture structure, connect the continuous weak uranium anomalies of air-released uranium with consistent extension direction to obtain the distribution of fracture structures in the caprock of the sedimentary basin.

2. The method of fault inference for a sedimentary basin cap rock according to claim 1, wherein, In step a, the basic database includes aerial uranium content data with survey line number, point number, coordinates, and elevation.

3. The method of fault inference for a sedimentary basin cap rock according to claim 1, wherein, In step b, the baseline background value is taken as 1 / 5 of the average value of the whole area, the minimum amplitude of the anomaly is taken as 2σ, and σ is the standard deviation of the uranium content released by air in the sedimentary basin area.

4. The method of claim 1, wherein, In step c, anomaly identification and extraction are performed on the aerial uranium content data line by line according to the measurement line. For local maximum values ​​that are greater than the baseline background value, it is determined whether the difference between the local maximum value and the adjacent local minimum value is greater than the minimum amplitude of the anomaly. If the difference is greater than the minimum amplitude of the anomaly, the corresponding coordinates and the anomalous amplitude of the aerial uranium are extracted to form a weak anomaly database of aerial uranium content.

5. The method of claim 1, wherein, In step d, the weak uranium anomaly data is projected onto the aerial uranium scattering planar map to remove lithological and human-related interference anomalies, which are manifested as anomalies in blocky concentrated distribution areas or single-point anomalies. Then, based on the known fault distribution characteristics, anomalies with anomalies on continuous survey lines and whose distribution direction is consistent with the known fault distribution direction are retained, and the corresponding anomaly coordinates and amplitudes are extracted to form a weak uranium scattering anomaly database of the basin caprock fault structure.

6. The method of fault inference for a sedimentary basin cap rock according to claim 1, wherein, In step e, the weak anomalies of uranium ionization (UO) in the fracture structure are projected onto the UO planar map. The weak UO OO anomalies that are continuous and have the same extension direction are connected to form the distribution of the fault structure in the caprock of the sedimentary basin, thus forming the distribution map of the fault structure in the caprock of the basin.

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