An equivalent conversion method for automatically converting a three-dimensional geological model into a finite element model

Abstract

The present invention discloses an equivalent conversion method for automatically converting a 3D geological model into a finite element model, which relates to the technical field of engineering information models. The method includes: obtaining the mesh nodes of each geological body model in the 3D geological model in the CAD platform and the original connection relationships of the mesh nodes; establishing a set of formation interface points and corresponding set plane boundaries for each geological body model; establishing the full model boundary of the 3D geological model; determining the formation type; establishing new connection relationships that integrate the set of formation interface points, the top surface set, the bottom surface set, and the lens body set and the mesh nodes corresponding to the mesh node numbers within the set; and reconstructing and generating a model in the CAE software according to the numbers, spatial coordinates of the mesh nodes, and the new connection relationships of the mesh nodes. The present invention cross-verifies and corrects the mesh nodes obtained from the CAD platform, and then reconstructs and calculates the model in the CAE platform by re-establishing the connection method, realizing the automatic conversion of the model from the CAD platform to the CAE platform.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering information models, and in particular to a method for automatically converting a three-dimensional geological model into an equivalent finite element model. Background Art

[0002] The three-dimensional geological model is the basic model for carrying out geotechnical engineering design. Most of the existing three-dimensional geological models are established using CAD software, which does not have numerical analysis functions. The existing publicly disclosed methods for converting CAD into a CAE (Computer Aided Engineering) model are mainly divided into two categories:

[0003] (1) Model reconstruction technology, that is, extracting the three-dimensional geological model data from the CAD model and regenerating it within the CAE platform. For example, in the invention patent CN111159797B, the calculation model is regenerated in the finite element by extracting information from the BIM (three-dimensional geological model); in the invention patent CN114595610B, the technical model is regenerated in the finite element by extracting tunnel and simple formation parameters;

[0004] The disadvantage of this technology is that it cannot achieve the equivalent conversion of complex three-dimensional geological models. The main reason is that most three-dimensional geological models in CAD are expressed in the form of Mesh, with relatively low accuracy. The directly reconstructed CAE model usually cannot be calculated because there are embeddings or separations between adjacent formation bodies; or because of some deformed areas in the CAD model, the mesh cannot be divided in the CAE.

[0005] (2) Transitional software conversion technology, that is, during the conversion from CAD to CAE, the CAD model is processed by transitional software and then imported into the CAE. For example, in the invention patent CN114462131B, the model conversion is achieved through STL2STP; in the invention patent CN116090078B, the model conversion is achieved through EMTransfer or Hypermesh;

[0006] The disadvantage of this technology is that technicians need to manually perform a large amount of correction work on the model in the transitional software. Every time the model in CAD is adjusted, it needs to be reprocessed in the transitional software, resulting in a large workload; and this method cannot achieve the automated calculation and analysis of the BIM model. Summary of the Invention

[0007] In order to overcome the above defects in the prior art, the present invention provides a method for automatically converting a three-dimensional geological model into an equivalent finite element model, which realizes the conversion of the three-dimensional geological model from CAD to CAE through a method combining equivalent correction and model reconstruction.

[0008] To achieve the above object, the present invention adopts the following technical solutions, including:

[0009] A method for equivalent conversion of a three-dimensional geological model to a finite element model, comprising the following steps:

[0010] Step 1: Obtain the grid nodes of each geological body model in the three-dimensional geological model and the original connection relationship of the grid nodes; the grid nodes include their numbers and spatial coordinates; the spatial coordinates include the horizontal coordinate X, the horizontal coordinate Y, and the vertical coordinate Z; the original connection relationship of the grid nodes is that the grid nodes are connected to each other according to the original connection relationship to form a plurality of grid surfaces, and the plurality of grid surfaces can enclose to form a complete geological body model, the number of geological body models is N, N≥1, and the N geological body models are combined into a three-dimensional geological model;

[0011] Step 2: Establish a set of formation interface points and a corresponding set plane boundary for each geological body model; establish a full model boundary for the three-dimensional geological model; the set of formation interface points includes an upper and a lower formation interface point set;

[0012] Step 3: Define a formation type judgment rule, and determine the formation type as a conventional formation, a pinch-out formation, or a lenticular formation according to the set plane boundary of the geological body model;

[0013] Step 4: According to the set of formation interface points and the original connection relationship of the geological body model, establish a fused set of formation interface points, a top surface set, a bottom surface set, and a lenticular body set, and establish a new connection relationship between the grid node numbers corresponding to the grid nodes within each set;

[0014] Step 5: Generate a CAE model by reconstruction in CAE software according to the numbers, spatial coordinates, and new connection relationships of the grid nodes.

[0015] Preferably, in step 2, the process of establishing the set of formation interface points and the corresponding set plane boundary for each geological body model is as follows:

[0016] Step 2.1: Select a geological body model and obtain its grid nodes;

[0017] Step 2.2: Project each grid node vertically onto the geological body model in turn, and classify the grid node numbers into the upper and lower formation interface point sets and a temporary number set according to the projection relationship, specifically as follows:

[0018] If the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the largest vertical coordinate Z, the grid node number is classified into the upper stratum interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the smallest vertical coordinate Z, the grid node number is classified into the lower stratum interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node does not coincide with the projection point p with the largest and smallest vertical coordinates Z, the grid node number is classified into the temporary number set; if the number of projection points p obtained by projecting the grid node is equal to one, the grid node number is classified into both the upper and lower stratum interface point sets, and is defined as a special grid node number;

[0019] Step 2.3: Determine whether there is data in the temporary number set. If so, execute step 2.4; otherwise, execute step 2.5.

[0020] Step 2.4: Select a grid node number in the temporary number set, define the grid node as MB, and classify the MB number into the upper or lower stratum interface point set according to the original connection relationship. The specific steps are as follows:

[0021] Step 2.4.1: According to the original connection relationship, all grid node numbers directly connected to the MB are screened, and non-special grid node numbers among the grid node numbers directly connected to the MB are classified into the screening number set;

[0022] Step 2.4.2: Determine whether there is a grid node number in the screening number set that belongs to the upper or lower stratum interface point set. If so, define the grid node as PB, and determine the ownership of the MB number based on the PB number, specifically:

[0023] If the number of PB belongs to the upper stratum interface point set, the number of MB is included in the set; otherwise, it is included in the lower stratum interface point set, and MB is removed from the temporary number set, and step 2.4.2 is terminated directly; if there is no PB, step 2.4.3 is executed;

[0024] Step 2.4.3: According to the original connection relationship, screen all the grid node numbers directly connected to the grid nodes corresponding to all the grid node numbers in the screening number set, and classify the non-special grid node numbers therein into the screening number set. Select the execution content according to whether there are new non-special grid node numbers included in the screening number set. If there are, directly return to step 2.4.2; if not, directly remove MB from the temporary number set and end step 2.4.3;

[0025] Repeat step 2.4 until the temporary number set is empty;

[0026] Step 2.5: Obtain the boundary point numbers in the upper or lower formation interface point set based on the upper or lower formation interface point set and the original connection relationship, and then determine the set plane boundary according to the original connection relationship. The specific steps are as follows:

[0027] Step 2.5.1: Screen out the grid node numbers that meet the boundary point rules from the upper or lower formation interface point set and define them as boundary point numbers. The boundary point rules include two points, and meeting either of them means meeting the boundary point rules. Specifically: (1) The grid node number is a special grid node number; (2) The grid node number itself is a non-special grid node number in the upper or lower formation interface point set, and after being judged by the original connection relationship, there is a grid node number of a non-special grid node number in the lower or upper formation interface point set that is directly connected to it.

[0028] Step 2.5.2: Obtain all the boundary point numbers, and define the boundary obtained by connecting the boundary point numbers that are directly connected in the original connection relationship in sequence and projecting them vertically onto the fixed horizontal plane as the set plane boundary.

[0029] Repeat steps 2.1 to 2.5 to establish the formation interface point set and the set plane boundary of each geological body model.

[0030] The full model boundary of the three-dimensional geological model meets two requirements: (1) On the fixed horizontal plane, all set plane boundaries are not located outside the full model boundary; (2) Under the condition of meeting the previous requirement, the area included in the full model boundary is the smallest.

[0031] Preferably, the formation type judgment rules in step 3 are the lenticular formation rule and the pinching-out formation rule respectively; the lenticular formation rule is that the set plane boundary corresponding to the selected geological body model is completely located within the full model boundary; the pinching-out formation rule is that the set plane boundary corresponding to the selected geological body model is partially located within the full model boundary and partially coincides with the full model boundary.

[0032] The determination of the formation type is as follows: If the set plane boundary corresponding to the selected geological body model meets the lenticular formation rule, its formation type is defined as the lenticular formation; if the set plane boundary corresponding to the selected geological body model meets the pinching-out formation rule, its formation type is defined as the pinching-out formation; if neither is met, its formation type is defined as the conventional formation.

[0033] Preferably, the specific steps of establishing the integrated formation interface point set, the top surface set, the bottom surface set and the lenticular body set in step 4, and establishing the new connection relationship of the grid nodes corresponding to the grid node numbers in the set are as follows:

[0034] Step 4.1: Select a set of upper or lower stratigraphic interface points of a geological body model, and vertically interpolate and project the grid nodes corresponding to each grid node number in the set to all the stratigraphic interface point sets of the remaining N - 1 geological body models; Denote the set of stratigraphic interface points of the selected geological body model as the selected set, and establish the corresponding relationship between the two at the same time; Denote the set of stratigraphic interface points of the geological body model to be projected as the projection set, and establish the corresponding relationship between the two at the same time; When performing vertical interpolation projection, store the results separately according to the differences between the selected set and the projection set, and call it the comparison set. The comparison set corresponds to both the selected set and the projection set at the same time;

[0035] Step 4.2: Compare each selected set with the corresponding comparison set in turn. If there is a coincidence relationship between the two in terms of the surface area, it is recorded that the selected set and the projection set corresponding to the comparison set coincide in terms of the surface area, and a set of fused stratigraphic interface points is established. At the same time, judge whether to establish an independent set and its attributes;

[0036] The specific process of Step 4.2 is as follows:

[0037] Step 4.2.1: Establish a temporary set of fused stratigraphic interface points corresponding to the transition of the comparison set; The so-called transition correspondence means corresponding to the same selected set and projection set as the comparison set at the same time;

[0038] Step 4.2.2: Compare the selected set with the comparison set, and select the grid node numbers in the selected set that meet the error coincidence respectively, and store them in the temporary set of fused stratigraphic interface points corresponding to the transition of this comparison set;

[0039] The grid node numbers that meet the error coincidence are: the grid nodes corresponding to the grid node numbers in the selected set and the grid nodes corresponding to the grid node numbers in the comparison set satisfy the same horizontal coordinates X and Y, and the absolute value of the difference in the vertical coordinate Z is less than the error ε1;

[0040] Step 4.2.3: Connect the grid nodes corresponding to the grid node numbers in the non-empty temporary set of fused stratigraphic interface points according to the original connection relationship. If a surface can be formed after connection, it is recorded that the selected set and the comparison projection set corresponding to this temporary set of fused stratigraphic interface points coincide in terms of the surface area;

[0041] Step 4.2.4: Judge whether all the grid node numbers in the selected set are subsets of the union of all the corresponding temporary sets of fused stratigraphic interface points; If not, establish an independent set, and store the grid node numbers in the selected set that are not included in this union in the independent set. At the same time, determine its attributes according to the grid node numbers stored in the independent set; If so, do not establish an independent set;

[0042] If there is no corresponding set of temporary fusion formation interface points for the selected set, an independent set is established, and all the grid node numbers in the selected set are stored in the independent set. At the same time, the attributes are determined according to the grid node numbers stored in the independent set;

[0043] The independent set corresponds to the set of formation interface points corresponding to the selected set;

[0044] The determination of its attributes according to the grid node numbers stored in the independent set is specifically as follows: If the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are greater than the Z values of the grid nodes with the same horizontal coordinates as them among the grid nodes corresponding to all the comparison set grid node numbers corresponding to the selected set, the attribute of the independent set is defined as Top; If the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are less than the Z values of the grid nodes with the same horizontal coordinates as them among the grid nodes corresponding to all the comparison set grid node numbers corresponding to the selected set, the attribute of the independent set is defined as Down; Otherwise, its attribute is defined as Mid;

[0045] Repeat until all the sets of formation interface points of the geological body models are used as the selected set to perform all the operations in steps 4.1 - 4.2;

[0046] Step 4.3: Merge the corresponding sets of temporary fusion formation interface points with the same inversion for the selected set and the projection set into one, and merge the corresponding relationships; Then delete the sets of temporary fusion formation interface points with empty sets and the grid nodes corresponding to the grid node numbers in the sets that cannot form a surface when connected according to the original connection relationship;

[0047] Step 4.4: Obtain the two corresponding sets of formation interface points in the set of fusion formation interface points, denoted as the fusion corresponding set pair, and then obtain the two corresponding geological body models. If there is a geological body model with a formation type of lenticular formation among them, convert the set of fusion formation interface points into an independent set, and this independent set corresponds to the set of formation interface points corresponding to the lenticular formation in the fusion corresponding set pair; The attribute of this independent set is Mid;

[0048] Step 4.5: Place all the sets of fusion formation interface points and independent sets in the set group to be corrected, and correct each set in the set group to be corrected;

[0049] Step 4.6: Repair the set of fusion formation interface points, and establish new connection relationships for the grid nodes corresponding to the grid node numbers therein;

[0050] Step 4.7: Obtain all the independent sets with the attribute of Mid, and establish c lenticular sets and their new connection relationships; where c ≥ 0;

[0051] Step 4.8: Obtain all independent sets with attributes of Top and Down, and establish a top surface sets and b bottom surface sets; where a≥1 and b≥1.

[0052] Preferably, in step 4.1, the specific method of the vertical interpolation projection is: in the projection set, obtain points with the same horizontal coordinates X and Y of the grid nodes corresponding to all grid node numbers in the selected set through spatial interpolation;

[0053] In step 4.3, the "inversion being the same" means that the projection set corresponding to the temporary fusion formation interface point set A and the selected set corresponding to the temporary fusion formation interface point set B correspond to the same formation interface point set, and the selected set corresponding to the temporary fusion formation interface point set A and the projection set corresponding to the temporary fusion formation interface point set B correspond to the same formation interface point set;

[0054] In step 4.3, the "merging the corresponding relationship" means that the merged set is transformed into a fused formation interface point set, and directly corresponds to the formation interface point sets corresponding to the selected set and the projection set corresponding to the two temporary fusion formation interface point sets.

[0055] Preferably, for the correction of each set in the set group to be corrected in step 4.5, the specific process is as follows:

[0056] Step 4.5.1: Select a set from the set group to be corrected as the set to be corrected, and obtain the spatial coordinates of the grid nodes corresponding to all grid node numbers in this set;

[0057] Step 4.5.2: Obtain the interpolated vertical coordinate Z1 of the grid nodes corresponding to all grid node numbers in the set to be corrected through orthogonal test; solve the absolute value of the difference between the vertical coordinate Z of each grid node and the interpolated vertical coordinate Z1, and place the grid node numbers with the absolute value greater than the deviation ε2 into the set of nodes to be corrected, and the remaining node numbers into the set of standard nodes;

[0058] The orthogonal test for obtaining the interpolated vertical coordinate Z1 of the grid nodes in step 4.5.2 is specifically as follows:

[0059] Step 4.5.2a: Place all grid node numbers in the set to be corrected into the orthogonal test set;

[0060] Step 4.5.2b: Select the grid node corresponding to a grid node number in the orthogonal test set, denoted as the node to be solved, and remove its number from the orthogonal test set;

[0061] Step 4.5.2c: Obtain, by means of spatial interpolation, a point with the same horizontal coordinate as the node to be determined among the grid nodes corresponding to all the grid node numbers in the orthogonal test set as the interpolation node; the vertical coordinate Z of the interpolation node is the interpolated vertical coordinate Z1 of the node to be determined.

[0062] Step 4.5.3: Conduct a distortion check on the grid nodes corresponding to the grid node numbers in the set of nodes to be corrected. If the check result shows distortion, modify the value of the vertical coordinate Z of this grid node to the value of the interpolated vertical coordinate Z1; if the check result shows no distortion, keep the value of the vertical coordinate Z of this grid node unchanged; repeat this step until the distortion check has been conducted on all the grid nodes corresponding to the grid node numbers in the set of nodes to be corrected.

[0063] The distortion check described in Step 4.5.3 is specifically as follows:

[0064] Step 4.5.3a: Select a grid node number from the set of nodes to be corrected; obtain the grid node corresponding to this grid node number, denoted as the node to be inspected.

[0065] Step 4.5.3b: Obtain, from the set of standard nodes, multiple grid node numbers that can minimally and uniquely enclose or minimally and uniquely enclose the node to be inspected with the smallest large interior angle in a fixed horizontal plane, denoted as the standard node group.

[0066] The minimally unique enclosure of the node to be inspected within the plane range means that the projections of the grid nodes corresponding to multiple grid node numbers in the set of standard nodes, when connected, can form a polygon by themselves on the fixed horizontal plane. The polygon does not contain the projections of all the grid nodes corresponding to the grid node numbers in the set of standard nodes on the fixed horizontal plane, but contains the projection of the node to be inspected, and the number of sides of the polygon is the smallest and the area of the polygon is the smallest.

[0067] The minimally unique enclosure of the node to be inspected with the smallest large interior angle means that in the case where the projections of the grid nodes corresponding to any multiple grid node numbers in the set of standard nodes, when connected, cannot contain the projection of the node to be inspected, select multiple grid node numbers corresponding to the grid nodes in the set of standard nodes and connect them with the node to be inspected, and the projections can form a polygon on the fixed horizontal plane. The polygon does not contain the projections of all the grid nodes corresponding to the grid node numbers in the set of standard nodes on the fixed horizontal plane, and the interior angle corresponding to the projection of the node to be inspected is the largest, and the number of sides of the polygon is the smallest and the area of the polygon is the smallest.

[0068] Step 4.5.3c: Solve for the average node of the standard node group in space, and solve for the average distance in space between the standard node group and the average node, denoted as La; solve for the distance Lb in space between the node to be inspected and the average node; if Lb / La is greater than the slenderness ratio, return that the node to be inspected is deformed, otherwise return not deformed;

[0069] The X, Y, and Z of the average node are equal to the average values of the X, Y, and Z of the grid nodes corresponding to all the grid node numbers in the standard node group; the slenderness ratio is a set parameter;

[0070] Step 4.5.4: Clear the set of nodes to be corrected, and remove the selected set to be corrected from the group of sets to be corrected;

[0071] Repeat steps 4.5.1 - 4.5.4 until the group of sets to be corrected is empty.

[0072] Preferably, for step 4.6, repair and fuse the set of formation interface points, and establish new connection relationships for the grid nodes corresponding to the grid node numbers therein, specifically as follows:

[0073] Step 4.6.1: Select a set of formation interface points to be fused, and connect the grid nodes corresponding to the grid node numbers in this set according to the original connection relationships to form two grid surfaces; extract the outlines of the two grid surfaces, the grid node numbers on the outlines, and their original connection relationships, denoted as the old outlines, old outline node numbers, and old outline connection relationships;

[0074] Step 4.6.2: Project the old outline onto the fixed horizontal plane in the vertical direction to obtain a new outline projection in the fixed horizontal plane that can exactly enclose the projection of the old outline;

[0075] Step 4.6.3: Obtain the old outline node numbers corresponding to the new outline projection as the new outline node numbers, and determine whether new grid nodes and their corresponding numbers and original connection relationships need to be added; if addition is required, store the newly added grid node numbers in the selected set of formation interface points to be fused, and use the newly added grid node numbers as the new outline node numbers; according to the connection relationships of the vertices of the new outline projection, add the connection relationships between the newly added grid nodes and the existing grid nodes to the original connection relationships;

[0076] For the determination in step 4.6.3 of whether new grid nodes and their corresponding numbers and original connection relationships need to be added, specifically as follows:

[0077] Step 4.6.3a: Determine whether there is an intersection between the two old contour projections, and the intersection does not coincide with the projection point of the grid node corresponding to the old contour node number; if so, it is necessary to add a new grid node with the same horizontal coordinate as the intersection, and assign it a number that is different from the existing grid node numbers, and execute step 4.6.3b; if not, it does not need to be added, and end;

[0078] Step 4.6.3b: Get the edge of the old contour corresponding to the projection of the old contour that forms the intersection, obtain the points on the two old contour edges with the same horizontal coordinates as the intersection through linear interpolation, and solve the average value of the vertical coordinates Z of the two points as the value of the vertical coordinate Z of the newly added grid node;

[0079] Step 4.6.4: Determine whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid at the same time. If necessary, store the newly added grid node number in the unselected fused stratum interface point set or the independent set with the attribute Mid.

[0080] Step 4.6.4 determines whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid, as follows:

[0081] Step 4.6.4a: Search for the unselected fused stratum interface point set corresponding to the same stratum interface point set as the selected fused stratum interface point set and the independent set with the attribute of Mid;

[0082] Step 4.6.4b: connect the unselected fused stratum interface point set in step 4.6.4a and the grid nodes corresponding to the grid node numbers in the independent set with the attribute Mid according to the original connection relationship to form at least one grid surface SA, and project it to a fixed horizontal plane along the vertical direction;

[0083] Step 4.6.4c: If the point where the newly added grid node is projected onto the fixed horizontal plane along the vertical direction is located on the contour of the projection of a certain grid surface SA, the number of the newly added grid node is stored in the corresponding unselected fused stratum interface point set described in 4.6.4a or in the independent set with the attribute Mid;

[0084] Step 4.6.5: If there are points that are spatially close to the grid nodes corresponding to the grid node numbers in the selected fused stratum interface point set, only the number of one of the points is retained in the set, and the numbers of the remaining points are discarded; the grid nodes are spatially close means that the spatial distance between the grid nodes is less than the distance difference ε3; the distance difference ε3 is an artificially set fixed parameter;

[0085] Step 4.6.6: Taking the new contour projection as the boundary, establish the new connection relationships of the grid nodes corresponding to the grid node numbers in the selected set of fusion formation interface points according to the principle of restricted growth of the triangular mesh;

[0086] The statement of taking the new contour projection as the boundary and following the principle of restricted growth of the triangular mesh means that after the grid nodes corresponding to the grid node numbers in the set of fusion formation interface points are connected according to the new connection relationships, the following conditions are satisfied: (1) All grids are triangular meshes and all grid nodes corresponding to the grid node numbers in the set are vertices of triangles; (2) The projection range of all grids onto the fixed horizontal plane does not exceed the new contour projection; (3) There is no overlap or intersection in the projections of all triangular meshes onto the fixed horizontal plane.

[0087] Preferably, the specific process of establishing c lens body sets in Step 4.7 is as follows:

[0088] Step 4.7.1: Select an independent set with the attribute of Mid, called the independent set NA. Among the remaining independent sets with the attribute of Mid, screen all independent sets that can cross-set correspond to the same geological body model as the independent set NA, called the independent set group NB;

[0089] Step 4.7.2: According to the number of formation interface point sets corresponding to the independent set NA, establish the same number of temporary lens body sets, and copy all the grid node numbers in the independent set NA to each of the temporary lens body sets. During each copying process, transfer the corresponding relationship of one formation interface point set of the independent set NA to this temporary lens body set at the same time;

[0090] Step 4.7.3: In the independent set group NB, screen the independent set NC that can cross-set correspond to the same geological body model as the temporary lens body set, copy all the grid node numbers in the independent set NC to this temporary lens body set, and transfer the corresponding relationship of one formation interface point set of the independent set NC to this temporary lens body set;

[0091] The corresponding relationship of the formation interface point set transferred by the independent set NC satisfies that the formation interface point set in this corresponding relationship corresponds to the same geological body model as the formation interface point set corresponding to the temporary lens body set;

[0092] The transfer of the corresponding relationship of the formation interface point set from the independent set to the temporary lens body set means deleting the corresponding relationship between the independent set and this formation interface point set and establishing the corresponding relationship between the temporary lens body set and this formation interface point set;

[0093] The cross-set correspondence means that there is at least one same among all the geological body models corresponding to one of the formation interface point sets corresponding to the independent set;

[0094] After the transfer in Steps 4.7.2 and 4.7.3 ends, immediately determine the independent set. If the independent set no longer corresponds to any formation interface point set, delete the independent set.

[0095] Repeat Steps 4.7.1 - 4.7.3 until all independent sets with the attribute of Mid are deleted.

[0096] Step 4.7.4: Keep the stored content and corresponding relationship of the temporary lens body set unchanged, and convert the temporary lens body set into a lens body set.

[0097] Step 4.7.5: Establish new connection relationships for all lens body sets according to the lens body triangular mesh growth principle.

[0098] The lens body triangular mesh growth principle described in Step 4.7.5 is satisfied as follows: (1) All meshes are triangular meshes and all mesh nodes corresponding to the mesh node numbers in the set are the vertices of the triangle; (2) The meshes can enclose a unique closed space.

[0099] Preferably, the specific process of establishing a top surface sets and b bottom surface sets in Step 4.8 is as follows:

[0100] Step 4.8.1: Select an independent set with the attribute of Top or Down, denoted as independent set ND, obtain the formation interface point set corresponding to the independent set ND, denoted as formation interface point set C, and then obtain all the fused formation interface point sets corresponding to the formation interface point set, denoted as fused formation interface point set C'.

[0101] Step 4.8.2: Connect the mesh nodes corresponding to the mesh node numbers in the formation interface point set C according to the original connection relationship to obtain the mesh surface SB; connect the mesh nodes corresponding to the mesh node numbers in the fused formation interface point set C' according to the new connection relationship to obtain the mesh surface SC; project the outlines of the mesh surface SB and SC onto the fixed horizontal plane at the same time, obtain the part of the outline projection of the mesh surface SC that does not coincide with the outline projection of the mesh surface SB, and store the mesh node numbers corresponding to the non - coincident part in different mesh boundary groups according to the new connection relationship.

[0102] The mesh node numbers within the mesh boundary group satisfy that they can form a line after being connected according to the new connection relationship.

[0103] Step 4.8.3: Store the mesh node numbers in the mesh boundary group that meet the relationship of integrating into the independent set into the selected independent set.

[0104] The satisfaction of the incorporation into the independent set relationship refers to the grid boundary group: the triangular meshes formed by connecting the grid nodes corresponding to the grid node numbers in the grid boundary group with any two grid nodes corresponding to the grid node numbers in the independent set cannot overlap with the projection of the grid surface SC along the vertical direction onto the fixed horizontal plane;

[0105] Step 4.8.4: Establish a new connection relationship for this independent set. The new connection relationship meets the following requirements: the grid surface formed by connecting the grid nodes corresponding to the grid node numbers in the independent set according to the new connection relationship does not exceed the contour projection of the grid surface SB along the vertical direction onto the fixed horizontal plane, does not overlap with the projection of the grid surface SC, and is all triangular meshes;

[0106] Step 4.8.5: Convert it into a top surface set or a bottom surface set according to the attribute of this independent set. Specifically: if the attribute is Top, it is converted into a top surface set; if the attribute is Down, it is converted into a bottom surface set;

[0107] If the integrated formation interface point set C' is not obtained in Step 4.8.1, directly execute Step 4.8.5.

[0108] Preferably, the generation of the CAE model by reconstruction in the CAE software in Step 5 is as follows:

[0109] Step 5.1: Generate the grid nodes corresponding to all the grid node numbers in the integrated interface point set, top surface set, bottom surface set, and lens body set in the CAE software;

[0110] Step 5.2: Select a geological body model of a non-lens body formation type, respectively obtain the integrated interface point set, top surface set, or bottom surface set corresponding to its upper and lower formation interface point sets, and connect them on the CAE platform according to the new connection relationship to form two grid surfaces corresponding to the upper and lower formation interface point sets, which are respectively recorded as the upper and lower grid surfaces of the geological body;

[0111] Step 5.3: Through the stretching operation of the CAE platform, stretch the upper / lower grid surface of the geological body downward / upward to the lower / upper grid surface to form the CAE model corresponding to this geological body model;

[0112] Repeat Steps 5.2 - 5.3 until the CAE models corresponding to all the geological body models of non-lens body formations are established;

[0113] Step 5.4: Select a geological body model of a lens body formation type, obtain its corresponding lens body set, and form a closed body on the CAE platform according to the new connection relationship, which is the CAE model corresponding to this geological body model; repeat this step to establish the CAE models of all lens body formations;

[0114] Step 5.5: In the CAE platform, through Boolean operation, subtract the CAE model of the lenticular formation from the CAE model of the non-lenticular formation; the CAE model of the three-dimensional geological model is jointly composed of the CAE model after Boolean operation and the CAE model of the lenticular formation.

[0115] The advantages of the present invention are as follows:

[0116] (1) Through the method of vertical interpolation projection, the determination of the contact surface of the geological body model in the CAD platform is realized, and the contact surface is integrated, avoiding the problem that there are small gaps or embeddings in the reconstruction of the contact surface of the geological body model in the CAE platform, which may lead to the inability to calculate.

[0117] (2) By adopting the form of spatial interpolation, cross-validation and distortion correction are carried out for each point in the formation surface, avoiding the problem that the reconstructed geological body model in the CAE platform cannot be meshed.

[0118] (3) The entire conversion process can be realized by a computer, that is, the automatic conversion of the geological model from the CAD platform to the CAE can be realized. At the same time, the method of model reconstruction is adopted to complete the conversion of the three-dimensional geological model in the CAD platform to the finite element model in the CAE platform, without the intervention of software manufacturers.

[0119] (4) The grid node numbers are stored corresponding to the spatial coordinates and connection relationships, and only the numbers are stored in the set, realizing the synchronous change of the numbers corresponding to the spatial coordinates and connection relationships in all sets when the spatial coordinates and connection relationships change. Description of the Drawings

[0120] Figure 1 It is a schematic cross-sectional view of a three-dimensional geological model.

[0121] Figure 2 It is a schematic diagram of the corresponding relationships of various sets.

[0122] Figure 3 It is a schematic diagram of dividing the upper and lower formation interface point sets according to the projection relationship.

[0123] Figure 4 It is a schematic diagram of the smallest unique enclosing node to be inspected within the plane range.

[0124] Figure 5 It is a schematic diagram of the smallest unique enclosing semi-enclosing node to be inspected with a large interior angle.

[0125] Figure 6 It is a schematic diagram of distortion inspection.

[0126] Figure 7 It is a schematic diagram of establishing a new connection relationship for the integrated formation interface point set.

[0127] The reference numerals are as follows:

[0128] 1 - Mesh node; 2 - Mesh node number; 3 - Spatial coordinates; 4 - Average node; 5 - Conventional formation; 6 - Pinch-out formation; 7 - Lenticular formation; 8 - Projection point p; 9 - Node to be inspected; 10 - Intersection point; 11 - Old contour projection; 12 - New contour projection. Specific implementation manner

[0129] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0130] As Figures 1-7 shown, a method for equivalent conversion of a three-dimensional geological model to a finite element model includes the following steps:

[0131] Step 1: Obtain the mesh nodes of each geological body model in the three-dimensional geological model in the CAD platform and the original connection relationship of the mesh nodes, and store them separately.

[0132] The mesh nodes include their numbers and spatial coordinates; the spatial coordinates of the mesh nodes include the horizontal coordinate X, the horizontal coordinate Y, and the vertical coordinate Z.

[0133] The original connection relationship of the mesh nodes is as follows: In the CAD platform, the mesh nodes are connected to each other according to the original connection relationship to form multiple mesh surfaces, and a complete geological body model can be surrounded by multiple mesh surfaces; the number of the geological body models is N (N≥1), and N geological body models are combined into a three-dimensional geological model.

[0134] Step 2: Establish a set of formation interface points and corresponding set plane boundaries for each geological body model; establish a full model boundary for the three-dimensional geological model; the set of formation interface points includes upper and lower formation interface point sets.

[0135] The specific process of establishing the set of formation interface points and corresponding set plane boundaries for each geological body model in Step 2 is as follows:

[0136] Step 2.1: Select a geological body model, obtain its mesh nodes from the storage result of Step 1, and at the same time establish upper and lower formation interface point sets for this geological body model.

[0137] Step 2.2: Vertically project each mesh node to this geological body model in the CAD platform in turn, and classify the mesh node numbers into the upper and lower formation interface point sets and the temporary number set according to the projection relationship, specifically as follows:

[0138] If the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the largest vertical coordinate Z, the grid node number is included in the upper stratum interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the smallest vertical coordinate Z, the grid node number is included in the lower stratum interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node does not coincide with the projection point p with the largest and smallest vertical coordinates Z, the grid node number is included in the temporary number set; if the number of projection points p obtained by projecting the grid node is equal to one, the grid node number is included in both the upper and lower stratum interface point sets, and is defined as a special grid node number.

[0139] Step 2.3: Determine whether there is data in the temporary number set. If so, execute step 2.4; otherwise, execute step 2.5.

[0140] Step 2.4: Select a grid node number in the temporary number set, define the grid node as MB, and classify the MB number into the upper or lower stratum interface point set according to the original connection relationship. The specific steps are as follows:

[0141] Step 2.4.1: According to the original connection relationship, all grid node numbers directly connected to the MB are screened, and non-special grid node numbers among the grid node numbers directly connected to the MB are classified into the screening number set.

[0142] Step 2.4.2: Determine whether there is a grid node number in the screening number set that belongs to the upper or lower stratum interface point set. If so, define the grid node as PB, and determine the ownership of the MB number based on the PB number, specifically:

[0143] If the number of PB belongs to the upper stratum interface point set, the number of MB is included in the set; otherwise, it is included in the lower stratum interface point set, and MB is removed from the temporary number set, and step 2.4.2 is ended directly;

[0144] If there is no PB, proceed to step 2.4.3.

[0145] Step 2.4.3: According to the original connection relationship, screen the numbers of all grid nodes directly connected to the grid nodes corresponding to all grid node numbers in the screening number set, and classify the non-special grid node numbers among them into the screening number set. According to whether there are new non-special grid node numbers included in the screening number set, select the execution content. If there are new non-special grid node numbers, return to step 2.4.2 directly; if not, remove MB directly from the temporary number set and end step 2.4.3.

[0146] Repeat step 2.4 until the temporary number set is empty.

[0147] Step 2.5: Obtain the boundary point numbers in the upper or lower formation interface point set through the upper or lower formation interface point set and the original connection relationship, and then determine the boundary of the set plane according to the original connection relationship. The specific steps are as follows:

[0148] Step 2.5.1: Screen out the grid node numbers that meet the boundary point rules from the upper or lower formation interface point set and define them as boundary point numbers. The boundary point rules include two points, and meeting any one of them means meeting the boundary point rules. Specifically: (1) The grid node number is a special grid node number; (2) The grid node number itself is a non-special grid node number located in the upper (or lower) formation interface point set, and through the determination of the original connection relationship, there is a grid node number of a non-special grid node number in the lower (or upper) formation interface point set that is directly connected to it.

[0149] Step 2.5.2: Obtain all the boundary point numbers, connect the boundary point numbers that are directly connected in the original connection relationship in sequence, and project them vertically onto the fixed horizontal plane. The boundary obtained is defined as the boundary of the set plane.

[0150] Repeat steps 2.1 to 2.5 to establish the formation interface point set and the boundary of the set plane for each geological body model.

[0151] The full model boundary of the three-dimensional geological model meets two requirements: (1) On the fixed horizontal plane, all the boundaries of the set planes are not located outside the full model boundary; (2) Under the condition of meeting the previous requirement, the area included in the full model boundary is the smallest.

[0152] Step 3: Define the formation type judgment rules, and determine the formation type as a normal formation, a pinched-out formation, or a lenticular formation according to the boundary of the set plane of the geological body model.

[0153] The formation type judgment rules are respectively the lenticular formation rule and the pinched-out formation rule.

[0154] The lenticular formation rule is that the boundary of the set plane corresponding to the selected geological body model is completely located within the full model boundary.

[0155] The pinched-out formation rule is that the boundary of the set plane corresponding to the selected geological body model is partially located within the full model boundary and partially coincides with the full model boundary.

[0156] The determination of the formation type is as follows: If the boundary of the set plane corresponding to the selected geological body model meets the lenticular formation rule, its formation type is defined as a lenticular formation; if the boundary of the set plane corresponding to the selected geological body model meets the pinched-out formation rule, its formation type is defined as a pinched-out formation; if neither is met, its formation type is defined as a normal formation.

[0157] Step 4: Establish a fused formation interface point set, a top surface set, a bottom surface set, and a lens body set based on the formation interface point sets and the original connection relationships of the geological body models, as well as the new connection relationships of the grid nodes corresponding to the grid node numbers within the said sets.

[0158] The specific steps for establishing the fused formation interface point set, the top surface set, the bottom surface set, and the lens body set, as well as the new connection relationships of the grid nodes corresponding to the grid node numbers within the said sets in Step 4 are as follows:

[0159] Step 4.1: Select a formation interface point set (upper or lower formation interface point set) of a geological body model, and vertically interpolate and project the grid nodes corresponding to each grid node number in the set to all formation interface point sets of the remaining N - 1 geological body models; denote the formation interface point set of the selected geological body model as the selected set, and at the same time establish the corresponding relationship therebetween (establish the corresponding relationship between the selected set and the formation interface point set of the selected geological body model); denote the formation interface point set of the geological body model to be projected as the projected set, and at the same time establish the corresponding relationship therebetween (establish the corresponding relationship between the projected set and the formation interface point set of the geological body model to be projected); during vertical interpolation and projection, store the results separately according to the differences between the selected set and the projected set, and call it the comparison set, and the comparison set corresponds to the selected set and the projected set at the same time.

[0160] The specific method of the vertical interpolation and projection is to obtain the points with the same horizontal coordinates X and Y of the grid nodes corresponding to all grid node numbers in the selected set through spatial interpolation in the projected set; the spatial interpolation is Kriging spatial interpolation.

[0161] Step 4.2: Compare each selected set with the corresponding comparison set in turn. If there is a relationship of overlapping surface areas between the two, denote that the selected set corresponding to the comparison set and the projected set have overlapping surface areas, and establish a fused formation interface point set, and at the same time judge whether to establish an independent set and its attributes.

[0162] The determination of the relationship of overlapping surface areas, the establishment of the fused formation interface point set, and the judgment of whether to establish an independent set and its attributes in Step 4.2 are as follows:

[0163] Step 4.2.1: Establish a temporary fused formation interface point set corresponding to the transition of the comparison set; the transition correspondence means corresponding to the same selected set and projected set as the comparison set at the same time.

[0164] Step 4.2.2: Compare the selected set with the comparison set, and separately select the grid node numbers in the selected set that meet the error coincidence, and store them in the temporary fused formation interface point set corresponding to the transition of the comparison set.

[0165] The grid node numbers that meet the error coincidence are as follows: The grid nodes corresponding to the grid node numbers in the selected set and the grid nodes corresponding to the grid node numbers in the comparison set satisfy the same horizontal coordinates X and Y, and the absolute value of the difference in the vertical coordinate Z is less than the error ε1; the error ε1 is a fixed parameter set manually.

[0166] Step 4.2.3: Connect the grid nodes corresponding to the grid node numbers in the non-empty temporary fusion formation interface point set according to the original connection relationship. If a surface can be formed after connection, it is recorded that the surface regions of the selected set and the comparison projection set corresponding to this temporary fusion formation interface point set coincide.

[0167] Step 4.2.4: Determine whether all the grid node numbers in the selected set are subsets of the union of all the corresponding temporary fusion formation interface point sets; if not, establish an independent set, store the grid node numbers in the selected set that are not included in this union in the independent set, and determine their attributes according to the grid node numbers stored in the independent set; if so, do not establish an independent set.

[0168] Furthermore, if there is no corresponding temporary fusion formation interface point set for the selected set, establish an independent set, store all the grid node numbers in the selected set in the independent set, and determine their attributes according to the grid node numbers stored in the independent set;

[0169] The independent set corresponds to the formation interface point set corresponding to the selected set.

[0170] The determination of their attributes according to the grid node numbers stored in the independent set is specifically as follows: If the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are greater than the Z values of the grid nodes with the same horizontal coordinates among the grid nodes corresponding to all the grid node numbers in the comparison sets corresponding to the selected set, define the attribute of the independent set as Top; if the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are less than the Z values of the grid nodes with the same horizontal coordinates among the grid nodes corresponding to all the grid node numbers in the comparison sets corresponding to the selected set, define the attribute of the independent set as Down; otherwise, define its attribute as Mid.

[0171] Repeat until all the formation interface point sets of all geological body models are used as the selected set to perform all the operations in steps 4.1 - 4.2.

[0172] Step 4.3: Merge the temporary fusion formation interface point sets that are reversed the same for the corresponding selected set and the projection set into one, and merge the corresponding relationships; then delete the temporary fusion formation interface point sets with an empty set and those where the grid nodes corresponding to the grid node numbers in the set cannot form a surface when connected according to the original connection relationship.

[0173] The said inversion sameness means that the projection set corresponding to the temporary fusion formation interface point set A and the selected set corresponding to the temporary fusion formation interface point set B correspond to the same formation interface point set, and the selected set corresponding to the temporary fusion formation interface point set A and the projection set corresponding to the temporary fusion formation interface point set B correspond to the same formation interface point set.

[0174] The said merging correspondence means that the merged set is transformed into a fusion formation interface point set, and directly corresponds to the formation interface point sets corresponding to the selected sets and the projection sets of the two temporary fusion formation interface point sets.

[0175] Step 4.4: Obtain two corresponding formation interface point sets in the fusion formation interface point set, denoted as the fusion corresponding set pair, and then obtain the corresponding two geological body models. If there is a geological body model with a formation type of lenticular formation among them, then convert this fusion formation interface point set into an independent set, and this independent set corresponds to the formation interface point set corresponding to the lenticular formation in the fusion corresponding set pair; the attribute of this independent set is Mid.

[0176] Step 4.5: Place all the fusion formation interface point sets and independent sets into the set group to be corrected, and correct each set in the set group to be corrected.

[0177] The correction of each set in the set group to be corrected in Step 4.5 is as follows:

[0178] Step 4.5.1: Select a set from the set group to be corrected as the set to be corrected, and obtain the spatial coordinates of the grid nodes corresponding to all the grid node numbers in this set.

[0179] Step 4.5.2: Obtain the interpolated vertical coordinate Z1 of the grid nodes corresponding to all the grid node numbers in the set to be corrected through orthogonal test; solve the absolute value of the difference between the vertical coordinate Z of each grid node and the interpolated vertical coordinate Z1, and place the grid node numbers with the absolute value greater than the deviation ε2 into the set of nodes to be corrected, and place the remaining node numbers into the set of standard nodes.

[0180] The orthogonal test in Step 4.5.2 to obtain the interpolated vertical coordinate Z1 of the grid nodes is as follows:

[0181] Step 4.5.2a: Place all the grid node numbers in the set to be corrected into the orthogonal test set.

[0182] Step 4.5.2b: Select the grid node corresponding to a grid node number in the orthogonal test set, denoted as the node to be solved, and remove its number from the orthogonal test set.

[0183] Step 4.5.2c: Obtain, by means of spatial interpolation, points with the same horizontal coordinates as the node to be determined among the grid nodes corresponding to all the grid node numbers in the orthogonal test set as interpolation nodes; the vertical coordinate Z of the interpolation nodes is the interpolated vertical coordinate Z1 of the node to be determined.

[0184] The deviation ε2 described in Step 4.5.2 is a fixed parameter set manually.

[0185] Step 4.5.3: Conduct a distortion check on the grid nodes corresponding to the grid node numbers in the set of nodes to be corrected. If the check result shows distortion, modify the value of the vertical coordinate Z of the grid node to the value of the interpolated vertical coordinate Z1; if the check result shows no distortion, keep the value of the vertical coordinate Z of the grid node unchanged; repeat this step until the distortion check has been conducted on all the grid nodes corresponding to the grid node numbers in the set of nodes to be corrected.

[0186] The distortion check described in Step 4.5.3 is specifically as follows:

[0187] Step 4.5.3a: Select a grid node number from the set of nodes to be corrected; obtain the grid node corresponding to the grid node number, denoted as the node to be inspected.

[0188] Step 4.5.3b: Obtain, from the set of standard nodes, multiple grid node numbers that can minimally and uniquely enclose or minimally and uniquely enclose the node to be inspected with the smallest large interior angle in a fixed horizontal plane, denoted as the standard node group.

[0189] The minimum unique enclosure of the node to be inspected within the plane range means that when the grid nodes corresponding to multiple grid node numbers in the set of standard nodes are connected and projected onto the fixed horizontal plane, they can form a polygon by themselves. The polygon does not contain the projections of all the grid nodes corresponding to the grid node numbers in the set of standard nodes within the fixed horizontal plane, but contains the projection of the node to be inspected, and the number of sides of the polygon is the smallest and the area of the polygon is the smallest.

[0190] The minimum unique enclosure of the node to be inspected with the smallest large interior angle means that in the case where the polygon formed by the projection of the connection of any multiple grid nodes corresponding to the grid node numbers in the set of standard nodes onto the fixed horizontal plane cannot contain the projection of the node to be inspected, select multiple grid nodes corresponding to the grid node numbers in the set of standard nodes and connect them with the node to be inspected, and the projection onto the fixed horizontal plane can form a polygon. The polygon does not contain the projections of all the grid nodes corresponding to the grid node numbers in the set of standard nodes within the fixed horizontal plane, and the interior angle corresponding to the projection of the node to be inspected is the largest, and the number of sides of the polygon is the smallest and the area of the polygon is the smallest.

[0191] Step 4.5.3c: Solve for the average node of the standard node group in space, and solve for the average distance in space between the standard node group and the average node, denoted as La; solve for the distance Lb in space between the node to be inspected and the average node; if Lb / La is greater than the slenderness ratio, return that the node to be inspected is deformed, otherwise return not deformed.

[0192] The X, Y, and Z of the average node described in Step 4.5.3c are equal to the average values of the X, Y, and Z of the grid nodes corresponding to all the grid node numbers in the standard node group; the slenderness ratio is a fixed parameter set manually.

[0193] Step 4.5.4: Clear the set of nodes to be corrected, and remove the selected set to be corrected from the group of sets to be corrected.

[0194] Repeat Steps 4.5.1 - 4.5.4 until the group of sets to be corrected is empty.

[0195] Step 4.6: Repair and fuse the set of formation interface points, and establish new connection relationships for the grid nodes corresponding to the grid node numbers therein.

[0196] The repair and fusion of the set of formation interface points described in Step 4.6, and the establishment of new connection relationships for the grid nodes corresponding to the grid node numbers therein are specifically as follows:

[0197] Step 4.6.1: Select a set of formation interface points, connect the grid nodes corresponding to the grid node numbers in this set according to the original connection relationships to form two grid surfaces; extract the outlines of the two grid surfaces, the grid node numbers on the outlines, and their original connection relationships, denoted as the old outlines, old outline node numbers, and old outline connection relationships.

[0198] Step 4.6.2: Project the old outline vertically onto a fixed horizontal plane to obtain a new outline projection in the fixed horizontal plane that can exactly enclose the projection of the old outline.

[0199] Step 4.6.3: Obtain the old outline node numbers corresponding to the new outline projection as the new outline node numbers, and determine whether new grid nodes and their corresponding numbers and original connection relationships need to be added; if addition is required, store the newly added grid node numbers in the selected set of formation interface points, and use the newly added grid node numbers as the new outline node numbers; according to the connection relationships of the vertices of the new outline projection, add the connection relationships between the newly added grid nodes and the existing grid nodes to the original connection relationships.

[0200] The determination of whether new grid nodes and their corresponding numbers and original connection relationships need to be added described in Step 4.6.3 is specifically as follows:

[0201] Step 4.6.3a: Determine whether there is an intersection between the two old contour projections, and the intersection does not coincide with the projection point of the grid node corresponding to the old contour node number; if so, it is necessary to add a new grid node with the same horizontal coordinate as the intersection, and assign it a number that is different from the existing grid node numbers, and execute step 4.6.3b; if not, it does not need to be added, and end;

[0202] Step 4.6.3b: Get the edge of the old contour corresponding to the projection of the old contour that forms the intersection, obtain the points on the two old contour edges with the same horizontal coordinates as the intersection through linear interpolation, and solve the average value of the vertical coordinates Z of the two points as the value of the vertical coordinate Z of the newly added grid node.

[0203] Step 4.6.4: Determine whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid. If necessary, store the newly added grid node number in the unselected fused stratum interface point set or the independent set with the attribute Mid.

[0204] Step 4.6.4 determines whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid, as follows:

[0205] Step 4.6.4a: Search for the unselected fused stratum interface point set corresponding to the same stratum interface point set as the selected fused stratum interface point set and the independent set with the attribute of Mid;

[0206] Step 4.6.4b: Connect the unselected fused stratum interface point set described in 4.6.4a and the grid nodes corresponding to the grid node numbers in the independent set with the attribute Mid according to the original connection relationship to form at least one grid surface SA, and project it onto a fixed horizontal plane along the vertical direction;

[0207] Step 4.6.4c: If the point where the newly added grid node is projected onto the fixed horizontal plane along the vertical direction is located on the contour of the projection of a certain grid surface SA, the number of the newly added grid node is stored in the corresponding unselected fused formation interface point set described in 4.6.4a or in an independent set with the attribute Mid.

[0208] Step 4.6.5: If there are spatially similar points in the grid nodes corresponding to the grid node numbers in the selected fused formation interface point set, only the number of one of the points is retained in the set, and the numbers of the remaining points are discarded; the grid nodes are spatially similar when the spatial distance between the grid nodes is less than the distance difference ε3; the distance difference ε3 is an artificially set fixed parameter.

[0209] Step 4.6.6: Using the projection of the new contour as the boundary, establish new connection relationships for the grid nodes corresponding to the grid node numbers in the selected set of fusion formation interface points according to the principle of restricted growth of the triangular mesh.

[0210] The statement in Step 4.6.6 that uses the projection of the new contour as the boundary and follows the principle of restricted growth of the triangular mesh means that after the grid nodes corresponding to the grid node numbers in the set of fusion formation interface points are connected according to the new connection relationships, the following conditions are satisfied: (1) all grids are triangular grids and all grid nodes corresponding to the grid node numbers in the set are the vertices of the triangles; (2) the projected range of all grids onto a fixed horizontal plane does not exceed the projection of the new contour; (3) there is no overlap or intersection in the projections of all triangular grids onto the fixed horizontal plane.

[0211] Step 4.7: Obtain all independent sets with the attribute of Mid, and establish c lens body sets and their new connection relationships; where c ≥ 0.

[0212] The specific process of establishing c lens body sets described in Step 4.7 is as follows:

[0213] Step 4.7.1: Select an independent set with the attribute of Mid, called independent set NA. Among the remaining independent sets with the attribute of Mid, screen all independent sets that can correspond to the same geological body model as independent set NA across sets, called independent set group NB.

[0214] Step 4.7.2: According to the number of formation interface point sets corresponding to independent set NA, establish the same number of temporary lens body sets, and copy all the grid node numbers in independent set NA to each of the temporary lens body sets. During each copying process, at the same time, transfer the corresponding relationship of one formation interface point set of independent set NA to this temporary lens body set.

[0215] Step 4.7.3: In independent set group NB, screen independent set NC that can correspond to the same geological body model as the temporary lens body set across sets, copy all the grid node numbers in independent set NC to this temporary lens body set, and transfer the corresponding relationship of one formation interface point set of independent set NC to this temporary lens body set.

[0216] The corresponding relationship of the formation interface point set transferred by the independent set NC satisfies that the formation interface point set in this corresponding relationship corresponds to the same geological body model as the formation interface point set corresponding to the temporary lens body set.

[0217] The transfer of the corresponding relationship of the formation interface point set from the independent set to the temporary lens body set means deleting the corresponding relationship between the independent set and this formation interface point set and establishing the corresponding relationship between the temporary lens body set and this formation interface point set.

[0218] The cross-set correspondence means that there is at least one same among all geological body models corresponding to one of the formation interface point sets corresponding to the independent sets.

[0219] Further, after the transfer described in steps 4.7.2 and 4.7.3 ends, immediately determine the independent set. If the independent set no longer corresponds to any formation interface point set, then delete the independent set.

[0220] Repeat steps 4.7.1 - 4.7.3 until all independent sets with the attribute of Mid are deleted.

[0221] Step 4.7.4: Keep the stored content and corresponding relationship of the temporary lens body set unchanged, and convert the temporary lens body set into a lens body set.

[0222] Step 4.7.5: Establish new connection relationships for all lens body sets according to the lens body triangular mesh growth principle.

[0223] The lens body triangular mesh growth principle described in step 4.7.5 satisfies: (1) all meshes are triangular meshes and all mesh nodes corresponding to the mesh node numbers in the set are the vertices of the triangle; (2) the meshes can enclose a unique closed space.

[0224] Step 4.8: Obtain all independent sets with the attributes of Top and Down, and establish a top surface sets and b bottom surface sets; where a ≥ 1 and b ≥ 1.

[0225] The process of establishing a top surface sets and b bottom surface sets described in step 4.8 is as follows:

[0226] Step 4.8.1: Select an independent set with the attribute of Top or Down, denoted as the independent set ND, obtain the formation interface point set corresponding to the independent set ND, denoted as the formation interface point set C, and then obtain all the fused formation interface point sets corresponding to the formation interface point set, denoted as the fused formation interface point set C'.

[0227] Step 4.8.2: Connect the mesh nodes corresponding to the mesh node numbers in the formation interface point set C according to the original connection relationship to obtain the mesh surface SB; connect the mesh nodes corresponding to the mesh node numbers in the fused formation interface point set C' according to the new connection relationship to obtain the mesh surface SC; project the contours of the mesh surfaces SB and SC onto a fixed horizontal plane at the same time, obtain the part of the contour projection of the mesh surface SC that does not coincide with the contour projection of the mesh surface SB, and store the mesh node numbers corresponding to the non - coincident part in different mesh boundary groups according to the new connection relationship.

[0228] The mesh node numbers within the mesh boundary group satisfy that they can form a line after being connected according to the new connection relationship.

[0229] Step 4.8.3: Store the grid node numbers in the grid boundary group that satisfy the relationship of integrating into the independent set into the selected independent set.

[0230] The relationship of satisfying the integration into the independent set described in Step 4.8.3 means that for the grid boundary group: the triangular meshes formed by connecting the grid nodes corresponding to the grid numbers in the grid boundary group with the grid nodes corresponding to any two grid node numbers in the independent set cannot overlap with the projection of the grid surface SC when projected vertically onto the fixed horizontal plane.

[0231] Step 4.8.4: Establish a new connection relationship for this independent set, and the new connection relationship shall meet the following requirements: the grid surface formed by connecting the grid nodes corresponding to the grid node numbers in the independent set according to the new connection relationship will not exceed the contour projection of the grid surface SB when projected vertically onto the fixed horizontal plane, and will not overlap with the projection of the grid surface SC, and all are triangular meshes.

[0232] Step 4.8.5: Convert it into a top surface set or a bottom surface set according to the attribute of this independent set, specifically: if the attribute is Top, convert it into a top surface set; if the attribute is Down, convert it into a bottom surface set.

[0233] Furthermore, if the integrated formation interface point set C' is not obtained in Step 4.8.1, then directly execute Step 4.8.5.

[0234] Step 5: Generate a model by reconstruction in the CAE software according to the grid node numbers, spatial coordinates and the new connection relationship of the grid nodes.

[0235] The generation of the model by reconstruction in the CAE software described in Step 5 is specifically as follows:

[0236] Step 5.1: Generate the grid nodes corresponding to all the grid node numbers in the integrated interface point set, top surface set, bottom surface set and lens body set in the CAE software.

[0237] Step 5.2: Select a geological body model of a non-lens body formation type, respectively obtain the integrated interface point set, top surface set or bottom surface set corresponding to its upper and lower formation interface point sets, and connect them to form two grid surfaces corresponding to the upper and lower formation interface point sets in the CAE platform according to the new connection relationship, which are respectively denoted as the upper and lower grid surfaces of the geological body.

[0238] Step 5.3: Through the stretching operation of the CAE platform, stretch the upper / lower grid surface of the geological body downward / upward to the lower / upper grid surface to form the CAE model corresponding to this geological body model.

[0239] Repeat Steps 5.2 - 5.3 until the CAE models corresponding to all the geological body models of non-lens body formations are established.

[0240] Step 5.4: Select the geological body model with the type of lenticular formation, obtain the corresponding lenticular set, and form a closed body in the CAE platform according to the new connection relationship, which is the CAE model corresponding to the geological body model; repeat this step to establish the CAE models of all lenticular formations.

[0241] Step 5.5: In the CAE platform, subtract the CAE model of the lenticular formation from the CAE model of the non-lenticular formation through Boolean operation; the CAE model after Boolean operation and the CAE model of the lenticular formation together constitute the CAE model of the three-dimensional geological model.

[0242] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An equivalent conversion method for automatically converting a three-dimensional geological model into a finite element model, characterized in that It includes the following steps: Step 1: Obtain the grid nodes of each geological body model in the 3D geological model and the original connection relationship of the grid nodes; the grid nodes include their numbers and spatial coordinates; the spatial coordinates include the horizontal coordinate X, the horizontal coordinate Y, and the vertical coordinate Z; the original connection relationship of the grid nodes is that the grid nodes are connected to each other according to the original connection relationship to form multiple grid surfaces, and the multiple grid surfaces can enclose to form a complete geological body model. The number of geological body models is N, N≥1, and the N geological body models are combined into a 3D geological model; Step 2: Establish the formation interface point set of each geological body model and the corresponding set plane boundary; establish the full model boundary of the 3D geological model; the formation interface point set includes the upper and lower formation interface point sets; Step 3: Define the formation type judgment rule, and determine the formation type as a conventional formation, a pinched-out formation, or a lenticular formation according to the set plane boundary of the geological body model; Step 4: According to the formation interface point set and the original connection relationship of the geological body model, establish the fused formation interface point set, the top surface set, the bottom surface set, and the lenticular body set, and establish the new connection relationship of the grid nodes corresponding to the grid node numbers in each set; Step 5: According to the numbers, spatial coordinates, and new connection relationship of the grid nodes, generate a CAE model by reconstruction in the CAE software.

2. The equivalent conversion method of a three-dimensional geological model to a finite element model according to claim 1, characterized in that The specific process of establishing the formation interface point set of each geological body model and the corresponding set plane boundary in Step 2 is as follows: Step 2.1: Select a geological body model and obtain its grid nodes; Step 2.2: Project each grid node vertically onto the geological body model in turn, and classify the grid node numbers into the upper and lower formation interface point sets and the temporary number set according to the projection relationship, specifically as follows: If the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the largest vertical coordinate Z, then classify the grid node number into the upper formation interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node coincides with the projection point p with the smallest vertical coordinate Z, then classify the grid node number into the lower formation interface point set; if the number of projection points p obtained by projecting the grid node is greater than one, and the grid node does not coincide with the projection points p with the largest and smallest vertical coordinates Z, then classify the grid node number into the temporary number set; if the number of projection points p obtained by projecting the grid node is equal to one, then classify the grid node number into both the upper and lower formation interface point sets and define it as a special grid node number; Step 2.3: Determine whether there is data in the temporary number set. If there is, execute Step 2.4; otherwise, execute Step 2.5; Step 2.4: Select a grid node number in the temporary number set, define the grid node as MB, and classify the number of MB into the upper or lower formation interface point set according to the original connection relationship. The specific steps are as follows: Step 2.4.1: According to the original connection relationship, screen all the grid node numbers directly connected to MB, and classify the non-special grid node numbers among the grid node numbers directly connected to MB into the screening number set; Step 2.4.2: Judge whether there is a grid node number belonging to the upper or lower formation interface point set among the grid node numbers in the screening number set. If so, define this grid node as PB, and judge the attribution of the MB number according to the number of PB. Specifically: If the number of PB belongs to the upper formation interface point set, then classify the number of MB into this set; otherwise, classify it into the lower formation interface point set. At the same time, remove MB from the temporary number set and directly end Step 2.4.2; if there is no PB, execute Step 2.4.3; Step 2.4.3: According to the original connection relationship, screen the numbers of the grid nodes directly connected to all the grid nodes corresponding to the grid node numbers in the screening number set, and classify the non-special grid node numbers among them into the screening number set. According to whether there are new non-special grid node numbers classified into the screening number set, select the content to execute. If so, directly return to Step 2.4.2; if not, directly remove MB from the temporary number set and end Step 2.4.3; Repeat Step 2.4 until the temporary number set is empty; Step 2.5: Through the upper or lower formation interface point set and the original connection relationship, obtain the boundary point numbers in the upper or lower formation interface point set, and then determine the set plane boundary according to the original connection relationship. The specific steps are as follows: Step 2.5.1: Screen out the grid node numbers that meet the boundary point rules from the upper or lower formation interface point set and define them as boundary point numbers; the boundary point rules include two points, and meeting any one of them means meeting the boundary point rules. Specifically: (1) The grid node number is a special grid node number; (2) The grid node number itself is a non-special grid node number located in the upper or lower formation interface point set, and through the judgment of the original connection relationship, there is a grid node number of a non-special grid node number located in the lower or upper formation interface point set directly connected to it; Step 2.5.2: Obtain all the boundary point numbers, and define the boundary obtained by connecting the boundary point numbers directly connected in the original connection relationship in sequence and projecting them vertically onto the fixed horizontal plane as the set plane boundary; Repeat Steps 2.1 to 2.5 to establish the formation interface point set and the set plane boundary of each geological body model; The full model boundary of the three-dimensional geological model meets two requirements: (1) On the fixed horizontal plane, all the set plane boundaries are not located outside the full model boundary; (2) Under the condition of meeting the previous requirement, the area included in the full model boundary is the smallest.

3. A method for automatically converting a three-dimensional geological model into an equivalent finite element model according to claim 1, characterized in that The formation type judgment rules in Step 3 are the lenticular formation rule and the pinching-out formation rule respectively; the lenticular formation rule is that the set plane boundary corresponding to the selected geological body model is completely located within the full model boundary; the pinching-out formation rule is that the set plane boundary corresponding to the selected geological body model is partially located within the full model boundary and partially coincides with the full model boundary; The determination of the formation type is as follows: If the set plane boundary corresponding to the selected geological body model satisfies the lenticular formation rule, its formation type is defined as the lenticular formation; if the set plane boundary corresponding to the selected geological body model satisfies the pinch-out formation rule, its formation type is defined as the pinch-out formation; if neither is satisfied, its formation type is defined as the conventional formation.

4. A method for automatically equivalent conversion of a three-dimensional geological model to a finite element model according to claim 1, characterized in that The establishment of the integrated formation interface point set, top surface set, bottom surface set, and lenticular body set in step 4, and the establishment of the new connection relationship between the grid node numbers corresponding to the grid nodes in the set are as follows: Step 4.1: Select the upper or lower formation interface point set of a geological body model, and vertically interpolate and project the grid nodes corresponding to each grid node number in the set to all formation interface point sets of the remaining N - 1 geological body models; Denote the formation interface point set of the selected geological body model as the selected set, and establish the corresponding relationship between the two at the same time; Denote the formation interface point set of the geological body model to be projected as the projection set, and establish the corresponding relationship between the two at the same time; When performing vertical interpolation projection, the results are stored separately according to the differences between the selected set and the projection set, and are called the comparison set, and the comparison set corresponds to both the selected set and the projection set at the same time; Step 4.2: Compare each selected set with the corresponding comparison set in turn. If there is a surface region coincidence relationship between the two, record that the selected set and the projection set corresponding to the comparison set have a surface region coincidence, and establish an integrated formation interface point set, and at the same time judge whether to establish an independent set and its attributes; The specific process of step 4.2 is as follows: Step 4.2.1: Establish a temporary integrated formation interface point set corresponding to the transition of the comparison set; The so-called transition correspondence means corresponding to the same selected set and projection set as the comparison set at the same time; Step 4.2.2: Compare the selected set with the comparison set, and select the grid node numbers in the selected set that meet the error coincidence respectively, and store them in the temporary integrated formation interface point set corresponding to the transition of the comparison set; The grid node numbers that meet the error coincidence are: The grid nodes corresponding to the grid node numbers in the selected set and the grid nodes corresponding to the grid node numbers in the comparison set satisfy that the horizontal coordinates X and Y are the same, and the absolute value of the difference in the vertical coordinate Z is less than the error ε1; Step 4.2.3: Connect the grid nodes corresponding to the grid node numbers in the non-empty temporary integrated formation interface point set according to the original connection relationship. If a surface can be formed after connection, record that the selected set and the comparison projection set corresponding to the temporary integrated formation interface point set have a surface region coincidence; Step 4.2.4: Judge whether all the grid node numbers in the selected set are subsets of the union of all the corresponding temporary integrated formation interface point sets; If not, establish an independent set, and store the grid node numbers in the selected set that are not included in the union in the independent set, and determine its attributes according to the grid node numbers stored in the independent set; If so, do not establish an independent set; If there is no corresponding set of temporary fusion formation interface points for the selected set, an independent set is established, and all the grid node numbers in the selected set are stored in the independent set. At the same time, their attributes are determined according to the grid node numbers stored in the independent set; The independent set corresponds to the set of formation interface points corresponding to the selected set; The determination of their attributes according to the grid node numbers stored in the independent set is specifically as follows: If the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are greater than the Z values of the grid nodes with the same horizontal coordinates in the grid nodes corresponding to all the comparison set grid node numbers corresponding to the selected set, the attribute of the independent set is defined as Top; If the Z values of the grid nodes corresponding to all the grid node numbers in the independent set are less than the Z values of the grid nodes with the same horizontal coordinates in the grid nodes corresponding to all the comparison set grid node numbers corresponding to the selected set, the attribute of the independent set is defined as Down; Otherwise, its attribute is defined as Mid; Repeat until all the sets of formation interface points of the geological body models are used as the selected set to perform all the operations in steps 4.1 - 4.2; Step 4.3: Merge the temporary fusion formation interface point sets with the same inversion corresponding to the selected set and the projection set into one, and merge the corresponding relationships; Then delete the temporary fusion formation interface point sets with empty sets and the grid nodes corresponding to the grid node numbers in the sets that cannot form a surface according to the original connection relationship; Step 4.4: Obtain two sets of formation interface points corresponding in the set of fusion formation interface points, denoted as the fusion corresponding set pair, and then obtain the corresponding two geological body models. If there is a geological body model with a formation type of lens formation among them, convert the set of fusion formation interface points into an independent set, and this independent set corresponds to the set of formation interface points corresponding to the lens formation in the fusion corresponding set pair; The attribute of this independent set is Mid; Step 4.5: Place all the sets of fusion formation interface points and independent sets in the set group to be corrected, and correct each set in the set group to be corrected; Step 4.6: Repair the set of fusion formation interface points, and establish new connection relationships for the grid nodes corresponding to the grid node numbers therein; Step 4.7: Obtain all the independent sets with the attribute of Mid, and establish c lens sets and their new connection relationships; c≥0; Step 4.8: Obtain all the independent sets with the attributes of Top and Down, and establish a top surface set and b bottom surface sets; a≥1, b≥1.

5. The equivalent conversion method of a three-dimensional geological model automatically to a finite element model according to claim 4, characterized in that, In step 4.1, the specific method of the vertical interpolation projection is: obtain the points with the same horizontal coordinates X and Y as the grid nodes corresponding to all the grid node numbers in the selected set through spatial interpolation in the projection set; In step 4.3, "the same inversion" means that the projection set corresponding to the temporary fusion formation interface point set A and the selected set corresponding to the temporary fusion formation interface point set B correspond to the same set of formation interface points, and the selected set corresponding to the temporary fusion formation interface point set A and the projection set corresponding to the temporary fusion formation interface point set B correspond to the same set of formation interface points; In step 4.3, the merging correspondence relationship means that the merged set is transformed into a fused formation interface point set, and directly corresponds to the formation interface point sets of the selected set and the projection set that respectively correspond to the two temporary fused formation interface point sets.

6. A method for automatically performing equivalent conversion from a three-dimensional geological model to a finite element model according to claim 4, characterized in that, For the calibration of each set in the set group to be calibrated in step 4.5, the specific process is as follows: Step 4.5.1: Select a set from the set group to be calibrated as the set to be calibrated, and obtain the spatial coordinates of the grid nodes corresponding to all the grid node numbers in this set; Step 4.5.2: Obtain the interpolated vertical coordinate Z1 of the grid nodes corresponding to all the grid node numbers in the set to be calibrated through orthogonal test; solve the absolute value of the difference between the vertical coordinate Z of each grid node and the interpolated vertical coordinate Z1, and place the grid node numbers with the absolute value greater than the deviation ε2 into the set of nodes to be calibrated, and place the remaining node numbers into the set of standard nodes; The orthogonal test for obtaining the interpolated vertical coordinate Z1 of the grid nodes in step 4.5.2 is specifically as follows: Step 4.5.2a: Place all the grid node numbers in the set to be calibrated into the orthogonal test set; Step 4.5.2b: Select the grid node corresponding to a grid node number in the orthogonal test set, denote it as the node to be solved, and remove its number from the orthogonal test set; Step 4.5.2c: Obtain the point with the same horizontal coordinate as the node to be solved in the grid nodes corresponding to all the grid node numbers in the orthogonal test set through spatial interpolation as the interpolated node; the vertical coordinate Z of the interpolated node is the interpolated vertical coordinate Z1 of the node to be solved; Step 4.5.3: Conduct a distortion inspection on the grid nodes corresponding to the grid node numbers in the set of nodes to be calibrated. If the inspection result is distorted, modify the value of the vertical coordinate Z of this grid node to the value of the interpolated vertical coordinate Z1; if the inspection result is not distorted, keep the value of the vertical coordinate Z of this grid node unchanged; Repeat this step until the distortion inspection has been carried out on all the grid nodes corresponding to the grid node numbers in the set of nodes to be calibrated; The distortion inspection in step 4.5.3 is specifically as follows: Step 4.5.3a: Select a grid node number from the set of nodes to be calibrated; obtain the grid node corresponding to this grid node number, and denote it as the node to be inspected; Step 4.5.3b: Obtain multiple grid node numbers in the set of standard nodes that can uniquely enclose the node to be inspected with the minimum area or enclose the node to be inspected with the minimum large interior angle in the fixed horizontal plane, and denote it as the standard node group; The minimum unique enclosure of the node to be inspected in the plane range satisfies that the projections of the grid nodes corresponding to the multiple grid node numbers in the set of standard nodes can form a polygon by themselves after being connected and projected onto the fixed horizontal plane. The polygon does not contain the projections of the grid nodes corresponding to all the grid node numbers in the set of standard nodes in the fixed horizontal plane, but contains the projection of the node to be inspected, and the number of sides of the polygon is the minimum, and the area of the polygon is the minimum; The minimum unique polygon enclosing the node to be inspected with the largest interior angle means that when the polygon formed by projecting the grid nodes corresponding to any number of grid node numbers in the standard node set onto a fixed horizontal plane cannot contain the projection of the node to be inspected, select multiple grid nodes corresponding to grid node numbers in the standard node set and connect them to the node to be inspected, and then project the connections onto the fixed horizontal plane to form a polygon. The polygon does not contain the projections of the grid nodes corresponding to all grid node numbers in the standard node set in the fixed horizontal plane, and the interior angle corresponding to the projection of the node to be inspected is the largest, and the number of sides of the polygon is the smallest, and the area of the polygon is the smallest; Step 4.5.3c: Solve the average node of the standard node group in space, and solve the average distance in space between the standard node group and the average node, denoted as La; solve the distance Lb in space between the node to be inspected and the average node; if Lb / La is greater than the slenderness ratio, then return that the node to be inspected is deformed, otherwise return not deformed; The X, Y, and Z of the average node are equal to the averages of the X, Y, and Z of the grid nodes corresponding to all grid node numbers in the standard node group; the slenderness ratio is a set parameter; Step 4.5.4: Clear the set of nodes to be corrected, and remove the selected set to be corrected from the group of sets to be corrected; Repeat steps 4.5.1 - 4.5.4 until the group of sets to be corrected is empty.

7. A method for automatically equivalent conversion of a three-dimensional geological model to a finite element model according to claim 4, characterized in that Step 4.6 repairs and fuses the set of formation interface points, and establishes new connection relationships for the grid nodes corresponding to the grid node numbers therein, specifically as follows: Step 4.6.1: Select a set of formation interface points, connect the grid nodes corresponding to the grid node numbers in the set according to the original connection relationships to form two grid surfaces; extract the outlines of the two grid surfaces, the grid node numbers on the outlines, and their original connection relationships, denoted as the old outlines, the old outline node numbers, and the old outline connection relationships; Step 4.6.2: Project the old outlines vertically onto a fixed horizontal plane to obtain a new outline projection in the fixed horizontal plane that can exactly enclose the projection of the old outlines; Step 4.6.3: Obtain the old outline node numbers corresponding to the new outline projection as the new outline node numbers, and determine whether new grid nodes and their corresponding numbers and original connection relationships need to be added; if so, store the newly added grid node numbers in the selected set of formation interface points, and use the newly added grid node numbers as the new outline node numbers; according to the connection relationships of the vertices of the new outline projection, add the connection relationships between the newly added grid nodes and the existing grid nodes to the original connection relationships; The determination in step 4.6.3 of whether new grid nodes and their corresponding numbers and original connection relationships need to be added is specifically as follows: Step 4.6.3a: Determine whether there are intersection points between the two old outline projections, and the intersection points do not coincide with the projection points of the grid nodes corresponding to the old outline node numbers; if so, then addition is required, add a grid node with the same horizontal coordinate as the intersection point, assign it a number that is different from all existing grid node numbers, and execute step 4.6.3b; if not, then addition is not required, and end; Step 4.6.3b: Get the edge of the old contour corresponding to the projection of the old contour that forms the intersection, obtain the points on the two old contour edges with the same horizontal coordinates as the intersection through linear interpolation, and solve the average value of the vertical coordinates Z of the two points as the value of the vertical coordinate Z of the newly added grid node; Step 4.6.4: Determine whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid at the same time. If necessary, store the newly added grid node number in the unselected fused stratum interface point set or the independent set with the attribute Mid. Step 4.6.4 determines whether the newly added grid node number needs to be stored in the unselected fused stratum interface point set or the independent set with the attribute Mid, as follows: Step 4.6.4a: Search for the unselected fused stratum interface point set corresponding to the same stratum interface point set as the selected fused stratum interface point set and the independent set with the attribute of Mid; Step 4.6.4b: connect the unselected fused stratum interface point set in step 4.6.4a and the grid nodes corresponding to the grid node numbers in the independent set with the attribute Mid according to the original connection relationship to form at least one grid surface SA, and project it to a fixed horizontal plane along the vertical direction; Step 4.6.4c: If the point where the newly added grid node is projected onto the fixed horizontal plane along the vertical direction is located on the contour of the projection of a certain grid surface SA, the number of the newly added grid node is stored in the unselected fused stratum interface point set of 4.6.4a or in the independent set with the attribute Mid; Step 4.6.5: If there are points that are spatially close to the grid nodes corresponding to the grid node numbers in the selected fused stratum interface point set, only the number of one of the points is retained in the set, and the numbers of the remaining points are discarded; the grid nodes are spatially close means that the spatial distance between the grid nodes is less than the distance difference ε3; the distance difference ε3 is an artificially set fixed parameter; Step 4.6.6: Using the new contour projection as the boundary and in accordance with the triangulated network restricted growth principle, establish a new connection relationship between the grid node numbers and the grid nodes in the selected fused stratum interface point set; The method of taking the new contour projection as the boundary and restricting the growth of the triangulated network according to the principle of limiting the growth of the triangulated network means that the grid nodes corresponding to the grid node numbers in the fused stratum interface point set are connected according to the new connection relationship to meet the following requirements: (1) all grids are triangular grids and the grid nodes corresponding to all grid node numbers in the set are vertices of triangles; (2) the range of all grids after being projected onto a fixed horizontal plane does not exceed the projection of the new contour; and (3) the projections of all triangular grids onto the fixed horizontal plane do not overlap or intersect with each other.

8. A method for automatically equivalent conversion of a three-dimensional geological model to a finite element model according to claim 4, characterized in that Step 4.7 describes the establishment of c lens sets. The specific process is as follows: Step 4.7.1: Select an independent set with the attribute Mid, called the independent set NA, and select all independent sets that can correspond to the same geological body model across sets with the independent set NA from the other independent sets with the attribute Mid, called the independent set group NB; Step 4.7.2: Based on the number of formation interface point sets corresponding to the independent set NA, establish the same number of temporary lens sets. Copy all the grid node numbers in the independent set NA to each of the temporary lens sets, and during each copying process, transfer the corresponding relationship of one formation interface point set in the independent set NA to this temporary lens set; Step 4.7.3: In the independent set group NB, screen out the independent set NC that can cross - set correspond to the same geological body model as the temporary lens set. Copy all the grid node numbers in the independent set NC to the temporary lens set, and transfer the corresponding relationship of one formation interface point set in the independent set NC to the temporary lens set; The corresponding relationship of the formation interface point set transferred by the independent set NC satisfies that the formation interface point set in this corresponding relationship corresponds to the same geological body model as the formation interface point set corresponding to the temporary lens set; The transfer of the corresponding relationship of the formation interface point set from the independent set to the temporary lens set means deleting the corresponding relationship between the independent set and this formation interface point set and establishing the corresponding relationship between the temporary lens set and this formation interface point set; The cross - set correspondence means that there is at least one same among all the geological body models corresponding to one of the formation interface point sets corresponding to the independent set; After the transfer in Steps 4.7.2 and 4.7.3 is completed, immediately determine this independent set. If this independent set no longer corresponds to any formation interface point set, then delete this independent set; Repeat Steps 4.7.1 - 4.7.3 until all independent sets with the attribute of Mid are deleted; Step 4.7.4: Keep the stored content and corresponding relationship of the temporary lens set unchanged, and convert the temporary lens set into a lens set; Step 4.7.5: According to the lens triangular grid growth principle, establish new connection relationships for all lens sets; The lens triangular grid growth principle described in Step 4.7.5 satisfies: (1) All grids are triangular grids and all grid nodes corresponding to the grid node numbers in the set are the vertices of the triangle; (2) The grids can enclose a unique closed space.

9. A method for automatically equivalent conversion of a three-dimensional geological model to a finite element model according to claim 4, characterized in that The specific process of establishing a top surface set and b bottom surface sets described in Step 4.8 is as follows: Step 4.8.1: Select an independent set with the attribute of Top or Down, denoted as the independent set ND. Obtain the formation interface point set corresponding to the independent set ND, denoted as the formation interface point set C, and then obtain all the fused formation interface point sets corresponding to this formation interface point set, denoted as the fused formation interface point set C'; Step 4.8.2: Connect the grid nodes corresponding to the grid node numbers in the formation interface point set C according to the original connection relationship to obtain the grid surface SB; connect the grid nodes corresponding to the grid node numbers in the fused formation interface point set C' according to the new connection relationship to obtain the grid surface SC; Project the contours of the grid surfaces SB and SC onto the fixed horizontal plane simultaneously, obtain the parts of the projected contour of the grid surface SC that do not coincide with the projected contour of the grid surface SB, and store the grid node numbers corresponding to the non - coincident parts in different grid boundary groups according to the new connection relationship; The grid node numbers within the grid boundary group satisfy that they can form a line after being connected according to the new connection relationship; Step 4.8.3: Store the grid node numbers in the grid boundary group that meet the relationship of integrating into the independent set into the selected independent set; The so - called relationship of integrating into the independent set means for the grid boundary group: the triangular meshes formed by connecting the grid nodes corresponding to the grid node numbers in the grid boundary group with any two grid nodes corresponding to the grid node numbers in the independent set and projected vertically onto the fixed horizontal plane cannot overlap with the projection of the grid surface SC; Step 4.8.4: Establish a new connection relationship for this independent set. The new connection relationship meets the following requirements: the grid surface formed by connecting the grid nodes corresponding to the grid node numbers in the independent set according to the new connection relationship will not exceed the projected contour of the grid surface SB and will not overlap with the projection of the grid surface SC when projected vertically onto the fixed horizontal plane, and all are triangular meshes; Step 4.8.5: Convert the independent set into a top - surface set or a bottom - surface set according to its attribute. Specifically: if the attribute is Top, convert it into a top - surface set; if the attribute is Down, convert it into a bottom - surface set; If the integrated formation interface point set C' is not obtained in step 4.8.1, directly execute step 4.8.

5.

10. A method for automatically equivalent conversion of a three-dimensional geological model into a finite element model according to claim 1, characterized in that The generation of the CAE model through reconstruction in the CAE software described in step 5 is specifically as follows: Step 5.1: Generate the grid nodes corresponding to all grid node numbers in the integrated interface point set, top - surface set, bottom - surface set, and lenticular body set in the CAE software; Step 5.2: Select a geological body model of a non - lenticular - body formation type, respectively obtain the integrated interface point set, top - surface set, or bottom - surface set corresponding to its upper and lower formation interface point sets, and connect them in the CAE platform according to the new connection relationship to form two grid surfaces corresponding to the upper and lower formation interface point sets, which are respectively denoted as the upper and lower grid surfaces of the geological body; Step 5.3: Through the stretching operation of the CAE platform, stretch the upper / lower grid surface of the geological body downward / upward to the lower / upper grid surface to form the CAE model corresponding to this geological body model; Repeat steps 5.2 - 5.3 until the CAE models corresponding to all geological body models of non - lenticular - body formations are established; Step 5.4: Select a geological body model of a lenticular - body formation type, obtain its corresponding lenticular body set, and form a closed body in the CAE platform according to the new connection relationship, which is the CAE model corresponding to this geological body model; repeat this step to establish the CAE models of all lenticular - body formations; Step 5.5: In the CAE platform, perform a Boolean operation to subtract the CAE model of the lenticular - body formation from the CAE model of the non - lenticular - body formation; the CAE model after the Boolean operation and the CAE model of the lenticular - body formation together constitute the CAE model of the three - dimensional geological model.

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