A method for quantitatively calculating fracture ore-controlling factors of sandstone-type uranium deposits

Abstract

The present application relates to a kind of quantitative calculation method for sandstone type uranium fracture ore-controlling factor, including the accurate positioning and accurate calibration of target ore-bearing strata of target mining area, fine layer tracking is carried out to target ore-bearing strata of target mining area, and well quality control is connected, different scale fracture scanning body is extracted in target ore-bearing strata, transverse smoothing filtering is carried out to fracture scanning body to obtain final fracture scanning body, fracture scanning attribute results at target line or target stratum interface are extracted and the like steps.Compared with conventional method, the present application has the following advantages: three-dimensional visualization and stereoscopic of target ore layer fracture information can be realized, quantitative description of different scale fracture ore-controlling factor can be realized, it is helpful for fracture ore-controlling factor to participate in quantitative prediction of favorable mineralization zone, it is helpful for quantitative comprehensive analysis of sandstone type uranium in fracture ore-controlling factor aspect of ore-controlling law and genetic mechanism, and important basis and data support can be provided for next quantitative prospecting of sandstone type uranium.

Description

Technical Field

[0001] The present invention belongs to the field of sandstone-type uranium deposit exploration, and specifically relates to a new method for transparentizing and visualizing the structural ore-controlling factors of sandstone-type uranium deposits by using a three-dimensional seismic structural interpretation method in the field of geophysics, and more particularly to a quantitative calculation method for the ore-controlling factors of fractures in sandstone-type uranium deposits. Background Art

[0002] Sandstone-type uranium deposits are one of the most important types of uranium deposits currently explored in my country. They offer enormous resource potential and are amenable to low-cost, clean in-situ leaching. Therefore, they play a crucial role in economic efficiency, environmental protection, and national security. In 2021, Lei Angui's monograph, "Mineralization Mechanism and Exploration of the Qianjiadian Uranium Deposit," clearly identified faults as a key factor in the formation of sandstone-type uranium deposits. Therefore, in-depth research on the factors controlling the mineralization of sandstone-type uranium deposits is crucial.

[0003] At present, in the extraction and analysis of fault-controlling factors in sandstone-type uranium mineralization, there are mainly structural geological analysis methods, remote sensing image analysis methods, three-dimensional seismic data analysis methods, etc. Regarding the structural geological analysis method, in 2019, Dang Feipeng disclosed a relationship between the characteristics of ore-controlling faults and uranium mineralization in the Shangwei area of ​​southern Jiangxi. Through the structural geological analysis method, the spatial relationship and genetic connection between faults and uranium ore bodies were analyzed from the perspective of rock and ore control at different levels of faults. In 2022, Chen Bailin disclosed an analysis of the ore-controlling structure of the Yangtze River uranium ore field in northern Guangdong. Based on the structural geological analysis method, the ore-controlling structure of the Yangtze River uranium ore field was analyzed, and it was concluded that the fault factor played a role in the occurrence space of uranium ore bodies and controlled the output of uranium ore bodies. About remote sensing image analysis method. In 2021, Yi Min disclosed an application of DEM texture enhancement in the identification of uranium-controlling faults in the southern Songliao Basin. The digital terrain model was established by combining remote sensing image data with the DEM texture enhancement method to analyze the role of fault factors in the basin. In 2021, Hu Huiling disclosed a study on the extraction of remote sensing geological mineralization information in the concentrated uranium mineralization area in southwestern Greenland. By combining the remote sensing image characteristics of the mining area with existing geological data, different mineral-controlling factors including fault factors were extracted to establish a prospecting model. Regarding the three-dimensional seismic data analysis method, in 2020, Sun Zhangqing disclosed a method for extracting the mineralization structural elements of sandstone-type uranium deposits based on three-dimensional seismic interpretation. It can intuitively and clearly obtain the mineralization controlling factors such as faults and grooves of sandstone-type uranium deposits, and can comprehensively analyze the mineralization mechanism and basic laws of sandstone-type uranium deposits in terms of structure. In 2021, Hu Huiting disclosed a method and system for identifying mineral-controlling faults in sandstone-type uranium deposits based on three-dimensional seismic data. The fracture factors of sandstone-type uranium deposits were interpreted and systematically divided through three-dimensional seismic data analysis, realizing the rapid identification of mineral-controlling faults in sandstone-type uranium deposits. In 2021, Liu Jun disclosed a fault prediction method and system. Based on three-dimensional seismic data, he established a fault mineral control factor prediction model, which can perform scale-based level prediction of fault mineral control factors and obtain a fault level prediction data body.

[0004] In summary, faults are a key controlling factor in sandstone-type uranium mineralization. Structural geological analysis, remote sensing image analysis, and three-dimensional seismic data analysis can all be used to investigate the controlling factors of faults in sandstone-type uranium deposits to a certain extent. However, each method has its own shortcomings. Structural geological analysis requires a large amount of costly exploration data as a foundation, and exploration data is scarce in newly explored areas, which affects the accuracy of the analysis. Remote sensing image analysis requires high-quality remote sensing imagery and requires comprehensive analysis in conjunction with other exploration data. Furthermore, since it can only analyze surface fault information, it cannot penetrate the subsurface structure of sandstone-type uranium reservoirs. Three-dimensional seismic data analysis can effectively extract underground fault factors, but current extraction methods remain at the qualitative level, with little research on quantitative extraction methods. This is clearly unfavorable for the quantitative prediction of fault-controlling factors in sandstone-type uranium deposits. With the continuous advancement of sandstone-type uranium exploration and development, the favorable prospecting space for sandstone-type uranium deposits is shrinking, and qualitative analysis methods are gradually becoming unable to meet actual production needs. Therefore, it is becoming increasingly important to conduct a more accurate quantitative analysis of the fracture-controlling factors of sandstone-type uranium deposits. Summary of the Invention

[0005] The purpose of the present invention is to provide a quantitative calculation method for the mineralization-controlling factors of sandstone-type uranium deposits based on three-dimensional seismic data, so as to solve the problem of in-depth research on the mineralization-controlling factors of sandstone-type uranium deposits using high-resolution three-dimensional seismic data fracture system interpretation method.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A quantitative calculation method for fracture ore-controlling factors of sandstone-type uranium deposits includes the following steps:

[0008] a. Read in the 3D seismic data and well logging data of the target mining area. The high-resolution 3D seismic data can accurately depict the stratigraphic structure of the target mining area and accurately locate the spatial position and range of the mineralized strata in the target mining area. The well logging data mainly includes natural gamma ray logging curves and acoustic time difference logging curves, which are used for precise positioning of the target strata in the target mining area and fine well-seismic calibration.

[0009] b. Accurately locate and calibrate the target mineral-bearing strata in the target mining area. The precise positioning of the target mineral-bearing strata is achieved by delineating the high-value area of ​​the natural gamma ray curve, while the precise calibration of the target mineral-bearing strata is achieved by creating synthetic seismic records from the acoustic time-of-day logging curve and fine well-seismic calibration;

[0010] c. Conduct fine horizon tracking and well-connected quality control on the target mineral-bearing strata in the target mining area. Fine horizon tracking is completed through wave group feature comparison, progressive horizon tracking interpretation density, and well-connected profile closure inspection quality control. Quality control includes horizon tracking closure inspection and area-wide abnormal color code inspection.

[0011] d. Extract fracture scan volumes of different scales within the target mineral-bearing stratum. The fracture scan volume is a 0-1 distribution data volume with a value of 1 at the center of the largest fracture gradually transitioning to a value of 0 at the fracture edge or where there is no fracture. The larger the fracture, the closer the value at the center of the fracture is to 1, and the distribution range of non-zero values ​​is also relatively large.

[0012] e. Apply transverse smoothing filter to the fracture scan body to obtain the final fracture scan body, wherein: a transverse window with a range of N is selected, and the formula is used within the window To implement transverse smoothing filtering, the final fracture scan volume is obtained; wherein, is the final result of the smoothing filter of the point to be solved, x i The sample point values ​​involved in the calculation within the window;

[0013] f. Extract the scanned fracture attributes of the final target survey line profile or target formation interface. The target survey line profile attributes can clearly depict the fracture development and distribution of the target formation segment on the survey line, and the target formation interface plane attributes can clearly depict the relationship between the fracture development and distribution on the target formation interface and the spatial configuration of the drilled well.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This paper addresses the problems of conventional structural geological analysis methods, remote sensing image analysis methods, and 3D seismic data qualitative analysis methods, which suffer from high data cost, difficulty in penetrating the surface layer into the internal structure of the underground, and can only provide qualitative analysis. By comprehensively utilizing 3D seismic data and well logging data for fine horizon tracking, structural interpretation, and extraction of fault-controlling factors, this paper proposes a quantitative calculation method for fault-controlling factors in sandstone-type uranium deposits. This method has the following advantages:

[0016] 1. The method of the present invention fully utilizes the well logging data that can fully reflect the actual state of the underground formation and the three-dimensional seismic data that can depict the fracture information of the underground target formation with high resolution, thus truly realizing the three-dimensional visualization and stereoscopic representation of the fracture information of the target formation of the sandstone-type uranium reservoir;

[0017] 2. The method of the present invention can fully utilize well data and 3D seismic data to accurately locate and calibrate the target mineral-bearing strata. Through fine layer tracking and well-connected quality control, the spatial position of the interface of the mineral-bearing strata in 3D space can be concisely, intuitively and accurately depicted, thereby laying the foundation for the quantitative extraction of the mineral-controlling factors of the target stratum interface fracture.

[0018] 3. Compared with extracting fracture information from coherent volume attributes, the method of the present invention uses fracture scanning technology to calculate 3D seismic data volumes, which can better identify fractures of different scales, especially small fractures. As the basic data volume for quantitative calculation of fracture scanning volumes, it realizes the quantitative description of the fracture scanning volume of the target stratum segment, and this quantitative description has clear geological significance.

[0019] 4. The lateral filtering implemented on the fracture sweep volume in the present invention is obtained by calculating the mean value of the fracture sweep volume within a selected lateral window. The filtered fracture sweep volume has a smoother numerical distribution characteristic, avoiding the existence of more mutation points and singular points, thereby facilitating the quantitative prediction of the participation of fracture ore-controlling factors in favorable mineralization zones.

[0020] 5. The scanned fracture attributes of the target survey line profile or target stratum interface finally extracted by the present invention can not only clearly depict the development and distribution of fractures in the target stratum section on the survey line, but also clearly depict the relationship between the development and distribution of fractures on the target stratum interface and the spatial configuration of the drilled wells. Both are of great significance for the comprehensive quantitative analysis of the ore-control laws and genetic mechanisms of fracture-controlled factors in sandstone-type uranium deposits.

[0021] 6. The final fracture scanning attribute result body obtained quantitatively calculated the fracture ore-controlling factors of the target mineral-bearing strata in the target area. This result data body can be used as an important quantitative basic data body to participate in the prediction of favorable zones of sandstone-type uranium deposits in the target area and the deployment of the next exploration well location, thereby providing quantitative basic data and reference basis for the fracture ore-controlling factors to guide the next prospecting direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 The overall implementation flow chart of the method of the present invention;

[0024] Figure 2A schematic diagram illustrating a detailed implementation process of a specific embodiment of the method of the present invention;

[0025] Figure 3 is an analysis diagram of the effect of the embodiment, Figure 3a It is a fracture scan volume of the target mineral-bearing stratum; Figure 3b It is the fracture scan volume after the target mineral-bearing stratum is laterally smoothed and filtered. Figure 3c This is the final fracture scanning property result. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with embodiment:

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0028] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are used only to distinguish the description and should not be understood as indicating or implying relative importance.

[0029] like Figure 1 As shown, the quantitative calculation method of fracture ore-controlling factors of sandstone-type uranium deposits of the present invention comprises the following steps:

[0030] a. Read in the 3D seismic data and well logging data of the target mining area. The high-resolution 3D seismic data can accurately depict the stratigraphic structure of the target mining area and accurately locate the spatial position and range of the mineralized strata in the target mining area. The well logging data mainly includes natural gamma ray logging curves and acoustic time difference logging curves, which are used for precise positioning of the target strata in the target mining area and fine well-seismic calibration.

[0031] b. Accurately locate and calibrate the target mineral-bearing strata in the target mining area. The precise positioning of the target mineral-bearing strata is achieved by delineating the high-value area of ​​the natural gamma ray curve, while the precise calibration of the target mineral-bearing strata is achieved by creating synthetic seismic records from the acoustic time-of-day logging curve and fine well-seismic calibration;

[0032] c. Conduct fine horizon tracking and well-connected quality control on the target mineral-bearing strata in the target mining area. Fine horizon tracking is completed through wave group feature comparison, progressive horizon tracking interpretation density, and well-connected profile closure inspection quality control. Quality control includes horizon tracking closure inspection and area-wide abnormal color code inspection.

[0033] d. Extract fracture scan volumes of different scales within the target mineral-bearing stratum. The fracture scan volume is a 0-1 distribution data volume with a value of 1 at the center of the largest fracture gradually transitioning to a value of 0 at the fracture edge or where there is no fracture. The larger the fracture, the closer the value at the center of the fracture is to 1, and the distribution range of non-zero values ​​is also relatively large.

[0034] e. Apply transverse smoothing filter to the fracture scan body to obtain the final fracture scan body, wherein: a transverse window with a range of N is selected, and the formula is used within the window ( is the final result of the smoothing filter of the point to be solved, x i is the sample point value involved in the calculation within the window) to implement transverse smoothing filtering to obtain the final fracture scan volume;

[0035] f. Extract the scanned fracture attributes of the final target survey line profile or target formation interface. The target survey line profile attributes can clearly depict the fracture development and distribution of the target formation segment on the survey line, and the target formation interface plane attributes can clearly depict the relationship between the fracture development and distribution on the target formation interface and the spatial configuration of the drilled well.

[0036] In order to better illustrate the effect of the above specific implementation, a specific example is given below:

[0037] Example 1

[0038] a. Figure 2 As shown in step a, the three-dimensional seismic data and well logging data of the target mining area are read in, wherein: the high-resolution three-dimensional seismic data can finely depict the stratigraphic structure information of the target mining area and accurately locate the spatial position and range of the mineralized layer section of the target mining area; the well logging data mainly includes natural gamma ray logging curves and acoustic time difference logging curves, etc., which are used for precise positioning of the target layer section of the target mining area and fine well-seismic calibration. Analysis of the well logging data shows that the resistivity and gamma ray logging curves of the mineralized layer section logging data show high values;

[0039] b. Figure 2 As shown in step b, the target mineral-bearing stratum in the target mining area is accurately positioned and precisely calibrated, wherein: the accurate positioning of the target mineral-bearing stratum segment is achieved by delineating the high-value area of ​​the natural gamma curve, and the accurate calibration of the target mineral-bearing stratum segment is achieved by making synthetic seismic records from the acoustic time difference logging curve and fine well-seismic calibration. During the calibration, wells with missing data, substandard accuracy or abnormal data are eliminated;

[0040] c. Figure 2As shown in step c, the target mineral-bearing strata in the target mining area are finely tracked and well-connected quality control is performed, wherein: the fine layer tracking is completed through steps such as wave group feature comparison, progressive layer tracking interpretation density, and well-connected profile closure inspection quality control. The quality control content includes layer tracking closure inspection and full-area abnormal color code inspection. The layer tracking first uses sparse interpretation density to track the marker layer, then densifies the interpretation density to perform layer tracking, and then finely tracks the target mineral-bearing strata;

[0041] d. Figure 2 As shown in step d, fracture scan volumes of different scales are extracted within the target mineral-bearing stratum. The fracture scan volume is a data volume with a 0-1 distribution, with a value of 1 at the center of the largest fracture gradually transitioning to a value of 0 at the fracture edge or where there is no fracture. The larger the fracture, the closer the value at the center of the fracture is to 1, and the distribution range of non-zero values ​​is also relatively large. Analysis of the schematic diagram shows that fractures of different scales are clearly depicted, and the three-dimensional spatial configuration relationship of the fracture scan volume can be intuitively given.

[0042] e. Figure 2 As shown in step e, a transverse smoothing filter is applied to the fracture scan body to obtain the final fracture scan body, wherein: a transverse window with a range of N is selected, and the formula is used within the window. ( is the final result of the smoothing filter of the point to be solved, x i is the sample point value involved in the calculation within the window) to perform transverse smoothing filtering to obtain the final fracture scan volume. Analysis of the schematic diagram shows that the final quantitative fracture scan volume can intuitively and comprehensively reflect the spatial distribution information of the fracture;

[0043] f. Figure 2 As shown in step f, the properties of the final target survey line profile or the fault scanning volume on the target stratum interface are extracted, wherein: the target survey line profile property results can clearly depict the development and distribution of faults in the target stratum section on the survey line; the target stratum interface plane property results can clearly depict the relationship between the development and distribution of faults on the target stratum interface and the spatial configuration of the drilled mine. Analysis of the schematic diagram shows that the superposition of the target stratum layer fault scanning results and the mine location distribution information can intuitively and comprehensively display the spatial position relationship between the fault and the mineralization site.

[0044] Figure 3 shows Figure 2 The following phenomena and conclusions can be drawn from the analysis of some core results of the specific implementation process in the study area: 1. Figure 3a The basic spatial structural form of the fracture scanning body of different scales in the target mineralized strata. During the mineralization period, the geological movement of the strata was active, the fracture system of the target mineralized strata was well developed, and the fractures of different scales were widely distributed, which was conducive to the formation of oxidation fluid channels required for sandstone-type uranium mineralization; 2. Figure 3bThe fault scan volume after the target mineralized stratum is laterally smoothed and filtered. Sandstone-type uranium deposits are concentrated around the oxidizing fluid channels required for mineralization. The mineralization sites are mostly located in or near the fault system. This phenomenon and law are very helpful in guiding the analysis and prediction of favorable mineralization zones using high-precision 3D seismic data; 3. Figure 3c The final fault scanning attribute results are superimposed with the location information of the mine-bearing wells. By analyzing this map, we can intuitively and clearly find the corresponding relationship between the mineralization site and the fault ore-controlling factors in space. It can be found that most of the mine-bearing wells are located at the fault or in its vicinity.

[0045] Compared with conventional methods, the quantitative fracture control factor analysis method of the present invention has the following advantages: 1. The present invention method fully utilizes the logging data that can fully reflect the actual state of the underground strata and the three-dimensional seismic data that can depict the fracture information of the underground target strata with high resolution, and truly realizes the three-dimensional visualization and stereoscopicization of the fracture information of the target stratum of the sandstone-type uranium reservoir; 2. The present invention method can fully utilize the well data and three-dimensional seismic data to accurately locate and calibrate the target ore-bearing strata. Through fine layer tracking and well quality control, it can simply, intuitively and accurately depict the spatial position of the interface of the ore-bearing stratum segment in three-dimensional space, thereby laying the foundation for the quantitative extraction of the fracture control factors of the target stratum interface; 3. Compared with the coherent body attribute extraction of fracture information, the present invention method adopts fracture scanning technology to calculate the three-dimensional seismic data body, which can better identify fractures of different scales, especially small fractures. As the basic data body for the quantitative calculation of the fracture scanning body, it realizes the quantitative description of the fracture scanning body of the target stratum segment, and the quantitative description has clear geological significance; 4. The present invention implements the fracture scanning body Transverse filtering is obtained by calculating the mean of the fracture scan body in the selected transverse window. The filtered fracture scan body is smoother in numerical distribution characteristics, avoiding the existence of more mutation points and singular points, which is helpful for the quantitative prediction of the participation of fracture control factors in favorable mineralization zones; 5. The fracture scan body attribute results finally extracted by the present invention on the target survey line profile or target stratum interface can not only clearly depict the fracture development and distribution of the target stratum section on the survey line, but also clearly depict the spatial configuration relationship between the fracture development and distribution on the target stratum interface and the drilled mine wells. Both are of great significance for the comprehensive quantitative analysis of the mineralization control law and causal mechanism of the fracture control factors in the sandstone-type uranium mining area; 6. The fracture scan attribute result body finally obtained quantitatively calculates the fracture control factors of the target mineral-bearing strata in the target area. The result data body can be used as an important quantitative basic data body to participate in the prediction of favorable zones of sandstone-type uranium mines in the target area and the deployment of the next exploration well location, thereby providing quantitative basic data and reference basis for the fracture control factors to guide the next prospecting direction.

[0046] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A quantitative calculation method for fracture-controlling factors of sandstone-type uranium deposits, characterized by: The steps include: a. Read in the 3D seismic data and well logging data of the target mining area. The high-resolution 3D seismic data can accurately depict the stratigraphic structure of the target mining area and accurately locate the spatial position and range of the mineralized strata in the target mining area. The well logging data mainly includes natural gamma ray logging curves and acoustic time difference logging curves, which are used for precise positioning of the target strata in the target mining area and fine well-seismic calibration. b. Accurately locate and calibrate the target mineral-bearing strata in the target mining area. The precise positioning of the target mineral-bearing strata is achieved by delineating the high-value area of ​​the natural gamma ray curve, while the precise calibration of the target mineral-bearing strata is achieved by creating synthetic seismic records from the acoustic time-of-day logging curve and fine well-seismic calibration; c. Conduct fine horizon tracking and well-connected quality control on the target mineral-bearing strata in the target mining area. Fine horizon tracking is completed through wave group feature comparison, progressive horizon tracking interpretation density, and well-connected profile closure inspection quality control. Quality control includes horizon tracking closure inspection and area-wide abnormal color code inspection. d. Extract fracture scan volumes of different scales within the target mineral-bearing stratum. The fracture scan volume is a 0-1 distribution data volume with a value of 1 at the center of the largest fracture gradually transitioning to a value of 0 at the fracture edge or where there is no fracture. The larger the fracture, the closer the value at the center of the fracture is to 1, and the distribution range of non-zero values ​​is also relatively large. e. Apply transverse smoothing filter to the fracture scan body to obtain the final fracture scan body, wherein: a transverse window with a range of N is selected, and the formula is used within the window To implement transverse smoothing filtering, the final fracture scan volume is obtained; wherein, is the final result of the smoothing filter of the point to be solved, x i The sample point values ​​involved in the calculation within the window; f. Extract the properties of the final target survey line profile or the target formation interface, including: The target line profile attribute results can clearly depict the development and distribution of faults in the target formation segment on the survey line, and the target formation interface plane attribute results can clearly depict the relationship between the development and distribution of faults on the target formation interface and the spatial configuration of the drilled mine.

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