A method for modeling complex geology with strong heterogeneity based on ANSYS and APDL

Abstract

The application discloses a complex geology modeling method based on ANSYS and APDL for strong heterogeneity, which comprises the following steps: 1) obtaining layer coordinates; 2) obtaining fault coordinates and integrating data; 3) importing coordinate data to establish a geometric model; 4) dividing a grid; and 5) establishing a heterogeneous mechanical model. According to the characteristics of actual geological conditions, the application mainly considers factors such as structural forms and fault development conditions, establishes a geometric model with a complex form and divides a grid, combines the characteristics of the APDL language to create a command stream, improves operation accuracy and work efficiency, and improves the coincidence rate of the geometric model and the actual stratum form. In addition, the application considers the mechanical properties of rocks and the distribution law thereof, uses methods such as earthquakes, well logging and rock testing to obtain mechanical parameter data such as elastic modulus, Poisson's ratio and density in a three-dimensional space, compares attribute coordinates with finite element coordinates and performs attribute assignment, and establishes a heterogeneous mechanical model, so that the application has a wide application prospect in oil and gas reservoir exploration and development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geomechanical modeling methods in the process of oil and gas field exploration and development, and particularly relates to a strong heterogeneity complex geology modeling method based on ANSYS and APDL. BACKGROUND

[0002] Geostress has important influence on oil and gas migration, reservoir formation, fault sealing property, structural fracture and fracturing fracture prediction. The geostress measurement based on core or wellbore is the most direct and effective means to determine the geostress state, but such method can only obtain the geostress data in the extremely limited range around the well, therefore, the application of numerical simulation in the regional three-dimensional geostress research based on single well data is increasingly important. At present, the ANSYS software is relatively simple to operate, and gradually becomes the most popular finite element analysis software in the international range with its powerful general analysis function, and has been widely applied in many fields including civil engineering, petroleum and chemical industry, etc. Some domestic scholars use the ANSYS software to analyze the three-dimensional geostress and have achieved good application effect.

[0003] Due to the very complex actual underground conditions, it is impossible to use a certain and specific mathematical function relationship to represent the layer shape, and when establishing the geology model, the influence of factors such as stratigraphic structure fluctuation, fault development and mechanical characteristic change must be considered to reflect the real stratigraphic conditions as much as possible. Through investigation, the main method in domestic research is to simplify the complex model to establish the geometric model, and to simplify the heterogeneity parameters into a few homogeneous parameters to assign and establish the mechanical model, which leads to low reliability of the calculation result and is difficult to truly reflect the underground conditions. At present, there is no ANSYS modeling method for strong heterogeneity complex stratum.

[0004] At present, there are many research literatures on the numerical simulation analysis of geostress field using the ANSYS software, but there are few patents on the modeling method for strong heterogeneity actual stratum. The published patents are mainly in the research fields of machinery and materials, and there is no complex modeling method in the fields of geology and geostress research, which causes a large difference between the model and the actual situation, and most of the research results are used as theoretical guidance, and the original design goal of modeling and numerical simulation is not completely achieved.

[0005] Three-dimensional geology modeling is the basis for the research and analysis of geologic bodies, and has important significance in the process of oil and gas reservoir exploration and development, in which the structural shape, fault distribution and mechanical characteristic parameter assignment have great influence on the model and are important factors for the model to reflect the actual geologic body. At present, there is no ANSYS modeling method for strong heterogeneity complex stratum, and there is an urgent need for a geology modeling method suitable for strong heterogeneity complex geological conditions to improve the model coincidence rate and work efficiency.

[0006] The main problems to be solved urgently have the following three aspects:

[0007] (1) The formation structure is complex, the thickness changes greatly, and the continuity is poor. If the conventional scattered point artificial manual bottom-up modeling is adopted, the speed is slow, the efficiency is low, and errors are prone to occur in the process. Therefore, the machine is required to execute the command to model, so as to improve the efficiency.

[0008] (2) The fault shape is irregular, and a large number of repeated deletion and connection operations are required in the conventional modeling process. The efficiency is low, and errors are prone to occur. A new data arrangement mode is required to be established to facilitate machine language reading and execution.

[0009] (3) The actual formation lithology changes rapidly, has strong heterogeneity, and there is no clear mathematical relationship between the characteristic expression parameters. If the conventional method is adopted to distinguish only a small number of blocks to assign material parameters, the difference with the actual geological conditions is large. Therefore, the mechanical characteristic parameters of each unit participating in the calculation are required to be distinguished, so as to express the heterogeneity in the mechanical model to a large extent.

[0010] Therefore, a strong heterogeneity complex geological modeling method based on ANSYS and APDL is provided. The three-dimensional geometric model is accurately established, the mechanical parameters of each unit are finely assigned, the model coincidence rate and work efficiency are effectively improved, and the method has a wide application prospect in oil and gas reservoir exploration and development. SUMMARY

[0011] The present application aims to provide a strong heterogeneity complex geological modeling method based on ANSYS and APDL. According to the characteristics of the actual geological conditions, the structural form, fault development and other factors are mainly considered. The geometric model of complex form is established and the grid is divided. The command stream is created in combination with the characteristics of the APDL language to improve the operation accuracy and work efficiency, and the coincidence rate of the geometric model and the actual formation form is improved. The mechanical properties of rock and their distribution law are considered. The elastic modulus, Poisson's ratio, density and other mechanical parameter data in the three-dimensional space are obtained by using seismic, logging, rock testing and other methods. The attribute coordinates and the finite element coordinates are compared and the attribute assignment is performed to establish the heterogeneous mechanical model.

[0012] The method is suitable for ANSYS mechanical modeling research with high coincidence rate requirement in domestic oil and gas reservoir exploration and development. The establishment of related geometric model and mechanical model is carried out by using the method, the model coincidence rate and work efficiency are effectively improved, and the method has a wide application prospect in oil and gas reservoir exploration and development.

[0013] In order to achieve the above-mentioned application purposes, the technical scheme of the present application is as follows:

[0014] A strong heterogeneity complex geological modeling method based on ANSYS and APDL comprises the following steps,

[0015] 1) Obtain layer coordinates, according to the structural form of the study area, obtain three-dimensional coordinate data along the main structural axis at equal intervals or within 10% non-equal intervals on the top and bottom surfaces of the target layer, respectively, wherein the X and Y coordinates of the corresponding points of each layer surface should correspond to the same;

[0016] 2) Obtain fault coordinates and integrate data, obtain three-dimensional coordinate data of the two plates of the fault in the corresponding layer surface in step 1), said two plates refer to the two side block bodies formed after the bottom layer is broken, replace the coordinates of each point near the fault position in the layer surface with the true three-dimensional coordinates of the fault, arrange the coordinates in rows or columns and number them, and integrate them into a complete keypoint file, said integration is arranged in a certain format, including keypoint number, X coordinate, Y coordinate and Z coordinate information, and separated by ",";

[0017] 3) Import coordinate data to establish a geometric model, import the keypoint coordinate data integrated in step 2) into ANSYS, use APDL language to write executable command stream, in the three-dimensional coordinate points of the top surface and the bottom surface, connect each point in order to form a pseudo-triangular prism, and establish a geometric model from top to bottom, improve the accuracy and efficiency of the geometric model;

[0018] 4) Divide the grid, select solid element type and Tet-free method to divide the grid in ANSYS, determine the grid size according to the calculation accuracy requirement and calculation speed requirement, such as: if the subsequent calculation result requires an accuracy of 50 meters, the grid element length needs to be less than 50 meters, if the calculation result requires an accuracy of 20 meters, the grid element length needs to be less than 20 meters, the calculation speed is related to the number of grid elements and the device hardware, when the device hardware is the same, the more the number of grid elements, the slower the general calculation speed, under the condition of meeting the calculation accuracy, the number of grids can be reduced to speed up the calculation speed;

[0019] 5) Establish a heterogeneous mechanical model, use the comprehensive inversion calculation of the sedimentary facies, logging data and three-dimensional seismic body data in the study area to obtain the mechanical characteristic parameters of Young's modulus, Poisson's ratio and density of each three-dimensional coordinate point in the depth domain, and export the text data; use APDL language to write executable command stream to calculate the distance between each attribute point and the center point of the element, obtain the center point of each element and its nearest mechanical coordinate point, and assign values to each element attribute accordingly, to establish a heterogeneous mechanical model. The model established by this method includes the geometric structural form information of the study area, the three-dimensional geometric information of each element of the finite element, the mechanical parameter information in each element, etc., which has a high coincidence rate with the actual geological environment information.

[0020] Further, the structural form of the study area in step 1) includes stratigraphic trend, anticline axis trend, syncline axis trend and fault trend.

[0021] Further, the main structural axial direction in the step 1) is a anticline axial direction and a main large-scale fault axial direction.

[0022] Further, after the coordinates of the points near the fault position in the layer are replaced by the real three-dimensional coordinates of the fault in the step 2), the key point coordinates are used to control the fault shape, and the model has a high coincidence rate with the actual geological shape.

[0023] Further, in the step 3), the X coordinates and Y coordinates of the top 3 points and the bottom 3 points of the triangular prism correspond to each other, so that the sides of the triangular prism are planes, and the top surface and the bottom surface are planes, thereby avoiding that the layer with multiple point groups becomes a curved surface to cause the geometric model to be not closed, the APDL language is used for programming, the machine is executable, and the working efficiency is improved.

[0024] Further, the step 3) further comprises checking the quality of the geometric model, including checking the three-dimensional geometric shape, the structural shape coincidence degree and the contact relationship between the geometric bodies.

[0025] Further, the step 3) further comprises checking the quality of the geometric model, including checking the three-dimensional geometric shape, the structural shape coincidence degree and the contact relationship between the geometric bodies.

[0026] Further, the step 4) further comprises checking the quality of the grid, including the grid element shape and the grid quantity.

[0027] Further, the step 4) further comprises checking the quality of the grid, including the grid element shape and the grid quantity.

[0028] Further, the step 5) utilizes the APDL language to write an executable command stream for comparison, specifically as follows: 1) obtaining three-dimensional coordinates and mechanical property values; 2) obtaining the center point coordinates of the elements; 3) calculating the distance between the center point coordinates of the elements and the three-dimensional property coordinates; 4) selecting the nearest property; and 5) corresponding to each element property, the elastic modulus, Poisson's ratio and density values are given.

[0029] Further, the center point of the element is simplified as the average value of the coordinates of four corner points, and the regular solid grid is generally an 8-node hexahedral grid, which is degraded to a 4-node tetrahedral shape due to the complexity and irregularity of the geological geometric model, and after the degradation, various complex and irregular model mechanical operations are supported.

[0030] The present application has the following advantages:

[0031] 1. The application forms a strong heterogeneous complex geological modeling method based on ANSYS software and APDL, which can guide the geological modeling work of many domestic oil and gas enrichment areas, and the coincidence rate of the model with the actual geological conditions is improved by about 5%, and plays an important role in the process of domestic oil and gas reservoir exploration and development.

[0032] 2. The method in the application focuses on establishing a strong heterogeneous complex geological model by ANSYS, fully considers the complexity of actual geological conditions, structural morphology, fault development, mechanical property change and other factors, and forms a set of geological modeling method suitable for complex structural morphology and strong mechanical heterogeneity, which can effectively guide the establishment of strong heterogeneous complex geological model and improve the coincidence rate and work efficiency of the model.

[0033] 3. In the application, the data integration method and APDL geometric modeling: combining the characteristics of ANSYS software and APDL language, the data integration method is improved to express the complex geological structural morphology as a limited number of coordinate data with regularity, and the modeling direction is changed from the conventional bottom-up modeling to top-down modeling, which improves the coincidence rate and operation accuracy of the model and improves the work efficiency.

[0034] 4. In the application, the APDL establishes a heterogeneous mechanical model: comprehensive utilization of various geological data analysis in the study area, obtaining the mechanical characteristic parameters such as Young's modulus, Poisson's ratio and density of each three-dimensional coordinate point, giving the attribute value of the point with the smallest relative distance of each unit, and using APDL language to establish a mechanical model with strong heterogeneity. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a geological modeling method flow chart of the application.

[0036] Figure 2 It is a schematic diagram for replacing each point coordinate near the fault position in the layer with the real three-dimensional coordinates of the fault.

[0037] Figure 3 It is a schematic diagram of the three-prism geometric model.

[0038] Figure 4 It is a schematic diagram of the hexagonal unit and tetrahedral geometric model.

[0039] Figure 5 It is a geometric model entity diagram of embodiment 2 of the application.

[0040] Figure 6 It is a comparison diagram of the geometric model before and after checking and modifying in embodiment 2 of the application. PREFERRED EMBODIMENT

[0041] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0042] Example 1

[0043] This embodiment provides a method for modeling highly heterogeneous and complex geological conditions based on ANSYS and APDL, including the following steps:

[0044] 1) Obtain the layer coordinates. Based on the structural morphology of the study area, obtain three three-dimensional coordinate data at equal intervals or non-equal intervals within 10% along the main structural axis on the top and bottom surfaces of the target layer. The X and Y coordinates of the corresponding points of each layer should be the same. The main structural axis is the anticline axis and the main large-scale fault axis. The structural morphology of the study area includes the azimuth of the stratigraphic dip, the azimuth of the anticline axis, the azimuth of the syncline axis, and the strike of the fault.

[0045] 2) Obtain fault coordinates and integrate the data. Using the three-dimensional coordinate data of the two fault blocks at their corresponding planes obtained in step 1), where "two blocks" is a technical term referring to the rock masses on either side of the fault plane that have undergone relative displacement, replace the coordinates of points near the fault location on the plane with the actual three-dimensional coordinates of the fault, such as... Figure 2 As shown, the replacement method is A-AF, B-BF, C-CF, D-DF, E-EF, F-FF, A'-AF', B'-BF', C'-CF', D'-DF', E'-EF', F'-FF'. After replacement, the fault morphology can be controlled by the key point coordinates. The model has a high degree of consistency with the actual geological morphology. The coordinates are arranged in rows or columns and numbered. They are integrated and arranged in a certain format, including key point number, X coordinate, Y coordinate, and Z coordinate information, separated by "," to become a complete keypoint file.

[0046] 3) Import coordinate data to establish a geometric model. Import the keypoint coordinate data integrated in step 2) into ANSYS. Use APDL language to write an executable command stream. In the 3D coordinate points of the top and bottom surfaces, connect each coordinate point with its two adjacent coordinate points in sequence to form a prism-like shape, such as... Figure 3 As shown, the geometric model is built from top to bottom in either a counter-clockwise (A1-B1-C1-A2-B2-C2) or clockwise (A1-C1-B1-A2-C2-B2) sequence, improving the accuracy and efficiency of the geometric model. The X and Y coordinates of the three points on the top face and the three points on the bottom face of the triangular prism are respectively equal, ensuring that all lateral faces of the prism are planes. Simultaneously, the top and bottom faces are planes, preventing the surfaces formed by multiple points from becoming curved, which would cause the geometric model to be incomplete. The model is programmed using APDL language, making it machine-executable and further improving work efficiency.

[0047] Check the quality of the geometric model, including checking the three-dimensional geometric shape, the degree of conformity of the tectonic shape and the contact relationship between the geometric bodies, checking whether the overall shape of the model top surface and bottom surface is consistent with the actual geological tectonic shape, checking whether there are gaps between the three prisms in the model, if the check result is qualified, then proceed to the next step, if not, check whether the key point coordinates are wrong, modify and rebuild the model;

[0048] 4) Divide the grid, select the solid element type and Tet-free method in ANSYS to divide the grid, and the grid size precision is the standard to meet the calculation requirement;

[0049] Check the grid quality, including the shape of the grid element and the number of grids, use the ANSYS software to check the grid, require that the number of bad grids in the check result is not more than 1%, if the check result is qualified, then proceed to the next step, if not, modify the relevant parameters and redivide the grid;

[0050] 5) Establish a heterogeneous mechanical model, use the comprehensive inversion calculation of the sedimentary facies, well logging data and three-dimensional seismic body data in the study area to obtain the mechanical characteristic parameters of Young's modulus, Poisson's ratio and density of each three-dimensional coordinate point in the depth domain, and export the text data; use APDL language to write executable command stream for comparison to establish a heterogeneous mechanical model.

[0051] The specific steps of using APDL language to write executable command stream for comparison are: 1) obtaining three-dimensional coordinates and mechanical attribute values; 2) obtaining the coordinates of the center point of the element; 3) calculating the distance between the center point coordinates of the element and the three-dimensional attribute coordinates; 4) selecting the nearest attribute; 5) corresponding to each element attribute, assigning the elastic modulus, Poisson's ratio and density values,

[0052] In the step 5), the center point of the element is simplified as the average value of the coordinates of the four corner points, that is:

[0053] EL1=(ex1,ey1,ez1),

[0054] EL2=(ex2,ey2,ez2),

[0055] EL3=(ex3,ey3,ez3),

[0056] EL4=(ex4,ey4,ez4),

[0057] Center point coordinates:

[0058] ex=(ex1+ex2+ex3+ex4) / 4,

[0059] ey=(ey1+ey2+ey3+ey4) / 4,

[0060] ez = (ez1 + ez2 + ez3 + ez4) / 4;

[0061] As shown in Figure 4 the unit center point is simplified to the average value of the coordinates of the four corner points, and the regular entity grid is generally an 8-node hexahedral grid. Due to the complexity and irregularity of the geological geometric model, it will be degraded to a 4-node tetrahedral form. After degradation, various complex and irregular model mechanical operations are supported.

[0062] Embodiment 2

[0063] The embodiment provides a strong heterogeneous complex geological modeling method based on ANSYS and APDL, comprising the following steps,

[0064] 1) Obtain layer coordinates. According to the structural form of the study area, 3 three-dimensional coordinate data are obtained on the top and bottom surfaces of the target layer along the main structural axis at equal intervals or within 10% non-equal intervals, wherein the X and Y coordinates of the corresponding points of each layer surface should correspond to the same, the main structural axis is the axis of the anticline or the main large-scale fault axis, and the structural form of the study area includes the stratigraphic trend, the trend of the anticline axis, the trend of the syncline axis and the fault trend. The coordinates of each point on the top and bottom surfaces are shown in Table 1,

[0065] Table 1. Coordinates of each point on the top and bottom surfaces

[0066]

[0067] 2) Obtain fault coordinates and integrate data. In step 1), two plates of the fault are obtained, which are professional languages, that is, the three-dimensional coordinate data of the two side fault blocks on the corresponding layer surface after the stratum is broken. Replace the coordinates of each point near the fault position in the layer surface with the real three-dimensional coordinates of the fault. After replacement, the key point coordinates can be used to control the fault form, the model has high conformity with the actual geological form, the coordinates are arranged in rows or columns and numbered, integrated, arranged in a certain format, including point number, X coordinate, Y coordinate and Z coordinate information, and separated by "," to become a complete key point file;

[0068] 3) Import coordinate data to establish a geometric model. Import the keypoint coordinate data integrated in step 2) into ANSYS, use APDL language to write executable command stream, and connect each point in sequence to become a similar three-prism shape in the three-dimensional coordinate points on the top and bottom surfaces, as Figure 3As shown, the geometric model is established from top to bottom in the order of A1-B1-C1-A2-B2-C2 counterclockwise or A1-C1-B1-A2-C2-B2 clockwise, the accuracy and work efficiency of the geometric model are improved, the X coordinates and Y coordinates of the three points of the vertex of each triangular prism and the three points of the bottom surface are respectively equal, the sides of the triangular prism are guaranteed to be planes, the vertex surface and the bottom surface are planes, the layer of the multi-point group surface is avoided to become a curved surface to cause the geometric model to be not closed, the APDL language is programmed, the machine is executable, the work efficiency is improved, and the established geometric model is as shown in Figure 5 ;

[0069] The quality of the geometric model is checked, including checking the three-dimensional geometric shape, the conformity of the structural shape, and the contact relationship between the geometric bodies, checking whether the overall shape of the top surface and the bottom surface of the model is consistent with the actual geological structural shape, and checking whether there is a gap between the triangular prisms in the model, if the checking result is qualified, the next step is performed, if not, whether the key point coordinates and the connection mode are wrong is checked, and the model is re-established after modification;

[0070] It is checked whether there is a gap in the geometric model, and it is checked that there is no gap in the model;

[0071] It is checked whether the geometric model shape is consistent with the actual structural shape, and it is checked that there is a problem in the model: the fault connection mode is wrong before modification, which is not consistent with the actual fault trend, and the geometric model is consistent with the actual fault trend after modifying the connection mode of the key points, and the comparison chart of the geometric model before and after modification is as shown in Figure 6 .

[0072] 4) Dividing the grid, selecting the solid element type and the Tet-free method in ANSYS to divide the grid, and the grid size precision is taken as the standard to meet the calculation requirement;

[0073] The grid size is determined according to the calculation precision requirement and the calculation speed requirement, such as: if the subsequent calculation result requires a precision of 50 meters, the grid element length needs to be less than 50 meters, and if the calculation result requires a precision of 20 meters, the grid element length needs to be less than 20 meters. The calculation speed is related to the number of grid elements and the device hardware, when the device hardware is the same, the more the number of grid elements, the slower the general calculation speed is. In the case of meeting the calculation precision, the number of grids can be reduced, and the grid size is selected to be 50 meters in this embodiment;

[0074] The grid quality is checked, including the grid element shape and the grid number, the ANSYS software is used for grid checking, the bad grid in the checking result is required to be less than 1%, if the checking result is qualified, the next step is performed, if not, the related parameters are modified and the grid is re-divided;

[0075] 5) Establish a heterogeneous mechanical model, use the research area sedimentary facies, logging data and three-dimensional seismic body data comprehensive inversion calculation, obtain the depth domain of each three-dimensional coordinate point of Young's modulus, Poisson's ratio and density of mechanical characteristic parameters as shown in Table 2, and export text data; use APDL language to write executable command stream for comparison, establish a heterogeneous mechanical model;

[0076] The specific comparison of using APDL language to write executable command stream is 1) obtaining three-dimensional coordinates and mechanical attribute values; 2) obtaining the coordinates of the center point of the unit; 3) calculating the distance between the center point of the unit and the three-dimensional attribute coordinates; 4) selecting the nearest attribute; 5) corresponding to each unit attribute, assigning elastic modulus, Poisson's ratio and density values;

[0077] The center point of the unit is simplified to the average value of the coordinates of the four corner points, and the regular entity grid is generally an 8-node hexahedral grid. Due to the complexity and irregularity of the geological geometric model, it will be degraded to a 4-node tetrahedral form. After degradation, it supports various complex and irregular model mechanical operations;

[0078] The center point of the unit in step 5) is simplified to the average value of the coordinates of the four corner points, and the coordinates of the four nodes in a unit in the model are shown in Table 3. According to the center point coordinates of the unit, the arithmetic average of the three-dimensional coordinates of the four nodes can be simplified, that is: (4091.55, 623.3525, -3694.525). The distance between the center point of the unit and each mechanical attribute point coordinate is calculated, and the mechanical attribute of the nearest coordinate point is selected for unit assignment.

[0079] Table 2 Mechanical parameter table of each three-dimensional coordinate point

[0080]

[0081] Table 3 Coordinates of four nodes in a unit in the model

[0082]

[0083] In this embodiment, by comparing the three-dimensional coordinate data of different positions in the model with the actual stratum coordinate data, the coincidence rate of the geometric model form established by the above method with the actual structure form reaches 90%; the grid unit length in the finite element model is 50 meters, and the number of grid units participating in the calculation is 2662975, which meets the requirements of calculation accuracy and speed. After subsequent load application and calculation analysis, the error between the in-situ stress calculation result and the measured value is controlled within 13%, and the simulation result has high reliability.

[0084] It is to be understood that the present application is described by way of example only, and that modifications or alterations can be made to the features and embodiments described without departing from the spirit and scope of the application. In addition, modifications can be made to the features and embodiments described to accommodate specific situations and materials without departing from the spirit and scope of the application. Accordingly, the application is not limited to the specific embodiments disclosed herein, but rather, the scope of the application includes all embodiments falling within the scope of the claims.

Claims

1. A method for modeling highly heterogeneous and complex geological conditions based on ANSYS and APDL, characterized in that: It comprises the following steps, 1) Obtain layer coordinates, according to the structural configuration of the study area, along the main structural axis, respectively at the top and bottom of the target layer, obtain three-dimensional coordinate data with equal intervals or non-equal intervals within 10% difference, wherein the X and Y coordinates of the corresponding points of each layer correspond to the same; 2) Obtain fault coordinates and integrate data, obtain three-dimensional coordinate data of the two plates of the fault in the corresponding layer in step 1), replace the coordinates of each point near the fault position in the layer with the real three-dimensional coordinates of the fault, arrange the coordinates in rows or columns and number them, and integrate them into a complete keypoint file; 3) Import coordinate data to establish a geometric model, import the keypoint coordinate data integrated in step 2) into ANSYS, use APDL language to write executable command stream, connect each point in sequence to form a pseudo-triangular prism in the three-dimensional coordinate points on the top and bottom surfaces, and establish a geometric model from top to bottom, thereby improving the accuracy and efficiency of the geometric model; 4) Divide the grid, select the solid element type and Tet-free method to divide the grid in ANSYS, and determine the grid size according to the calculation accuracy and speed requirements; 5) Establish a heterogeneous mechanical model, use the comprehensive inversion calculation of the sedimentary facies, logging data and three-dimensional seismic body data in the study area to obtain the mechanical characteristic parameters of Young's modulus, Poisson's ratio and density of each three-dimensional coordinate point in the depth domain, and export the text data; use APDL language to write executable command stream for comparison, obtain the center point of each unit and its nearest mechanical coordinate point, and correspondingly assign values to each unit attribute, and establish a heterogeneous mechanical model.

2. The modeling method of claim 1, wherein: The structural configuration of the study area in step 1) includes the direction of strata, the direction of anticline axis, the direction of syncline axis and the direction of fault.

3. The modeling method of claim 1, wherein: After replacing the coordinates of each point near the fault position in the layer with the real three-dimensional coordinates of the fault in step 2), the keypoint coordinates are used to control the fault configuration, and the model has high conformity with the actual geological configuration.

4. The modeling method of claim 1, wherein: In step 3), the X and Y coordinates of the top 3 points and the bottom 3 points of the triangular prism correspond to each other, ensuring that each side of the triangular prism is a plane, and the top and bottom surfaces are planes, avoiding the layer with multiple point groups becoming a curved surface, leading to an open geometric model, programming with APDL language, machine executable, and improving the work efficiency.

5. The modeling method of claim 1, wherein: Step 3) further comprises checking the quality of the geometric model, including checking the three-dimensional geometric configuration, the conformity of the structural configuration and the contact relationship between the geometric bodies.

6. The modeling method of claim 5, wherein: The specific method of checking the quality of the geometric model is to check whether the overall configuration of the top and bottom surfaces of the model is consistent with the actual geological structural configuration, and whether there are gaps between the triangular prisms in the model, if the checking result is qualified, the next step is performed, if not, check whether the keypoint coordinates and their connection mode are wrong, and modify and re-model after modification.

7. The modeling method of claim 1, wherein: Step 4) further comprises checking the quality of the grid, including the shape and number of the grid elements.

8. The modeling method of claim 7, wherein: The grid quality checking is specifically checking the grid by using the ANSYS software, and the bad grid in the checking result is required to be less than 1%, if the checking result is qualified, the next step is carried out, if not, the related parameters are modified to redivide the grid.

9. The modeling method of claim 1, wherein: The step 5) of comparing by using the APDL language to write the executable command stream is specifically: 1) obtaining three-dimensional coordinates and mechanical property values; 2) obtaining the unit center point coordinates; 3) calculating the distance between the unit center point coordinates and the three-dimensional property coordinates; 4) selecting the nearest property; and 5) corresponding to each unit property, the elastic modulus, Poisson's ratio and density values are given.

10. The modeling method of claim 9, wherein: The unit center point is simplified as the average value of the coordinates of the four corner points.

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