Method and device for evaluating fracturing property of coal seam roof

Abstract

The invention provides a coal seam roof fracturing performance evaluation method and device. The method comprises the steps that coal seam roof information is acquired; wherein the coal seam roof information comprises roof rock stratum information of a plurality of different layers; for the roof rock stratum of any layer, analyzing the corresponding roof rock stratum information, and determining a rock stratum index and a rock index; comparing the relative importance between the rock stratum indexes and / or the rock indexes in pairs to determine a first weight corresponding to each rock stratum index and a second weight corresponding to each rock index; and performing weighted summation on each rock stratum index and the first weight corresponding to each rock stratum index, and performing weighted summation on each rock index and the second weight corresponding to each rock index to obtain a fracturing performance score of the roof rock stratum, thereby comprehensively evaluating the fracturing performance of the roof rock stratum. And the roof rock stratum with the high fracturing priority is accurately determined from the roof rock stratums of all the layers of the coal seam roof.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to a method and device for evaluating the fracturability of a coal seam roof. Background Art

[0002] The conditions of coal mine roof are complex, and the coal seam roof is often exposed above the goaf for a long time. During the coal mining process, it is easy to occur strong mine pressure hazards such as support crushing and hurricanes caused by the sudden collapse of a large area of ​​coal seam roof. In order to ensure the safety of the mining process and prevent strong mine pressure, fracturing technology will be used to treat the hard roof and create an artificial crack network in the roof rock layer.

[0003] Since there are different layers of roof rock in the roof of a coal mine, the degree of crack development caused by fracturing in different layers of roof rock is different. Therefore, the effect of strong mine pressure prevention and control after fracturing of the roof rock is also different. Therefore, it is particularly important to judge the fracturing properties of roof rock layers in different layers in order to select the appropriate layer of roof rock for fracturing. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the first purpose of this application is to propose a method for evaluating the fracturing properties of coal seam roof, so as to provide a scientific and reasonable basis for the fracturing properties of roof rock strata at different levels, so as to accurately determine the roof rock strata with higher fracturing priority from the roof rock strata at various levels of the coal seam roof.

[0006] The second objective of the present application is to provide a device for evaluating the fracturability of a coal seam roof.

[0007] The third objective of the present application is to provide an electronic device.

[0008] A fourth objective of the present application is to provide a computer-readable storage medium.

[0009] A fifth object of the present application is to provide a computer program product.

[0010] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a method for evaluating the fracturability of a coal seam roof, comprising: obtaining information about a coal seam roof located above a coal mine working face; wherein the coal seam roof information includes information about roof rock layers at multiple different levels; for a roof rock layer at any level in a coal seam roof, analyzing the corresponding roof rock layer information to determine a rock layer index and a rock index for evaluating the fracturability of the roof rock layer; and performing a pairwise comparison of the relative importance of the rock layer indexes, the rock indexes, and the rock layer indexes. To determine the first weight corresponding to each of the rock formation indicators and the second weight corresponding to each of the rock indicators; for the roof rock formation at any level, weighted sum of each of the rock formation indicators and the first weight corresponding to each of the rock formation indicators, and weighted sum of each of the rock indicators and the second weight corresponding to each of the rock indicators, to obtain the fracturing score of the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at each level of the coal seam roof.

[0011] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a coal seam roof fracturing evaluation device, including: a first acquisition module, used to obtain coal seam roof information located above the coal mine mining face; wherein the coal seam roof information includes roof rock strata information of multiple different layers; a first determination module, used to analyze the corresponding roof rock strata information of any layer in the coal seam roof, and determine the rock strata index and rock index used to evaluate the fracturing of the roof rock strata; a second determination module, used to compare the relative rock strata indexes, the rock indexes, and the rock strata indexes with each other. The importance of the rock formation indicators is compared in pairs to determine the first weight corresponding to each of the rock formation indicators and the second weight corresponding to each of the rock indicators; a scoring module is used to perform weighted summation of each of the rock formation indicators and the first weight corresponding to each of the rock formation indicators, and to perform weighted summation of each of the rock indicators and the second weight corresponding to each of the rock indicators for the roof rock formation at any level, so as to obtain the fracturing score of the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at each level of the coal seam roof.

[0012] To achieve the above-mentioned purpose, the third aspect embodiment of the present application proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the coal seam roof fracturing susceptibility evaluation method disclosed in the embodiment of the present application.

[0013] To achieve the above-mentioned purpose, the fourth aspect embodiment of the present application proposes a computer-readable storage medium, in which computer execution instructions are stored. When the computer execution instructions are executed by the processor, they are used to implement the coal seam roof fracturing evaluation method disclosed in the embodiment of the present application.

[0014] To achieve the above-mentioned purpose, the fifth aspect of the present application proposes a computer program product, including a computer program, which, when executed by a processor, implements the coal seam roof fracturing evaluation method disclosed in the embodiment of the present application.

[0015] The coal seam roof fracturing evaluation method and device provided in the present application obtain coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers; for the roof rock strata at any layer in the coal seam roof, the corresponding roof rock strata information is analyzed to determine the rock strata index and rock index used to evaluate the fracturing of the roof rock strata; the relative importance of the rock strata indexes, the rock indexes, and the rock strata indexes are compared in pairs to determine the first weight corresponding to each rock strata index and the second weight corresponding to each rock index; for the roof rock strata at any layer, the weighted sum of each rock strata index and the first weight corresponding to each rock strata index is performed, and the weighted sum of each rock index and the second weight corresponding to each rock index is performed. A weighted sum is performed to obtain a fracturing score for the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at various levels of the coal seam roof, thereby obtaining the fracturing score for the roof rock formation through the rock formation index and the rock formation index, and in the process of obtaining the fracturing score, not only the rock formation factors of the roof rock formation that affect the fracturing score are taken into account, but also the factors of the rock inherent in the roof rock formation are taken into account, thereby comprehensively evaluating the fracturing of the roof rock formation from multiple angles, and then based on the fracturing score, the roof rock formation with a higher fracturing priority can be accurately determined from the roof rock formations at various levels of the coal seam roof, providing a scientific and reasonable basis for the selection of fracturing layers, so as to improve the safety of the mining process and the effect of preventing and controlling strong mine pressure.

[0016] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A schematic diagram of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 1 ; Figure 2 A schematic diagram of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 2 ; Figure 3 A process example of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 3 ; Figure 4 A schematic diagram of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 4 ; Figure 5 A schematic diagram of the structure of a coal seam roof fracturability evaluation device provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0019] It should be noted that the acquisition, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of national laws and regulations.

[0020] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0021] Figure 1 A schematic diagram of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 1 .

[0022] Step 101, obtaining coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers.

[0023] It should be noted that the coal seam roof fracturability evaluation method provided in the embodiment of the present application can be performed by a coal seam roof fracturability evaluation device (also referred to as a coal seam roof fracturability evaluator), wherein the coal seam roof fracturability evaluation device can be implemented by software and / or hardware. The coal seam roof fracturability evaluation device can be an electronic device, or can be configured in an electronic device to implement the coal seam roof fracturability evaluation function.

[0024] The embodiment of the present application is described by taking the coal seam roof fracturing evaluation method configured in an electronic device as an example.

[0025] Among them, the electronic device can be any device with computing capabilities, such as a personal computer, a mobile terminal, a server, etc. The mobile terminal can be, for example, a vehicle-mounted device, a mobile phone, a tablet computer, a personal digital assistant, a wearable device, and other hardware devices with various operating systems, touch screens and / or display screens.

[0026] Among them, it should be noted that the coal seam roof has multiple roof rock strata with different layers, and the coal seam roof information also includes roof rock strata information at different levels. Therefore, in order to further understand the number of layered roof rock strata of the coal seam roof, geological drilling is carried out on the coal seam roof by using a coal mine coring drill to obtain cores of roof rock strata at different levels. For example, if there are six layered rock strata on the coal seam roof, the coal seam roof includes roof rock strata at six different levels, and the coal seam roof information includes roof rock strata information at six different levels.

[0027] Step 102, for any layer of the roof rock layer in the coal seam roof, the corresponding roof rock layer information is analyzed to determine the rock layer index and rock index used to evaluate the fracturing property of the roof rock layer.

[0028] Among them, it should be noted that the rock formation indicators include but are not limited to the thickness of the roof rock formation, the in-situ compressive strength of the roof rock formation, the rock integrity coefficient of the roof rock formation and the ground stress difference coefficient of the roof rock formation; the rock indicators include but are not limited to the fracture toughness of the rock and the comprehensive brittleness index of the rock.

[0029] It should be understood that there are rock formation indicators and / or rock indicators that have a positive impact on the evaluation of the fracturing ability of the roof rock formation, and there are also rock formation indicators and / or rock indicators that have a negative impact on the evaluation of the fracturing ability of the roof rock formation. For example, the rock formation indicators and / or rock indicators that have a positive impact on the evaluation of the fracturing ability of the roof rock formation include the rock integrity coefficient and the comprehensive brittleness index of the rock. Therefore, in order to conduct a more comprehensive evaluation of the fracturing ability of the roof rock formation in the future, the specific number of rock formation indicators and / or rock indicators that have a positive or negative impact on the evaluation of the fracturing ability of the roof rock formation can be determined based on actual conditions, and this embodiment does not make any specific limitations.

[0030] It should be understood that in order to determine the stratum indicators and rock indicators used to evaluate the fracturing properties of the roof rock strata, and the specific number of stratum indicators and rock indicators is not limited, there are correspondingly multiple ways to analyze the roof rock strata. For example, by measuring the roof rock strata at different levels through a rock borehole probe, the in-situ compressive strength of the roof rock strata can be obtained.

[0031] Step 103, compare the relative importance of the formation indicators, the rock indicators, and the formation indicators and rock indicators in pairs, so as to determine the first weight corresponding to each formation indicator and the second weight corresponding to each rock indicator.

[0032] It should be noted that the first weights corresponding to different rock formation indicators are not the same, and the second weights corresponding to different rock indicators are also not the same.

[0033] Step 104, for the roof rock layer of any layer, weighted sum of each rock layer indicator and the first weight corresponding to each rock layer indicator, and weighted sum of each rock indicator and the second weight corresponding to each rock indicator are performed to obtain the fracturing score of the roof rock layer.

[0034] Among them, the fracturability score is used to indicate the priority of selecting the corresponding roof rock layer from the roof rock layers at various levels of the coal seam roof for fracturing.

[0035] For example, weighting each rock formation indicator and the first weight corresponding to each rock formation indicator, and weighted summing each rock indicator and the second weight corresponding to each rock indicator to obtain the fracturability score of the roof rock formation can be expressed as: ; Among them, FI is used to represent the fracturing score of the roof rock formation. Used to indicate rock formation indicators, or, rock indicators; It is used to represent the first weight corresponding to the formation index, or the second weight corresponding to the rock index; n is used to represent the total number of formation indexes and rock indexes.

[0036] The coal seam roof fracturing evaluation method provided in the embodiment of the present application obtains coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock layer information of multiple different layers; for the roof rock layer at any layer in the coal seam roof, the corresponding roof rock layer information is analyzed to determine the rock layer index and rock index used to evaluate the fracturing of the roof rock layer; the relative importance of the rock layer indexes, the rock indexes, and the rock layer indexes are compared in pairs to determine the first weight corresponding to each rock layer index and the second weight corresponding to each rock index; for the roof rock layer at any layer, the weighted sum of each rock layer index and the first weight corresponding to each rock layer index is performed, and the weighted sum of each rock index and the second weight corresponding to each rock index is performed. A weighted sum is performed to obtain a fracturing score for the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at various levels of the coal seam roof, thereby obtaining the fracturing score for the roof rock formation through the rock formation index and the rock formation index, and in the process of obtaining the fracturing score, not only the rock formation factors of the roof rock formation that affect the fracturing score are taken into account, but also the factors of the rock inherent in the roof rock formation are taken into account, thereby comprehensively evaluating the fracturing of the roof rock formation from multiple angles, and then based on the fracturing score, the roof rock formation with a higher fracturing priority can be accurately determined from the roof rock formations at various levels of the coal seam roof, providing a scientific and reasonable basis for the selection of fracturing layers, so as to improve the safety of the mining process and the effect of preventing and controlling strong mine pressure.

[0037] In the embodiment of the present application, in order to make it clear how to analyze the roof rock layer at any level and determine the rock layer index and rock index used to evaluate the fracturability of the roof rock layer, the following is combined with Figure 2 An exemplary description is given of one possible implementation of determining formation indicators and rock indicators for evaluating the fracturability of roof rock formations. Figure 2 Process of the coal seam roof fracturing evaluation method provided in the embodiment of the present application Figure 2 .

[0038] like Figure 2 As shown, the method for evaluating the fracturability of a coal seam roof may include the following steps: Step 201, obtaining coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock layers at multiple different levels.

[0039] It should be noted that the execution process of step 201 can be implemented in any of the embodiments of the present application. The embodiments of the present application do not limit this and will not be described in detail.

[0040] Step 202, for any layer of the roof rock layer in the coal seam roof, determine the rock layer index according to the thickness, in-situ compressive strength, rock integrity coefficient of the roof rock layer and ground stress difference coefficient of the roof rock layer involved in the roof rock layer information.

[0041] In order to accurately obtain the thickness of the roof rock layer information, as an example, the cores of the roof rock layers at different levels are analyzed to obtain the thickness of the roof rock layers at different levels.

[0042] In order to accurately obtain the in-situ compressive strength, as an example, the in-situ compressive strength of the roof rock layer can be obtained by measuring the roof rock layers at different levels through a rock drilling probe.

[0043] In order to obtain the rock mass integrity coefficient of the roof rock layer, as a possible implementation method, the rock mass integrity coefficient is determined according to the elastic wave longitudinal wave velocity of the rock mass and the elastic wave longitudinal wave velocity of the rock.

[0044] As an example, the roof rock layer is measured by a rock wave velocity tester to obtain the elastic wave longitudinal wave velocity of the rock mass of the roof rock layer and the elastic wave longitudinal wave velocity of the rock; the rock integrity coefficient is determined based on the elastic wave longitudinal wave velocity of the rock mass and the elastic wave longitudinal wave velocity of the rock.

[0045] For example, the rock mass integrity factor can be determined using the formula: ; in, Used to express the rock mass integrity factor; Used to represent the elastic longitudinal wave velocity of rock mass; Used to indicate the elastic and longitudinal wave velocity of rocks.

[0046] In order to obtain the geostress difference coefficient of the roof rock layer, as a possible implementation method, the geostress difference coefficient of the roof rock layer is determined according to the three-dimensional geostress of the rock including the maximum principal stress of the rock, the intermediate principal stress of the rock and the minimum principal stress of the rock.

[0047] As an example, the geostress difference coefficient is determined based on the ratio of the difference between the maximum principal stress of the rock and the minimum principal stress of the rock to the minimum principal stress of the rock.

[0048] For example, the determination of the ground stress difference coefficient can be expressed as: ； in, Used to express the coefficient of difference in ground stress; Used to express the maximum principal stress of rock; Used to represent the intermediate principal stress of rock; Used to represent the minimum principal stress of rock.

[0049] It should be understood that in order to evaluate the degree of force balance of the rock mass of the roof rock layer and then score the fracturing ability of the roof rock layer, the geostress difference coefficient can be introduced as one of the rock layer indicators. The geostress difference coefficient is usually determined based on the ratio between the difference between the maximum principal stress of the rock and the minimum principal stress of the rock, and the sum of the maximum principal stress of the rock and the minimum principal stress of the rock. However, in order to more significantly reflect the differences between the geostresses of the roof rock layer, the formula for calculating the geostress difference coefficient can be improved. After determining the maximum principal stress and the minimum principal stress by comparing the three-dimensional geostress of the rock, the geostress difference coefficient can be determined based on the difference between the maximum principal stress of the rock and the minimum principal stress of the rock and the ratio between the minimum principal stress of the rock, so as to better understand the distribution of geostress in the roof rock layer.

[0050] Step 203, determining rock indexes according to the fracture toughness of the rock and the comprehensive brittleness index of the rock involved in the roof rock layer information.

[0051] In order to obtain the fracture toughness of rock, as a possible implementation method, for the roof rock layer at any level, the fracture toughness of the rock is determined based on the drill core obtained by drilling and coring the roof rock layer.

[0052] As an example, the drill cores of the roof rock layers at each level are obtained by drilling and coring the roof of the coal seam; for the roof rock layers at any level, the fracture toughness of the rock is determined by conducting a semi-circular disk three-point bending test based on the drill cores.

[0053] In order to accurately obtain the comprehensive brittleness index of rock, as a possible implementation method, the comprehensive brittleness index of rock is determined according to the mass ratio of target brittle minerals involved in the occurrence characteristics of the roof rock layer and the elastic modulus and Poisson's ratio of the rock involved in the rock physical and mechanical parameters.

[0054] As an example, the occurrence characteristics and rock physical and mechanical parameters of the roof rock layer are obtained; the comprehensive brittleness index of the rock is determined based on the mass ratio of the target brittle minerals involved in the occurrence characteristics and the elastic modulus and Poisson's ratio of the rock of the roof rock layer involved in the rock physical and mechanical parameters.

[0055] As another example, at least one target brittle mineral is determined from various minerals contained in the rock involved in the occurrence characteristics; the mass ratio of the target brittle mineral is determined based on the ratio of the mass of at least one target brittle mineral to the mass of the rock, and the mass ratio of various minerals is determined based on the ratio of the mass of various minerals contained in the rock to the mass of the rock; the physical and mechanical parameters of the rock are analyzed to determine the elastic modulus of the rock and the Poisson's ratio of the rock in the roof rock layer; the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock and the minimum Poisson's ratio of the rock are determined from the elastic modulus and Poisson's ratio of the rock in the roof rock layer of each layer; for the roof rock layer of any layer, the comprehensive brittleness index of the rock is determined based on the mass ratio of the target brittle mineral, the mass ratios of various minerals, the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock, the minimum Poisson's ratio of the rock, the elastic modulus of the rock and the Poisson's ratio of the rock.

[0056] It should be noted that the elastic modulus and Poisson's ratio of the roof rock layers at different levels are not the same. If there are several roof rock layers at different levels, there will be several elastic moduli and Poisson's ratios of the rocks. For example, if there are three roof rock layers at different levels, there will be three elastic moduli of the rocks, which are expressed as , and , among the elastic moduli of these three rocks, The value of is the largest, then can be the maximum elastic modulus of rock, The value of is the smallest, then can be the minimum elastic modulus of rock; and the Poisson's ratio of the three rocks are expressed as , and , among the Poisson's ratios of these three rocks, The value of is the largest, then can be the maximum value of the Poisson's ratio of rock, The value of is the smallest, then It can be the minimum value of Poisson's ratio of rock.

[0057] For example, according to the mass ratio of the target brittle mineral, the mass ratio of various minerals, the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock, the minimum Poisson's ratio of the rock, the elastic modulus of the rock and the Poisson's ratio of the rock, the comprehensive brittleness index of the rock can be expressed by the formula: ; in, Indicates the comprehensive brittleness index of rock; , b represents the preset weight; It represents the elastic modulus of rock; Indicates the maximum value of elastic modulus of rock; represents the minimum elastic modulus of rock; V represents the Poisson's ratio of rock; Indicates the maximum value of Poisson's ratio of rock; Indicates the minimum Poisson's ratio of rock.

[0058] It should be noted that, since different roof rock layers have different occurrence characteristics, the target brittle minerals contained in different roof rock layers are also different. The specific composition of the target brittle mineral is determined according to the actual situation, and this embodiment does not make specific limitations. For example, assuming that the occurrence characteristics of the roof rock layer are analyzed, it is found that the target brittle mineral contained in the rock of the roof rock layer is quartz, and the various minerals contained in the rock of the roof rock layer are quartz, calcite and clay. According to the ratio of the mass of quartz to the mass of the rock, the mass ratio of quartz is determined. ; Determine the mass ratio of calcite based on the ratio of the mass of calcite to the mass of rock ; Determine the mass ratio of clay based on the ratio of the mass of clay to the mass of rock .

[0059] For example, assuming the preset weight a is , the preset weight b is , then the comprehensive brittleness index of rock can be expressed as: ; in, Indicates the comprehensive brittleness index of rock; It represents the elastic modulus of rock; Indicates the maximum value of elastic modulus of rock; represents the minimum elastic modulus of rock; V represents the Poisson's ratio of rock; Indicates the maximum value of Poisson's ratio of rock; Indicates the minimum Poisson's ratio of rock; + + Used to indicate ; Used to express the mass ratio of quartz brittle minerals.

[0060] It should be understood that due to the dimensional influence between the initially obtained rock formation indicators and rock indicators, in order to subsequently obtain the fracturing score of the roof rock layer based on the rock formation indicators and rock indicators, the rock formation indicators and rock indicators can be normalized. However, it is known that among the rock formation indicators and rock indicators, there are rock formation indicators and / or rock indicators that positively affect the fracturing score of the roof rock layer, and rock formation indicators and / or rock indicators that negatively affect the fracturing score of the roof rock layer. Therefore, the formula for normalizing the rock formation indicators and / or rock indicators that positively affect the fracturing score of the roof rock layer is not the same as the formula for normalizing the rock formation indicators and / or rock indicators that negatively affect the fracturing score of the roof rock layer.

[0061] As an example, for the top rock layer of any layer, each rock layer index is normalized to obtain a normalized rock layer index; each rock index is normalized to obtain a normalized rock index.

[0062] For example, if the rock formation index has a rock integrity coefficient that positively affects the fracturability score of the roof rock formation, the formula for normalizing the rock integrity coefficient through the range transformation method can be expressed as: ; Wherein, T is used to represent the normalized rock mass integrity coefficient; X is used to represent the rock mass integrity coefficient; It is used to indicate the maximum value of the rock mass integrity coefficient among the rock mass integrity coefficients of the top rock layers at each level; Used to express the minimum value of the rock integrity coefficient among the rock integrity coefficients of the roof rock layers at each level.

[0063] The rock formation index has a geostress difference coefficient that negatively affects the fracturability score of the roof rock formation. The formula for normalizing the geostress difference coefficient through the range transformation method can be expressed as: ; Among them, T is used to represent the normalized geostress difference coefficient; X is used to represent the geostress difference coefficient; It is used to indicate the maximum value of the ground stress difference coefficient among the ground stress difference coefficients of the top rock layers at each level; Used to express the minimum value of the geostress difference coefficient among the geostress difference coefficients of the top rock layers at each level.

[0064] Step 204, compare the relative importance of the formation indicators, the rock indicators, and the formation indicators and rock indicators in pairs to determine the first weight corresponding to each formation indicator and the second weight corresponding to each rock indicator.

[0065] Step 205, for the roof rock layer of any layer, weighted sum of each rock layer indicator and the first weight corresponding to each rock layer indicator, and weighted sum of each rock indicator and the second weight corresponding to each rock indicator are performed to obtain the fracturing score of the roof rock layer.

[0066] It should be noted that the execution process of step 204 and step 205 can be implemented in any way in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be repeated.

[0067] The coal seam roof fracturing evaluation method provided in the embodiment of the present application determines the rock formation index for the roof rock formation at any level according to the thickness, in-situ compressive strength, rock integrity coefficient of the roof rock formation and the geostress difference coefficient of the roof rock formation involved in the roof rock formation information; and determines the rock index according to the fracture toughness of the rock and the comprehensive brittleness index of the rock involved in the roof rock formation information. Thus, the roof rock formation is analyzed in a variety of ways, taking into account the influence of the intrinsic occurrence characteristics of the roof rock formation and the mechanical and physical parameters of the rock when fracturing the roof rock formation. From the perspective of two major categories of rock formations and rocks, multiple indicators are introduced to comprehensively evaluate the fracturing of the roof rock formation, thereby providing a scientific and quantitative evaluation for the fracturing of the coal seam roof and improving the accuracy of the subsequent selection of a suitable fracturing level for the coal seam roof.

[0068] In the embodiment of the present application, in order to clearly understand the relative importance of the rock formation indicators, the rock indicators, and the rock formation indicators and the rock indicators, so as to determine the first weight corresponding to each rock formation indicator and the second weight corresponding to each rock indicator, the following is combined with Figure 3 A possible implementation method for determining the first weight corresponding to each rock formation indicator and the second weight corresponding to each rock indicator is described exemplarily. Figure 3 Process of the coal seam roof fracturing evaluation method provided in the embodiment of the present application Figure 3 .

[0069] like Figure 3 As shown, the method for evaluating the fracturability of a coal seam roof may include the following steps: Step 301, obtaining coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers.

[0070] Step 302: Analyze the corresponding roof rock formation information for any layer in the coal seam roof to determine the rock formation index and rock index for evaluating the fracturing property of the roof rock formation.

[0071] It should be noted that the execution process of step 301 and step 302 can be implemented in any way in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be repeated.

[0072] Step 303, by using the hierarchical analysis method, the relative importance between the normalized rock formation indicators, between the normalized rock indicators, and between the normalized rock formation indicators and the normalized rock indicators are compared pairwise to construct a corresponding judgment matrix.

[0073] For example, an example of the judgment matrix is ​​shown in Table 1. The normalized rock formation indicators include the normalized thickness of the roof rock layer, the normalized in-situ compressive strength of the roof rock layer, the normalized rock integrity coefficient of the roof rock layer, and the normalized ground stress difference coefficient of the roof rock layer. The normalized rock indicators include the normalized fracture toughness of the rock and the normalized comprehensive brittleness index of the rock.

[0074] Table 1 Example of judgment matrix

[0075] Step 304, solving the judgment matrix to obtain a first eigenvector corresponding to each rock formation indicator and a second eigenvector corresponding to each rock indicator.

[0076] It can be understood that the first eigenvectors corresponding to different rock formation indicators are not the same, and the second eigenvectors corresponding to different rock indicators are also not the same.

[0077] Step 305: normalize the first eigenvector and the second eigenvector to determine a first weight corresponding to each rock formation indicator and a second weight corresponding to each rock indicator.

[0078] As an example, the first eigenvector is normalized to determine the first weight corresponding to each rock formation indicator, and the second eigenvector is normalized to determine the second weight corresponding to each rock indicator.

[0079] For example, by calculating Table 1, The first weight corresponding to (coefficient of geostress difference) is 0.3751; the first weight corresponding to H (thickness of rock layer) is 0.2436; The first weight corresponding to (in-situ compressive strength) is 0.1534; The first weight corresponding to (rock mass integrity coefficient) is 0.093; The second weight corresponding to (comprehensive brittleness index of rock) is 0.093, and The second weight corresponding to (comprehensive brittleness index of rock) is 0.0419, so the fracturability score of the roof rock layer can be expressed as ; Among them, FI is used to represent the fracturing score of the roof rock formation.

[0080] Step 306, for the roof rock layer of any layer, weighted sum of each rock layer indicator and the first weight corresponding to each rock layer indicator, and weighted sum of each rock indicator and the second weight corresponding to each rock indicator are performed to obtain the fracturing score of the roof rock layer.

[0081] It should be noted that for the specific description of step 306, reference may be made to other descriptions of this embodiment, which will not be repeated here.

[0082] The coal seam roof fracturing evaluation method provided in the embodiment of the present application uses a hierarchical analysis method to compare the relative importance of normalized rock formation indicators, normalized rock indicators, and normalized rock formation indicators and normalized rock indicators in pairs to construct a corresponding judgment matrix, solve the judgment matrix to obtain the first eigenvector corresponding to each rock formation indicator and the second eigenvector corresponding to each rock indicator, normalize the first eigenvector and the second eigenvector to determine the first weight corresponding to each rock formation indicator and the second weight corresponding to each rock indicator, thereby analyzing the rock formation indicators and rock indicators through the hierarchical analysis method to determine the first weight corresponding to the rock formation indicators and the second weight corresponding to the rock indicators, and then significantly representing the rock formation indicators and / or rock indicators that have a greater impact on the subsequent fracturing score of the roof rock formation, thereby improving the accuracy of selecting a suitable fracturing layer for the coal seam roof.

[0083] Figure 4 A schematic diagram of a method for evaluating the fracturability of a coal seam roof provided in an embodiment of the present application Figure 4 .

[0084] like Figure 4 As shown, the method for evaluating the fracturability of a coal seam roof may include the following steps: Step 401, obtaining coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock layers at multiple different levels.

[0085] Step 402: Analyze the corresponding roof rock formation information for any layer in the coal seam roof to determine the rock formation index and rock index for evaluating the fracturing property of the roof rock formation.

[0086] Step 403, compare the relative importance of the formation indicators, the rock indicators, and the formation indicators and rock indicators in pairs, so as to determine the first weight corresponding to each formation indicator and the second weight corresponding to each rock indicator.

[0087] Step 404, for the roof rock layer at any level, weighted sum of each rock layer indicator and the first weight corresponding to each rock layer indicator, and weighted sum of each rock indicator and the second weight corresponding to each rock indicator are performed to obtain the fracturing score of the roof rock layer.

[0088] It should be noted that for the specific description of steps 401 to 403, reference may be made to other descriptions of this embodiment, which will not be repeated here.

[0089] Step 405, for the roof rock layer at any level, obtain the fracturability score of the roof rock layer.

[0090] Step 406, determining a target score interval in which the fracturability score is located from a plurality of set candidate score intervals; wherein each candidate score interval has a corresponding fracturing priority level.

[0091] Step 407, determining the fracturing priority level of the roof rock formation according to the fracturing priority level corresponding to the target scoring interval.

[0092] It should be understood that the fracturing scores of roof rock strata at different levels are different, and the specific values ​​are different. If you do not have relevant industry knowledge, you cannot intuitively judge whether the roof rock strata at the corresponding level are suitable for fracturing from the fracturing score. Therefore, based on the historically obtained fracturing score, fracturing is carried out on the corresponding roof rock strata, and the priority of the fracturing of the roof rock strata that has been fractured in the past is determined according to the degree of development of cracks caused by the historically fractured roof rock strata and the prevention and control effect of strong mine pressure. Therefore, based on the relationship between the historically obtained fracturing score and the priority of the fracturing of the roof rock strata, multiple candidate scoring intervals can be set to facilitate intuitive judgment of the roof rock strata at the appropriate level for fracturing.

[0093] For example, the comparison table of fracturing score and fracturing priority is shown in Table 2. Assuming that the fracturing score of the roof rock formation is 0.4, according to Table 2, the candidate score interval where the fracturing score (0.4) is located is the second candidate score interval in the comparison table of fracturing score and fracturing priority, then the fracturing priority of the roof rock formation (fracturing score 0.4) can be expressed as "average fracturing".

[0094] Table 2 Comparison of fracturing performance scores and fracturing priority levels

[0095] In this embodiment, for the roof rock layer at any level, the fracturing score of the roof rock layer is obtained, and the target score interval of the fracturing score is determined from the set multiple candidate score intervals; wherein each candidate score interval has a corresponding fracturing priority level, and the fracturing priority level of the roof rock layer is determined according to the fracturing priority level corresponding to the target score interval, thereby determining the fracturing score of the roof rock layer, thereby determining the target score interval of the fracturing score of the roof rock layer from the set multiple candidate score intervals, determining the fracturing priority level of the roof rock layer according to the fracturing priority level corresponding to the target score interval, pre-setting multiple fracturing priority levels, and accurately determining the fracturing priority level of the roof rock layer from the pre-set multiple fracturing priority levels according to the fracturing score of the roof rock layer, thereby achieving a more intuitive determination of the priority of fracturing the roof rock layer, so as to quickly select the roof rock layer of a suitable level for fracturing from the roof rock layers of multiple levels.

[0096] In order to implement the above-mentioned embodiment, the present application also proposes a device for evaluating the fracturability of a coal seam roof.

[0097] Figure 5 A schematic structural diagram of a coal seam roof fracturability evaluation device provided in an embodiment of the present application is shown.

[0098] like Figure 5 As shown, the coal seam roof fracturability evaluation device 500 includes: a first acquisition module 501, a first determination module 502, a second determination module 503 and a scoring module 504.

[0099] The first acquisition module 501 is used to acquire the coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers; The first determination module 502 is used to analyze the corresponding roof rock layer information of any layer in the coal seam roof to determine the rock layer index and rock index used to evaluate the fracturability of the roof rock layer; The second determination module 503 is used to compare the relative importance of the rock formation indicators, the rock indicators, and the rock formation indicators and the rock indicators in pairs, so as to determine the first weight corresponding to each rock formation indicator and the second weight corresponding to each rock indicator; Scoring module 504 is used to perform weighted summation of each rock layer indicator and the first weight corresponding to each rock layer indicator, and to perform weighted summation of each rock indicator and the second weight corresponding to each rock indicator, for the roof rock layer at any level, so as to obtain a fracturing score for the roof rock layer; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock layer for fracturing from the roof rock layers at each level of the coal seam roof.

[0100] In one embodiment of the present application, the rock formation indicators include but are not limited to the thickness of the roof rock formation, the in-situ compressive strength of the roof rock formation, the rock mass integrity coefficient of the roof rock formation, and the ground stress difference coefficient of the roof rock formation; the rock indicators include but are not limited to the fracture toughness of the rock and the comprehensive brittleness index of the rock; the first determination module 502 is specifically used to: For any layer of roof rock, the rock index is determined according to the thickness, in-situ compressive strength, rock mass integrity coefficient of the roof rock and the ground stress difference coefficient of the roof rock. The rock index is determined based on the fracture toughness of the rock involved in the roof rock layer information and the comprehensive brittleness index of the rock.

[0101] In one embodiment of the present application, the first determining module 502 is specifically configured to: Obtaining the thickness, in-situ compressive strength, elastic wave longitudinal wave velocity of the rock mass, elastic wave longitudinal wave velocity of the rock, and three-dimensional geostress of the rock; wherein the three-dimensional geostress of the rock includes the maximum principal stress of the rock, the intermediate principal stress of the rock, and the minimum principal stress of the rock; The rock mass integrity coefficient is determined based on the elastic wave longitudinal wave velocity of the rock mass and the elastic wave longitudinal wave velocity of the rock; The ground stress difference coefficient is determined according to the ratio between the difference between the maximum principal stress of the rock and the minimum principal stress of the rock and the minimum principal stress of the rock; The rock formation indicators are determined based on the thickness, in-situ compressive strength, rock integrity coefficient and ground stress difference coefficient.

[0102] In one embodiment of the present application, the first determining module 502 is specifically configured to: Obtaining drill cores of roof rock layers at various levels obtained by drilling and coring the roof of the coal seam; For the roof rock layer at any level, the fracture toughness of the rock is determined by conducting a half-disk three-point bending test based on the drill core; Obtain the occurrence characteristics and rock physical and mechanical parameters of the roof rock layer; The comprehensive brittleness index of the rock is determined based on the mass ratio of the target brittle minerals involved in the occurrence characteristics and the elastic modulus of the top rock layer and the Poisson's ratio of the rock involved in the rock physical and mechanical parameters.

[0103] In one embodiment of the present application, the first determining module 502 is specifically configured to: Determine at least one target brittle mineral from various minerals contained in the rock involved in the occurrence characteristics; Determining the mass ratio of the target brittle mineral based on the ratio of the mass of at least one target brittle mineral to the mass of the rock, and determining the mass ratio of various minerals contained in the rock based on the ratio of the mass of various minerals contained in the rock to the mass of the rock; Analyze the physical and mechanical parameters of the rock to determine the elastic modulus and Poisson's ratio of the top rock layer; From the elastic modulus and Poisson's ratio of the rock in the roof rock layer of each layer, determine the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock, and the minimum Poisson's ratio of the rock; For the top rock layer of any layer, the comprehensive brittleness index of the rock is determined according to the mass ratio of the target brittle mineral, the mass ratio of various minerals, the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock, the minimum Poisson's ratio of the rock, the elastic modulus of the rock and the Poisson's ratio of the rock.

[0104] In one embodiment of the present application, the first determination module 502, the comprehensive brittleness index of the rock is obtained according to the following formula: ; in, Indicates the comprehensive brittleness index of rock; , b represents the preset weight; It represents the elastic modulus of rock; Indicates the maximum value of elastic modulus of rock; represents the minimum elastic modulus of rock; V represents the Poisson's ratio of rock; Indicates the maximum value of Poisson's ratio of rock; Indicates the minimum Poisson's ratio of rock.

[0105] In one embodiment of the present application, the device includes a normalization module, which is specifically used to: For the top rock layer of any horizon, normalize the rock layer indicators to obtain the normalized rock layer indicators; Each rock index is normalized to obtain a normalized rock index.

[0106] In one embodiment of the present application, the second determining module 503 is specifically configured to: By using the analytic hierarchy process, the relative importance of normalized rock formation indicators, normalized rock indicators, and normalized rock formation indicators and normalized rock indicators are compared pairwise to construct the corresponding judgment matrix. Solving the judgment matrix to obtain the first eigenvector corresponding to each rock formation indicator and the second eigenvector corresponding to each rock indicator; Normalizing the first eigenvector to determine first weights corresponding to respective rock formation indicators; The second eigenvector is normalized to determine the second weight corresponding to each rock indicator.

[0107] In one embodiment of the present application, the device further comprises a fracturing priority module, which is specifically used to: For the roof rock layer at any level, obtain the fracturability score of the roof rock layer; Determine a target score interval for the fracturability score from a plurality of set candidate score intervals; wherein each candidate score interval has a corresponding fracturing priority level; The fracturing priority level of the roof rock formation is determined according to the fracturing priority level corresponding to the target scoring interval.

[0108] The coal seam roof fracturing evaluation device provided in the embodiment of the present application obtains coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock layer information of multiple different layers; for the roof rock layer at any layer in the coal seam roof, the corresponding roof rock layer information is analyzed to determine the rock layer index and rock index used to evaluate the fracturing of the roof rock layer; the relative importance of the rock layer indexes, the rock indexes, and the rock layer indexes are compared in pairs to determine the first weight corresponding to each rock layer index and the second weight corresponding to each rock index; for the roof rock layer at any layer, the weighted sum of each rock layer index and the first weight corresponding to each rock layer index is performed, and the weighted sum of each rock index and the second weight corresponding to each rock index is performed. A weighted sum is performed to obtain a fracturing score for the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at various levels of the coal seam roof, thereby obtaining the fracturing score for the roof rock formation through the rock formation index and the rock formation index, and in the process of obtaining the fracturing score, not only the rock formation factors of the roof rock formation that affect the fracturing score are taken into account, but also the factors of the rock inherent in the roof rock formation are taken into account, thereby comprehensively evaluating the fracturing of the roof rock formation from multiple angles, and then based on the fracturing score, the roof rock formation with a higher fracturing priority can be accurately determined from the roof rock formations at various levels of the coal seam roof, providing a scientific and reasonable basis for the selection of fracturing layers, so as to improve the safety of the mining process and the effect of preventing and controlling strong mine pressure.

[0109] It should be noted that the above explanation of the embodiment of the method for evaluating the fracturability of the coal seam roof is also applicable to the device for evaluating the fracturability of the coal seam roof of this embodiment, and will not be repeated here.

[0110] In order to implement the above embodiments, the present application also proposes an electronic device.

[0111] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0112] like Figure 6 As shown, the electronic device 600 may include: a processor 602, and a memory 603 communicatively connected to the processor 602; the memory 603 stores computer-executable instructions; the processor 602 executes the computer-executable instructions stored in the memory 603 to implement the method provided in the aforementioned embodiment. Furthermore, the electronic device 600 further includes: The transceiver 601 is used for communication between the memory 603 and the processor 602 .

[0113] The memory 603 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0114] If the memory 603, the processor 602 and the transceiver 601 are implemented independently, the transceiver 601, the memory 603 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0115] Optionally, in a specific implementation, if the memory 603, the processor 602 and the transceiver 601 are integrated on a chip, the memory 603, the processor 602 and the transceiver 601 can communicate with each other through an internal interface.

[0116] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0117] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0118] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0119] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0120] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0121] The present application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by limiting data collection and deleting the data. In addition, when applicable, such personal information is de-identified to protect the privacy of the user.

[0122] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0123] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0124] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0125] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0126] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0127] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0128] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0129] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for evaluating the fracturability of a coal seam roof, characterized in that: The following steps are involved: Acquire the coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers; For any layer of the roof rock layer in the coal seam roof, the corresponding roof rock layer information is analyzed to determine the rock layer index and rock index used to evaluate the fracturing ability of the roof rock layer; Comparing the relative importance of the formation indicators, the rock indicators, and the formation indicators and the rock indicators in pairs, so as to determine the first weight corresponding to each of the formation indicators and the second weight corresponding to each of the rock indicators; For the roof rock layer at any level, a weighted sum is taken for each rock layer indicator and the first weight corresponding to each rock layer indicator, and a weighted sum is taken for each rock indicator and the second weight corresponding to each rock indicator, so as to obtain a fracturing score for the roof rock layer; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock layer for fracturing from the roof rock layers at each level of the coal seam roof.

2. The method according to claim 1, characterized in that in, The rock formation indicators include but are not limited to the thickness of the roof rock formation, the in-situ compressive strength of the roof rock formation, the rock mass integrity coefficient of the roof rock formation and the ground stress difference coefficient of the roof rock formation; the rock indicators include but are not limited to the fracture toughness of the rock and the comprehensive brittleness index of the rock; The roof rock layer of any layer in the coal seam roof is analyzed for the corresponding roof rock layer information to determine the rock layer index and rock index used to evaluate the fracturing property of the roof rock layer, including: For the roof rock layer at any level, determine the rock layer index according to the thickness, the in-situ compressive strength, the rock mass integrity coefficient of the roof rock layer and the ground stress difference coefficient of the roof rock layer involved in the roof rock layer information; The rock index is determined according to the fracture toughness of the rock involved in the roof rock layer information and the comprehensive brittleness index of the rock.

3. The method according to claim 2, characterized in that The rock formation index for the roof rock formation at any level is determined according to the thickness, the in-situ compressive strength, the rock mass integrity coefficient of the roof rock formation and the ground stress difference coefficient of the roof rock formation involved in the roof rock formation information, including: Obtaining the thickness, the in-situ compressive strength, the elastic wave longitudinal wave velocity of the rock mass, the elastic wave longitudinal wave velocity of the rock, and the three-dimensional geostress of the rock involved in the roof rock stratum information; wherein the three-dimensional geostress of the rock includes the maximum principal stress of the rock, the intermediate principal stress of the rock, and the minimum principal stress of the rock; Determining the rock mass integrity coefficient according to the elastic wave longitudinal wave velocity of the rock mass and the elastic wave longitudinal wave velocity of the rock; Determine the in-situ stress difference coefficient according to the ratio of the difference between the maximum principal stress of the rock and the minimum principal stress of the rock to the minimum principal stress of the rock; The rock formation index is determined according to the thickness, the in-situ compressive strength, the rock mass integrity coefficient and the ground stress difference coefficient.

4. The method according to claim 2, characterized in that: Determining the rock index according to the fracture toughness of the rock involved in the roof rock layer information and the comprehensive brittleness index of the rock includes: Obtaining drill cores of roof rock layers at various levels obtained by drilling and coring the coal seam roof; For the roof rock layer at any level, based on the drill core, a half-disc three-point bending test is performed to determine the fracture toughness of the rock; Obtaining the occurrence characteristics and rock physical and mechanical parameters of the roof rock layer; The comprehensive brittleness index of the rock is determined based on the mass ratio of the target brittle minerals involved in the occurrence characteristics and the elastic modulus of the rock in the top rock layer and the Poisson's ratio of the rock involved in the rock physical and mechanical parameters.

5. The method according to claim 4, characterized in that Determining the comprehensive brittleness index of the rock according to the mass ratio of the target brittle mineral involved in the occurrence characteristics and the elastic modulus of the rock of the roof rock layer and the Poisson's ratio of the rock involved in the rock physical and mechanical parameters includes: Determine at least one target brittle mineral from various minerals contained in the rock involved in the occurrence characteristics; Determining the mass ratio of the target brittle mineral according to the ratio of the mass of at least one of the target brittle minerals to the mass of the rock, and determining the mass ratio of each of the minerals according to the ratio of the mass of each of the minerals contained in the rock to the mass of the rock; Analyze the physical and mechanical parameters of the rock to determine the elastic modulus of the rock and the Poisson's ratio of the rock in the roof rock layer; Determine the maximum value of the elastic modulus of the rock, the minimum value of the elastic modulus of the rock, the maximum value of the Poisson's ratio of the rock, and the minimum value of the Poisson's ratio of the rock from the elastic modulus and the Poisson's ratio of the rock in each layer; For the roof rock layer at any level, the comprehensive brittleness index of the rock is determined according to the mass ratio of the target brittle mineral, the mass ratio of various minerals, the maximum elastic modulus of the rock, the minimum elastic modulus of the rock, the maximum Poisson's ratio of the rock, the minimum Poisson's ratio of the rock, the elastic modulus of the rock and the Poisson's ratio of the rock.

6. The method according to claim 5, characterized in that in, The comprehensive brittleness index of the rock is obtained according to the following formula: ； in, Indicates the comprehensive brittleness index of the rock; , b represents the preset weight; represents the elastic modulus of the rock; represents the maximum value of elastic modulus of the rock; represents the minimum elastic modulus of the rock; V represents the Poisson's ratio of the rock; represents the maximum value of Poisson's ratio of the rock; Indicates the minimum Poisson's ratio of the rock.

7. The method according to any one of claims 1 to 6, characterized in that: After analyzing the corresponding roof rock formation information of any layer in the coal seam roof to determine the rock formation index and rock index for evaluating the fracturing performance of the roof rock formation, the method includes: For the roof rock layer at any level, normalize each rock layer index to obtain a normalized rock layer index; Each of the rock indicators is normalized to obtain a normalized rock indicator.

8. The method according to claim 7, characterized in that The relative importance of the formation indicators, the rock indicators, and the formation indicators and the rock indicators are compared in pairs to determine the first weight corresponding to each of the formation indicators and the second weight corresponding to each of the rock indicators, including: By using the hierarchical analysis method, the relative importance between the normalized rock formation indicators, between the normalized rock indicators, and between the normalized rock formation indicators and the normalized rock indicators are compared in pairs to construct a corresponding judgment matrix; Solving the judgment matrix to obtain a first eigenvector corresponding to each of the rock formation indicators and a second eigenvector corresponding to each of the rock indicators; Normalizing the first characteristic vector to determine the first weight corresponding to each of the rock formation indicators; The second eigenvector is normalized to determine the second weight corresponding to each of the rock indicators.

9. The method according to claim 1, characterized in that: After performing weighted summation of each rock formation index and the first weight corresponding to each rock formation index, and performing weighted summation of each rock index and the second weight corresponding to each rock index for the roof rock formation at any level to obtain the fracturability score of the roof rock formation, the method further includes: For the roof rock formation at any level, obtaining the fracturability score of the roof rock formation; Determining a target score interval in which the fracturability score is located from a plurality of set candidate score intervals; wherein each of the candidate score intervals has a corresponding fracturing priority level; The fracturing priority level of the roof rock formation is determined according to the fracturing priority level corresponding to the target scoring interval.

10. A coal seam roof fracturing evaluation device, characterized in that: The following steps are involved: The first acquisition module is used to acquire the coal seam roof information located above the coal mine working face; wherein the coal seam roof information includes roof rock strata information of multiple different layers; The first determination module is used to analyze the corresponding roof rock layer information of any layer in the coal seam roof, and determine the rock layer index and rock index used to evaluate the fracturing ability of the roof rock layer; A second determination module is used to compare the relative importance of the rock formation indicators, the rock indicators, and the rock formation indicators and the rock indicators in pairs, so as to determine the first weight corresponding to each of the rock formation indicators and the second weight corresponding to each of the rock indicators; A scoring module is used to perform weighted summation of each rock formation indicator and the first weight corresponding to each rock formation indicator, and to perform weighted summation of each rock indicator and the second weight corresponding to each rock indicator, for the roof rock formation at any level, so as to obtain a fracturing score for the roof rock formation; wherein the fracturing score is used to indicate the priority of selecting the corresponding roof rock formation for fracturing from the roof rock formations at each level of the coal seam roof.

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