Method and device for determining fault center depth, electronic equipment and medium

Abstract

The present disclosure relates to a fault center depth determination method and device, electronic equipment and medium, the method comprising: obtaining gravity acquisition data for a target fault, the gravity measurement line corresponding to the gravity acquisition data being set according to the extension direction of the target fault and the target position point of the depth to be analyzed, the point distance corresponding to the gravity measurement point in the gravity measurement line being not greater than the vertical fault interval of the target fault; determining the gravity horizontal total gradient information corresponding to each gravity measurement point according to the gravity acquisition data; determining the fault center depth of the target position point according to the half-extreme width corresponding to the gravity horizontal total gradient information. This method can efficiently and quickly realize the fault center depth evaluation and the accuracy of the evaluation result meets the requirements. In the case of low exploration degree or less known information in deep or super deep exploration area, the fault center depth can also be evaluated, and the applicability is wide.

Description

Technical Field

[0001] This disclosure relates to the field of geophysical exploration technology, and in particular to a method, apparatus, electronic device and medium for determining the depth of a fault center. Background Technology

[0002] A fault, also known as a fracture, is a common geological phenomenon in nature where rocks or strata break apart and undergo relative displacement. Human activities and the formation and accumulation of energy and mineral resources are closely related to faults; therefore, fault research is an important part of geological research. When rocks or strata fracture, the rocks or strata on both sides of the fault shift relative to each other, resulting in different rocks or strata appearing on either side of certain locations on the fault plane.

[0003] In realizing the concept disclosed herein, the inventors discovered at least the following technical problems in the related technologies: In actual exploration and production, it is desirable to be able to quickly determine the specific depth of many locations of faults, but the current related technologies lack a simple, fast and efficient method to assess the depth of faults; moreover, some solutions can only qualitatively study the location of faults and cannot perform quantitative calculations or quickly assess the specific depth. Summary of the Invention

[0004] To solve the above-mentioned technical problems, or at least partially solve them, embodiments of this disclosure provide a method, apparatus, electronic device, and medium for determining the depth of a fault center.

[0005] In a first aspect, embodiments of this disclosure provide a method for determining the center depth of a fault. The method includes: acquiring gravity acquisition data for a target fault, wherein gravity survey lines corresponding to the gravity acquisition data are set according to the extension direction of the target fault and the target location point at the depth to be analyzed, and the point spacing between gravity survey points in the gravity survey lines is not greater than the vertical displacement of the target fault; determining the total horizontal gravity gradient information corresponding to each gravity survey point based on the gravity acquisition data; and determining the center depth of the fault at the target location point based on the half-maximum width corresponding to the total horizontal gravity gradient information.

[0006] In some embodiments, the total gravity gradient information includes: the correspondence between the total gravity gradient of each gravity measuring point and the position of each gravity measuring point, wherein the position is represented by the relative distance of each gravity measuring point to a specified measuring point; wherein the half-maximum width is determined by: obtaining the half-maximum width according to the correspondence; or, determining the half-maximum width according to the curve of the position relationship.

[0007] In some embodiments, determining the fault center depth of the target location point based on the half-maximum width corresponding to the total gravity gradient information includes: determining the maximum value of the total gravity gradient at each gravity measuring point based on the total gravity gradient information; determining the value of the half-maximum and the corresponding two half-maximum positions based on the maximum value; determining the half-maximum width based on the two half-maximum positions; and determining a preset proportion of the half-maximum width as the fault center depth of the target location point.

[0008] In some embodiments, the preset ratio is related to the angle between the gravity survey line and the extension direction. When the angle between the gravity survey line and the extension direction is a right angle, the preset ratio is equal to 1 / 2. When there is a deviation between the angle between the gravity survey line and the extension direction and a right angle, the preset ratio is the product of 1 / 2 and a preset correction coefficient; the preset correction coefficient is related to the deviation value corresponding to the angle.

[0009] In some embodiments, the gravity acquisition data includes observed gravity values ​​for each gravity measuring point. Specifically, determining the total gravity horizontal gradient information corresponding to each gravity measuring point based on the gravity acquisition data includes: applying Bouguer correction and normal field correction to the observed gravity values ​​based on the coordinates and elevation values ​​of each gravity measuring point, and applying terrain correction to the observed gravity values ​​of each gravity measuring point based on terrain data to obtain Bouguer gravity anomaly data corresponding to each measuring point; calculating the total gravity horizontal gradient or gravity horizontal gradient for each gravity measuring point on the gravity measuring line based on the Bouguer gravity anomaly data to obtain the total gravity horizontal gradient corresponding to each gravity measuring point; determining the position of each gravity measuring point on the gravity measuring line, where the position is represented by the relative distance of each gravity measuring point to a specified measuring point; and determining the total gravity horizontal gradient information corresponding to each gravity measuring point based on the position of each gravity measuring point and the corresponding total gravity horizontal gradient.

[0010] In some embodiments, gravity survey lines formed by gravity measuring points pass through the target location and are arranged along a first direction. The first direction and the extending direction have a preset angle, which is a right angle or deviates from a right angle. The gravity survey lines extend to both sides from the fault location corresponding to the target location, and the extension length exceeds a preset value; the preset value is a preset multiple of the fault center depth value estimated from other data.

[0011] In some embodiments, a gravity survey line corresponds to one or more target faults; in the case of multiple target faults, multiple extreme points and corresponding half-extreme widths are determined based on the above-mentioned total gravity level gradient information, and the fault center depth of the corresponding target location point in the multiple target faults can be determined.

[0012] Secondly, embodiments of this disclosure provide an apparatus for determining the center depth of a fault. The apparatus includes a data acquisition module, a gravity distribution determination module, and a depth determination module. The data acquisition module acquires gravity data for a target fault. The gravity survey lines corresponding to the gravity data are set according to the extension direction of the target fault and the target location point at the depth to be analyzed. The distance between gravity measurement points in the gravity survey lines is not greater than the vertical displacement of the target fault. The gravity distribution determination module determines the total horizontal gravity gradient information corresponding to each gravity measurement point based on the gravity data. The depth determination module determines the center depth of the fault at the target location point based on the half-maximum width corresponding to the total horizontal gravity gradient information.

[0013] Thirdly, embodiments of this disclosure provide an electronic device. The electronic device includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, communication interface, and memory communicate with each other via the communication bus; the memory stores computer programs; and the processor, when executing the program stored in the memory, implements the method for determining the fault center depth as described above.

[0014] Fourthly, embodiments of this disclosure provide a computer-readable storage medium. The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for determining the fault center depth as described above.

[0015] The technical solutions provided in the embodiments of this disclosure have at least some or all of the following advantages:

[0016] Considering that the gravity anomaly characteristics at corresponding locations on the ground on both sides of a fault will differ depending on the fault center depth—the greater the fault center depth, the gentler the gravity anomaly change above the fault, and vice versa—by acquiring gravity data for the target fault, and since the gravity survey lines corresponding to the aforementioned gravity data are set according to the extension direction of the target fault and the target location points at the depth to be analyzed, the point spacing between gravity measurement points on the aforementioned gravity survey lines is no greater than the vertical fault displacement of the target fault. Therefore, the gravity change characteristics corresponding to the gravity measurement points on the gravity survey lines can be refined. This method reflects different fault depth characteristics. Based on the gravity acquisition data, the total gravity gradient information corresponding to each gravity measurement point is determined. The total gravity gradient information reflects the gravity variation characteristics. The fault center depth of the target location point is evaluated based on the half-maximum width corresponding to the total gravity gradient information. This method can efficiently and quickly evaluate the fault center depth, and the accuracy of the evaluation results meets the requirements. It can also evaluate the fault center depth when the exploration level is low or when there is little known information in deep or ultra-deep exploration areas, and it has wide applicability. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a method for determining the depth of the fault center according to an embodiment of the present disclosure is shown schematically.

[0020] Figure 2A A schematic diagram of a fault geological model with a center depth of 1 km according to an embodiment of the present disclosure is shown.

[0021] Figure 2B A schematic diagram of a fault geological model with a center depth of 2 km according to an embodiment of the present disclosure is shown.

[0022] Figure 3A A schematic diagram illustrates Bouguer gravity anomaly data obtained by forward modeling a fault with a center depth of 1 km according to an embodiment of the present disclosure.

[0023] Figure 3B A schematic diagram illustrates Bouguer gravity anomaly data obtained from forward modeling of a fault with a center depth of 2 km according to an embodiment of the present disclosure.

[0024] Figure 4A The diagram schematically illustrates a gravity horizontal total gradient profile plotted for a fault model with a center depth of 1 km according to an embodiment of the present disclosure, and a schematic diagram of determining the center depth of the fault at the target location point in the target fault based on the half-maximum width.

[0025] Figure 4B The diagram schematically illustrates a gravity horizontal total gradient profile plotted for a fault model with a center depth of 2 km according to an embodiment of the present disclosure, and a schematic diagram of determining the center depth of the fault at the target location point in the target fault based on the half-maximum width.

[0026] Figure 5 This diagram schematically illustrates Bouguer gravity anomaly data obtained after collecting geological exploration data on a fault in a basin according to an embodiment of the present disclosure.

[0027] Figure 6The illustration schematically shows a gravity horizontal gradient profile obtained by drawing gravity horizontal gradient information corresponding to each gravity measuring point in a basin according to an embodiment of the present disclosure, and a schematic diagram of determining the fault center depth of the target location point in the target fault based on the half-maximum width.

[0028] Figure 7 A structural block diagram of a device for determining the depth of the fault center according to an embodiment of the present disclosure is shown schematically.

[0029] Figure 8 A schematic block diagram of an electronic device provided in an embodiment of the present disclosure is shown. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0031] In actual exploration and production, there is a desire to quickly determine the specific depth of many locations along a fault, but a simple, fast, and efficient method has not yet been found.

[0032] Because different rocks and strata generally have varying densities, gravity differences will appear at corresponding locations on the ground on both sides of a fault. When the fault reaches a certain scale, these gravity differences become significant enough to identify the fault's location and strike through gravity measurements and exploration. When the fault center depth differs, the gravity anomaly characteristics at corresponding locations on both sides of the fault will also differ; the greater the fault center depth, the gentler the change in gravity anomaly above the fault, and vice versa. Based on the above analysis, embodiments of this disclosure consider using gravity data analysis to assess the fault center depth. Since gravity exploration is often the first method used in areas with low exploration levels, and other data are often unavailable for reference, and seismic data is often insufficient to obtain reliable deep-seated information in areas requiring deep or ultra-deep exploration, obtaining fault depth information through gravity exploration is of great significance for geological research and practical exploration.

[0033] In view of this, embodiments of the present disclosure provide a method for determining the depth of the fault center. Considering that the gravity anomaly characteristics at corresponding locations on the ground on both sides of the fault will differ depending on the fault center depth—the greater the fault center depth, the gentler the change in gravity anomaly above the fault, and vice versa—the method acquires gravity data for the target fault. Since the gravity survey lines corresponding to the gravity data are set according to the extension direction of the target fault and the target location points at the depth to be analyzed, the distance between gravity measurement points on the gravity survey lines is no greater than the vertical fault displacement of the target fault. Therefore, the gravity measurement points on the gravity survey lines... The corresponding gravity variation characteristics can finely reflect the different fault depth characteristics. Based on the gravity acquisition data, the total gravity horizontal gradient information corresponding to each gravity measurement point is determined. This total gravity horizontal gradient information reflects the gravity variation characteristics. The fault center depth at the target location is evaluated based on the half-maximum width corresponding to the total gravity horizontal gradient information. This method can efficiently and quickly assess the fault center depth with satisfactory accuracy. It can also assess the fault center depth even in areas with low exploration levels or limited known information in deep or ultra-deep exploration areas, demonstrating wide applicability. In this field, the term "depth" is used when no specific reference is needed, while "center depth" is used when a specific reference is required.

[0034] The following is a detailed description with reference to specific embodiments.

[0035] A first exemplary embodiment of this disclosure provides a method for determining the depth of a fault center. This method can be performed by an electronic device with computing capabilities.

[0036] Figure 1 A flowchart illustrating a method for determining the depth of the fault center according to an embodiment of the present disclosure is shown schematically.

[0037] Reference Figure 1 As shown, the method for determining the depth of the fault center provided in this embodiment includes the following steps: S110, S120 and S130.

[0038] In step S110, gravity acquisition data for the target fault is obtained. The gravity survey line corresponding to the gravity acquisition data is set according to the extension direction of the target fault and the target location point at the depth to be analyzed. The point distance between the gravity measurement points in the gravity survey line is not greater than the vertical fault distance of the target fault.

[0039] In some implementation scenarios, the gravity acquisition data obtained in step S110 can be acquired by an electronic device from the acquisition device, and the acquisition device and the electronic device performing the depth analysis can be different devices. In other implementation scenarios, the aforementioned electronic device and the acquisition device are the same device, and the acquisition device can integrate data processing functions. After the acquisition device acquires gravity acquisition data for the target fault, the data processing logic corresponding to steps S120 and S130 is executed.

[0040] The target fault refers to the fault for which depth assessment is to be performed. For the target fault, since the main body of the fault extends along a certain direction, such as extending along the east-west direction or along the north-south direction, under the influence of geological activity, the depth corresponding to different fault locations on the main body of the fault is different in most cases. The fault location for the depth to be analyzed (for example, it can be the center location or any other fault location to be analyzed) is described as the target location point.

[0041] In some embodiments, gravity survey lines formed by gravity measuring points pass through the target location and are arranged along a first direction. The first direction and the extending direction have a preset angle, which is a right angle or deviates from a right angle. The gravity survey lines extend to both sides from the fault location corresponding to the target location, and the extension length exceeds a preset value; the preset value is a preset multiple of the fault center depth value estimated from other data.

[0042] In some embodiments, for target faults whose development depth needs to be studied, the strike of the fault body is clearly defined, which is the direction of extension of the target fault. The direction of the gravity survey line is designed to be perpendicular to the strike of the target fault body or at an angle deviating from a right angle. The distance between gravity points should not be greater than the vertical fault displacement (i.e., the vertical distance at which the strata or rocks break). The gravity survey line should extend from the fault location to both sides for at least a multiple of the fault center depth value estimated from other data (e.g., 1, 2, 10, or more times, the specific value being selected based on the sufficiency of the data required for actual exploration and the consideration of data acquisition costs). For areas where gravity area measurement is carried out, gravity data can be extracted perpendicular to the target fault by deploying gravity area measurement survey lines according to the gravity area measurement survey line scheme.

[0043] In some embodiments, the first direction, extension length, and acquisition location and spacing of gravity measuring points are determined by collecting and analyzing existing exploration data.

[0044] Specifically, the distribution characteristics of faults can be determined by analyzing existing exploration data, thus identifying the first direction corresponding to the gravity survey line. This first direction is set to have a preset angle with the extension direction of the target fault. This angle can be a right angle or a right angle with a deviation value, which can be set according to the actual situation. When calculating the fault center depth at the target location point, this angle can be used to determine the corresponding preset proportion. For example, the first direction can be set to be perpendicular to the extension direction of the target fault.

[0045] The vertical displacement of the target fault can also be obtained based on existing exploration data. The distance between gravity measuring points in the gravity survey line is set to be no greater than the vertical displacement of the target fault. By setting the distance between gravity measuring points to be no greater than the vertical displacement of the target fault, the distance between the collected gravity measuring points is kept small. In this way, the gravity information collected can be used to extract more refined gravity features that reflect the depth of the fault.

[0046] After determining the acquisition locations, point spacing, and the first direction and extension length of the gravity measurement line, acquisition instruments can be deployed to collect corresponding data. For example, a gravimeter can be used to measure the gravity value at each gravity measurement point to obtain the observed gravity value, and a positioning device can be used to measure the coordinates and elevation of each gravity measurement point to obtain the coordinates and elevation of each gravity measurement point.

[0047] In step S120, based on the gravity acquisition data mentioned above, the total gravity gradient information corresponding to each gravity measurement point is determined.

[0048] The above-mentioned total gravity gradient information includes the correspondence between the total gravity gradient of each gravity measuring point and the position of each gravity measuring point.

[0049] In some embodiments, the gravity acquisition data mentioned above includes: observed gravity values ​​for each gravity measuring point.

[0050] In step S120 above, based on the gravity acquisition data, the total gravity gradient information corresponding to each gravity measuring point is determined, including:

[0051] Bouguer correction and normal field correction are applied to the observed gravity values ​​based on the coordinates and elevation values ​​of each gravity measuring point, and terrain correction is applied to the observed gravity values ​​of each gravity measuring point based on the terrain data, so as to obtain the Bouguer gravity anomaly data corresponding to each measuring point.

[0052] Based on the above Bouguer gravity anomaly data, the total horizontal gradient or gravity gradient of gravity is calculated for each gravity measuring point on the above gravity measuring line to obtain the total horizontal gradient of gravity corresponding to each gravity measuring point.

[0053] Determine the position of each gravity measuring point on the aforementioned gravity measuring line. The aforementioned position is represented by the relative distance of each gravity measuring point to the specified measuring point.

[0054] Based on the location of each gravity measuring point and the corresponding total gravity gradient, the total gravity gradient information corresponding to each gravity measuring point is determined.

[0055] The above-mentioned horizontal gravity gradient calculation refers to dividing the Bouguer gravity anomaly or residual gravity anomaly value between two adjacent points by the distance between the two points. The above-mentioned total horizontal gravity gradient calculation refers to dividing the Bouguer gravity anomaly or residual gravity anomaly value between two adjacent points by the distance between the two points and then taking the absolute value. The above-mentioned residual gravity anomaly refers to the gravity anomaly obtained by removing regional gravity anomalies from the Bouguer gravity anomaly.

[0056] The specified measuring point can be the leftmost or rightmost endpoint of the gravity measuring line, or other gravity measuring points.

[0057] In some embodiments, a total gravity gradient profile can be drawn based on the aforementioned total gravity gradient information. Specifically, the horizontal axis of the profile is distance, and the vertical axis is the total gravity gradient. Based on the distance from each gravity measuring point to the designated measuring point and the total gravity gradient of each gravity measuring point, the corresponding position coordinates are drawn on the profile, and the position coordinates are connected in sequence to obtain the curve of the above correspondence, which is the total gravity gradient profile (hereinafter referred to as the profile).

[0058] In step S130, the fault center depth of the target location point is determined based on the half-maximum width corresponding to the total gravity gradient information.

[0059] In some embodiments, the total gravity gradient information includes: the correspondence between the total gravity gradient of each gravity measuring point and the position of each gravity measuring point, wherein the position is represented by the relative distance of each gravity measuring point to a specified measuring point; wherein the half-maximum width is determined by: obtaining the half-maximum width according to the correspondence; or, determining the half-maximum width according to the curve of the correspondence.

[0060] In some embodiments, step S130 above, determining the fault center depth of the target location point based on the half-maximum width corresponding to the total gravity gradient information, includes:

[0061] Based on the above total gravity gradient information, determine the maximum value of the total gravity gradient at each gravity measuring point;

[0062] Based on the above maximum value, determine the value of the half-extreme and the corresponding two half-extreme positions; since the half-extreme positions are the two intersection points calculated by intersecting the half-extreme line with the curve (e.g., the cross-sectional view in the example above), the half-extreme positions may coincide with the measured gravity measurement points, or they may not coincide with the measured gravity measurement points.

[0063] The half-extreme width is determined based on the two half-extreme positions mentioned above. The preceding three steps are the process of determining the half-extreme width, which can be seen as a specific implementation process for obtaining the half-extreme width based on the correspondence; or it can be seen as a specific implementation process for determining the half-extreme width based on the curve of the above correspondence. For the curve, the process of determining the two half-extreme positions corresponding to the half-extreme is to draw the half-extreme line (the half-extreme line is a horizontal line with a value half of the maximum value) and intersect it with the profile to obtain two intersection points; the distance between the two intersection points is read to determine the half-extreme width.

[0064] The preset ratio of the above-mentioned half-extreme width is determined as the fault center depth of the above-mentioned target location point.

[0065] In some embodiments, the preset ratio is related to the angle between the gravity survey line and the extension direction. When the angle between the gravity survey line and the extension direction is a right angle, the preset ratio is equal to 1 / 2. When there is a deviation between the angle between the gravity survey line and the extension direction and a right angle, the preset ratio is the product of 1 / 2 and a preset correction coefficient; the preset correction coefficient is related to the deviation value corresponding to the angle.

[0066] In the embodiment including steps S110 to S130 above, considering that the gravity anomaly characteristics at corresponding locations on the ground on both sides of the fault will be different when the fault center depth is different, the greater the fault center depth, the gentler the change in gravity anomaly above the fault, and vice versa; by acquiring gravity acquisition data for the target fault, since the gravity survey line corresponding to the above gravity acquisition data is set according to the extension direction of the above target fault and the target location point at the depth to be analyzed, the point distance corresponding to the gravity measurement point in the above gravity survey line is not greater than the vertical fault displacement of the above target fault, therefore the gravity measurement point corresponding to the gravity measurement point on the gravity survey line Gravity variation characteristics can accurately reflect different fault depth characteristics. Based on the gravity acquisition data, the total gravity gradient information corresponding to each gravity measurement point is determined. The total gravity gradient information reflects the gravity variation characteristics. The fault center depth at the target location is evaluated based on the half-maximum width corresponding to the total gravity gradient information. This method can efficiently and quickly assess the fault center depth with satisfactory accuracy. It can also assess the fault center depth even in areas with low exploration levels or limited known information in deep or ultra-deep exploration areas, making it widely applicable.

[0067] The following examples demonstrate the implementation process and corresponding effects of the above method using fault model data and measured gravity data. Example 1 is an example of determining the fault center depth using fault model gravity forward modeling data, mainly demonstrating the correctness of the estimation results of this method, including two comparative examples 11 and 12. Example 2 is an example of determining the fault center depth using measured gravity data, mainly demonstrating the technical feasibility and beneficial effects of this method.

[0068] Figure 2A A schematic diagram of a fault geological model with a center depth of 1 km according to an embodiment of the present disclosure is shown. Figure 3A A schematic diagram illustrates Bouguer gravity anomaly data obtained by forward modeling a fault with a center depth of 1 km according to an embodiment of the present disclosure. Figure 4A The diagram schematically illustrates a gravity horizontal gradient profile plotted for a fault model with a center depth of 1 km according to an embodiment of the present disclosure, and a schematic diagram of determining the center depth of the fault at a target location point in the target fault based on the half-maximum width.

[0069] Reference Figures 2A to 4A As shown, the fault geological model used in Example 11 includes two sets of horizontal strata, with the lower strata having a density 0.1 g / cm³ greater than the upper strata. 3 , Figure 2AIn the geological model of the fault, the interface depth between the two strata before the fault occurs is -900m. The fault occurs at coordinate 0, with the strata on the left side of the fault dropping downwards at a vertical displacement of 200m. The interface depth between the two strata decreases to -1100m, while the interface depth on the right side of the fault remains unchanged. At this point, the upper part of the faulted strata is at a depth of -900m, the lower part is at -1100m, and the center depth is -1000m. The first direction of gravity survey line extension, gravity point spacing, and gravity survey line length can be determined by analyzing geological exploration data. In actual exploration work, existing exploration data in the study area are first collected and analyzed to determine the fault distribution, identify the target fault at the depth to be studied, and determine its main strike (i.e., the extension direction of the target fault). Then, gravity survey lines are laid out, with the first direction of the gravity survey lines set perpendicular to the main strike of the target fault. For this example model study, the gravity survey line direction is perpendicular to the fault direction, and the profile direction for the gravity forward modeling calculation adopts the gravity survey line direction. The gravity point spacing should not be greater than the vertical fault displacement; the smaller the point spacing, the more accurate the determination of the maximum value of the horizontal gravity gradient. In this example model study, the gravity point spacing is the same as the gravity point spacing calculated in the model forward modeling, which is 100m. The length of the gravity survey line should extend from the fault location to both sides to more than twice the estimated fault depth, i.e., more than 1000m, to ensure sufficient research data in subsequent implementation. In this example, to demonstrate the complete gravity curve shape, the survey line extends 10000m from the fault location to both sides.

[0070] Then, gravity data acquisition is performed. Gravity instruments are used to measure the gravity values ​​at each gravity measurement point, and positioning instruments are used to measure the coordinates and elevations of each gravity measurement point. For model gravity studies, the gravity values ​​at each calculation point can be obtained through gravity forward modeling, and the coordinates of the gravity points are the distance values ​​set in the model forward modeling. The above two processes can be considered as the process of acquiring gravity acquisition data corresponding to step S110.

[0071] Subsequently, Bouguer and normal field corrections were applied to the observed gravity values ​​at each gravity measuring point using the coordinates and elevations of the measuring points. Topographic corrections were then applied using the coordinates, elevations, and terrain data of the gravity measuring points, yielding Bouguer gravity anomaly data for each point. For the model gravity analysis, the elevation of the gravity measuring points was set to 0; therefore, the Bouguer correction, normal field correction, and terrain correction values ​​for each gravity measuring point were all 0. Thus, the calculated gravity anomaly data is equivalent to the Bouguer gravity anomaly. Figure 3AAs shown. Bouguer gravity anomaly calculation is a fundamental calculation task in gravity exploration. Textbooks contain complete calculation formulas, and gravity data processing personnel are familiar with the data processing methods, so they will not be elaborated here. The gravity anomaly obtained by model gravity forward modeling is equivalent to the Bouguer gravity anomaly obtained by implementing step S120 of the embodiments provided in this disclosure. The purpose is to obtain basic gravity data for fault depth research. Using model data for methodological research is also a commonly used method in technical research, and therefore it can also verify the correctness of the method provided in the embodiments of this disclosure.

[0072] Next, by calculating the total horizontal gradient of the Bouguer gravity anomaly, the total horizontal gravity gradient at each gravity measuring point along the survey line is obtained. For example, by calculating the horizontal gradient value of the gravity anomaly obtained from the previous gravity forward model calculation and taking its absolute value, the total horizontal gravity gradient (which can also be described as the total horizontal gravity gradient anomaly) is obtained. Based on the distance from each gravity measuring point to the starting point (i.e., the specified measuring point) and the total horizontal gravity gradient at each gravity measuring point, the corresponding positions are marked on the profile diagram. Connecting the corresponding positions of each point forms the total horizontal gravity gradient curve, which is the total horizontal gravity gradient profile diagram. See [link to relevant documentation]. Figure 4A As shown.

[0073] Continue to refer to Figure 4A As shown in the diagram, the location of the maximum value of the total horizontal gradient is indicated on the gravity gradient profile. The maximum value is located near the x-axis (0), and its approximate value is 0.268 × 10⁻⁶. -8 s -2 Near the maximum value of the total horizontal gradient curve, draw a horizontal line segment with a value half that of the maximum value. This is called the semi-extreme line. The value of the semi-extreme line is half that of the maximum value of the total horizontal gradient curve, which is 0.134 × 10⁻⁶. -8 s -2 The semi-extreme line intersects the total horizontal gradient curve of gravity on both sides of the maximum value, with the two intersection points at... Figure 4A C1 and C2 are illustrated below. By drawing perpendicular lines from C1 and C2 and intersecting them on the horizontal axis, the width between the two intersection points on the horizontal axis is obtained, which gives the half-maximum width of the total horizontal gradient of gravity. Figure 4A It can be seen that the positions of C1 and C2 on the horizontal axis are -1000m and 1000m respectively, and thus the half-maximum width of the total horizontal gradient of gravity is 2000m.

[0074] The center depth of the target fault is determined by half the half-maximum width of the total horizontal gravity gradient. Therefore, with a half-maximum width of 2000m, half of this half-maximum width is calculated to be 1000m. Thus, the center depth of the fault is estimated to be 1000m. This completes the estimation of the center depth of the target location (e.g., the center, or other fault locations) within the fault. Model validation shows that the estimated center depth of the target fault is... Figure 2A The fault geological model in the example has a consistent fault center depth of 1000m, demonstrating that the method provided in this disclosure has high accuracy in determining the fault center depth.

[0075] Figure 2B A schematic diagram of a fault geological model with a center depth of 2 km according to an embodiment of the present disclosure is shown. Figure 3B A schematic diagram illustrates Bouguer gravity anomaly data obtained from forward modeling of a fault with a center depth of 2 km according to an embodiment of the present disclosure. Figure 4B The diagram schematically illustrates a gravity horizontal gradient profile plotted for a fault model with a center depth of 2 km according to an embodiment of the present disclosure, and a schematic diagram of determining the depth of a target location point in the target fault based on the half-maximum width.

[0076] To verify the applicability of this method, refer to Figure 2B As shown, Example 12 provides another model for verification. Compared to the model in Example 11, the depth is increased by 1 km. Specifically, before the fault occurs, the interface depth between the two strata is -1900 m. The fault occurs at coordinate 0, with the strata on the left side of the fault dropping downwards at a vertical displacement of 200 m. The interface depth between the two strata decreases to -2100 m, while the interface depth on the right side of the fault remains unchanged. At this point, the upper part of the fault-triggered strata is at a depth of -1900 m, the lower part is at -2100 m, and the central depth is -2000 m.

[0077] The model gravity anomaly was calculated using the same procedure as in Example 11. See [link / reference] Figure 3B As shown. The total horizontal gradient of gravity was calculated for the model's gravity anomaly, and the depth of the fault center was estimated. See [link to relevant documentation]. Figure 4B As shown, the obtained half-maximum width of the total horizontal gradient is 4 km. Taking half of this width as the fault center depth, the fault center depth is calculated to be 2 km. This is consistent with... Figure 2B The center depth of the fault is consistent with that of the model, which is 2 km. Comparing Examples 11 and 12, it can be seen that the fault center depth determined by gravity data is consistent with the fault center depth displayed by the model, further illustrating that the method provided in this embodiment has universal applicability to models of different depths.

[0078] In some embodiments of this disclosure, a gravity survey line corresponds to one or more target faults; in the case of multiple target faults, multiple extreme points and corresponding half-extreme widths are determined based on the above-mentioned total gravity level gradient information, and the fault center depth of the corresponding target location point in the multiple target faults can be determined.

[0079] Figure 5 This diagram schematically illustrates Bouguer gravity anomaly data obtained after collecting geological exploration data on a fault in a basin according to an embodiment of the present disclosure. Figure 6 The illustration schematically shows a gravity horizontal gradient profile obtained by drawing gravity horizontal gradient information corresponding to each gravity measuring point in a basin according to an embodiment of the present disclosure, and a schematic diagram of determining the fault center depth of the target location point in the target fault based on the half-maximum width.

[0080] Reference Figure 5 and Figure 6 As shown in Example 2, actual gravity exploration data was used to estimate the depth of the fault center. The study area in this example is located in a basin. To understand the basic geological structure of the basin, gravity exploration was carried out in the area, and the fault depth estimation was based on this actual gravity data. By collecting regional gravity data, it was found that the area mainly has east-west trending structures, and the faults are distributed in a near-east-west direction. To conduct structural research, detailed research on the faults is required. Therefore, area gravity measurement work was deployed, and the direction of the gravity survey lines was determined to be north-south. The exploration scale was determined to be 1:50,000, and the distance between gravity points and lines was 500m. The gravity survey line range of this gravity exploration was relatively large, covering multiple faults, which met the requirement that the gravity range should be extended by 1 times the estimated depth from the fault. Gravity values ​​were measured at each gravity measurement point using a gravimeter to obtain the observed gravity values ​​at the gravity measurement points. The coordinates and elevations of each gravity measurement point were measured using a positioning instrument to obtain the coordinates and elevations of the gravity measurement points. Bouguer and normal field corrections were applied to the observed gravity values ​​at each gravity measuring point using the coordinates and elevations of the measuring points. Topographic corrections were then applied to the observed gravity values ​​using terrain data, yielding Bouguer gravity anomaly data for each measuring point. (Refer to...) Figure 5 As shown, distinct gravity gradient zones exist at 4000m-6000m and 20000m-23000m, indicating the presence of faults in these areas. The total horizontal gradient of the Bouguer gravity anomaly data was calculated to obtain the total horizontal gravity gradient at each gravity measuring point along the survey line. This total horizontal gravity gradient is obtained by dividing the Bouguer gravity anomaly value of two adjacent points by the distance between them and then taking the absolute value. A profile of the total horizontal gravity gradient was drawn based on the information from each gravity measuring point; see [link to profile]. Figure 6 As shown, two distinct maxima of the total horizontal gravity gradient were found on the gravity gradient profile. The two maxima of the total horizontal gravity gradient are approximately 4.52 × 10⁻⁶. -8 s-2 and 5.24×10 -8 s -2 Then, take half of its value, which is 2.26 × 10 -8 s -2 and 2.62×10 -8 s -2 Draw a semi-extreme line near each of the two maxima. These semi-extreme lines intersect the total horizontal gradient curve of gravity on either side of the maxima. (See [reference]). Figure 6 As shown, perpendicular lines are drawn from the intersection points of the half-maxima lines of the two maxima with the total gravity gradient curve, intersecting the horizontal axis. Reading from these intersection points, the half-maxima widths of the two maxima of the total gravity gradient are approximately 2400m and 3600m, respectively. Based on these half-maxima widths of 2400m and 3600m, the estimated center depths of the two faults are approximately 1200m and 1800m, respectively. This demonstrates the ability to estimate fault center depth using gravity data. This example shows that fault center depth can be quickly estimated using gravity data. The method is feasible and the process is simple. The depth estimation process does not involve complex processes such as gravity profile modeling and inversion, greatly simplifying the work process, reducing its difficulty and intensity, and promoting the use of gravity methods—which offer low exploration costs and high acquisition efficiency—for fault depth research and geological exploration.

[0081] A second exemplary embodiment of this disclosure provides an apparatus for determining the depth of the fault center.

[0082] Figure 7 A structural block diagram of a device for determining the depth of the fault center according to an embodiment of the present disclosure is shown schematically.

[0083] Reference Figure 7 As shown, the fault center depth determination device 700 provided in this embodiment includes: a data acquisition module 710, a gravity distribution determination module 720, and a depth determination module 730.

[0084] The aforementioned data acquisition module 710 is used to acquire gravity acquisition data for the target fault. The gravity survey line corresponding to the gravity acquisition data is set according to the extension direction of the target fault and the target location point at the depth to be analyzed. The point distance between the gravity measurement points in the gravity survey line is not greater than the vertical fault distance of the target fault.

[0085] The gravity distribution determination module 720 is used to determine the total gravity level gradient information corresponding to each gravity measuring point based on the gravity acquisition data.

[0086] The depth determination module 730 is used to determine the fault center depth of the target location point based on the half-maximum width corresponding to the total gravity gradient information.

[0087] The apparatus of this embodiment may also include more functional modules, and the details of the implementation of each functional module can be referred to the relevant description of the first embodiment, which will not be repeated here.

[0088] Any plurality of the functional modules included in the aforementioned device 700 may be combined into one module, or any one of the modules may be split into multiple modules. Alternatively, at least a portion of the functionality of one or more of these modules may be combined with at least a portion of the functionality of other modules and implemented in one module. At least one of the functional modules included in the aforementioned device 700 may be at least partially implemented as hardware circuitry, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a System-on-Chip, a System-on-Substrate, a System-on-Package, an Application-Specific Integrated Circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging circuitry, or implemented in software, hardware, or firmware, or in any appropriate combination of any of these three implementation methods. Alternatively, at least one of the functional modules included in the aforementioned device 700 may be at least partially implemented as a computer program module, which, when run, can perform corresponding functions.

[0089] A third exemplary embodiment of this disclosure provides an electronic device.

[0090] Figure 8 A schematic block diagram of an electronic device provided in an embodiment of the present disclosure is shown.

[0091] Reference Figure 8 As shown, the electronic device 800 provided in this embodiment includes a processor 801, a communication interface 802, a memory 803, and a communication bus 804. The processor 801, the communication interface 802, and the memory 803 communicate with each other through the communication bus 804. The memory 803 is used to store computer programs. When the processor 801 executes the program stored in the memory, it implements the method for determining the fault center depth as described above.

[0092] A fourth exemplary embodiment of this disclosure also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for determining the fault center depth as described above.

[0093] The computer-readable storage medium may be included in the device or apparatus described in the above embodiments; or it may exist independently and not assembled into the device or apparatus. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0094] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0095] It should be noted that the collection, gathering, updating, analysis, processing, use, transmission, and storage of user personal information involved in the technical solutions provided in this disclosure comply with the provisions of relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. Necessary measures are taken to prevent unauthorized access to user personal information data and to safeguard user personal information security, network security, and national security.

[0096] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0097] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for determining the depth of a fault center, characterized in that, include: Gravity acquisition data is obtained for the target fault. The gravity survey line corresponding to the gravity acquisition data is set according to the extension direction of the target fault and the target location point at the depth to be analyzed. The point distance between gravity measurement points in the gravity survey line is not greater than the vertical fault distance of the target fault. Based on the gravity acquisition data, determine the total gravity gradient information corresponding to each gravity measurement point; The fault center depth at the target location is determined based on the half-maximum width corresponding to the total gravity gradient information.

2. The method according to claim 1, characterized in that, The total gravity gradient information includes: the correspondence between the total gravity gradient of each gravity measuring point and the position of each gravity measuring point, wherein the position is represented by the relative distance of each gravity measuring point to a specified measuring point; The half-extreme width is determined by: obtaining the half-extreme width according to the correspondence; or, determining the half-extreme width according to the curve of the correspondence.

3. The method according to claim 1 or 2, characterized in that, Based on the half-maximum width corresponding to the total gravity gradient information, the fault center depth at the target location is determined, including: Based on the total gravity gradient information, determine the maximum value of the total gravity gradient at each gravity measuring point; Based on the maximum value, determine the value of the half-extreme and the corresponding positions of the two half-extremes; The half-extreme width is determined based on the two half-extreme positions; The preset ratio of the half-extreme width is determined as the fault center depth of the target location point.

4. The method according to claim 3, characterized in that, The preset ratio is related to the angle between the gravity measuring line and the extension direction; When the angle between the gravity measuring line and the extension direction is a right angle, the preset ratio is equal to 1 / 2; When there is a deviation between the angle between the gravity measuring line and the extension direction and a right angle, the preset ratio is the product of 1 / 2 and a preset correction coefficient; the preset correction coefficient is related to the deviation value corresponding to the angle.

5. The method according to claim 1, characterized in that, The gravity acquisition data includes: observed gravity values ​​for each gravity measuring point; Specifically, based on the gravity acquisition data, the total gravity level gradient information corresponding to each gravity measurement point is determined, including: Bouguer correction and normal field correction are applied to the observed gravity values ​​based on the coordinates and elevation values ​​of each gravity measuring point, and terrain correction is applied to the observed gravity values ​​of each gravity measuring point based on the terrain data, so as to obtain the Bouguer gravity anomaly data corresponding to each measuring point. Based on the Bouguer gravity anomaly data, the total horizontal gradient or gravity gradient of gravity is calculated for each gravity measuring point on the gravity measuring line to obtain the total horizontal gradient of gravity corresponding to each gravity measuring point. The position of each gravity measuring point on the gravity measuring line is determined, and the position is represented by the relative distance of each gravity measuring point to a specified measuring point; Based on the location of each gravity measuring point and the corresponding total gravity gradient, the total gravity gradient information corresponding to each gravity measuring point is determined.

6. The method according to claim 1, characterized in that, The gravity measuring line formed by gravity measuring points passes through the target location point and is arranged along the first direction as a whole. There is a preset angle between the first direction and the extension direction. The angle is a right angle or has a deviation from the right angle. The gravity survey line extends from the fault location corresponding to the target location point to both sides, and the extension length exceeds a set value; the set value is a preset multiple of the fault center depth value estimated by other data.

7. The method according to claim 1, characterized in that, A gravity survey line corresponds to one or more target faults; when it corresponds to multiple target faults, multiple extreme points and corresponding half-extreme widths are determined based on the total gravity level gradient information, and the fault center depth of the corresponding target location point in the multiple target faults can be determined.

8. A device for determining the depth of a fault center, characterized in that, include: The data acquisition module is used to acquire gravity data for the target fault. The gravity survey line corresponding to the gravity data is set according to the extension direction of the target fault and the target location point of the depth to be analyzed. The point distance between the gravity measurement points in the gravity survey line is not greater than the vertical fault distance of the target fault. The gravity distribution determination module is used to determine the total gravity level gradient information corresponding to each gravity measuring point based on the gravity acquisition data. The depth determination module is used to determine the fault center depth of the target location point based on the half-maximum width corresponding to the total gravity gradient information.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method of any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1-7.

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