Fine identification and division method for soft and hard composite coal seam of driving working face

Abstract

The invention discloses a fine identification and division method for a soft and hard composite coal seam of a driving working face, and relates to the technical field of coal and gas outburst prevention and control, and the method comprises the following steps: obtaining parameter data of a drill bit drilling speed Ik, a drilling hole gas total flow Ic, a drilling cutting amount Is and a flushing fluid leakage amount Il in a drilling process in real time through a built-in module of a drilling bit; data values recorded by all the modules are transmitted to an index weight calculation module in sequence, determination of parameter weights of all the indexes is completed, and a region division comprehensive index I is obtained; and the region division module sets a threshold value according to a built-in I parameter, sequentially connects data points conforming to the range to draw a contour map, and finally realizes fine identification and division of a three-dimensional space of the complex soft and hard composite coal body region. According to the method, changes of four parameters in the drilling process of the drill bit are quantitatively coupled, inversion of physical structure properties of the drilled coal body is completed, and then fine identification and division of the soft and hard composite coal body area of the driving working face are achieved.

Description

Technical Field

[0001] The patent of this invention relates to the technical field of identification and division of coal and gas outburst danger areas, specifically a method for fine identification and division of soft and hard composite coal seams in the excavation working face. Background Art

[0002] Coal and gas outburst is one of the most serious dynamic disasters in the coal mining process, which seriously threatens the safe production of coal mines. Coal and gas outburst is an extremely complex coal-rock dynamic process. Stress, gas and coal's own characteristics are usually regarded as three important factors for the occurrence of disasters. According to the statistical analysis of existing outburst accidents, the geological structure zone is the key location for coal and gas outburst. The physical structure and basic characteristics of coal change under the influence of geological structure, providing important conditions for the occurrence of outburst accidents. Therefore, accurate identification and division of dangerous areas is a favorable guarantee for the precise measurement of coal and gas outburst areas and the formulation of targeted, regionalized and graded outburst prevention measures, thereby reducing the blindness of coal and gas outburst prevention and control work, improving the timeliness of work, ensuring safe and efficient production of mines, and effectively reducing the occurrence of coal and gas outburst disasters.

[0003] However, conventional coal and gas outburst prediction usually uses sensitive indicators such as drill cuttings or gas outburst initial velocity to predict outbursts in a certain area or local working face based on production conditions. There are often large outburst prediction ranges, imprecise monitoring ranges, small amounts of information, and omissions and false alarms, which make it impossible to accurately predict and divide outburst danger areas. Therefore, the present invention fully considers the differences in the inherent properties of the coal body in front during the advancement of the working face. During the drilling and detection process, the inversion calculation is performed based on the changes in drilling parameters, thereby revealing the characteristics of the structural parameters of the coal body in front of the working face, and realizing the refined identification and division of the soft and hard composite coal seams in the excavation working face. Summary of the invention

[0004] The purpose of this application is to provide a method for fine identification and division of soft and hard composite coal seams in an excavation working face to solve or alleviate the problems existing in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] The present application provides a method for fine identification and division of soft and hard composite coal seams in an excavation working face, characterized in that the method comprises the following steps:

[0007] The coal body in front of the S101 excavation face is affected by geological tectonic action, and is prone to complex coal seam structures such as soft-hard composite coal seams and coal seam thickness variation zones. In order to obtain the basic parameter characteristics of the coal body, drilling detection is used to directly touch the coal body;

[0008] S102 When the drill bit contacts the coal body, the drill bit starts drilling under power drive, and the speed meter in the drilling speed measuring module built into the drill bit receives the signal and starts to measure and record the drilling speed of the drill bit per unit time in real time. k At the same time, the gas pressure sensor in the drilling gas total flow module dynamically monitors the gas pressure value I at the point where the drill bit contacts the coal body in real time. p , and then get the total borehole gas flow rate I per unit time c ;

[0009] S103 During the drilling process, the coal body is broken by the drilling of the drill bit. The cuttings collector in the cuttings measuring module arranged at the drill bit position collects the cuttings and coal powder, and records the cuttings amount per unit drilling length in real time through the weight sensor. s ;

[0010] At S104, when the sensor in the flushing fluid loss module senses that liquid is flowing out, the liquid flow meter starts and records in real time the flushing fluid loss per unit time through the borehole during the drilling process. l ;

[0011] S105 Then, the drill bit drilling speed I recorded by each module is recorded in turn. k 、Total gas flow rate of drilling hole I c 、Drilling cuttings amount I s and flushing fluid loss I l The data set is transmitted to the index weight calculation module to complete the determination of the weight of each index parameter, and then the specific data value of the regional division comprehensive index I per unit time in the process of coal body drilling is obtained. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) (1); where I is the comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, where α+β+λ+μ=1;

[0012] S106 After all the holes in the mining face are drilled, the data set K of the comprehensive index I of regional division obtained during the drilling of each hole is transmitted to the regional division module, and the soft and hard composite coal body regions are identified and divided according to the value set of the built-in I parameter value range, so as to complete the refined quantitative identification and division of the soft and hard composite coal body regions in the complex coal seam based on the data point set K of the comprehensive index I of regional division.

[0013] Preferably, the drill bit is built with a drilling speed measurement module, a total gas flow module, a cuttings measurement module and a flushing fluid loss module, which are used to measure and obtain basic parameters of the coal body. The drilling speed measurement module consists of a speed meter, a data processor and a data storage device. The speed meter is mainly used to detect the speed fluctuation of the drill bit during drilling into the coal body, and to measure and record the drilling speed value of the drill bit in real time. k ; For the hard coal distribution area, the coal body strength is relatively large, and the drilling speed is relatively slow. For the soft coal distribution area affected by the geological structure, the coal quality is soft and the coal body strength is relatively small, so the drilling speed is significantly improved. When the drill bit passes through the boundary area between soft and hard coal, the drilling speed of the drill bit fluctuates greatly.

[0014] Preferably, the borehole gas total flow module mainly includes a gas pressure sensor, a data processor and a data storage device, wherein the gas pressure sensor is mainly used for real-time dynamic monitoring of the gas pressure I of the coal body contacted by the drill bit during drilling. p The real-time changes of the gas pressure value I p The value is transmitted to the data processor to obtain the total gas flow rate I per unit time in the borehole c ; Among them, the gas pressure I p and total borehole gas flow I c The conversion principle is as follows: During the drilling process, the coal seam gas flows radially under the driving force of the pressure difference. In a very short time, the gas flow in the coal seam can be regarded as a radial stable flow and obeys Darcy's law. Therefore, the gas flow rate per unit area can be expressed as: Where, λ is the permeability coefficient of coal seam, m 2 / (MPa 2 d); dp——pressure difference within the length dx, Pa; dr - the minimum length consistent with the flow direction, m. The gas pressure distribution relationship of radial stable field in coal seam is: Where, p0——coal seam gas pressure, MPa; p1——drilling gas pressure, MPa; R0——Gas source radius of the borehole, m; R1——drilling radius, m; Combining formula (1) and formula (2), we can get the gas radial steady flow equation: When the gas flows out through the borehole, r = R1, and the borehole gas flow rate can be expressed as: Where, m is the drilling distance per unit time, m.

[0015] Preferably, the cuttings amount measuring module comprises a cuttings collector, a weight sensor and a data storage device, wherein the cuttings collector is mainly used to collect cuttings and coal powder discharged during the drilling process of the drill bit, and the weight sensor can sense the weight of the cuttings in the cuttings collector in real time and record the cuttings amount of the drill bit within a unit drilling length in real time. s , and I s The value is transmitted to the data storage device in time; the amount of drill cuttings in the coal body of the excavation working face is mainly affected by four factors: the gas content of the drilled coal body, the size of the ground stress, the degree of coal body damage and the drill bit diameter. The drill bit diameter is a fixed value, and the amount of drill cuttings mainly depends on the gas content of the drilled coal body, the ground stress energy value and the degree of coal body damage. The above three influencing factors show significant differences between soft and hard coal bodies. For soft coal bodies affected by geological structures, the degree of damage is greater, the gas content and initial gas desorption are both greater, the ground stress energy value is higher, and the amount of drill cuttings per unit hole length is higher than that of primary coal. Based on this, the amount of drill cuttings I can be measured according to the drill bit built-in drill cuttings measurement module s The fluctuation of the value can accurately identify the transition area between soft and hard coal.

[0016] Preferably, the flushing fluid loss module mainly includes: a liquid flow meter, a data processor and a data storage device; the flushing fluid loss during the drilling process is directly related to the structural properties of the contacted coal body itself. When the coal body itself has a high degree of fissure development and good permeability, the flushing fluid loss during the drilling process is relatively large, while for low-permeability coal bodies with poor permeability, the flushing fluid loss is relatively small; the built-in liquid flow meter in the flushing fluid loss module can monitor the flushing fluid loss during the drilling process in real time, and then obtain the flushing fluid loss per unit time I through the borehole according to the calculation result of the data processor. l .

[0017] Preferably, the data processor built into the index weight calculation module determines the drilling speed I and the drilling speed I of the drill bit by using a hierarchical analysis method. k The weight value α, the total borehole gas flow I cThe weight value β, the amount of drill cuttings I s The weight value λ and the flushing fluid loss I l The weight value μ is used to obtain the specific data value of the comprehensive index I of regional division per unit time during the coal body drilling process. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) Where, I——comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, where α+β+λ+μ=1;

[0018] Preferably, the regional division module is mainly based on the regional division comprehensive index I data set K calculated by the index weight calculation module, and according to the set interval value of the I value range, the data points within the specified interval value are plotted as contour lines, thereby realizing accurate identification and division of soft and hard composite coal body areas based on the regional division comprehensive index I data point set K.

[0019] Preferably, the regional division comprehensive index I data set K is mainly composed of regional division index K obtained during different drilling processes. i The data subsets are composed of K (K1, K2, K3, K4, ...), and the regional division index K of different boreholes is i The data subset is obtained by calculating the data points I per unit time in each drilling process according to formula (1) i Composition, namely K i (I1, I2, I3, I4, ...); During the drilling process of the coal seam, due to the differences in the mechanical strength properties of the coal body, the composition of the coal body fracture structure, and the gas storage and transportation capacity of the coal body, the drill bit drilling speed I calculated by the built-in drilling speed measurement module is k , the total borehole gas flow rate I calculated by the borehole gas total flow rate module c , the amount of drilling cuttings I calculated by the drilling cuttings measurement module s The flushing fluid loss volume I calculated by the flushing fluid loss module lThere are significant differences. According to formula (1), the specific data points of the regional division comprehensive index I reflecting the characteristic parameters of the coal body itself at different positions in the same borehole drilling process under different drilling distances can be calculated. Based on this, the value interval range of the regional division comprehensive index I data point set K is set, and the regional division comprehensive index I that meets the interval range is i Contour maps are drawn in sequence according to the size of the data values, thereby realizing the connection of the data points of the regional division comprehensive index I at different drilling distances in the same borehole and between different boreholes, and finally realizing the refined identification and division of the three-dimensional space of the soft and hard composite coal body area in the complex coal seam.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention at least include:

[0021] The present invention provides a drilling speed measuring module, a drilling gas total flow module, a cuttings volume measuring module and a flushing fluid loss volume module in the drilling bit to obtain parameter data in real time during the drilling process; the drilling speed I recorded by each module is sequentially calculated. k 、Total gas flow rate of drilling hole I c 、Drilling cuttings amount I s and flushing fluid loss I l The data set is transmitted to the indicator weight calculation module to complete the determination of the weight of each indicator parameter, obtain the regional division comprehensive index I per unit time during the coal body drilling process, and realize the inversion of the basic properties of the coal body; the regional division module sets the value according to the built-in I parameter value range, and converts the regional division comprehensive index I that meets the interval range into i Contour maps are drawn in sequence according to the size of the data values, and then the data points of the regional division comprehensive index I at different drilling distances of the same borehole and between different boreholes are connected, finally realizing the refined identification and division of the soft and hard composite coal seams of the excavation working face, which has important practical significance for the accurate prediction of local areas of coal and gas outbursts and the accurate and efficient management of disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a flow chart of the method for fine identification of soft and hard composite coal body areas in complex coal seams of the present invention;

[0024] Figure 2 It is a schematic diagram of a device for fine identification of soft and hard composite coal body areas in a complex coal seam according to the present invention;

[0025] Figure 3 This is a schematic diagram of the regional division comprehensive indicator data set K of the present invention;

[0026] Figure 4 This is a schematic diagram of the division of the soft and hard composite coal body regions in a complex coal seam according to the present invention; DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the embodiments and drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “top”, “bottom”, “inside” and “outside” indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device, component or structure must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0029] The specific implementation method of the present invention will be further described below in conjunction with the accompanying drawings.

[0030] like Figure 1-4 As shown, a method for fine identification and division of soft and hard composite coal seams in an excavation working face is characterized in that the method comprises the following steps:

[0031] The coal body in front of the S101 excavation face is affected by geological tectonic action, and is prone to complex coal seam structures such as soft-hard composite coal seams and coal seam thickness variation zones. In order to obtain the basic parameter characteristics of the coal body, drilling detection is used to directly touch the coal body;

[0032] S102 When the drill bit contacts the coal body, the drill bit starts drilling under power drive, and the speed meter in the drilling speed measuring module built into the drill bit receives the signal and starts to measure and record the drilling speed of the drill bit per unit time in real time. k At the same time, the gas pressure sensor in the drilling gas total flow module dynamically monitors the gas pressure value I at the point where the drill bit contacts the coal body in real time. p , and then get the total borehole gas flow rate I per unit time c ;

[0033] S103 During the drilling process, the coal body is broken by the drilling of the drill bit. The cuttings collector in the cuttings measuring module arranged at the drill bit position collects the cuttings and coal powder, and records the cuttings amount per unit drilling length in real time through the weight sensor. s ;

[0034] At S104, when the sensor in the flushing fluid loss module senses that liquid is flowing out, the liquid flow meter starts and records in real time the flushing fluid loss per unit time through the borehole during the drilling process. l ;

[0035] S105 Then, the drill bit drilling speed I recorded by each module is recorded in turn. k 、Total gas flow rate of drilling hole I c 、Drilling cuttings amount I s and flushing fluid loss I l The data set is transmitted to the index weight calculation module to complete the determination of the weight of each index parameter, and then the specific data value of the regional division comprehensive index I per unit time in the process of coal body drilling is obtained. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) (1); Where, I——comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, where α+β+λ+μ=1;

[0036] S106 After all the holes in the mining face are drilled, the data set K of the comprehensive index I of regional division obtained during the drilling of each hole is transmitted to the regional division module, and the soft and hard composite coal body regions are identified and divided according to the value set of the built-in I parameter value range, so as to complete the refined quantitative identification and division of the soft and hard composite coal body regions in the complex coal seam based on the data point set K of the comprehensive index I of regional division.

[0037] like Figure 2As shown, the drill bit has built-in drilling speed measurement module, drilling gas total flow module, cuttings measurement module and flushing fluid loss module, which are used to measure and obtain basic parameters of coal body. The drilling speed measurement module consists of three parts: a speed meter, a data processor and a data storage device. The speed meter is mainly used to detect the speed fluctuation of the drill bit during drilling into the coal body, and to measure and record the drilling speed value of the drill bit in real time. k ; For the hard coal distribution area, the coal body strength is relatively large, and the drilling speed is relatively slow. For the soft coal distribution area affected by the geological structure, the coal quality is soft and the coal body strength is relatively small, so the drilling speed is significantly improved. When the drill bit passes through the boundary area between soft and hard coal, the drilling speed of the drill bit fluctuates greatly.

[0038] like Figure 2 As shown, the borehole gas total flow module mainly includes a gas pressure sensor, a data processor and a data storage device, wherein the gas pressure sensor is mainly used for real-time dynamic monitoring of the gas pressure I of the coal body contacted by the drill bit during drilling. p The real-time changes of the gas pressure value I p The value is transmitted to the data processor to obtain the total gas flow rate I per unit time in the borehole c ; Among them, the gas pressure I p and total borehole gas flow I c The conversion principle is as follows: During the drilling process, the coal seam gas flows radially under the driving force of the pressure difference. In a very short time, the gas flow in the coal seam can be regarded as a radial stable flow and obeys Darcy's law. Therefore, the gas flow rate per unit area can be expressed as: Where, λ is the permeability coefficient of coal seam, m 2 / (MPa 2 d); dp——pressure difference within the length dx, Pa: dr——the minimum length consistent with the flow direction, m. The gas pressure distribution relationship of radial stable field in coal seam is: Where, p0——coal seam gas pressure, MPa; p1——drilling gas pressure, MPa; R0——Gas source radius of the borehole, m; R1——drilling radius, m; Combining formula (1) and formula (2), we can get the gas radial steady flow equation: When the gas flows out through the borehole, r = R1, and the borehole gas flow rate can be expressed as: Where, m is the drilling distance per unit time, m.

[0039] like Figure 1-2 As shown, the drilling cuttings amount measuring module comprises a drilling cuttings collector, a weight sensor and a data storage device, wherein the drilling cuttings collector is mainly used to collect the drilling cuttings and coal powder discharged during the drilling process of the drill bit, and the weight sensor can sense the weight of the drilling cuttings in the drilling cuttings collector in real time and record the drilling cuttings amount per unit drilling length in real time. s , and I s The value is transmitted to the data storage device in time; the amount of drill cuttings in the coal body of the excavation working face is mainly affected by four factors: the gas content of the drilled coal body, the size of the ground stress, the degree of coal body damage and the drill bit diameter. The drill bit diameter is a fixed value, and the amount of drill cuttings mainly depends on the gas content of the drilled coal body, the ground stress energy value and the degree of coal body damage. The above three influencing factors show significant differences between soft and hard coal bodies. For soft coal bodies affected by geological structures, the degree of damage is greater, the gas content and initial gas desorption are both greater, the ground stress energy value is higher, and the amount of drill cuttings per unit hole length is higher than that of primary coal. Based on this, the amount of drill cuttings I can be measured according to the drill bit built-in drill cuttings measurement module s The fluctuation of the value can accurately identify the transition area between soft and hard coal.

[0040] like Figure 2 As shown in FIG. 1 , the flushing fluid loss module mainly includes: a liquid flow meter, a data processor and a data storage device; the flushing fluid loss during the drilling process is directly related to the structural properties of the contacted coal body itself. When the coal body itself has a high degree of fissure development and good permeability, the flushing fluid loss during the drilling process is relatively large, while for low-permeability coal bodies with poor permeability, the flushing fluid loss is relatively small; the built-in liquid flow meter in the flushing fluid loss module can monitor the flushing fluid loss during the drilling process in real time, and then obtain the flushing fluid loss per unit time I through the borehole according to the calculation result of the data processor. l .

[0041] like Figure 1-2 As shown, the data processor built into the index weight calculation module determines the drilling speed I and k The weight value α, the total borehole gas flow I c The weight value β, the amount of drill cuttings I s The weight value λ and the flushing fluid loss I l The weight value μ is used to obtain the specific data value of the comprehensive index I of regional division per unit time during the coal body drilling process. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) Where, I——comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, where α+β+λ+μ=1;

[0042] like Figure 2-4 As shown, the regional division module is mainly based on the regional division comprehensive index I data set K calculated by the index weight calculation module. According to the set interval value of the I value range, the data points within the specified interval value are plotted as contour lines, thereby realizing the accurate identification and division of the soft and hard composite coal body area based on the regional division comprehensive index I data point set K.

[0043] like Figure 1-4 As shown, the regional division comprehensive index I dataset K is mainly composed of regional division index K obtained during different drilling processes. i The data subsets are composed of K (K1, K2, K3, K4, ...), and the regional division index K of different boreholes is i The data subset is obtained by calculating the data points I per unit time in each drilling process according to formula (1) i Composition, namely K i (I1, I2, I3, I4, ...); During the drilling process of the coal seam, due to the differences in the mechanical strength properties of the coal body, the composition of the coal body fracture structure, and the gas storage and transportation capacity of the coal body, the drill bit drilling speed I calculated by the drill bit built-in drilling speed measurement module is k , the total borehole gas flow rate I calculated by the borehole gas total flow rate module c , the amount of drilling cuttings I calculated by the drilling cuttings measurement module s The flushing fluid loss volume I calculated by the flushing fluid loss module lThere are significant differences. According to formula (1), the specific data points of the regional division comprehensive index I reflecting the characteristic parameters of the coal body itself at different positions in the same borehole drilling process under different drilling distances can be calculated. Based on this, the value interval range of the regional division comprehensive index I data point set K is set, and the regional division comprehensive index I data point I that meets the interval range is set. i Contour maps are drawn in sequence according to the size of the data values, thereby realizing the connection of the data points of the comprehensive index I for regional division at different drilling distances in the same borehole and between different boreholes, and finally realizing the refined identification and division of the three-dimensional space of the soft and hard composite coal body area of ​​complex coal seams and gas.

[0044] At this point, those skilled in the art should recognize that, although the exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A method for fine identification and division of soft and hard composite coal seams in an excavation working face, characterized in that: The method comprises the following steps: The coal body in front of the S101 excavation face is affected by geological tectonic action, and is prone to complex coal seam structures such as soft-hard composite coal seams and coal seam thickness variation zones. In order to obtain the basic parameter characteristics of the coal body, drilling detection is used to directly touch the coal body; S102 When the drill bit contacts the coal body, the drill bit starts drilling under power drive, and the speed meter in the drilling speed measuring module built into the drill bit receives the signal and starts to measure and record the drilling speed of the drill bit per unit time in real time. k At the same time, the gas pressure sensor in the drilling gas total flow module dynamically monitors the gas pressure value I at the point where the drill bit contacts the coal body in real time. p , and then get the total borehole gas flow rate I per unit time c ; S103 During the drilling process, the coal body is broken by the drilling of the drill bit. The cuttings collector in the cuttings measuring module arranged at the drill bit position collects the cuttings and coal powder, and records the cuttings amount per unit drilling length in real time through the weight sensor. s ; At S104, when the sensor in the flushing fluid loss module senses that liquid is flowing out, the liquid flow meter starts and records in real time the flushing fluid loss per unit time through the borehole during the drilling process. l ; S105 Then, the drill bit drilling speed I recorded by each module is recorded in turn. k 、Total gas flow rate of drilling hole I c 、Drilling cuttings amount I s and flushing fluid loss I l The data set is transmitted to the index weight calculation module to complete the determination of the weight of each index parameter, and then the specific data value of the regional division comprehensive index I per unit time in the process of coal body drilling is obtained. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) (1); Where, I——comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, where α+β+λ+μ=1; S106 When all the boreholes in the mining face have been drilled, the data set K of the regional division comprehensive index I obtained during the drilling process of each borehole is transmitted to the regional division module, and the soft-hard composite coal body region is identified and divided according to the value set of the built-in I parameter value range, so as to complete the refined quantitative identification and division of the soft-hard composite coal body region of the complex coal seam based on the data point set K of the regional division comprehensive index I as the basic division basis; The method for finely identifying and dividing soft and hard composite coal seams in an excavation working face is completed by relying on a device for finely identifying and dividing soft and hard composite coal seams in an excavation working face, and is characterized in that the device mainly includes a drilling speed measurement module, a total borehole gas flow module, a drill cuttings measurement module, a flushing fluid loss module, an indicator weight calculation module and an area division module.

2. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized by: The drill bit has built-in drilling speed measurement module, drilling gas total flow module, cuttings measurement module and flushing fluid loss module, which are used to measure and obtain basic parameters of coal body. The drilling speed measurement module consists of three parts: a speed meter, a data processor and a data storage device. The speed meter is mainly used to detect the speed fluctuation of the drill bit during drilling into the coal body, and to measure and record the drilling speed value of the drill bit in real time. k ; For the hard coal distribution area, the coal body strength is relatively large, and the drilling speed is relatively slow. For the soft coal distribution area affected by the geological structure, the coal quality is soft and the coal body strength is relatively small, so the drilling speed is significantly improved. When the drill bit passes through the boundary area between soft and hard coal, the drilling speed of the drill bit fluctuates greatly.

3. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized by: The drilling gas total flow module mainly includes a gas pressure sensor, a data processor and a data storage device, wherein the gas pressure sensor is mainly used for real-time dynamic monitoring of the gas pressure of the coal body contacted by the drill bit during drilling. p The real-time changes of the gas pressure value I p The value is transmitted to the data processor to obtain the total gas flow rate I per unit time in the borehole c ; Among them, the gas pressure I p and total borehole gas flow I c The conversion principle is as follows: During the drilling process, the coal seam gas flows radially under the driving force of the pressure difference. In a very short time, the gas flow in the coal seam can be regarded as a radial stable flow and obeys Darcy's law. Therefore, the gas flow rate per unit area can be expressed as: Where, λ is the permeability coefficient of coal seam, m 2 / (MPa 2 d); dp——pressure difference within the length dx, Pa; dr——the minimum length consistent with the flow direction, m. The gas pressure distribution relationship of radial stable field in coal seam is: Where, p0——coal seam gas pressure, MPa; p1——drilling gas pressure, MPa; R0——Gas source radius of the borehole, m; R1——drilling radius, m; Combining formula (2) and formula (3), we can get the gas radial steady flow equation: When the gas flows out through the borehole, r = R1, and the borehole gas flow rate can be expressed as: Where, m is the drilling distance per unit time, m.

4. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized in that: The drilling cuttings amount measuring module comprises a drilling cuttings collector, a weight sensor and a data storage device. The drilling cuttings collector is mainly used to collect the drilling cuttings and coal powder discharged during the drilling process of the drill bit. The weight sensor can sense the weight of the drilling cuttings in the drilling cuttings collector in real time and record the drilling cuttings amount per unit drilling length in real time. s , and I s The value is transmitted to the data storage device in time; the amount of drill cuttings of the coal body at the excavation working face is mainly affected by four factors: the gas content of the drilled coal body, the size of the ground stress, the degree of coal body damage and the drill bit diameter. The drill bit diameter is a fixed value, and the amount of drill cuttings mainly depends on the gas content of the drilled coal body, the ground stress energy value and the degree of coal body damage. The above three influencing factors show significant differences for soft and hard coal bodies. For soft coal bodies affected by geological structures, the degree of damage is greater, the gas content and initial gas desorption are both greater, the ground stress energy value is higher, and the amount of drill cuttings per unit hole length is higher than that of primary coal. Based on this, the amount of drill cuttings I can be measured according to the drill bit built-in drill cuttings measurement module s The fluctuation of the value can accurately identify the transition area between soft and hard coal.

5. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized by: The flushing fluid loss module mainly includes: a liquid flow meter, a data processor and a data storage device; the flushing fluid loss during the drilling process is directly related to the structural properties of the contacted coal body itself. When the coal body itself has a high degree of crack development and good permeability, the flushing fluid loss during the drilling process is relatively large, while for low-permeability coal bodies with poor permeability, the flushing fluid loss is relatively small; the built-in liquid flow meter in the flushing fluid loss module can monitor the flushing fluid loss during the drilling process in real time, and then obtain the flushing fluid loss per unit time I through the borehole according to the calculation result of the data processor. l。 6. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized by: The data processor built into the index weight calculation module determines the drilling speed I and the drilling speed I of the drill bit by using the hierarchical analysis method. k The weight value α, the total borehole gas flow I c The weight value β, the amount of drill cuttings I s The weight value λ and the flushing fluid loss I l The weight value μ is used to obtain the specific data value of the comprehensive index I of regional division per unit time during the coal body drilling process. The expression of I is as follows: I=ξ(αI k +βI c +λI s +μI l ) Where, I——comprehensive index of regional division; I k ——Drilling speed, m / min; I c ——Total gas flow rate in drilling hole, mL / min; I s ——drill cuttings, kg / m; I l ——Flushing fluid leakage, mL / min; ξ——comprehensive index coefficient of regional division; α, β, λ, μ——weight coefficients of each sub-indicator, among which α+β+λ+μ=1.

7. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 1 is characterized by: The regional division module is mainly based on the regional division comprehensive index I data set K calculated by the index weight calculation module. According to the set interval value of the I value range, the data points within the specified interval value are plotted as contour lines, thereby realizing the accurate identification and division of the soft and hard composite coal body area based on the regional division comprehensive index I data point set K.

8. The method for fine identification and division of soft and hard composite coal seams in an excavation working face according to claim 7 is characterized in that: The regional division comprehensive index I dataset K is mainly composed of the regional division index K obtained during the drilling process of different boreholes. i The data subsets are composed of K (K1, K2, K3, K4, ...), and the regional division index K of different boreholes is i The data subset is obtained by calculating the data points I per unit time in each drilling process according to formula (1) i Composition, namely K i (I1, I2, I3, I4, ...); During the drilling process of the coal seam, due to the differences in the mechanical strength properties of the coal body, the composition of the coal body fracture structure, and the gas storage and transportation capacity of the coal body, the drill bit drilling speed I calculated by the drill bit built-in drilling speed measurement module is k , the total borehole gas flow rate I calculated by the borehole gas total flow rate module c , the amount of drilling cuttings I calculated by the drilling cuttings measurement module s The flushing fluid loss volume I calculated by the flushing fluid loss module l There are significant differences. According to formula (1), the specific data points I of the regional division comprehensive index I reflecting the characteristic parameters of the coal body itself at different positions in the same borehole drilling process under different drilling distances can be calculated. i Based on this, the value interval range of the regional division comprehensive index I data point set K is set, and the regional division comprehensive index I that meets the interval range is set. i Contour maps are drawn in sequence according to the size of the data values, and then the connection of the data points of the regional division comprehensive index I at different drilling distances in the same borehole and between different boreholes is completed, finally realizing the refined identification and division of the three-dimensional space of the soft and hard composite coal body area in the complex coal seam.

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