Thin coal seam three-dimensional geological modeling method conforming to thickness distribution information

Abstract

The invention provides a thin coal seam three-dimensional geologic modeling method conforming to thickness distribution information, and the method comprises the steps: building a thin coal seam three-dimensional geologic model in the process of building the thin coal seam three-dimensional geologic model; data such as drilling, geophysical prospecting and realistic data are comprehensively utilized, known thickness data are fully utilized, a spatial interpolation mode is adopted, it is guaranteed that the thickness distribution of the constructed thin coal seam three-dimensional model is consistent with known data distribution, meanwhile, a mineable line and a zero coal line can be matched, and links such as tedious interspersing correction and pinching-out manual recognition in the thin coal seam construction process are avoided; and meanwhile, the thickness data information is actively introduced, so that the accuracy is prevented from being improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal geological exploration, relates to three-dimensional geological modeling of coal seams, and specifically relates to a three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information. Background Art

[0002] In underground coal mines, the spatial three-dimensional distribution of thin coal seams shows that the depth range scale is much smaller than the horizontal range scale. The display of thin coal seams on geological profiles is not obvious, but from the plane map, thin coal seams are very intuitively distributed regionally. At the same time, due to the thin layers and the influence of adverse geological structures such as faults, local pinch-out is prone to occur, that is, it is reflected as a discontinuous distribution on the horizontal scale. At present, the three-dimensional geological modeling of coal seams mainly relies on the use of surface and volume expression through interpolation of surface drilling, underground tunnel measurement data, geophysical exploration and other data. According to the document "A Review of Related Technologies for Three-Dimensional Geological Modeling of Coal Mines", although a variety of spatial data models have been proposed to support three-dimensional geological modeling, including surface-based TIN models and irregular volume-based GTP models, TEN models, etc., these models still have challenges in expressing the discontinuity caused by local pinch-out of thin coal seams and the accuracy of thickness distribution.

[0003] The three-dimensional geological model is mainly constructed by interpolating sparse and heterogeneous multi-source data. The constructed geological model is required to be completely consistent with the known multi-source data, and the inferred area meets the geological rationality. For thin coal seams with drastic thickness changes, uneven distribution, complex and changeable internal structure, and local pinch-out, the requirements are higher. When the known data is directly used for thin layers and the interpolation method is used to calculate the undulating shape of the top and bottom plates, the interpolation modeling is prone to the interlacing between the top and bottom plates, which makes it difficult to control the discontinuous distribution shape of the horizontal level, resulting in inconsistency with the geophysical exploration results. The document "3D Geological Modeling of Coal Seam Working Face-ResearchGate" points out that the current method has low prediction accuracy for coal seam working faces with complex geological structures and is difficult to meet the actual needs of coal mining. The document "Three-dimensional Coal Seam Modeling of Comprehensive Mining Face Based on Transparent Geology" further explains the limitations of existing three-dimensional coal seam modeling methods in expressing three-dimensional entities in space, especially in the modeling of the dynamic change process of the top and bottom plates during mining.

[0004] In addition, the document "Construction and Error Analysis of Three-Dimensional Geological Model of Intelligent Mining Working Face" analyzes the construction method of intelligent mining geological model, and points out the error problems faced by existing methods when constructing high-precision three-dimensional geological model of mining working face.

[0005] The above existing technologies all show that although the existing technologies provide a certain basis for the 3D geological modeling of thin coal seams, it is still necessary to study the discontinuity problem caused by local pinch-out in the 3D geological modeling of thin coal seams and the model accuracy problem that conforms to the existing thickness distribution information. Therefore, it is an inevitable trend of the development of technology in this field to develop a new 3D geological modeling method for thin coal seams to overcome the limitations of the existing technologies. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information, so as to solve the technical problem that the model accuracy and spatial continuity expression in the prior art need to be further improved.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0008] A three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information, the method comprising the following steps:

[0009] Step 1: obtain the boundary of the mining area where the thin coal seam is located, and use consistent triangulation to construct the grid surface of the TIN of the bottom plate of the thin coal seam. The grid surface of the TIN of the bottom plate of the thin coal seam is recorded as T1.

[0010] Step 2: Search for boreholes that expose thin coal seams, calculate the coordinates of coal points based on the borehole coordinates and borehole inclination data, and generate a three-dimensional space discrete point group PG1 containing thickness attribute information.

[0011] Step three, collect coal exploration records and geological realistic data of the working face, combine the spatial position of the working face, calculate the spatial position and coal thickness information of the exposed coal seam floor on the working face, and generate a three-dimensional space discrete point group PG2 containing thickness attribute information.

[0012] Step 4: Extract the coal seam bottom contour lines from the exploration results map, generate three-dimensional discrete line Line1 based on the horizontal position of the coal seam bottom contour lines and the marked elevation information, and repeatedly encrypt the discrete line Line1 by inserting the midpoint of the line segment until the accuracy is not less than that of T1.

[0013] Step 5: Use the discrete point group PG1 obtained in step 2 and the discrete line Line1 obtained in step 4 as fuzzy control point constraints of T1.

[0014] Step six, using a discrete smooth interpolation algorithm, impose a boundary constraint on the outer contour of T1 that only allows vertical movement.

[0015] Step seven, calculate the discrete smooth interpolation of T1, construct and store the undulating shape of the thin coal seam floor.

[0016] Step eight, copy the grid surface T1 of the TIN of the thin coal seam bottom plate to generate the grid surface of the TIN of the thin coal seam top plate. The grid surface of the TIN of the thin coal seam top plate is recorded as T2.

[0017] Step nine, search for boreholes that have not exposed thin coal seams, generate the axes of each borehole based on the hole mouth coordinates and inclinometric data, calculate the intersection of each axis with T1, and generate a three-dimensional discrete point group PG3 containing thickness attribute information. The coal seam thickness attribute of each point in the three-dimensional discrete point group PG3 is 0 by default; use each point in the three-dimensional discrete point group PG1 obtained in step two as known data and use Kriging interpolation to calculate the thickness attribute value of each point in the three-dimensional discrete point group PG3; take the opposite of the thickness attribute value of each point in the three-dimensional discrete point group PG3 to form a virtual negative thickness.

[0018] Step ten, extract the isopach lines of the thin coal seam in the exploration results map, generate a three-dimensional space discrete line Line2 with a uniform elevation set to 0 based on the horizontal position of the isopach lines, and repeatedly encrypt the three-dimensional space discrete line Line2 by inserting line segments into midpoints until the accuracy is not less than that of T1; extract the points that make up the three-dimensional space discrete line Line2 to generate a three-dimensional space discrete point group PG4 containing thickness attribute information, and the thickness attribute value of each point is determined based on the thickness value of the thickness contour line where the point is located.

[0019] Step 11, extract the mineable line of the thin coal seam in the mining engineering plan, set the elevation to 0 according to the horizontal position of the line, generate the three-dimensional space discrete line Line3, and repeatedly encrypt the three-dimensional space discrete line Line3 by inserting the line segment into the midpoint until the accuracy is not less than that of T1; extract the points that make up the three-dimensional space discrete line Line3 to generate the three-dimensional space discrete point group PG5 containing thickness attribute information, and the thickness attribute value of each point is uniformly set to 0.8 meters.

[0020] Step 12, extract the zero coal line of the thin coal seam in the plan view of the mining project, set the elevation to 0 according to the horizontal position of the line, generate a three-dimensional discrete line Line4, and repeatedly encrypt the three-dimensional discrete line Line4 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; extract the points that make up the three-dimensional discrete line Line4 to generate a three-dimensional discrete point group PG6 containing thickness attribute information, and the thickness attribute value of each point is uniformly set to 0 meters.

[0021] Step thirteen, project the three-dimensional space discrete point group PG1 obtained in step two, the three-dimensional space discrete point group PG2 obtained in step three, the three-dimensional space discrete point group PG3 obtained in step nine, the three-dimensional space discrete point group PG4 obtained in step ten, the three-dimensional space discrete point group PG5 obtained in step eleven and the three-dimensional space discrete point group PG6 obtained in step twelve along the vertical direction onto T2 generated in step eight, and recalculate the spatial position of each point in each three-dimensional space discrete point group. The thickness attribute value of each point remains unchanged before and after the projection.

[0022] In step fourteen, the three-dimensional space discrete point group PG1 obtained in step two, the three-dimensional space discrete point group PG2 obtained in step three, the three-dimensional space discrete point group PG3 obtained in step nine, the three-dimensional space discrete point group PG4 obtained in step ten, the three-dimensional space discrete point group PG5 obtained in step eleven and the three-dimensional space discrete point group PG6 obtained in step twelve are used as known thickness points, and discrete smooth interpolation is used to calculate the thickness value of each point in T2 to establish a thickness distribution model based on the coal seam floor.

[0023] Step 15: In the thickness distribution model obtained in step 14, the elevation value of each point in T2 is added to the respective thickness value as the new elevation value of each point, and the spatial position of T2 is updated.

[0024] Step 16, based on T2 whose spatial position is updated in step 15, use T2 to clip T1, and remove the part of T1 located on the upper part of T2, to generate a TIN grid surface of the thin coal seam floor with local pinch-out, recorded as T3.

[0025] Step 17, copy T3 obtained in step 16 to generate a TIN grid surface containing a thin coal seam roof with local pinch-out, denoted as T4, project each point constituting T4 onto T2 along the vertical direction, and update the spatial coordinates of each point constituting T4.

[0026] Step 18, extract the contour line of T3 obtained in step 16 and the contour lines of T4 obtained in step 17, generate a TIN grid surface of the side surface of the thin coal seam, recorded as T5; combine T3, T4 and T5 to generate a closed surface model of the thin coal seam.

[0027] Step 19: The points and triangular grids that make up T3 and T4 are completely consistent. The corresponding triangular grids of T3 and T4 are extracted one by one according to the corresponding relationship, and triangular prisms are generated to complete the construction of the three-dimensional geological entity model of the thin coal seam that conforms to the thickness distribution information.

[0028] The present invention also has the following technical features:

[0029] In step 2, the three-dimensional space discrete point group PG1 refers to a set of isolated points, each isolated point serves as a node of the discrete point group, and thickness data is stored on each node.

[0030] In step 4, the three-dimensional space discrete line Line1 is composed of nodes and node connection relationships, and the accuracy includes discrete line accuracy and triangulation accuracy; the discrete line accuracy is the length of the line segment composed of two nodes, and the triangulation accuracy is the side length of the triangle in the triangulation.

[0031] In step five, multi-source heterogeneous data including coal points seen in boreholes, floor contours and realistic data are unified and integrated into data reflecting the spatial position of the coal seam floor.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] (I) The method of the present invention can use a multi-source data fusion method in the three-dimensional geological modeling of thin coal seams to make the thickness distribution of the constructed coal seam three-dimensional model consistent with the existing information to improve the model accuracy, and automatically handle the spatial discontinuity expression problem caused by local pinch-out.

[0034] (II) Improved data utilization rate of the present invention: The modeling method of thin coal seams proposed in this patent can make full use of the coal points seen in drilling holes, realistic data, coal exploration ledger data, coal seam floor contour lines, equal thickness lines and other geophysical exploration results, as well as data such as coal seam mineable lines and zero coal lines in the mining engineering plan, thereby maximizing the use of known data.

[0035] (III) The modeling accuracy of the present invention is high: the constructed three-dimensional geological model of the thin coal seam is consistent with the known exploration data in terms of geometry, and the thickness and pinch-out position are consistent with the geophysical exploration results and the mining engineering plane. Figure 1 High modeling accuracy.

[0036] (IV) The production efficiency of the present invention is improved: The modeling method adopted by this patent solidifies the data extraction, processing and modeling process of thin coal seams. Each link and step can form a standardized process, which improves the efficiency of three-dimensional geological modeling of thin coal seams. In one modeling process, the closed surface model and the entity model of the thin coal seam can be generated at the same time, enriching the expression of the three-dimensional geological model of the thin coal seam. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic flow chart of the thin coal seam three-dimensional geological modeling method according to the thickness distribution information of the present invention.

[0038] Figure 2 It is a schematic diagram of the initial form of the thin coal seam floor of the present invention.

[0039] Figure 3The invention is a schematic diagram of coal points seen in drilling holes, realistic data and bottom plate contour lines reflecting the spatial position of the thin coal seam bottom plate.

[0040] Figure 4 It is a schematic diagram of the interpolated shape of the thin coal seam floor of the present invention.

[0041] Figure 5 It is a schematic diagram of drilling holes, realistic data, and thickness contour lines that reflect coal seam thickness attribute information of the present invention.

[0042] Figure 6 It is a schematic diagram of the distribution of coal seam thickness after interpolation according to the present invention.

[0043] Figure 7 It is a schematic diagram of a grid surface of a TIN containing a thin coal seam floor with local pinch-out constructed according to the present invention.

[0044] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0045] It should be noted that, unless otherwise specified, all methods in the present invention adopt methods known in the prior art.

[0046] The present invention provides a three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information. In the process of constructing a three-dimensional geological model of a thin coal seam, the method comprehensively utilizes drilling, geophysical, and realism data, and fully utilizes known thickness data to adopt a spatial interpolation method to ensure that the thickness distribution of the constructed thin coal seam three-dimensional model is consistent with the known data distribution, and can match the mineable line and the zero coal line, avoiding the tedious interlacing correction and pinch-out manual identification links in the thin coal seam construction process, which can significantly improve efficiency, and actively introduce thickness data information to avoid improving accuracy.

[0047] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0048] Example:

[0049] This embodiment provides a three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information, characterized in that: Figure 1 As shown, the method comprises the following steps:

[0050] Step 1: obtain the boundary of the mining area where the thin coal seam is located, and use consistent triangulation to construct the grid surface of the TIN (irregular triangulated network) of the bottom plate of the thin coal seam. The grid surface of the TIN of the bottom plate of the thin coal seam is recorded as T1.

[0051] In this embodiment, specifically, Figure 2As shown, T1 is used to store the initial position and shape of the bottom plate of the thin coal seam.

[0052] In this step, consistent triangulation can be used to directly generate a triangulated network that is strictly consistent with the boundary and has a uniform mesh, avoiding the appearance of deformed meshes and facilitating subsequent editing and modification of the model.

[0053] In this step, the well field boundary can be obtained by technicians based on actual geological data through three-dimensional geological modeling software, or it can be directly imported from the outside, and there is no limitation here.

[0054] Step 2: Search for boreholes that expose thin coal seams, calculate the coordinates of coal points based on the borehole coordinates and borehole inclination data, and generate a three-dimensional space discrete point group PG1 containing thickness attribute information.

[0055] In step 2, the three-dimensional space discrete point group PG1 refers to a set of isolated points, each isolated point serves as a node of the discrete point group, and thickness data is stored on each node.

[0056] In this step, the borehole coordinates and inclinometer data define the geometric shape of the borehole. When a coal seam appears in the borehole, the depth information in the borehole will be recorded. The coordinates of the coal point can be calculated using this depth information combined with the borehole geometry. The depth difference between the coal seam in the borehole and the upper stratum is the coal thickness.

[0057] In this step, the coordinates of the points in the three-dimensional space discrete point group PG1 are used as known sample data for interpolation construction of the coal seam floor in the subsequent step seven, and the thickness attribute information in the three-dimensional space discrete point group PG1 is used as known sample data for interpolation generation of a thickness distribution model for thickness attributes in the subsequent step fourteen.

[0058] Step three, collect coal exploration records and geological realistic data of the working face, combine the spatial position of the working face, calculate the spatial position and coal thickness information of the exposed coal seam floor on the working face, and generate a three-dimensional space discrete point group PG2 containing thickness attribute information.

[0059] In this step, the coal exploration ledger data and realistic data are both real data revealed during the mining process. Making full use of such real data can help improve the accuracy of the constructed model.

[0060] In this step, the coordinates of the midpoints of the three-dimensional space discrete point group PG2 are used as known sample data for interpolation construction of the coal seam floor in the subsequent step seven, and the thickness attribute information in the three-dimensional space discrete point group PG2 is used as known sample data for interpolation generation of a thickness distribution model for thickness attributes in the subsequent step fourteen.

[0061] Step 4: Extract the coal seam bottom contour lines from the exploration results map, generate three-dimensional discrete line Line1 based on the horizontal position of the coal seam bottom contour lines and the marked elevation information, and repeatedly encrypt the discrete line Line1 by inserting the midpoint of the line segment until the accuracy is not less than that of T1.

[0062] In step 4, the three-dimensional space discrete line Line1 is composed of nodes and node connection relationships (two nodes form a line segment), and the accuracy includes the discrete line accuracy and the triangulation accuracy; the discrete line accuracy is the length of the line segment composed of two nodes, and the triangulation accuracy is the side length of the triangle in the triangulation.

[0063] In this step, the geophysical exploration result map is a known geophysical exploration result map.

[0064] In this step, the encryption process can be implemented using various known methods, which are not limited here.

[0065] In this step, the coal seam floor contour data reveals the undulating state and spatial position of the coal seam floor between the boreholes, effectively supplementing the problem of insufficient data for revealing the spatial position of the coal seam due to the sparse distribution of coal points in the boreholes throughout the mining area, and further improving the accuracy of the constructed model.

[0066] Step 5: Use the discrete point group PG1 obtained in step 2 and the discrete line Line1 obtained in step 4 as fuzzy control point constraints of T1.

[0067] In step five, multi-source heterogeneous data including coal points seen in boreholes, floor contours and realistic data are unified and integrated into data reflecting the spatial position of the coal seam floor.

[0068] Specifically, in this embodiment, the schematic diagram of the coal point (drilling data), the realistic data and the bottom plate contour line (geophysical data) reflecting the spatial position of the thin coal seam bottom plate is as follows: Figure 3 shown.

[0069] In this step, the fuzzy control point is a type of constraint in the discrete smooth interpolation algorithm theory. In the subsequent interpolation process, the nodes on T1 will interpolate iteratively to approximate PG1 and Line1.

[0070] Step six, using a discrete smooth interpolation algorithm, impose a boundary constraint on the outer contour of T1 that only allows vertical movement.

[0071] In this step, the boundary constraint is a type of constraint in the discrete smooth interpolation algorithm theory. After the constraint is imposed on the outer contour of T1, the nodes on the outer contour line of T1 can only move along the vertical direction in the subsequent interpolation process.

[0072] Step seven, calculate the discrete smooth interpolation of T1, construct and store the undulating shape of the thin coal seam floor.

[0073] In this step, discrete smooth interpolation is used to ensure that the constructed coal seam floor is consistent with the drilling, geophysical and realistic data used, thus ensuring the accuracy of the model.

[0074] In this embodiment, the schematic diagram of the interpolated shape of the thin coal seam floor is as follows: Figure 4 shown.

[0075] Step eight, copy the grid surface T1 of the TIN of the thin coal seam bottom plate to generate the grid surface of the TIN of the thin coal seam top plate. The grid surface of the TIN of the thin coal seam top plate is recorded as T2.

[0076] Step 9: Search for boreholes that do not expose thin coal seams. Generate the axes of each borehole based on the borehole coordinates and inclinometric data, calculate the intersection of each axis with T1, and generate a three-dimensional discrete point group PG3 containing thickness attribute information. The coal seam thickness attribute of each point in the three-dimensional discrete point group PG3 is 0 by default. Use the points in the three-dimensional discrete point group PG1 obtained in step 2 as known data and use Kriging interpolation to calculate the thickness attribute value of each point in the three-dimensional discrete point group PG3. Take the opposite of the thickness attribute value of each point in the three-dimensional discrete point group PG3 to form a virtual negative thickness.

[0077] In this embodiment, the schematic diagram of the drilling hole, realistic data and thickness contour lines reflecting the coal seam thickness attribute information is as follows: Figure 5 shown.

[0078] In this step, the virtual negative thickness indicates that the thickness at that location is less than 0. When it is known that there are positive and negative thicknesses, after subsequent thickness interpolation, due to the continuity of thickness change, there must be some locations where the thickness is 0, and the calculation of the pinch-out position of the thin coal seam is automatically completed.

[0079] In this step, the failure of a borehole to reveal a coal seam means that the coal seam will pinch out near the borehole. Kriging interpolation is used to calculate the virtual thickness of such a borehole to serve the subsequent automatic processing of pinch-out.

[0080] Step ten, extract the isopach lines of the thin coal seam in the exploration results map, generate a three-dimensional space discrete line Line2 with a uniform elevation set to 0 based on the horizontal position of the isopach lines, and repeatedly encrypt the three-dimensional space discrete line Line2 by inserting line segments into midpoints until the accuracy is not less than that of T1; extract the points that make up the three-dimensional space discrete line Line2 to generate a three-dimensional space discrete point group PG4 containing thickness attribute information, and the thickness attribute value of each point is determined based on the thickness value of the thickness contour line where the point is located.

[0081] In this step, the geophysical exploration result map is a known geophysical exploration result map.

[0082] In this step, the encryption process can be implemented using various known methods, which are not limited here.

[0083] Step 11, extract the mineable line of the thin coal seam in the mining engineering plan, set the elevation to 0 according to the horizontal position of the line, generate the three-dimensional space discrete line Line3, and repeatedly encrypt the three-dimensional space discrete line Line3 by inserting the line segment into the midpoint until the accuracy is not less than that of T1; extract the points that make up the three-dimensional space discrete line Line3 to generate the three-dimensional space discrete point group PG5 containing thickness attribute information, and the thickness attribute value of each point is uniformly set to 0.8 meters.

[0084] In this step, the mining engineering plan is a known mining engineering plan.

[0085] In this step, the encryption process can be implemented using various known methods, which are not limited here.

[0086] Step 12, extract the zero coal line of the thin coal seam in the plan view of the mining project, set the elevation to 0 according to the horizontal position of the line, generate a three-dimensional discrete line Line4, and repeatedly encrypt the three-dimensional discrete line Line4 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; extract the points that make up the three-dimensional discrete line Line4 to generate a three-dimensional discrete point group PG6 containing thickness attribute information, and the thickness attribute value of each point is uniformly set to 0 meters.

[0087] In this step, the mining engineering plan is a known mining engineering plan.

[0088] In this step, the encryption process can be implemented using various known methods, which are not limited here.

[0089] Step thirteen, project the three-dimensional space discrete point group PG1 obtained in step two, the three-dimensional space discrete point group PG2 obtained in step three, the three-dimensional space discrete point group PG3 obtained in step nine, the three-dimensional space discrete point group PG4 obtained in step ten, the three-dimensional space discrete point group PG5 obtained in step eleven and the three-dimensional space discrete point group PG6 obtained in step twelve along the vertical direction onto T2 generated in step eight, and recalculate the spatial position of each point in each three-dimensional space discrete point group. The thickness attribute value of each point remains unchanged before and after the projection.

[0090] In step fourteen, the three-dimensional space discrete point group PG1 obtained in step two, the three-dimensional space discrete point group PG2 obtained in step three, the three-dimensional space discrete point group PG3 obtained in step nine, the three-dimensional space discrete point group PG4 obtained in step ten, the three-dimensional space discrete point group PG5 obtained in step eleven and the three-dimensional space discrete point group PG6 obtained in step twelve are used as known thickness points, and discrete smooth interpolation is used to calculate the thickness value of each point in T2 to establish a thickness distribution model based on the coal seam floor.

[0091] Specifically, in this embodiment, the distribution diagram of coal seam thickness after interpolation is as follows: Figure 6 shown.

[0092] Step 15: In the thickness distribution model obtained in step 14, the elevation value of each point in T2 is added to the respective thickness value as the new elevation value of each point, and the spatial position of T2 is updated.

[0093] Step 16, based on T2 whose spatial position is updated in step 15, use T2 to clip T1, and remove the part of T1 located on the upper part of T2, to generate a TIN grid surface of the thin coal seam floor with local pinch-out, recorded as T3.

[0094] In this step, after T2 cuts T1, T1 will be layered into multiple independent parts. After the part located on the upper part of T2 is removed, the local pinch-out processing of the thin coal seam is automatically completed, solving the problem of discontinuous distribution in the horizontal range.

[0095] Specifically, in this embodiment, a schematic diagram of a TIN grid surface of a thin coal seam floor with local pinch-out is shown in FIG. Figure 7 shown.

[0096] Step 17, copy T3 obtained in step 16 to generate a TIN grid surface containing a thin coal seam roof with local pinch-out, denoted as T4, project each point constituting T4 onto T2 along the vertical direction, and update the spatial coordinates of each point constituting T4.

[0097] Step 18, extract the contour line of T3 obtained in step 16 and the contour lines of T4 obtained in step 17, generate a TIN grid surface of the side surface of the thin coal seam, recorded as T5; combine T3, T4 and T5 to generate a closed surface model of the thin coal seam.

[0098] In this step, the closed surface model is visually consistent with the solid and has a good visualization effect. At the same time, the internal hollowing can save the storage space of the model.

[0099] Step 19: The points and triangular grids that make up T3 and T4 are completely consistent. The corresponding triangular grids of T3 and T4 are extracted one by one according to the corresponding relationship, and triangular prisms are generated to complete the construction of the three-dimensional geological entity model of the thin coal seam that conforms to the thickness distribution information.

[0100] In this step, there is a description of the topological relationship in the internal space of the entity model, which can store and describe the distribution of hydrology, acquisition, gas, mine pressure and other attributes in the coal seam space.

Claims

1. A three-dimensional geological modeling method for thin coal seams that conforms to thickness distribution information, characterized in that: The method comprises the following steps: Step 1: Obtain the boundary of the mine field where the thin coal seam is located, and use consistent triangulation to construct the grid surface of the TIN of the bottom plate of the thin coal seam. The grid surface of the TIN of the bottom plate of the thin coal seam is recorded as T1. Step 2: Search for the boreholes that expose the thin coal seam, calculate the coordinates of the coal points based on the borehole coordinates and the borehole inclination data, and generate a three-dimensional space discrete point group PG1 containing thickness attribute information; Step 3: Collect coal prospecting records and geological data of the working face, calculate the spatial position and coal thickness information of the exposed coal seam floor on the working face in combination with the spatial position of the working face, and generate a three-dimensional space discrete point group PG2 containing thickness attribute information; Step 4: extract the coal seam floor contour line in the exploration result map, generate a three-dimensional discrete line Line1 according to the horizontal position of the coal seam floor contour line and the marked elevation information, and repeatedly encrypt the discrete line Line1 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; Step 5: Use the discrete point group PG1 obtained in step 2 and the discrete line Line1 obtained in step 4 as the fuzzy control point constraints of T1; Step 6: Using a discrete smooth interpolation algorithm, a boundary constraint is imposed on the outer contour of T1 that only allows vertical movement; Step 7, calculating discrete smooth interpolation of T1, constructing and storing the undulating shape of the thin coal seam floor; Step 8, copy the grid surface T1 of the TIN of the thin coal seam bottom plate to generate the grid surface of the TIN of the thin coal seam top plate, and the grid surface of the TIN of the thin coal seam top plate is recorded as T2; Step nine, search for boreholes that do not reveal thin coal seams, generate the axes of each borehole based on the borehole coordinates and the inclinometric data, calculate the intersection of each axis with T1, generate a three-dimensional space discrete point group PG3 containing thickness attribute information, and the coal seam thickness attribute of each point in the three-dimensional space discrete point group PG3 is 0 by default; use each point in the three-dimensional space discrete point group PG1 obtained in step two as known data and use Kriging interpolation to calculate the thickness attribute value of each point in the three-dimensional space discrete point group PG3; take the opposite of the thickness attribute value of each point in the three-dimensional space discrete point group PG3 to form a virtual negative thickness; Step 10, extract the isopach lines of the thin coal seam in the exploration result map, generate a three-dimensional space discrete line Line2 with a uniform elevation set to 0 according to the horizontal position of the isopach lines, and repeatedly encrypt the three-dimensional space discrete line Line2 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; extract the points constituting the three-dimensional space discrete line Line2 to generate a three-dimensional space discrete point group PG4 containing thickness attribute information, and the thickness attribute value of each point is determined according to the thickness value of the thickness contour line where each point is located; Step 11, extract the mineable line of the thin coal seam in the plan view of the mining project, set the elevation to 0 according to the horizontal position of the line, generate the three-dimensional space discrete line Line3, and repeatedly encrypt the three-dimensional space discrete line Line3 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; extract the points constituting the three-dimensional space discrete line Line3 to generate the three-dimensional space discrete point group PG5 containing thickness attribute information, and the thickness attribute value of each point is uniformly set to 0.8 meters; Step 12: extract the zero coal line of the thin coal seam in the plan view of the mining project, set the elevation to 0 according to the horizontal position of the line, generate the three-dimensional space discrete line Line4, and repeatedly encrypt the three-dimensional space discrete line Line4 by inserting the midpoint of the line segment until the accuracy is not less than that of T1; extract the points constituting the three-dimensional space discrete line Line4 to generate the three-dimensional space discrete point group PG6 containing thickness attribute information, and set the thickness attribute value of each point to 0 meters; Step 13, project the three-dimensional space discrete point group PG1 obtained in step 2, the three-dimensional space discrete point group PG2 obtained in step 3, the three-dimensional space discrete point group PG3 obtained in step 9, the three-dimensional space discrete point group PG4 obtained in step 10, the three-dimensional space discrete point group PG5 obtained in step 11, and the three-dimensional space discrete point group PG6 obtained in step 12 along the vertical direction onto T2 generated in step 8, and recalculate the spatial position of each point in each three-dimensional space discrete point group. The thickness attribute value of each point remains unchanged before and after the projection; Step 14: taking the three-dimensional space discrete point group PG1 obtained in step 2, the three-dimensional space discrete point group PG2 obtained in step 3, the three-dimensional space discrete point group PG3 obtained in step 9, the three-dimensional space discrete point group PG4 obtained in step 10, the three-dimensional space discrete point group PG5 obtained in step 11, and the three-dimensional space discrete point group PG6 obtained in step 12 as known thickness points, using discrete smooth interpolation to calculate the thickness value of each point in T2, and establishing a thickness distribution model based on the coal seam floor; Step 15, in the thickness distribution model obtained in step 14, the elevation value of each point in T2 is added to the respective thickness value as the new elevation value of each point, and the spatial position of T2 is updated; Step 16, based on T2 whose spatial position is updated in step 15, use T2 to clip T1, and remove the part of T1 located on the upper part of T2, to generate a TIN grid surface of the thin coal seam floor with local pinch-out, recorded as T3; Step 17, copy T3 obtained in step 16 to generate a TIN grid surface of the thin coal seam roof with local pinch-out, recorded as T4, project each point constituting T4 onto T2 along the vertical direction, and update the spatial coordinates of each point constituting T4; Step 18, extracting the contour line of T3 obtained in step 16 and the contour lines of T4 obtained in step 17, generating a TIN grid surface of the side surface of the thin coal seam, recorded as T5; merging T3, T4 and T5 to generate a closed surface model of the thin coal seam; Step 19: The points and triangular grids that make up T3 and T4 are completely consistent. The corresponding triangular grids of T3 and T4 are extracted one by one according to the corresponding relationship, and triangular prisms are generated to complete the construction of the three-dimensional geological entity model of the thin coal seam that conforms to the thickness distribution information.

2. The three-dimensional geological modeling method of thin coal seams according to thickness distribution information according to claim 1, characterized in that: In step 2, the three-dimensional space discrete point group PG1 refers to a set of isolated points, each isolated point serves as a node of the discrete point group, and thickness data is stored on each node.

3. The three-dimensional geological modeling method of thin coal seams according to thickness distribution information according to claim 1, characterized in that: In step 4, the three-dimensional space discrete line Line1 is composed of nodes and node connection relationships, and the accuracy includes discrete line accuracy and triangulation accuracy; the discrete line accuracy is the length of the line segment composed of two nodes, and the triangulation accuracy is the side length of the triangle in the triangulation.

4. The three-dimensional geological modeling method of thin coal seams according to thickness distribution information according to claim 1, characterized in that: In step five, multi-source heterogeneous data including coal points seen in boreholes, floor contours and realistic data are unified and integrated into data reflecting the spatial position of the coal seam floor.

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