Coal mine ground stress inversion method, apparatus and device, and storage medium

Abstract

The invention relates to a coal mine ground stress inversion method, device and equipment and a storage medium. The method comprises the following steps: determining an inversion target area of a coal mine, and establishing a corresponding three-dimensional coordinate system; actual measurement coordinates and rock stratum depth data corresponding to the actual drilling points are obtained, the actual measurement coordinates are converted into theoretical coordinates in a three-dimensional coordinate system, and a three-dimensional geologic model of the inversion target area is established according to the theoretical coordinates and the rock stratum depth data; acquiring a simulation result of the three-dimensional geologic model under the action of a preset working condition stress field, and respectively extracting a simulation stress component corresponding to each stress actual measurement point from the simulation result; determining an inversion regression equation based on the actually measured stress component and the simulated stress component of each stress actually measured point; and determining the ground stress distribution rule of the coal mine based on the inversion regression equation. By adopting the method, when the three-dimensional geologic model of the coal mine is constructed, the rock stratum depth data is considered, so that the precision of the final inversion result is relatively high.

Description

Technical Field

[0001] The present application relates to the technical field of coal mines, and in particular to a coal mine ground stress inversion method, a coal mine ground stress inversion device, a computer device and a computer-readable storage medium. Background Art

[0002] As the mining depth of coal mines increases, the ground stress shows a nonlinear growth trend. Understanding the size, direction and distribution characteristics of the ground stress is a necessary prerequisite for engineering design, production and construction, and prevention and control of rock burst.

[0003] Field testing of geostress is the most direct and effective method to obtain geostress, but the cost of field testing is high and the cycle is long, and only local geostress conditions can be obtained when measuring geostress at limited measuring points. Therefore, the geostress field in coal mine areas is often inverted by combining field testing of geostress with numerical simulation of geostress.

[0004] When inverting the geostress of a coal mine, it is necessary to construct a three-dimensional geological model of the coal mine. Most researchers mainly rely on the geological profile of the coal mine when constructing the three-dimensional geological model. This method ignores the height differences of various rock layers at different locations, that is, the undulating characteristics of the rock layers. Therefore, it has certain limitations, resulting in the inversion results of the coal mine geostress often being of low accuracy. Summary of the invention

[0005] Based on this, it is necessary to provide a coal mine ground stress inversion method, a coal mine ground stress inversion device, a computer device and a computer readable storage medium to address the above technical problems.

[0006] In a first aspect, the present application provides a method for inversion of geostress in a coal mine, the method comprising: determining an inversion target area of ​​the coal mine and establishing a corresponding three-dimensional coordinate system; the inversion target area has a plurality of actual drilling points and a plurality of geostress measured points; obtaining the measured coordinates and rock layer depth data corresponding to each of the actual drilling points, converting the measured coordinates into theoretical coordinates in the three-dimensional coordinate system, and establishing a three-dimensional geological model of the inversion target area based on the theoretical coordinates and the rock layer depth data; obtaining a simulation result of the three-dimensional geological model under the action of a preset working condition stress field, and extracting the simulated stress components corresponding to each of the geostress measured points from the simulation results; determining an inversion regression equation based on the measured stress components and the simulated stress components of each of the geostress measured points; the measured stress components are determined based on the principal stress measured results of the corresponding geostress measured points; and determining the geostress distribution law of the coal mine based on the inversion regression equation.

[0007] In one embodiment, the measured coordinates include measured coordinates of the horizontal axis, measured coordinates of the vertical axis and measured coordinates of the vertical axis, and the theoretical coordinates include theoretical coordinates of the horizontal axis, theoretical coordinates of the vertical axis and theoretical coordinates of the vertical axis; the step of converting the measured coordinates of the actual drilling point into theoretical coordinates in the three-dimensional coordinate system includes: determining the horizontal axis coordinate deviation and the vertical axis coordinate deviation of the origin in the three-dimensional coordinate system; the horizontal axis coordinate deviation is the measured horizontal axis coordinate of the origin, and the vertical axis coordinate deviation is the measured vertical axis coordinate of the origin; the difference between the measured horizontal axis coordinate of the actual drilling point and the horizontal axis coordinate deviation is used as its theoretical horizontal axis coordinate; the difference between the measured vertical axis coordinate of the actual drilling point and the vertical axis coordinate deviation is used as its theoretical vertical axis coordinate; the measured vertical axis coordinate of the actual drilling point is used as its theoretical vertical axis coordinate.

[0008] In one of the embodiments, the step of establishing a three-dimensional geological model of the inversion target area according to the theoretical coordinates of each of the actual drilling points and the rock formation depth data includes: establishing contour data of each coal rock layer according to the theoretical coordinates of each of the actual drilling points and the rock formation depth data; the coal rock layers are, from shallow to deep, the overlying rock layer, old roof, direct roof, coal layer, direct bottom, old bottom and lower rock layer; selecting points located at the junction of two adjacent coal rock layers from each of the actual drilling points as interface marking points of each of the coal rock layers; connecting the interface marking points of each of the coal rock layers respectively to obtain corresponding spline curves, and fitting the spline curves to obtain interface surface models of each of the coal rock layers; establishing a three-dimensional geological model of the inversion target area based on the contour data of each of the coal rock layers and the interface surface models.

[0009] In one of the embodiments, the step of establishing a three-dimensional geological model of the inversion target area based on the contour data and the interface surface model of each of the coal and rock layers includes: establishing a three-dimensional initial model of the inversion target area based on the contour data and the interface surface model of each of the coal and rock layers; gridding the three-dimensional initial model to obtain a three-dimensional transition model; assigning physical and mechanical parameters to each of the coal and rock layers in the three-dimensional transition model to obtain a three-dimensional geological model of the inversion target area.

[0010] In one embodiment, the number of preset working conditions is six, namely, self-weight stress state, horizontal extrusion structural movement in the x direction of the three-dimensional coordinate system, horizontal extrusion structural movement in the y direction of the three-dimensional coordinate system, shear deformation structural movement in the xy plane of the three-dimensional coordinate system, vertical shear deformation structural movement in the xz plane of the three-dimensional coordinate system, and vertical shear deformation structural movement in the yz plane of the three-dimensional coordinate system; the simulated stress components include three simulated normal stress components corresponding one-to-one in the x, y, and z directions of the three-dimensional coordinate system and one-to-one in the xy, xz, and yz planes of the three-dimensional coordinate system. The method comprises the steps of: performing a stress relief test on each of the in-situ stress measuring points to obtain a corresponding principal stress measuring result; the principal stress measuring result comprises stress values, azimuths and inclinations corresponding to the maximum principal stress, the intermediate principal stress and the minimum principal stress, respectively; determining the measured stress components of each in-situ stress measuring point according to the principal stress measuring results; the measured stress components comprise three measured normal stress components corresponding one-to-one to the x, y and z directions of the three-dimensional coordinate system and three measured shear stress components corresponding one-to-one to the xy, xz and yz planes of the three-dimensional coordinate system.

[0011] In one of the embodiments, the step of determining the inversion regression equation based on the measured stress components and the simulated stress components of each of the measured ground stress points includes: linearly superimposing the three simulated normal stress components and the three simulated shear stress components of each of the measured ground stress points, respectively, to form an initial regression equation with the measured stress components of the corresponding measured ground stress points; the initial regression equation has six undetermined regression coefficients and one error term; solving the six undetermined regression coefficients and the error term, and determining the inversion regression equation based on the solution results.

[0012] In one of the embodiments, the ground stress distribution law includes the stress distribution law in the x, y, and z directions of the three-dimensional coordinate system at different burial depths, as well as the distribution law of the maximum principal stress, intermediate principal stress, and minimum principal stress of the main coal seam.

[0013] In the second aspect, the present application also provides a coal mine geostress inversion device, the device comprising: an area determination module, used to determine the inversion target area of ​​the coal mine and establish a corresponding three-dimensional coordinate system; the inversion target area has multiple actual drilling points and multiple geostress measured points; a model establishment module, used to obtain the measured coordinates and rock layer depth data corresponding to each of the actual drilling points, convert the measured coordinates into theoretical coordinates in the three-dimensional coordinate system, and establish a three-dimensional geological model of the inversion target area based on the theoretical coordinates and the rock layer depth data; a stress simulation module, used to obtain the simulation results of the three-dimensional geological model under the action of a preset working condition stress field, and extract the simulated stress components corresponding to each of the geostress measured points from the simulation results; an equation determination module, used to determine the inversion regression equation based on the measured stress components and the simulated stress components of each of the geostress measured points; the measured stress components are determined according to the principal stress measured results of the corresponding geostress measured points; an inversion module, used to determine the geostress distribution law of the coal mine based on the inversion regression equation.

[0014] In a third aspect, an embodiment of the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of a coal mine ground stress inversion method when executing the computer program.

[0015] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of a method for coal mine ground stress inversion are implemented.

[0016] One of the above technical solutions has the following advantages or beneficial effects: the coal mine geostress inversion method adopts research methods such as theoretical analysis, field testing and numerical simulation, and conducts inversion research on the coal mine geostress based on the multivariate regression analysis method according to the coal mine engineering geological conditions and the measured results of geostress. Among them, this method takes into account the rock layer depth data when constructing the three-dimensional geological model of the coal mine, that is, pays attention to the undulating characteristics of each rock layer in the coal mine, so that the final inversion result has a high accuracy, ensuring that the inversion values ​​of most geostress measurement points are close to the measured values, and the error is controlled within an acceptable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a flow chart of a coal mine ground stress inversion method in one embodiment;

[0018] Figure 2 A contour map corresponding to the contour data of each coal rock layer in an embodiment;

[0019] Figure 3 A schematic diagram of the structure of an interface surface model in an embodiment;

[0020] Figure 4 A schematic diagram of a process for determining an inverse regression equation in one embodiment;

[0021] Figure 5 A schematic diagram of a flow chart of a coal mine ground stress inversion method in another embodiment;

[0022] Figure 6 A schematic diagram of the structure of a coal mine ground stress inversion device in one embodiment;

[0023] Figure 7 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] In one embodiment, Figure 1 As shown, a coal mine ground stress inversion method is provided, comprising the following steps:

[0027] S102, determining the inversion target area of ​​the coal mine and establishing a corresponding three-dimensional coordinate system; the inversion target area has a plurality of actual drilling points and a plurality of ground stress measurement points.

[0028] The inversion target area of ​​the coal mine is to determine the scope of the coal mine calculation model. Reasonable determination of the calculation model scope is a prerequisite for conducting initial geostress inversion research, and has a significant impact on the accuracy of numerical simulation results. Excessive expansion of the calculation scope will lead to an increase in the amount of calculation and reduce the accuracy of geostress inversion. On the other hand, if the model scope is too small, the key geographical and geological features of the study area may be ignored, which will lead to a lack of rationality in the analysis results. Therefore, in the process of constructing a three-dimensional geological model, it is necessary to select an appropriate and reasonable research boundary to ensure a true and objective inversion analysis of the geostress in the study area.

[0029] Specifically, the inversion target area can be determined by combining the geological exploration data of the coal mine with the location information of the on-site measurement points to determine the final inversion target area.

[0030] The three-dimensional coordinate system corresponding to the inverted target area can be based on the lower left corner of the inverted target area as the origin, with the east as the positive direction of the x-axis, the north as the positive direction of the y-axis, and the vertical direction as the positive direction of the z-axis. Of course, the way to establish the coordinate system can also be other, and only one specific implementation method is listed here.

[0031] Among them, the actual drilling point can be understood as the location point of the exploration drilling. Due to the complexity and invisibility of the rock distribution in coal mines, it is difficult to directly obtain the distribution information of the strata from the surface to the deep coal seam. The only way is to drill exploration holes on the surface to obtain the distribution of rock strata in a small area, so as to further infer the distribution of rock strata in a larger range. At the same time, as a data source for constructing rock interface contours, exploration drilling contains a lot of information. Through the drilling column chart, we can understand the type of rock strata, height and other information hidden underground.

[0032] In addition, the geostress measurement point can be understood as the coal mine location point where the actual geostress measurement was carried out. The specific geostress measurement method can adopt the hollow inclusion stress relief method or other existing methods. Through the geostress measurement test, the magnitude, direction and inclination of the principal stress at the geostress measurement point can be determined, which is helpful to study the variation law of the principal stress, lateral pressure coefficient and lateral pressure ratio with burial depth, as well as the subsequent establishment and solution of the inversion regression equation.

[0033] S104, obtaining the measured coordinates and rock depth data corresponding to each actual drilling point, converting the measured coordinates into theoretical coordinates in a three-dimensional coordinate system, and establishing a three-dimensional geological model of the inversion target area based on the theoretical coordinates and rock depth data.

[0034] In an embodiment of the present application, based on the coal mine mining engineering plan and drilling column chart and other data, multiple actual drilling points that are relatively evenly distributed in the inversion target area can be selected, the drilling column charts of the multiple actual drilling points can be analyzed, and the measured coordinates and rock depth data of the multiple actual drilling points can be extracted; and based on this information, a geological drilling database can be further established for subsequent modeling and analysis work.

[0035] Since the coordinate coefficients of the measured coordinates of each actual drilling point are large, it is not conducive to the establishment and calculation of the model. Therefore, it is necessary to convert the coordinate values ​​that appear in the model construction process (convert the measured coordinates into theoretical coordinates in the three-dimensional coordinate system) to ensure the smooth construction and rapid calculation of the model.

[0036] The establishment of a three-dimensional geological model can import data into existing three-dimensional model generation software, and then convert point coordinates into line coordinates, and then generate a surface model to finally obtain a three-dimensional geological model; in other words, the present application can establish a three-dimensional geological model of a coal mine based on the modeling idea of ​​"point-line-surface-body", and realize the construction of a complex three-dimensional geological model of a coal mine from basic exploration drilling information.

[0037] S106, obtaining simulation results of the three-dimensional geological model under the action of the preset working condition stress field, and extracting the simulated stress components corresponding to the stress measuring points in various places from the simulation results.

[0038] The preset working conditions can be determined based on the theoretical analysis of the factors affecting geostress and the actual situation on site; since the self-weight stress of the rock mass itself and the tectonic stress generated by tectonic movement are the main factors affecting the initial geostress distribution, the preset working conditions can be selected and set accordingly.

[0039] S108, determining an inversion regression equation based on the measured stress components and simulated stress components of the stress measurement points at various locations; the measured stress components are determined according to the measured principal stress results of the corresponding in-situ stress measurement points.

[0040] The simulated stress component is obtained by simulation software based on the three-dimensional geological model and the preset working condition stress field; different from the simulated stress component, the measured stress component is obtained through actual measurement of the ground stress measurement test. The combination of the two can be used to determine the inversion regression equation.

[0041] S110, based on the inverse regression equation, determine the distribution law of the ground stress in the coal mine.

[0042] In the above embodiments of the present application, the execution subject can be a computer device, and of course it can also be selected and changed according to the actual situation. In the coal mine geostress inversion method of the above embodiment, theoretical analysis, field testing and numerical simulation and other research methods are adopted. According to the engineering geological conditions of the coal mine and the measured results of geostress, the coal mine geostress is inverted based on the multivariate regression analysis method. Among them, when constructing the three-dimensional geological model of the coal mine, this method takes into account the rock layer depth data, that is, pays attention to the uneven characteristics of each rock layer in the coal mine, so that the final inversion result has a high accuracy, ensuring that the inversion values ​​of most of the geostress measurement points are close to the measured values, and the error is controlled within an acceptable range.

[0043] In one embodiment, the measured coordinates include the measured coordinates of the horizontal axis, the measured coordinates of the vertical axis and the measured coordinates of the vertical axis, and the theoretical coordinates include the theoretical coordinates of the horizontal axis, the theoretical coordinates of the vertical axis and the theoretical coordinates of the vertical axis; the step of converting the measured coordinates of the actual drilling point into the theoretical coordinates in the three-dimensional coordinate system in S104 specifically includes: determining the horizontal axis coordinate deviation and the vertical axis coordinate deviation of the origin in the three-dimensional coordinate system; the horizontal axis coordinate deviation is the measured horizontal axis coordinate of the origin, and the vertical axis coordinate deviation is the measured vertical axis coordinate of the origin; the difference between the measured horizontal axis coordinate of the actual drilling point and the horizontal axis coordinate deviation is used as its theoretical horizontal axis coordinate; the difference between the measured vertical axis coordinate of the actual drilling point and the vertical axis coordinate deviation is used as its theoretical vertical axis coordinate; the measured vertical axis coordinate of the actual drilling point is used as its theoretical vertical axis coordinate.

[0044] In one embodiment, the step of establishing a three-dimensional geological model of the inversion target area according to the theoretical coordinates and rock layer depth data of each actual drilling point in S104 specifically includes: establishing contour data of each coal rock layer according to the theoretical coordinates and rock layer depth data of each actual drilling point; the coal rock layers are, from shallow to deep, the overlying rock layer, the old roof, the direct roof, the coal layer, the direct bottom, the old bottom and the lower rock layer in order of depth; selecting points located at the junction of two adjacent coal rock layers from each actual drilling point as interface marking points of each coal rock layer; connecting the interface marking points of each coal rock layer respectively to obtain corresponding spline curves, and fitting the spline curves to obtain interface surface models of each coal rock layer; establishing a three-dimensional geological model of the inversion target area based on the contour data and interface surface models of each coal rock layer.

[0045] Among them, contour data can be understood as contour line data, which can include contour line maps. Figure 2 According to the height information of different rock layers in the borehole columnar diagram, the point coordinates of the corresponding rock layer can be extracted, and the rock layer contour map can be generated using the point coordinates (it should be noted that Figure 2 This is only a schematic diagram, and the height information of the old top, direct top, direct bottom and old bottom is not shown in the figure).

[0046] In one embodiment, the above-mentioned step of establishing a three-dimensional geological model of the inversion target area based on the contour data of each coal rock layer and the interface surface model includes: establishing a three-dimensional initial model of the inversion target area based on the contour data of each coal rock layer and the interface surface model; gridding the three-dimensional initial model to obtain a three-dimensional transition model; assigning physical and mechanical parameters to each coal rock layer in the three-dimensional transition model to obtain a three-dimensional geological model of the inversion target area.

[0047] The interface surface model, also known as the rock layer surface, can be specifically based on the geological borehole database established by the borehole column chart, marking the borehole marker points at the interface of the key strata, connecting the marker points and fitting based on the B-spline curve principle. For example, the upper interface of the coal seam is fitted by the coordinates of several points on the interface between the coal seam and the immediate top in the geological borehole database, and this interface is also used as the lower interface of the immediate top, and the lower interface of the coal seam is fitted by the coordinates of several points on the interface between the coal seam and the immediate bottom. Figure 3 This is a specific coal seam interface obtained by fitting. As shown in the figure, the undulation of the surface is very similar to the undulation of the stratum.

[0048] The three-dimensional initial model is meshed, and meshing is the basis of numerical simulation. The three-dimensional model has the characteristics of complex numerical calculation, large inversion range, and many mesh units. Unreasonable meshing will make the calculation difficult or even impossible. Therefore, the model size and meshing are particularly critical. The following principles should be followed when meshing: (1) The size of the mesh directly affects the error of the in-situ stress calculation. The two are in direct proportion, that is, the smaller the unit size, the more accurate the in-situ stress calculation result. On the other hand, the increase in the number of units in the model will increase the calculation time and require a larger computer capacity. Therefore, when determining the meshing size, it is necessary to comprehensively consider the computer's computing power and calculation accuracy. (2) In the fault zone and coal seam, a relatively small meshing size is used. The same rock layer is divided into the same unit group to avoid the same unit crossing the rock layer with significantly different properties. Meshing needs to comprehensively consider the calculation speed and construction effect of the numerical simulation software, as well as the lithological characteristics of the formation. A specific implementation method is to use the Griddle plug-in in the Rhino software to merge the fitted surfaces, and then use the hexahedral meshing method to divide the calculation model.

[0049] Physical and mechanical parameters may include, but are not limited to, bulk modulus, shear modulus, cohesion, tensile strength, internal friction angle, density, etc. of each coal rock layer.

[0050] In one embodiment, the number of preset working conditions is six, namely, self-weight stress state, horizontal extrusion structural movement in the x direction of the three-dimensional coordinate system, horizontal extrusion structural movement in the y direction of the three-dimensional coordinate system, shear deformation structural movement in the xy plane of the three-dimensional coordinate system, vertical shear deformation structural movement in the xz plane of the three-dimensional coordinate system, and vertical shear deformation structural movement in the yz plane of the three-dimensional coordinate system; the simulated stress components include three simulated normal stress components corresponding to the x, y, and z directions of the three-dimensional coordinate system and three simulated shear deformation structural movement corresponding to the xy, xz, and yz planes of the three-dimensional coordinate system. stress components; for the measured stress components of the stress measurement points in various places in S108, the determination steps may specifically include: performing a stress relief test on the stress measurement points in various places to obtain corresponding principal stress measurement results; the principal stress measurement results include stress values, azimuths and inclinations corresponding to the maximum principal stress, the intermediate principal stress and the minimum principal stress, respectively; determining the measured stress components of the stress measurement points in various places according to the principal stress measurement results; the measured stress components include three measured normal stress components corresponding one-to-one to the x, y, and z directions of the three-dimensional coordinate system and three measured shear stress components corresponding one-to-one to the xy, xz, and yz planes of the three-dimensional coordinate system.

[0051] In one embodiment, Figure 4 As shown, S108 specifically includes: linearly superimposing the three simulated normal stress components and the three simulated shear stress components of the stress measurement points at various locations, and forming an initial regression equation with the measured stress components of the corresponding stress measurement points; the initial regression equation has six undetermined regression coefficients and one error term; solving the values ​​of the six undetermined regression coefficients and the error term, and determining the inverse regression equation according to the solution results.

[0052] In one embodiment, the ground stress distribution law includes the stress distribution law in the x, y, and z directions of the three-dimensional coordinate system at different burial depths, and the distribution law of the maximum principal stress, the intermediate principal stress, and the minimum principal stress of the main mining coal seam. The main mining coal seam can be understood as the coal seam that is mainly mined in coal mining; these coal seams usually have high economic value and mining value and are the main mining objects of coal mining enterprises.

[0053] In the process of establishing a three-dimensional geological model of a coal mine, the present application first extracts the information of the exploration borehole column chart within the scope of the coal mine geostress inversion and establishes a geological borehole database; then the landmark points of the same coal layer in the geological borehole database are connected respectively to generate coal layer contour lines; next, the coal layer contour lines are fitted into coal layer surfaces, and finally, each coal layer surface is "face-to-face constructed" to achieve the establishment of a three-dimensional geological model of the coal mine within the inversion range and perform geostress inversion. The following takes a specific implementation method as an example, combined with Figure 5 , the above-mentioned coal mine ground stress inversion method is further introduced.

[0054] like Figure 5 As shown in Figure 2, the coal mine ground stress inversion method can specifically include:

[0055] Step 1: According to the positions of the on-site ground stress measurement points (including the above-mentioned multiple actual drilling points and multiple ground stress measurement points), the scope of the inversion target area is delineated and a three-dimensional coordinate system is established for the scope.

[0056] In this embodiment, based on the coal mine geological exploration data and the location information of the on-site measured points of the ground stress, a reasonable range of ground stress inversion can be established. Among them, the on-site measured points of the ground stress are all included in the range of ground stress inversion. The three-dimensional coordinate system takes the east as the positive direction of the x-axis, the north as the positive direction of the y-axis, and the vertical direction as the positive direction of the z-axis.

[0057] Step 2: Count the exploration boreholes in the inversion target area and establish a geological borehole database based on the borehole histogram information of the exploration boreholes.

[0058] According to the mining engineering plan and drilling column data provided by the coal mine, multiple exploration boreholes (i.e., multiple actual drilling points) with relatively uniform distribution in the inversion target area are selected, and the drilling column of the selected exploration boreholes is analyzed to extract the borehole spatial coordinate information (corresponding to the measured coordinates) and the depth information of each coal and rock layer (corresponding to the rock layer depth data), and establish a geological drilling database. The following table shows the measured coordinates and rock layer depth data corresponding to some actual drilling points (the rock layer depth data in the table only shows the coal layer depth value, and other rock layer depth values ​​are not shown).

[0059] Actual drilling point number Latitude(X) Longitude (Y) Height (H) Coal seam depth / m Final hole depth / m 01# 38397477.94 4031167.34 1097.76 683.39 825.03 02# 38392067.01 4031102.44 1043.63 567.00 719.59 03# 38396036.11 4031205.54 1039.95 607.05 752.02 04# 38397617.92 4029629.07 1017.54 578.95 718.03 05# 38396824.42 4029580.98 999.73 576.72 680.00

[0060] Step 3: Offset the coordinate values ​​of each actual drilling point in the global coordinate system to obtain new coordinate values ​​(i.e., theoretical coordinates) in the three-dimensional coordinate system to adapt to the inversion target area defined in step 1.

[0061] According to the inversion range defined in step 1, the coordinate values ​​of the measured coordinates of each actual drilling point are relatively large, and the coordinate values ​​of the global coordinate system need to be offset to make them translate into a small range. First, the position of the origin A is determined within the inversion range of the ground stress defined in step 1. In this implementation, the intersection of the western boundary and the southern boundary of the inversion range is selected as the origin position. The coordinate conversion operation is as follows:

[0062]

[0063] In the formula, x old 、x new are the x-axis values ​​before and after the coordinate transformation; new ,y old is the y-axis value before and after the coordinate transformation; xA old 、x A new They are the x-axis values ​​of the origin A before and after the coordinate transformation;

[0064] It should be noted that z new 、z old is the z-axis value before and after the coordinate transformation. Since the z-axis moves in the horizontal plane, z new =z old , the coordinate values ​​do not change.

[0065] Step 4: Figure 2 As shown, according to the height information of each coal and rock layer in the borehole columnar diagram, the point coordinates of the corresponding rock layer are extracted, and the rock layer contour map is generated using the point coordinates, thereby establishing the contour lines of each coal and rock layer; wherein, Figure 2 a in the figure shows the borehole column, and b shows the rock layer interface;

[0066] Step 5: Create a coal layer surface based on the information in the geological drilling database.

[0067] In this embodiment, according to the geological borehole database established in step 2, the landmark points of the exploration boreholes at the interface of each coal-rock layer are marked, and the landmark point data of each coal-rock layer is imported into the Rhino 3D modeling software, and the landmark points of each coal-rock layer are respectively connected and the rock layer surface is fitted based on the B-spline curve generation principle. Each coal-rock layer includes an overlying rock layer, an old roof, a direct roof, a coal layer, a direct bottom, an old bottom, and a lower rock layer.

[0068] For example, the following is fitted through several landmark points of the interface between coal seam and immediate roof in the geological drilling database: Figure 3 The upper interface of the coal seam shown is also the lower interface of the direct top. The undulation of the established curved surface is very similar to the undulation of the actual stratum.

[0069] Step 6: Based on the established coal and rock layer surface, a three-dimensional geological model of the coal mine is established and the model is meshed and parameterized.

[0070] In this embodiment, the griddle plug-in in the Rhino 3D modeling software is first used to merge the coal and rock layer surfaces fitted in step 5 to obtain a 3D geological model of the coal mine; then the hexahedral grid division method is used to grid the established 3D geological model of the coal mine.

[0071] Finally, the three-dimensional geological model of the coal mine with completed gridding is imported into the FLAC3D numerical calculation software. According to the physical and mechanical properties measurement report of each coal rock layer provided by the coal mine, the physical and mechanical parameters of each coal rock layer are assigned in combination with the physical and mechanical parameters of the coal rock mass in the coal mine.

[0072] Step 7: Based on the three principal stresses obtained from the field measured ground stress, convert them into the expression of six stress components.

[0073] According to the field test results of coal mine ground stress, the principal stresses σ1, σ2, and σ3 of the measured ground stress are converted into six stress components σ x , σ y , σ z , τ xy , τ yz , τ xz ; where σ1 is the maximum principal stress, σ2 is the intermediate principal stress, and σ3 is the minimum principal stress; σ x is the normal stress in the x direction, σ y is the normal stress in the y direction, σ z is the normal stress in the z direction; τ xy is the shear stress acting on the xy plane, τ yz is the shear stress acting on the yz plane, τ xz is the shear stress acting on the xz plane.

[0074] Assuming that the azimuth angle of the borehole at the field measurement point is α and the inclination angle is β, the cosine values ​​of the angles between the three principal stresses in the x, y, and z directions are l i 、m i and n i It can be expressed as:

[0075]

[0076] According to the measured principal stress values, azimuth and inclination of the field measurement points, six stress components can be derived, which are:

[0077]

[0078] Step 8: Based on the three-dimensional geological model of the coal mine established in step 6, the six stress components are combined to invert the ground stress of the coal mine.

[0079] like Figure 4 As shown in the figure, six working conditions are selected for geostress simulation, that is, boundary conditions are applied to the three-dimensional geological model of the coal mine after parameter assignment, namely: self-weight stress state, horizontal compression tectonic movement in the x-direction, horizontal compression tectonic movement in the y-direction, shear deformation tectonic movement in the xy horizontal plane, vertical shear deformation tectonic movement in the xz plane, and vertical shear deformation tectonic movement in the yz plane.

[0080] Substitute the above six working conditions into the three-dimensional geological model of the coal mine established in step 6, generate the initial stress fields under the six working conditions, and extract the six stress component data of the corresponding field measured points in the three-dimensional geological model of the coal mine under the six working conditions. Linearly superimpose the simulated values ​​and form a regression equation with the measured values, and the inversion equation of the multivariate regression analysis ground stress can be expressed as:

[0081] σ′=b1σ p1 +b2σ p2 +b3σ p3 +b4σ p4 +b5σ p5 +b6σ z +c

[0082] In the formula, σ p1 , σ p2 , σ p3 , σ p4 , σ p5 Represent the structural stresses of the five working conditions: normal stress in the x direction, normal stress in the y direction, normal stress in the z direction, shear stress acting on the xy plane, shear stress acting on the yz plane, and shear stress acting on the xz plane. z is the self-weight stress; b1, b2, b3, b4, b5, b6 are unknown regression coefficients, which are solved by Origin software in this embodiment; c is the error term.

[0083] The obtained multivariate regression coefficient value is multiplied by the corresponding boundary condition, and the multiplication result is re-substituted into the three-dimensional geological model of the coal mine for calculation. After calculation, the inversion stress value at any position within the inversion range of the coal mine is finally obtained.

[0084] It should be understood that, for the aforementioned various method embodiments, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flow chart of the method embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0085] Based on the same inventive concept, the embodiment of the present application also provides a coal mine ground stress inversion device for implementing the above-mentioned coal mine ground stress inversion method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more coal mine ground stress inversion device embodiments provided below can refer to the limitations of the coal mine ground stress inversion method above, and will not be repeated here.

[0086] In one embodiment, Figure 6 As shown, a coal mine ground stress inversion device is provided, including: a region determination module 601, a model establishment module 602, a stress simulation module 603, an equation determination module 604 and an inversion module 605, wherein:

[0087] The region determination module 601 is used to determine the inversion target region of the coal mine and establish a corresponding three-dimensional coordinate system; the inversion target region has multiple actual drilling points and multiple ground stress measurement points;

[0088] The model building module 602 is used to obtain the measured coordinates and rock depth data corresponding to each actual drilling point, convert the measured coordinates into theoretical coordinates in a three-dimensional coordinate system, and build a three-dimensional geological model of the inversion target area based on the theoretical coordinates and rock depth data;

[0089] The stress simulation module 603 is used to obtain the simulation results of the three-dimensional geological model under the action of the preset working condition stress field, and extract the simulated stress components corresponding to the stress measured points in various places from the simulation results;

[0090] The equation determination module 604 is used to determine the inversion regression equation based on the measured stress components and simulated stress components of the stress measurement points at various locations; the measured stress components are determined according to the principal stress measurement results of the corresponding ground stress measurement points;

[0091] The inversion module 605 is used to determine the distribution law of the ground stress of the coal mine based on the inversion regression equation.

[0092] In one embodiment, the measured coordinates include the measured coordinates of the horizontal axis, the measured coordinates of the vertical axis and the measured coordinates of the vertical axis, and the theoretical coordinates include the theoretical coordinates of the horizontal axis, the theoretical coordinates of the vertical axis and the theoretical coordinates of the vertical axis; the model building module 602 is specifically used to determine the horizontal axis coordinate deviation and the vertical axis coordinate deviation of the origin in the three-dimensional coordinate system; the horizontal axis coordinate deviation is the measured horizontal axis coordinate of the origin, and the vertical axis coordinate deviation is the measured vertical axis coordinate of the origin; the difference between the measured horizontal axis coordinate of the actual drilling point and the horizontal axis coordinate deviation is used as its theoretical horizontal axis coordinate; the difference between the measured vertical axis coordinate of the actual drilling point and the vertical axis coordinate deviation is used as its theoretical vertical axis coordinate; the measured vertical axis coordinate of the actual drilling point is used as its theoretical vertical axis coordinate.

[0093] In one embodiment, the model building module 602 is specifically used to establish the contour data of each coal rock layer according to the theoretical coordinates of each actual drilling point and the rock layer depth data; the coal rock layers are, from shallow to deep, the overlying rock layer, the old roof, the direct roof, the coal layer, the direct bottom, the old bottom and the lower rock layer; points located at the junction of two adjacent coal rock layers are selected from each actual drilling point as the interface marking points of each coal rock layer; the interface marking points of each coal rock layer are connected respectively to obtain the corresponding spline curves, and the spline curves are fitted to obtain the interface surface models of each coal rock layer; based on the contour data of each coal rock layer and the interface surface model, a three-dimensional geological model of the inversion target area is established.

[0094] In one embodiment, the model building module 602 is specifically used to establish a three-dimensional initial model of the inversion target area based on the contour data of each coal and rock layer and the interface surface model; grid the three-dimensional initial model to obtain a three-dimensional transition model; assign physical and mechanical parameters to each coal and rock layer in the three-dimensional transition model to obtain a three-dimensional geological model of the inversion target area.

[0095] In one embodiment, the number of preset working conditions is six, namely, self-weight stress state, horizontal extrusion structural movement in the x direction of the three-dimensional coordinate system, horizontal extrusion structural movement in the y direction of the three-dimensional coordinate system, shear deformation structural movement in the xy plane of the three-dimensional coordinate system, vertical shear deformation structural movement in the xz plane of the three-dimensional coordinate system, and vertical shear deformation structural movement in the yz plane of the three-dimensional coordinate system; the simulated stress components include three simulated normal stress components corresponding to the x, y, and z directions of the three-dimensional coordinate system and one-to-one corresponding to the xy, xz, and y planes of the three-dimensional coordinate system. three simulated shear stress components on the z plane; an equation determination module 604, specifically used to perform stress relief tests on stress measurement points at various locations to obtain corresponding principal stress measurement results; the principal stress measurement results include stress values, azimuths and inclinations corresponding to the maximum principal stress, the intermediate principal stress and the minimum principal stress, respectively; based on the principal stress measurement results, the measured stress components of the stress measurement points at various locations are determined; the measured stress components include three measured normal stress components corresponding one-to-one to the x, y, and z directions of the three-dimensional coordinate system and three measured shear stress components corresponding one-to-one to the xy, xz, and yz planes of the three-dimensional coordinate system.

[0096] In one embodiment, the equation determination module 604 is specifically used to linearly superimpose the three simulated normal stress components and the three simulated shear stress components of the stress measurement points at each location, and form an initial regression equation with the measured stress components of the corresponding stress measurement points; the initial regression equation has six undetermined regression coefficients and one error term; solve the values ​​of the six undetermined regression coefficients and the error term, and determine the inverse regression equation based on the solution results.

[0097] In one embodiment, the ground stress distribution law includes the stress distribution law in the x, y, and z directions of the three-dimensional coordinate system at different burial depths, as well as the distribution law of the maximum principal stress, intermediate principal stress, and minimum principal stress of the main coal seam.

[0098] For the specific definition of the coal mine geostress inversion device, please refer to the definition of the coal mine geostress inversion method mentioned above, which will not be repeated here. Each module in the above-mentioned coal mine geostress inversion device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0099] In addition, in the implementation of the coal mine ground stress inversion device of the above example, the logical division of each program module is only an example. In actual application, the above functions can be assigned to different program modules as needed, for example, for the configuration requirements of the corresponding hardware or the convenience of software implementation. That is, the internal structure of the coal mine ground stress inversion device is divided into different program modules to complete all or part of the functions described above.

[0100] In one embodiment, a computer device is also provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0101] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0102] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0103] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0104] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, and they should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0105] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0106] The terms "including" and "having" and any variations thereof in the embodiments herein are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or (module) units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices. "Multiple" mentioned herein refers to two or more.

[0107] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A coal mine ground stress inversion method, characterized in that: The method comprises: Determine the inversion target area of ​​the coal mine and establish a corresponding three-dimensional coordinate system; the inversion target area has multiple actual drilling points and multiple ground stress measurement points; Acquire the measured coordinates and rock depth data corresponding to each of the actual drilling points, convert the measured coordinates into theoretical coordinates in the three-dimensional coordinate system, and establish a three-dimensional geological model of the inversion target area according to the theoretical coordinates and the rock depth data; Acquire simulation results of the three-dimensional geological model under the action of a preset working condition stress field, and extract simulated stress components corresponding to each of the ground stress measured points from the simulation results; Determining an inversion regression equation based on the measured stress components of each of the in-situ stress measurement points and the simulated stress components; the measured stress components are determined according to the measured results of the principal stresses of the corresponding in-situ stress measurement points; Based on the inverse regression equation, the distribution law of the ground stress of the coal mine is determined.

2. The method according to claim 1, characterized in that The measured coordinates include the measured coordinates of the horizontal axis, the measured coordinates of the vertical axis and the measured coordinates of the vertical axis, and the theoretical coordinates include the theoretical coordinates of the horizontal axis, the theoretical coordinates of the vertical axis and the theoretical coordinates of the vertical axis; The step of converting the measured coordinates of the actual drilling point into theoretical coordinates in the three-dimensional coordinate system comprises: Determine the horizontal axis coordinate deviation and the vertical axis coordinate deviation of the origin in the three-dimensional coordinate system; the horizontal axis coordinate deviation is the horizontal axis measured coordinate of the origin, and the vertical axis coordinate deviation is the vertical axis measured coordinate of the origin; The difference between the measured horizontal axis coordinate of the actual drilling point and the horizontal axis coordinate deviation is used as its horizontal axis theoretical coordinate; The difference between the measured longitudinal coordinate of the actual drilling point and the longitudinal coordinate deviation is used as its longitudinal theoretical coordinate; The measured vertical axis coordinates of the actual drilling point are used as the theoretical vertical axis coordinates.

3. The method according to claim 1, characterized in that The step of establishing a three-dimensional geological model of the inversion target area according to the theoretical coordinates of each actual drilling point and the rock layer depth data comprises: According to the theoretical coordinates of each actual drilling point and the rock layer depth data, the contour data of each coal rock layer is established; the coal rock layer is composed of the overlying rock layer, the old top, the direct top, the coal layer, the direct bottom, the old bottom and the lower rock layer in order from shallow to deep; Selecting points located at the junction of two adjacent coal-rock layers from the actual drilling points as interface marking points of the coal-rock layers; connecting the interface marking points of the coal-rock layers respectively to obtain corresponding spline curves, and fitting the spline curves to obtain interface surface models of the coal-rock layers; Based on the contour data of each coal and rock layer and the interface surface model, a three-dimensional geological model of the inversion target area is established.

4. The method according to claim 3, characterized in that The step of establishing the three-dimensional geological model of the inversion target area based on the contour data of each coal and rock layer and the interface surface model comprises: Based on the contour data of each coal-rock layer and the interface surface model, a three-dimensional initial model of the inversion target area is established; Meshing the three-dimensional initial model to obtain a three-dimensional transition model; Physical and mechanical parameters are assigned to each of the coal and rock layers in the three-dimensional transition model to obtain a three-dimensional geological model of the inversion target area.

5. The method according to any one of claims 1 to 4, characterized in that The number of the preset working conditions is six, which are self-weight stress state, horizontal extrusion structural movement in the x direction of the three-dimensional coordinate system, horizontal extrusion structural movement in the y direction of the three-dimensional coordinate system, shear deformation structural movement in the xy plane of the three-dimensional coordinate system, vertical shear deformation structural movement in the xz plane of the three-dimensional coordinate system, and vertical shear deformation structural movement in the yz plane of the three-dimensional coordinate system; the simulated stress components include three simulated normal stress components corresponding one-to-one in the x, y, and z directions of the three-dimensional coordinate system and three simulated shear stress components corresponding one-to-one in the xy, xz, and yz planes of the three-dimensional coordinate system; The step of determining the measured stress components of each of the in-situ stress measuring points comprises: A stress relief test is performed on each of the ground stress measurement points to obtain corresponding principal stress measurement results; the principal stress measurement results include stress values, azimuths and inclinations corresponding to the maximum principal stress, the intermediate principal stress and the minimum principal stress, respectively; According to the measured results of the principal stress, the measured stress components of each of the ground stress measurement points are determined; the measured stress components include three measured normal stress components corresponding one-to-one in the x, y, and z directions of the three-dimensional coordinate system and three measured shear stress components corresponding one-to-one in the xy, xz, and yz planes of the three-dimensional coordinate system.

6. The method according to claim 5, characterized in that The step of determining the inversion regression equation based on the measured stress components of each of the ground stress measured points and the simulated stress components comprises: The three simulated normal stress components and the three simulated shear stress components of each of the in-situ stress measurement points are linearly superimposed to form an initial regression equation with the measured stress components of the corresponding in-situ stress measurement points; the initial regression equation has six undetermined regression coefficients and one error term; The six unknown regression coefficients and the error term are solved, and the inverse regression equation is determined according to the solution results.

7. The method according to any one of claims 1 to 4, characterized in that The ground stress distribution law includes the stress distribution law of different burial depths in the x, y, and z directions of the three-dimensional coordinate system, as well as the distribution law of the maximum principal stress, the intermediate principal stress, and the minimum principal stress of the main coal seam.

8. A coal mine ground stress inversion device, characterized in that: The device comprises: The region determination module is used to determine the inversion target region of the coal mine and establish a corresponding three-dimensional coordinate system; the inversion target region has multiple actual drilling points and multiple ground stress measurement points; A model building module, used to obtain the measured coordinates and rock depth data corresponding to each of the actual drilling points, convert the measured coordinates into theoretical coordinates in the three-dimensional coordinate system, and build a three-dimensional geological model of the inversion target area according to the theoretical coordinates and the rock depth data; A stress simulation module, used to obtain simulation results of the three-dimensional geological model under the action of a preset working condition stress field, and to extract simulated stress components corresponding to each of the ground stress measured points from the simulation results; An equation determination module, used to determine an inversion regression equation based on the measured stress components of each of the in-situ stress measurement points and the simulated stress components; the measured stress components are determined according to the measured results of the principal stresses of the corresponding in-situ stress measurement points; The inversion module is used to determine the distribution law of the ground stress of the coal mine based on the inversion regression equation.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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