A generalized triangular prism geological model construction method based on adaptive interpolation

Abstract

The application discloses a generalized triangular prism geological model construction method based on adaptive interpolation, and aims at the contradiction between sparse drilling and high-precision generalized triangular prism geological model requirements and the fusion problem of the generalized triangular prism element model and existing interpolation methods, and provides an automatic fine interpolation method based on the existing generalized triangular prism element model, so that a more refined generalized triangular prism model is obtained through the automatic interpolation method according to the set interpolation parameters after the input original drilling and the construction of the generalized triangular prism original model.

Description

Technical Field

[0001] This invention belongs to the field of three-dimensional geological model technology, specifically relating to an adaptive interpolation method for a generalized triangular prism geological model. Background Technology

[0002] In recent years, with the rapid development of modern industry and the economy, raw materials and resources have become increasingly scarce, and human underground development activities have gradually intensified, leading to a significant increase in the demand for information technology in underground space. In the development of large-scale water conservancy and hydropower projects in Southwest China, the geological problems of deep overburden layers are a key research focus during the engineering survey and design stages. It is necessary to construct large-area three-dimensional geological models to accurately understand the three-dimensional geometric structure of the project area, providing information support for the scientific construction and management of the project. The development of urban underground space is also accelerating, including subways, urban utility tunnels, and underground minerals. These all require the real-time and rapid construction and updating of existing three-dimensional geological models to provide three-dimensional information support for engineering planning, design, and construction management. Therefore, many fields, including geology, water conservancy and hydropower engineering, mining, hydrology, underground engineering, groundwater, and urban development, require precise geometric representation of underground geological structures. A true three-dimensional geological modeling platform is becoming a platform for expressing underground three-dimensional spatial information and displaying numerical analysis simulations. However, due to the high cost and sparse distribution of underground borehole sampling, it is usually necessary to quickly and accurately reconstruct underground 3D models based on sparse borehole data. Therefore, a modeling method that accurately reflects the geological structure and supports rapid model updates has become the key to solving these problems.

[0003] Compared to 3D geological modeling methods using volumetric models such as tetrahedrons, irregular triangular meshes, and raster models, the generalized triangular prism volumetric model directly constructs a 3D geological model of layered geological bodies using borehole data. The triangular prism volumetric model preserves the inherent connections between three boreholes, distinguishes between bedding and trans-bedding directions, and retains the basic geometric elements of the strata, resulting in better geological interpretation. This gives the generalized triangular prism a unique advantage in 3D geological modeling, making it suitable for geological modeling requiring speed, simplicity, frequent local updates, and large-area coverage. Consequently, there has been considerable research and application of generalized triangular prisms in recent years. However, because the generalized triangular prism model directly constructs the geological model based on the geometric connections of borehole data, the model's accuracy depends on the sparsity of the boreholes, which cannot meet the application requirements for highly refined geological models. Furthermore, commonly used geostatistical interpolation and geometric interpolation methods in geological modeling are for discrete points and cannot be converted to borehole source data, thus they cannot be directly applied to the generalized triangular prism volumetric model. This is a current challenge hindering the widespread application of the generalized triangular prism volumetric model in practical engineering and requires urgent research.

[0004] The generalized triangular prism model is a type of volume element model specifically designed for geological structures. Geological boreholes act as edges to divide strata into triangular prisms. Because boreholes are often skewed, the resulting triangular prisms are not standard and are thus called generalized triangular prisms. The apex and base triangles of the prism are located at the top and bottom layers of the strata, respectively, and the edges of the generalized triangular prism are the line segments containing the borehole. The generalized triangular prism possesses directionality, allowing for the differentiation of bedding planes and trans-bedding directions, thus providing better geological interpretation.

[0005] There has been considerable research and technological advancement in the development of generalized triangular prism element-based 3D geological models. However, to make this approach more universally applicable, the accuracy of geological models directly built upon generalized triangular prism elements currently depends on the distribution accuracy of borehole sampling. If the borehole sampling is uniform and dense, the model's geometric changes are smooth, resulting in high computational accuracy. However, when the borehole sampling intervals are large and elevation variations are significant, directly using the generalized triangular prism model leads to drastic changes and uneven stratigraphic interfaces due to the straight-line connections between boreholes. This reduces the applicability of sparse borehole sampling compared to geological modeling methods incorporating geoscientific interpolation, hindering practical applications and significantly diminishing its practical value. Furthermore, the source data for the generalized triangular prism element model is the entire borehole, and existing interpolation methods are based on discrete points, making direct application of geostatistical interpolation methods impossible. Summary of the Invention

[0006] To address the aforementioned shortcomings in existing technologies, the method for constructing a generalized triangular prism geological model based on adaptive interpolation provided by this invention solves the problem of low model accuracy due to sparse borehole data in engineering applications of the generalized triangular prism geological model.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: a method for constructing a generalized triangular prism geological model based on adaptive interpolation, comprising the following steps:

[0008] S1. Construct a basic generalized triangular prism geological model;

[0009] S2. Calculate the smoothness of the current generalized triangular prism geological model and determine whether it meets the set accuracy requirements;

[0010] If so, proceed to step S3;

[0011] If not, proceed to step S4;

[0012] S3. Based on the calculated smoothness, an adaptive interpolation method is used to perform virtual borehole interpolation on each of the generalized triangular prisms in the generalized triangular prism geological model until the interpolation stopping threshold is met. The current generalized triangular prism geological model is then reconstructed and optimized, and the process proceeds to step S4.

[0013] S4. Complete the construction of the generalized triangular prism geological model.

[0014] Further, step S1 specifically includes:

[0015] S11. Collect raw data on the geological structure of the area to be constructed;

[0016] The raw data includes borehole data, profile data, test data, and measurement data;

[0017] S12. Based on the borehole coordinates in the collected raw data, construct a constrained Delaunay triangulation.

[0018] S13. Based on the constructed constrained Delaunay triangulation, a generalized triangular prism is obtained by extending it downward by one triangle. A triangular prism is formed in each layer of the geological structure, thus obtaining a generalized triangular prism geological model.

[0019] Furthermore, the generalized triangular prism geological model in step S13 is a model formed by connecting boreholes of several generalized triangular prisms with boreholes as the edges of the prisms and the borehole openings as the three vertices of the triangles.

[0020] In the process of constructing the generalized triangular prism geological model, virtual boreholes are set at the boundaries of geological structure interruption layers and missing layers;

[0021] The generalized triangular prism geological model is divided into continuous interpolation units.

[0022] Furthermore, in step S2, the smoothness of the generalized triangular prism geological model refers to the magnitude of the undulation change of the current top surface region of the generalized triangular prism relative to the surrounding strata within the current stratum range;

[0023] The specific method for calculating the smoothness of a generalized triangular prism geological model is as follows:

[0024] A1. Calculate the smoothness of the top triangle in each generalized triangular prism in the generalized triangular prism geological model to obtain the smoothness of a single generalized triangular prism.

[0025] A2. According to the stratigraphic structure, calculate the smoothness of the generalized triangular prisms in other layers constructed from the same three boreholes in a single generalized triangular prism from top to bottom, and take the maximum value as the smoothness of the corresponding generalized triangular prism.

[0026] A3. Calculate the smoothness of all generalized triangular prisms according to the methods in steps A1 to A2, and complete the smoothness calculation of the generalized triangular prism geological model.

[0027] Furthermore, in step A2, the smoothness N of the generalized triangular prism top-GTP The calculation formula is:

[0028] N top-GTP =max(N) vi (1≤i≤3)

[0029] In the formula, N vi Let be the normal curvature of the current generalized triangular prism, and i be the index of the three points on the top surface of the generalized triangular prism;

[0030] The normal curvature of the triangular prism is Gaussian curvature, which is obtained by area-weighted summation using the normal vector averaging method or the Taubin method.

[0031] Further, step S3 specifically includes:

[0032] S31. Set the interpolation stop threshold according to the model accuracy requirements;

[0033] S32. When the virtual borehole interpolation of the current generalized triangular prism geological model does not exceed the corresponding set interpolation stop threshold, determine the interpolation unit that needs to be interpolated by virtual borehole and perform virtual borehole interpolation.

[0034] S33. Calculate the smoothness within the interpolation unit where virtual borehole interpolation is performed;

[0035] S34. Repeat steps S32-S33 until the interpolation stopping threshold is met;

[0036] S35. Optimize and reconstruct the current generalized triangular prism geological model.

[0037] Further, in step S32, the position f(x,y) of the difference unit that needs to be used for virtual borehole interpolation is:

[0038]

[0039] In the formula, the subscripts i, j, k are the vertices of the generalized triangular prism, n is the number of vertices, n = i + j + k, are the coefficients of the rectangular coordinate system, are the volume coordinates of the triangles in the generalized triangular prism, are the coefficients of the Bernstein-Bézie polynomials after the transformation to the barycentric coordinate system, are the row vectors composed of nth degree Bernstein polynomials, and are the column vectors composed of all B-net coefficients in the same order as .

[0040] Furthermore, in step S33, the method for adding a new virtual hole inside the generalized triangular prism is as follows:

[0041] When you need to add a virtual hole, add it at the center or centroid of the generalized triangular prism.

[0042] When multiple virtual boreholes need to be added, the Bernstein subdivision method of the reference triangle is used to add virtual boreholes at the subdivision node positions.

[0043] Furthermore, in step S3, optimizing and reconstructing the generalized triangular prism geological model with added virtual boreholes includes optimizing the distorted generalized triangular prisms and boundary generalized triangular prisms therein.

[0044] Furthermore, the specific method for optimizing the deformed generalized triangular prism is as follows:

[0045] Examine the topology of each generalized triangular prism, and reconstruct and optimize the erroneous topology of malformed generalized triangular prisms according to topological relationships;

[0046] The specific method for optimizing the boundary generalized triangular prism is as follows:

[0047] For each boundary generalized triangular prism, a new virtual drilling point is added in the middle to make its formation boundary a smooth closed polyline, thus achieving smoothing optimization of the boundary generalized triangular prism.

[0048] The beneficial effects of this invention are as follows:

[0049] (1) This invention addresses the contradiction between the requirements of sparse boreholes and high-precision generalized triangular prism geological models, as well as the problem of integrating generalized triangular prism volumetric models with existing interpolation methods. It provides an automated fine interpolation method based on existing generalized triangular prism volumetric models, thereby enabling the input of original boreholes, the construction of the original generalized triangular prism model, and the acquisition of a more refined generalized triangular prism model through the researched automatic interpolation method according to the set interpolation parameters.

[0050] (2) The generalized triangular prism model construction method provided by the present invention can be used as a supplement and extension of an existing modeling method, as part of the theory and method of generalized triangular prism three-dimensional geological modeling, thus forming a software toolkit, as part of the existing three-dimensional geological modeling software, to serve industry engineering applications, and has broad market application prospects in the future. Attached Figure Description

[0051] Figure 1 The flowchart of the method for constructing a generalized triangular prism geological model based on adaptive interpolation provided by the present invention is shown.

[0052] Figure 2 A flowchart for constructing a generalized triangular prism geological model provided by this invention.

[0053] Figure 3 The geometric meaning of the generalized triangular prism provided by this invention.

[0054] Figure 4A schematic diagram illustrating the smoothness of the generalized triangular prism provided by this invention.

[0055] Figure 5 A schematic diagram showing the comparison before and after interpolation of the generalized triangular prism provided by this invention.

[0056] Figure 6 A schematic diagram showing the comparison before and after optimization of the boundary generalized triangular prism provided by this invention. Detailed Implementation

[0057] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0058] Example 1:

[0059] like Figure 1-2 As shown, a method for constructing a generalized triangular prism geological model based on adaptive interpolation includes the following steps:

[0060] S1. Construct a basic generalized triangular prism geological model;

[0061] S2. Calculate the smoothness of the current generalized triangular prism geological model and determine whether it meets the set accuracy requirements;

[0062] If so, proceed to step S3;

[0063] If not, proceed to step S4;

[0064] S3. Based on the calculated smoothness, an adaptive interpolation method is used to perform virtual borehole interpolation on each of the generalized triangular prisms in the generalized triangular prism geological model until the interpolation stopping threshold is met. The current generalized triangular prism geological model is then reconstructed and optimized, and the process proceeds to step S4.

[0065] S4. Complete the construction of the generalized triangular prism geological model.

[0066] The embodiments of this invention mainly study the theory and method of interpolation and smoothing of generalized triangular prism geological models. For layered geological structures and corresponding sparse borehole sampling data, it can automatically reconstruct a refined generalized triangular prism geological model.

[0067] The generalized triangular prism geological model in this embodiment of the invention is composed of several generalized triangular prisms. A generalized triangular prism is a closed geometric unit composed of two top and bottom triangles and three quadrilaterals. Unlike a regular triangular prism, it does not require the top and bottom triangles to be perfectly parallel. It is a geometric data model specifically designed for sedimentary strata and borehole sampling data. Figure 3 As shown in (a). For a triangular prism, the three edges represent the borehole lines, and the six vertices represent the intersections of the strata and the borehole. The geographic coordinates and attributes of each point are usually known. Borehole drilling is the most effective method in geological exploration. A regional geological model is usually obtained from borehole data with coefficients. Layered structures are the most common type of Earth's geological structures, ranging from small rock strata to large Earth spheres. Therefore, the generalized triangular prism element is a more suitable choice for constructing three-dimensional geological models.

[0068] The generalized triangular prism also has two degenerate forms: the pyramid. Figure 3 (b) and tetrahedron Figure 3 (c) This is typically used to construct geological models of complex structures, such as boundary triangular prisms of faults and missing layers. A pyramid represents a prism with a borehole of length 0, while a tetrahedron represents three boreholes of a triangular prism intersecting at a single vertex. Past research has largely focused on the geometric models of geological entities; this invention focuses on the non-uniformly distributed property field within geological models based on generalized triangular prism volume elements. Furthermore, the calculation of the quadratic generalized triangular prism function requires that the four points on the lateral faces be coplanar. Figure 3 (d) illustrates a non-coplanar triangular prism, which leads to problems in calculating the solid functions of the triangular prism.

[0069] The generalized triangular prism element model in this embodiment of the invention has several significant advantages:

[0070] (1) The design based on the characteristics of geological borehole data can make good use of the characteristics of borehole data. The edges are used to represent the borehole line, and the top and bottom triangles represent the ground strata.

[0071] (2) It offers better geological interpretation, distinguishing between bedding-parallel and trans-bedding directions, while the triangular prism volume element model can easily interpret the direction of strata. Furthermore, compared to the tetrahedral volume element model, the three edges of the triangular prism indicate the trans-bedding direction, while the top and bottom triangular faces represent the bedding-parallel direction. It maintains the internal connections of the borehole data, thus providing better geological interpretation.

[0072] (3) The model is easy to build and update. The update only requires the insertion method of building TIN to add new holes to locally update the model.

[0073] (4) It requires little storage space.

[0074] (5) It can be easily converted into TIN model and tetrahedral volume element model.

[0075] (6) Simple topological relationships: Based on the characteristics of a generalized triangular prism, the relationships between borehole points, top and bottom triangles and lateral tetrahedrons can be defined in the data table. Adjacency and subordination relationships can be directly queried, which is very convenient for topological relationship query and spatial analysis in geosciences.

[0076] Based on this, the construction of the basic generalized triangular prism geological model in step S1 of the present invention is usually constructed by combining borehole features and the Delunay triangulation method. First, it is necessary to ensure that the associated boreholes are in the same triangular prism or on adjacent triangular prisms. Second, it is necessary to ensure that the geometric features of the connected triangular prisms are better and the mesh quality is better. At the same time, before constructing the triangular prism, it is also necessary to process the data supplementation of the geological structure expression to ensure that the automated construction algorithm can accurately reconstruct special geological structures, including faults, missing layers, etc.

[0077] Its construction method is as follows:

[0078] S11. Collect raw data on the geological structure of the area to be constructed;

[0079] The raw data includes borehole data, profile data, test data, and measurement data. Among the collected raw data, borehole data needs to be integrated with other data. Geological modeling data is often multiple data based on borehole data. These data need to be cross-corrected and made consistent. Borehole database and attribute database are created separately to ensure the consistency and structured storage of the two data.

[0080] S12. Based on the borehole coordinates in the collected raw data, construct a constrained Delaunay triangulation.

[0081] S13. Based on the constructed constrained Delaunay triangulation, a generalized triangular prism is obtained by extending it downward by one triangle. A triangular prism is formed in each layer of the geological structure, thus obtaining a generalized triangular prism geological model.

[0082] In step S13 of this embodiment, the generalized triangular prism geological model is a model formed by connecting boreholes of several generalized triangular prisms with boreholes as the edges of the prisms and the borehole openings as the three vertices of the triangles.

[0083] In this embodiment of the invention, during the construction of the generalized triangular prism geological model, virtual boreholes are set at the boundaries of the interrupted and missing layers of the geological structure. This ensures the correctness of the topological relationship of the geometric model, which is the basis for constructing the quadratic generalized triangular prism body function model.

[0084] In this embodiment of the invention, the generalized triangular prism geological model is divided into continuous interpolation units. Based on the discontinuous boundary of the attribute, the geology needs to be divided into many continuous interpolation units. When performing volume function fitting, each unit is performed independently, and different fitting parameters are set. These are consistent with the geological tectonic phenomena in nature. These boundaries include ground planes, fault planes, and artificially specified boundaries.

[0085] In step S2 of this embodiment, in the constructed generalized triangular prism geological model, each individual solid triangular prism element is composed of boreholes. In areas with significant variations in geological layer thickness, the elevation differences between the three vertices of a single triangular prism are substantial, resulting in insufficient geometric accuracy within the prism and failing to meet the requirements for high-precision modeling. Furthermore, the connection between two boreholes is a straight line. In areas with significant geological undulations and large spacing between boreholes, the transition between the two prisms is not smooth, leading to insufficient accuracy and an inability to reflect the true geological variations. Therefore, in this embodiment, the smoothness of the generalized triangular prism geological model is defined as the magnitude of the variation in the top surface area of ​​the current prism relative to the surrounding strata within the current geological range.

[0086] The specific method for calculating the smoothness of a generalized triangular prism geological model is as follows:

[0087] A1. Calculate the smoothness of the top triangle in each generalized triangular prism in the generalized triangular prism geological model to obtain the smoothness of a single generalized triangular prism.

[0088] A2. According to the stratigraphic structure, calculate the smoothness of the generalized triangular prisms in other layers constructed from the same three boreholes in a single generalized triangular prism from top to bottom, and take the maximum value as the smoothness of the corresponding generalized triangular prism.

[0089] A3. Calculate the smoothness of all generalized triangular prisms according to the methods in steps A1 to A2, and complete the smoothness calculation of the generalized triangular prism geological model.

[0090] In step A1 of this embodiment, the Gaussian curvature used in 3D CAD software is introduced as the main breakthrough point when calculating the smoothness of the generalized triangular prism. Gaussian curvature is the main basis for analyzing the internal surface quality and connectivity in surface modeling. When the Gaussian curvature of the surface changes significantly and rapidly, the internal changes of the surface are relatively large, resulting in poor surface smoothness. In this embodiment, maximum curvature and minimum curvature are defined, and the Gaussian curvature is the product of the maximum and minimum curvature. Gaussian curvature can reflect the degree of local undulation of the surface.

[0091] In embodiments of the present invention, such as Figure 4 As shown, a triangular prism is calculated together with its surrounding triangular prisms. The triangular prism T is calculated together with all its surrounding T. n The smoothness is obtained through joint calculation; in step A2 of this embodiment of the invention, the smoothness N of the generalized triangular prism is...top-GTP The calculation formula is:

[0092] N top-GTP =max(N) vi (1≤i≤3)

[0093] In the formula, N vi Let be the normal curvature of the current generalized triangular prism, and i be the index of the three points on the top surface of the generalized triangular prism, obtained by area weighted summation using the normal vector averaging method or the Taubin method.

[0094] Specifically, in this embodiment, the formula for calculating the normal curvature of the current point of the triangle in the triangular prism is as follows:

[0095]

[0096] In the formula, A(v) is the area of ​​the current triangle, and θ i For the current N i (v) Angles of adjacent triangles;

[0097] In step A3 of this embodiment, the smoothness N of the generalized triangular prism geological model... GTP for:

[0098]

[0099]

[0100] In the formula, the subscript n represents the stratum number, and h i is the current vertical height of the triangular prism, h is the maximum velocity of the model stratum, i is the stratum number, v is the angle of the top surface or ground of the triangular prism, G represents the case where the current triangular prism follows the Delaunay rule, and w represents the weight of the current triangular prism.

[0101] Step S3 of this embodiment of the invention uses an adaptive interpolation method, which differs from the traditional uniform geometric subdivision method. The method of this invention can achieve the same accuracy while maintaining a small amount of data. The specific implementation method is as follows:

[0102] S31. Set the interpolation stop threshold according to the model accuracy requirements;

[0103] S32. When the virtual borehole interpolation of the current generalized triangular prism geological model does not exceed the corresponding set interpolation stop threshold, determine the interpolation unit that needs to be interpolated by virtual borehole and perform virtual borehole interpolation.

[0104] S33. Calculate the smoothness within the interpolation unit where virtual borehole interpolation is performed;

[0105] S34. Repeat steps S32-S33 until the interpolation stopping threshold is met;

[0106] S35. Optimize and reconstruct the current generalized triangular prism geological model.

[0107] In step S32 of this embodiment, the position f(x,y) of the difference unit that needs to be used for virtual drilling interpolation is:

[0108]

[0109] In the formula, the subscripts i, j, k are the vertices of the generalized triangular prism, n is the number of vertices, n = i + j + k, a i,j Let λ1, λ2, λ3 be the coefficients in a rectangular coordinate system, and let b be the volume coordinates of the triangle in the generalized triangular prism. i,j,k Let B be the coefficients of the Bernstein-Bézier polynomial corresponding to f(x,y) after the barycentric coordinate system transformation. n Let f be a row vector composed of nth-degree Bernstein polynomials. b It is all the B-network coefficients b i,j,k According to B n A column vector consisting of columns in the same order.

[0110] in,

[0111]

[0112] like Figure 5 As shown in the figure, this embodiment compares the results before and after virtual drilling interpolation on the generalized triangular prism.

[0113] In step S33 of this embodiment of the invention, the method for adding a new virtual hole inside the generalized triangular prism is as follows:

[0114] When a single virtual borehole needs to be added, it is added at the center or centroid of the generalized triangular prism; when multiple virtual boreholes need to be added, the Bernstein subdivision method of the reference triangle is used to add virtual boreholes at the subdivision node positions.

[0115] In this embodiment of the invention, after adding the virtual boreholes, a smooth and refined generalized triangular prism element model can be obtained. However, the newly added virtual boreholes may form some deformed generalized triangular prisms, requiring optimization and reconstruction. Furthermore, since the method of adding virtual boreholes at the center of the triangular prisms using interpolation does not smooth the boundaries of unconformities, it also requires optimization. Therefore, in step S3 of this embodiment, optimizing the generalized triangular prism geological model with added virtual boreholes includes optimizing the deformed and boundary generalized triangular prisms.

[0116] For deformed generalized triangular prisms, the assignment method for selecting virtual borehole layers is based on the set of bedding points for each layer. However, the generalized triangular prism volume element is a volume model, while the formation is a solid unit. The assignment method that separates the upper and lower layers may produce deformed generalized triangular prisms. The specific optimization method is as follows:

[0117] Examine the topology of each generalized triangular prism, and reconstruct and optimize the erroneous topology of malformed generalized triangular prisms according to topological relationships.

[0118] like Figure 6 The comparison of optimizations for the boundary generalized triangular prisms shown illustrates the specific methods for optimizing these prisms:

[0119] For each boundary generalized triangular prism, a new virtual drilling point is added in the middle to make its formation boundary a smooth closed polyline, thus achieving smoothing optimization of the boundary generalized triangular prism.

[0120] In the description of this invention, it should be understood that the terms "center," "thickness," "upper," "lower," "horizontal," "top," "bottom," "inner," "outer," and "radial," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying the relative importance or the number of technical features implicitly specified. Therefore, a feature defined by "first," "second," and "third" may explicitly or implicitly include one or more of that feature.

Claims

1. A method for constructing a generalized triangular prism geological model based on adaptive interpolation, characterized in that, Includes the following steps: S1. Construct a basic generalized triangular prism geological model; S2. Calculate the smoothness of the current generalized triangular prism geological model and determine whether it meets the set accuracy requirements; If not, proceed to step S3; If so, proceed to step S4; Among them, the smoothness of the generalized triangular prism geological model refers to the magnitude of the undulation of the current top surface region of the generalized triangular prism relative to the surrounding strata within the current stratum range; The specific method for calculating the smoothness of a generalized triangular prism geological model is as follows: A1. Calculate the smoothness of the top triangle in each generalized triangular prism in the generalized triangular prism geological model to obtain the smoothness of a single generalized triangular prism. A2. According to the stratigraphic structure, calculate the smoothness of the generalized triangular prisms in other layers constructed from three identical boreholes in a single generalized triangular prism in the generalized triangular prism geological model from top to bottom, and take the maximum value as the smoothness of the corresponding generalized triangular prism. A3. Calculate the smoothness of all generalized triangular prisms according to the methods in steps A1 to A2, and complete the smoothness calculation of the generalized triangular prism geological model. S3. Based on the calculated smoothness, an adaptive interpolation method is used to perform virtual borehole interpolation on each of the generalized triangular prisms in the generalized triangular prism geological model until the interpolation stopping threshold is met. The current generalized triangular prism geological model is then reconstructed and optimized, and the process proceeds to step S4. S4. Complete the construction of the generalized triangular prism geological model.

2. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 1, characterized in that, Step S1 specifically involves: S11. Collect raw data on the geological structure of the area to be constructed; The raw data includes borehole data, profile data, test data, and measurement data; S12. Based on the borehole coordinates in the collected raw data, construct a constrained Delaunay triangulation. S13. Based on the constructed constrained Delaunay triangulation, a generalized triangular prism is obtained by extending it downward by one triangle. A triangular prism is formed in each layer of the geological structure, thus obtaining a generalized triangular prism geological model.

3. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 2, characterized in that, The generalized triangular prism geological model in step S13 is a model formed by connecting boreholes of several generalized triangular prisms with boreholes as the edges of the prisms and the borehole openings as the three vertices of the triangles. In the process of constructing the generalized triangular prism geological model, virtual boreholes are set at the boundaries of geological structure interruption layers and missing layers; The generalized triangular prism geological model is divided into continuous interpolation units.

4. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 1, characterized in that, In step A2, the smoothness of the generalized triangular prism The calculation formula is: In the formula, Let the normal curvature of the current generalized triangular prism be denoted as . Let be the serial numbers of the three points on the top face of the generalized triangular prism, and ; The normal curvature of the triangular prism is Gaussian curvature, which is obtained by area-weighted summation using the normal vector averaging method or the Taubin method.

5. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 1, characterized in that, Step S3 specifically involves: S31. Set the interpolation stop threshold according to the model accuracy requirements; S32. When the virtual borehole interpolation of the current generalized triangular prism geological model does not exceed the corresponding set interpolation stop threshold, determine the interpolation unit that needs to be interpolated by virtual borehole and perform virtual borehole interpolation. S33. Calculate the smoothness within the interpolation unit where virtual borehole interpolation is performed; S34. Repeat steps S32-S33 until the interpolation stopping threshold is met; S35. Optimize and reconstruct the current generalized triangular prism geological model.

6. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 5, characterized in that, In step S32, the position of the difference unit that needs to be used for virtual borehole interpolation for: In the formula, the subscript i,j,k The vertex of a generalized triangular prism. n Let n be the number of vertices. i+j+k , The coefficients are in a rectangular coordinate system. Let be the volume coordinates of the triangle in the generalized triangular prism. For the reason The coefficients of the Bernstein-Bézie polynomial after the barycentric coordinate system transformation Let be a row vector composed of nth-degree Bernstein polynomials. It is all B-type coefficients According to A column vector consisting of columns in the same order.

7. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 5, characterized in that, In step S33, the method for adding a new virtual hole inside the generalized triangular prism is as follows: When you need to add a virtual hole, add it at the center or centroid of the generalized triangular prism. When multiple virtual boreholes need to be added, the Bernstein subdivision method of the reference triangle is used to add virtual boreholes at the subdivision node positions.

8. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 1, characterized in that, In step S3, the optimization and reconstruction of the generalized triangular prism geological model with added virtual boreholes includes optimizing the malformed generalized triangular prisms and boundary generalized triangular prisms.

9. The method for constructing a generalized triangular prism geological model based on adaptive interpolation according to claim 1, characterized in that, The specific method for optimizing the deformed generalized triangular prism is as follows: Examine the topology of each generalized triangular prism, and reconstruct and optimize the erroneous topology of malformed generalized triangular prisms according to topological relationships; The specific method for optimizing the boundary generalized triangular prism is as follows: For each boundary generalized triangular prism, a new virtual drilling point is added in the middle to make its formation boundary a smooth closed polyline, thus achieving smoothing optimization of the boundary generalized triangular prism.

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