Coal resource reserve dynamic estimation method based on three-dimensional geologic model

Abstract

The invention provides a coal resource reserve dynamic estimation method based on a three-dimensional geologic model. The method comprises the following steps: step 1, constructing the three-dimensional geologic model; step 2, carrying out grid division; step 3, calculating grid reserves; 4, calculating coal seam reserves; 5, carrying out expansion calculation; and step 6, dynamically calculating reserves. According to the method, the three-dimensional geologic model is subjected to segmented different-order gridding, and the two-dimensional to three-dimensional irregular volume calculation method based on integration and space line body intersection is adopted, so that the calculation of the mine coal seam reserves is realized; and a set of high-precision coal resource reserve dynamic estimation method based on the geological basic data and the three-dimensional geological model is formed. By the adoption of the method, high-order grids (curved surface grids) are adopted for the section with severe gradient change or sudden coal thickness change, linear low-order grids (linear grids) are adopted for the model smooth section to construct the model for calculation, precision and time are considered, and the application effect is good.

Description

Technical Field

[0001] The invention belongs to the technical field of coal geological exploration, relates to a three-dimensional geological model, and specifically relates to a method for dynamically estimating coal resource reserves based on a three-dimensional geological model. Background Art

[0002] Reserve management is an important part of the coal mine production process and a key link in the rational use of coal resources. Since obtaining the occurrence and spatial distribution characteristics of coal resources requires a lot of exploration work, and with limited exploration projects, people can only use various technical methods to estimate the reserve calculation parameters in order to get close to the actual resource reserves. The traditional method of calculating coal resource reserves is two-dimensional reserve calculation, which divides the block segments by exploration drilling, calculates the coal thickness, area, and apparent density of each block segment to obtain the block segment reserves, and then calculates the reserves of the mining area, coal seam, and mine. In the calculation process, the coal thickness uses the weighted average value and the area uses the plane projection method, which has certain errors and causes inaccuracy in coal resource reserves. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for dynamic estimation of coal resource reserves based on a three-dimensional geological model to solve the technical problem that the accuracy of the estimation method in the prior art needs to be further improved.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A method for dynamically estimating coal resource reserves based on a three-dimensional geological model, the method comprising the following steps:

[0006] Step 1: Build a 3D geological model:

[0007] Coal seam data is obtained, and a three-dimensional geological model is constructed using the coal seam data by adopting a discrete smooth interpolation or a Kriging interpolation algorithm, and a production block is determined according to a coordinate range.

[0008] The coal seam data include:

[0009] Coal seam coal point data, structural morphology data and coal seam roof and floor undulation data.

[0010] Roof data, floor data and interlayer data of the two tunnels and the cut coal seam.

[0011] Coal seam reserve boundary data, mining boundary data, zero point boundary data and reserve level data.

[0012] Step 2, mesh division:

[0013] The three-dimensional geological model is divided into p x×p y The grid is divided into p along the coal seam direction. x grids, divided into p along the coal seam dip y A grid.

[0014] The three-dimensional geological model adopts grids of different orders, and the grids include high-order grids and low-order grids.

[0015] Step 3, grid reserve calculation:

[0016] After the grid is divided in step 2, the grid thickness, grid volume and grid reserve of each grid are calculated.

[0017] Step 4, calculation of coal seam reserves:

[0018] According to the grid reserves obtained in step three, the coal seam reserves are accumulated.

[0019] Step 5, extended calculation:

[0020] The reserve calculation method of step 3 and step 4 is applied to the calculation of protective coal pillars, mining working faces, development coal volume, preparation coal volume and recovered coal volume, and then the recovery rate and loss rate of mines, coal seams and working faces are calculated.

[0021] Step 6, dynamic calculation of reserves:

[0022] As mining production progresses, the number of mined grids within the mining face in the three-dimensional geological model decreases dynamically, and the reserves can be dynamically calculated based on the dynamically reduced number of grids.

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] (I) The present invention realizes the calculation of coal seam reserves in mines by segmenting and gridding the three-dimensional geological model at different orders and adopting an irregular volume calculation method based on the intersection of integral and space lines from two-dimensional to three-dimensional, thus forming a set of dynamic estimation methods for coal resource reserves with high accuracy based on geological basic data and three-dimensional geological models.

[0025] (II) The method of the present invention is used to construct a model for calculation, i.e., a high-order grid (surface grid) is used in sections with drastic slope changes or sudden coal thickness changes, and a linear low-order grid (linear grid) is used in the flat section of the model. This takes into account both accuracy and time, and has a good application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a grid diagram of the three-dimensional geological model.

[0027] Figure 2 Schematic diagram of different grid division methods.

[0028] Figure 3 It is the model and footage diagram of the 2-1 coal seam mining face in a coal mine in the application example.

[0029] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0030] It should be noted that, unless otherwise specified, all methods in the present invention adopt methods known in the prior art.

[0031] In the context of intelligent coal mine construction, traditional coal resource reserve calculation methods urgently need to be further improved and developed. The traditional two-dimensional resource reserve calculation should be expanded to multi-dimensional space, and mine resource reserves should be dynamically managed from the time dimension. On the one hand, the calculation accuracy of coal reserves can be improved, and on the other hand, the three-dimensional dynamic display of mine coal resources can be realized, thereby improving the efficiency of coal resource management.

[0032] 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.

[0033] Example:

[0034] This embodiment provides a method for dynamically estimating coal resource reserves based on a three-dimensional geological model, the method comprising the following steps:

[0035] Step 1: Build a 3D geological model:

[0036] Obtain coal seam data, use the coal seam data, and construct a three-dimensional geological model using discrete smooth interpolation or Kriging interpolation algorithm, and determine the production block based on the coordinate range.

[0037] Coal seam data includes:

[0038] Coal seam coal point data, structural morphology data and coal seam roof and floor undulation data.

[0039] Roof data, floor data and interlayer data of the two tunnels and the cut coal seam.

[0040] Coal seam reserve boundary data, mining boundary data, zero point boundary data and reserve level data.

[0041] In step 1, the method for obtaining coal seam data is:

[0042] Step 101, based on the existing drilling detection exploration means, in-hole geophysical exploration means and three-dimensional seismic exploration means in the coal mine, obtain the coal seam coal point data, structural morphology data and coal seam roof and floor fluctuation data. In this embodiment, the above means are all commonly used means known in the art.

[0043] Step 102, describe the geology of the mining face and obtain the roof data, floor data and interlayer data of the two lanes and the cut coal seam.

[0044] Step 103, based on the coal seam floor contour map and the resource reserve estimation map, extract the coal seam reserve boundary line information, mineable boundary information, zero point boundary information and reserve level information.

[0045] In this embodiment, the coal seam floor contour map and resource reserve estimation map adopt the coal seam floor contour map and resource reserve estimation map commonly used in the art.

[0046] In this embodiment, the discrete smooth interpolation algorithm or the Kriging interpolation algorithm adopts the discrete smooth interpolation algorithm or the Kriging interpolation algorithm commonly used in the industry.

[0047] In step 1, the production block includes the protective coal pillar, the mining face, the development coal volume, the preparation coal volume and the recovery coal volume.

[0048] Step 2, mesh division:

[0049] like Figure 1 As shown, the three-dimensional geological model is divided into p x ×p y The grid is divided into p along the coal seam direction. x grids, divided into p along the coal seam dip y A grid.

[0050] Since the three-dimensional geological model has different ups and downs, in order to balance the calculation accuracy and calculation time, the three-dimensional geological model uses grids of different orders, including high-order grids and low-order grids.

[0051] In step 2, the high-order grids include 1st-order quadratic tetrahedral grids, Lagrangian 1st-order quadratic tetrahedral grids, and 2nd-order cubic tetrahedral grids; the low-order grids include 0th-order linear tetrahedral grids.

[0052] In step 2, the 3D geological model uses a high-order grid, i.e., a surface grid, in sections where the slope changes dramatically or the coal thickness changes suddenly, and a linear low-order grid, i.e., a linear grid, in the flat sections of the model.

[0053] In this step, the specific Figure 2 As shown, (1) is a 0th order first order tetrahedral mesh, (2) is a 1st order second order tetrahedral mesh, (3) is a Lagrangian 1st order second order tetrahedral mesh, and (4) is a 2nd order cubic tetrahedral mesh.

[0054] In step 2, the degrees of freedom of the grid are calculated according to formula I.

[0055] DOF=(n+1)×(n+3)×(n+4) / 2 Formula I.

[0056] Where:

[0057] DOF stands for degrees of freedom;

[0058] n represents the order, when n=0, DOF=6.

[0059] In this step, the parameters of the grid are shown in Table 1.

[0060] Table 1 Comparison of linear mesh and surface mesh parameters

[0061] Serial number Grid Method Grid Order Number of nodes Degrees of Freedom 1 Order 0 Tetrahedral Grid Level 0 4 6 2 Order 1 quadratic tetrahedral mesh Tier 1 10 20 6 Lagrangian 1st order quadratic tetrahedral mesh Tier 1 10 20 7 Second-order cubic tetrahedral mesh Tier 2 20 45

[0062] Specifically in this step, high-order grids have higher accuracy in numerical calculations, but of course they also bring about a greater amount of calculations. In all grid model calculations, first-order quadratic grids usually have a better cost-effectiveness, that is, they have a better balance between accuracy and calculation time. Therefore, the present invention uses first-order quadratic tetrahedral grids (surface grids) in sections where the slope changes drastically or the coal thickness changes suddenly, and uses zero-order first-order tetrahedral grids (linear grids) in the flat sections of the model. A comparative analysis will be performed later in the implementation method.

[0063] Step 3, grid reserve calculation:

[0064] After the grid is divided in step 2, the grid thickness, grid volume and grid reserve of each grid are calculated.

[0065] In step 3, if Figure 1 As shown, the grid thickness is calculated using Formula II, the grid volume is calculated using Formula III, and the grid reserve is calculated using Formula IV.

[0066] d i =z itop -z ibtm Formula II.

[0067] v i =abs[(x i+1 -x i )·(y i+1 -y i )]×d i Formula III.

[0068] r i =v i ×S i Formula IV.

[0069] Where:

[0070] d i represents the grid thickness of the i-th grid;

[0071] z itop represents the grid top elevation of the i-th grid;

[0072] Z ibtm Represents the grid base elevation of the i-th grid;

[0073] v i represents the grid volume of the i-th grid;

[0074] abs[] represents the absolute value function;

[0075] x i Represents the grid direction coordinates of the i-th grid;

[0076] x i+1 Represents the grid direction coordinates of the i+1th grid;

[0077] y i represents the grid inclination coordinate of the i-th grid;

[0078] y i+1 Represents the grid inclination coordinates of the i+1th grid;

[0079] r i represents the grid storage of the i-th grid;

[0080] s i Represents the grid apparent density of the ith grid.

[0081] Figure 1 In the figure, O represents the origin; x max Indicates the maximum value of the strike coordinate of the three-dimensional geological model; x min Indicates the minimum strike coordinate of the three-dimensional geological model; y max Indicates the maximum value of the dip coordinate of the three-dimensional geological model; y min Indicates the minimum value of the dip coordinate of the three-dimensional geological model; z max Indicates the maximum elevation of the coal seam roof in the three-dimensional geological model; z min Indicates the minimum coordinate value of the coal seam bottom plate in the three-dimensional geological model.

[0082] Step 4, calculation of coal seam reserves:

[0083] According to the grid reserves obtained in step three, the coal seam reserves are accumulated.

[0084] In step 4, the coal seam reserves are calculated using Formula V and Formula VI:

[0085]

[0086] N=p x ×p y Formula VI.

[0087] Where:

[0088] R e Indicates coal seam reserves;

[0089] r i represents the grid storage of the i-th grid;

[0090] N represents the total number of grids;

[0091] p x Indicates the number of grids divided along the coal seam trend;

[0092] p y Indicates the number of grids divided along the dip of the coal seam.

[0093] In this embodiment, p x 、p y The value determines the accuracy of reserve calculation and can be adjusted to meet the needs of different scenarios.

[0094] Step 5, extended calculation:

[0095] The reserve calculation method of step 3 and step 4 is applied to the calculation of protective coal pillars, mining working faces, development coal volume, preparation coal volume and recovered coal volume, and then the recovery rate and loss rate of mines, coal seams and working faces are calculated.

[0096] Step 6, dynamic calculation of reserves:

[0097] As mining production progresses, the number of mined grids within the mining face in the three-dimensional geological model decreases dynamically (grids "fall off"), and the reserves can be dynamically calculated based on the dynamically reduced ("falling off") number of grids.

[0098] In step 6, in the mining face, dynamic reserve calculation is performed using Formula VII, Formula VIII and Formula IX.

[0099]

[0100] R e ′=R e -r p Formula IX.

[0101] Where:

[0102] r p It indicates the amount of coal produced by mining;

[0103] n represents the number of grids where production has been completed;

[0104] r i represents the grid storage of the i-th grid;

[0105] l represents the mining footage of the working face;

[0106] x max Indicates the maximum strike coordinate of the three-dimensional geological model;

[0107] x min Indicates the minimum strike coordinate of the three-dimensional geological model;

[0108] R e ′ represents the remaining reserves of coal seam;

[0109] R e Indicates coal seam reserves.

[0110] Application examples:

[0111] This application example provides a method for dynamic estimation of coal resource reserves based on a three-dimensional geological model based on the above embodiment. This application example takes a coal mine working face as an example. The method includes the following steps:

[0112] Step 1: Build a 3D geological model:

[0113] Based on the data of drilling detection, borehole geophysical exploration, geological realism, etc. of a coal mine, and referring to the "Coal Seam Floor Contour Map and Resource Reserve Estimation Map", a 2-1 three-dimensional geological model of the coal mine was constructed; Figure 2 As shown, this is a detailed geological model of the coal seam 213 mining face.

[0114] Step 2, mesh division:

[0115] The working face model is divided into about 1200×7600 grids in the plane range. In the section where the coal seam slope changes continuously (i.e., from about 520m to 584m since the opening of the cut), the grid adopts the first-order quadratic tetrahedron grid, and each grid size is about 10cm×10cm. The remaining sections adopt the linear O-order first-order tetrahedron grid, and each grid size is about 20cm×20cm. The apparent density of coal resources in this working face is 1.31t / m 3 .

[0116] Step 3, grid reserve calculation:

[0117] Taking one of the grids as an example, its grid thickness, volume and reserves are calculated according to the formula.

[0118] d i =2.41m

[0119] v i =0.0964m 3

[0120] r i =0.126t

[0121] Step 4, calculation of coal seam reserves:

[0122] The method of step 3 is adopted to accumulate the reserves of the working face based on the reserves of the working face grid model.

[0123] R e =1.26Mt

[0124] Step 5, extended calculation:

[0125] In this application example, the mining face does not involve other reserve calculations.

[0126] Step 6, dynamic calculation of reserves:

[0127] like Figure 3 As shown, it is known that the average daily advance of the working face is 10m, and the grid "falls off" is 1200×50. Calculate the amount of coal produced by mining: p =7920t.

[0128] Therefore, the remaining reserves of the coal seam are: R e ′=1.252Mt.

[0129] Based on the above calculations, the comparison between the reserves calculated by this method and the reserves calculated by the mining company's traditional method is shown in Table 2.

[0130] Table 2 Reserve calculation results and errors

[0131]

[0132] In addition to the above methods, the 1st-order quadratic tetrahedron mesh and the 0th-order tetrahedron mesh are used to construct the entire model. The former has a mesh size of 10 cm × 10 cm, and the latter has a mesh size of 20 cm × 20 cm. The calculation accuracy and time comparison of the three models are shown in Table 3, taking the 213 working face as an example.

[0133] Table 3 Comparison of model calculation accuracy and time under three construction methods

[0134]

[0135] It can be seen from Table 3 above that when all 0-order tetrahedral meshes are used to construct the model for calculation, the absolute error is 0.26Mt and the relative error is 17.57%. This is because the elevation of the 213 working face presents a low-high-low trend along the strike direction, and the coal seam slope changes continuously from about 520m to 584m from the opening of the cut. This method ignores the surface change, resulting in a large difference in the reserve calculation, but the calculation time is only 108ms;

[0136] When the model is constructed using first-order quadratic tetrahedron meshes for calculation, the absolute error is 0.13Mt and the relative error is 8.78%. This method takes into account the fluctuations of the working face, so the reserve calculation error is within the allowable range. However, due to the huge number of nodes, the calculation time doubles to 1388ms.

[0137] It can be seen from the above application examples that the method of this application example, i.e., using high-order grids (surface grids) in sections with drastic slope changes or sudden coal thickness changes and using linear low-order grids (linear grids) in flat sections of the model to build a model for calculation, takes into account both accuracy and time, and has a good application effect.

Claims

1. A method for dynamic estimation of coal resource reserves based on a three-dimensional geological model, characterized in that: The method comprises the following steps: Step 1: Build a 3D geological model: Obtain coal seam data, use the coal seam data to construct a three-dimensional geological model using a discrete smooth interpolation or Kriging interpolation algorithm, and determine a production block according to a coordinate range; The coal seam data include: Coal seam coal point data, structural morphology data, and coal seam roof and floor undulation data; Roof data, floor data and interlayer data of two lanes and cut coal seam; Coal seam reserve boundary data, mining boundary data, zero point boundary data and reserve level data; Step 2, mesh division: The three-dimensional geological model is divided into p x ×p y The grid is divided into p along the coal seam direction. x grids, divided into p along the coal seam dip y A grid; The three-dimensional geological model uses grids of different orders, and the grids include high-order grids and low-order grids; Step 3, grid reserve calculation: After the grid is divided in step 2, the grid thickness, grid volume and grid reserve of each grid are calculated; Step 4, calculation of coal seam reserves: According to the grid reserves obtained in step three, the coal seam reserves are accumulated.

2. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 2, the high-order grid includes a 1st-order quadratic tetrahedral grid, a Lagrangian 1st-order quadratic tetrahedral grid and a 2nd-order cubic tetrahedral grid; the low-order grid includes a 0th-order linear tetrahedral grid.

3. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 2, the three-dimensional geological model uses a high-order grid, i.e., a curved grid, in sections where the slope changes drastically or the coal thickness changes suddenly, and uses a linear low-order grid, i.e., a linear grid, in flat sections of the model.

4. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 3, the grid thickness is calculated using formula II, the grid volume is calculated using formula III, and the grid reserve is calculated using formula IV; d i = z itop -z ibtm Formula II; v i = abs[(s i+1 - x i )·(y i+1 - y i )]×d i Formula Ⅲ; r i =v i ×s i Formula IV; Where: d i represents the grid thickness of the i-th grid; z itop represents the grid top elevation of the i-th grid; z ibtm Represents the grid base elevation of the i-th grid; v i represents the grid volume of the i-th grid; abs[ ] represents the absolute value function; x i Represents the grid direction coordinates of the i-th grid; x i+1 Represents the grid direction coordinates of the i+1th grid; y i represents the grid inclination coordinate of the i-th grid; y i+1 Represents the grid inclination coordinates of the i+1th grid; r i represents the grid storage of the i-th grid; s i Represents the grid apparent density of the ith grid.

5. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 4, the coal seam reserves are calculated using formula V and formula VI: N=p x ×p y Formula VI; Where: R e Indicates coal seam reserves; r i represents the grid storage of the i-th grid; N represents the total number of grids; p x Indicates the number of grids divided along the coal seam trend; p y Indicates the number of grids divided along the dip of the coal seam.

6. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: Also includes step 6; Step 6, dynamic calculation of reserves: As mining production progresses, the number of mined grids within the mining face in the three-dimensional geological model decreases dynamically, and the reserves can be dynamically calculated based on the dynamically reduced number of grids.

7. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 6, characterized in that: In step 6, in the mining face, dynamic calculation of reserves is performed using formulas VII, VIII and IX; R e ′=R e -r p Formula IX; Where: r p It indicates the amount of coal produced by mining; n represents the number of grids where production has been completed; r i represents the grid storage of the i-th grid; l represents the mining footage of the working face; x max Indicates the maximum strike coordinate of the three-dimensional geological model; x min Indicates the minimum value of the dip coordinate of the three-dimensional geological model; R e ′ represents the remaining reserves of coal seam; R e Indicates coal seam reserves.

8. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 1, the method for obtaining the coal seam data is: Step 101, based on the coal mine drilling detection exploration means, in-hole geophysical exploration means and three-dimensional seismic exploration means, obtain the coal seam coal point data, structural morphology data and coal seam roof and floor fluctuation data; Step 102, describing the geology of the mining face, obtaining the roof data, floor data and interlayer data of the two lanes and the cut coal seam; Step 103, based on the coal seam floor contour map and the resource reserve estimation map, extracting coal seam reserve boundary data, mineable boundary data, zero point boundary data and reserve level information; In step 1, the production block includes protective coal pillars, mining working faces, development coal volume, preparation coal volume and recovered coal volume.

9. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: In step 2, the degrees of freedom of the grid are calculated according to formula I; DOF=(n+1)×(n+3)×(n+4) / 2 Formula I; Where: DOF stands for degrees of freedom; n represents the order.

10. The method for dynamic estimation of coal resource reserves based on a three-dimensional geological model according to claim 1, characterized in that: Also includes step 5; Step 5, extended calculation: The reserve calculation method of step 3 and step 4 is applied to the calculation of protective coal pillars, mining working faces, development coal volume, preparation coal volume and recovered coal volume, and then the recovery rate and loss rate of mines, coal seams and working faces are calculated.

Images