Mine stope face gas concentration early warning method based on pre-drainage roadway extraction drill hole

Abstract

The invention relates to a mine stope face gas concentration early warning method based on pre-drainage roadway extraction drill holes, which comprises a data acquisition module, a gas concentration analysis module and a gas over-limit early warning module, and is characterized in that the data acquisition module collects single-hole accurate measurement data of the gas extraction drill holes in a working face extraction process; the gas concentration analysis module carries out corresponding fitting analysis on the collected single-hole accurate metering data of the gas extraction drill hole and the ground stress while-drilling monitoring data to obtain a gas concentration early warning index; and the gas over-limit early warning module carries out cooperative early warning on gas over-limit accidents in the recovery process according to the fitting result. According to the invention, real-time early warning of gas overrun of the mining roadway is realized, and the production safety of a mine is effectively ensured.

Description

Technical Field

[0001] The invention relates to the technical field of gas disaster prediction, and in particular to a gas concentration early warning method for a mine recovery working face based on pre-extraction laneway extraction drilling. Background Art

[0002] Coal energy is still the main component of my country's energy structure. Due to the special geological environment in my country, coal mining is mostly carried out in underground mining mode. Most mines contain gas, and more than half of them have a large amount of gas or gas outburst problems. In addition, the spatial density of coal is large, the permeability between coal seams is low, and it is not easy to extract before mining, so gas disasters are very likely to occur during mining. Coal mine gas overlimit is an abnormal phenomenon in which the gas concentration in the underground working environment of coal mines exceeds the prescribed safety limit. Gas overlimit is likely to cause catastrophic accidents such as coal and gas outbursts and gas explosions. Therefore, avoiding underground gas accumulation or gas overlimit is a key link in preventing and controlling coal and gas outbursts and gas explosions, and it is also a necessary means to provide workers with a good working environment. In order to prevent such accidents, coal mines are generally equipped with safety monitoring systems to realize online monitoring of environmental gas concentrations in key areas underground, as well as automatic alarms after gas overlimit.

[0003] The prevention and control of gas over-limit is a key link in the prevention and control of gas disasters in coal mines. However, there are many factors affecting gas disasters, the causes are complex and they are prone to forming coupled disasters. The existing safety monitoring system has problems such as single measurement parameters, inaccurate measurements and untimely responses. Therefore, there is an urgent need for a method to intelligently predict the gas concentration over-limit in the working face. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a gas concentration early warning method for the coal mine recovery working face based on the pre-extraction drilling holes. Through the intelligent analysis of the high-precision low gas flow monitoring data of the extraction drilling holes, a non-contact continuous intelligent early warning of the risk of gas exceeding the limit in the coal mine recovery working face is realized, which is conducive to the advanced prevention and control of coal mine gas accidents.

[0005] The object of the present invention is achieved in that: A gas concentration early warning method for a mine recovery working face based on pre-extraction drilling holes includes the following contents: S1, using the pre-extraction tunnel to extract the borehole; Use a drilling rig to drill through the coal seam in the drilling field of the high extraction roadway or the bottom extraction roadway. The drilling position is the entire extraction working face, including the 15 m outside the roadway contour line of the two extraction working face roadways on the extraction working face. S2. Install single-hole gas precision meter and drilling ground stress measuring instrument; Install single-hole gas precision meter and drilling ground stress measuring instrument for all through-layer boreholes within 3 drilling sites ahead of the current coal mining machine location; S3, install gas concentration analysis module, ground stress analysis module and gas over-limit warning module; The drilling rig is connected to the gas over-limit warning module, which is respectively connected to the ground stress analysis module and the gas concentration analysis module, which is connected to each while-drilling ground stress measuring instrument, and the gas concentration analysis module is connected to each single-hole gas precision meter, thereby obtaining the gas single-hole precision metering data and the while-drilling ground stress measurement data in real time while extracting gas; S4. Obtain gas monitoring data of at least three drilling sites of the leading coal mining machine in the entire mining face in real time, including the 15 m range outside the contour lines of the two tunnels; S5. Extract the current gas monitoring value M t Before the current time T 1 , T 2 Gas monitoring data for a certain period of time; S6. According to T Gas monitoring data for a period of time, gas concentration analysis module calculation indicators N t ; index N t is the average value of the gas monitoring data in the T1 period before the current moment, and the calculation method is: ; Gas short-term over-limit warning threshold N 0 Get the time before the current time T 1 Indicators for time periods N t ; S7. According to T Gas monitoring data for 2 time periods, gas concentration analysis module calculation indicators P t ; index P t The calculation method is: index P t Before the current time T 2 The average value of gas monitoring data in a time period is calculated as follows: ; in, y i forT 2. Gas monitoring data of the working face at different times within a time period; v is the working face advancement speed; l is the working face advancement distance; S8, when the indicator N t Greater than threshold N 0:00, a short-term warning of gas exceeding the limit is issued; when the gas monitoring value M t Greater than threshold M At 0:00, an emergency warning for gas exceeding the limit is issued; S9. As the working face advances, repeat steps S5 to S8 to issue dynamic real-time warnings for excessive gas concentrations at the working face.

[0006] Furthermore, the spacing of the through-layer drilling holes in step S1 is 2R, where R is the drilling extraction radius.

[0007] Furthermore, in step S1, a drilling site is arranged every 4 to 6 rows of through-layer drilling holes, and the distance between the drilling sites does not exceed 10 m.

[0008] Furthermore, the single-hole gas precision meter in step S2 is set in the middle of the through-layer borehole, and the drilling stress measuring instrument is set on the mining working face.

[0009] Furthermore, in step S5, the time period T 1 is 10~15 min; time period T 2 Determined according to the advancement speed of the working face.

[0010] Further, in step S6, this step is repeated continuously. If the indicator N t Greater than N 0, a short-term warning of gas exceeding the limit lasting 10 to 15 minutes is issued; if there are two or more consecutive short-term warnings of gas exceeding the limit, the gas electric interlocking operation is immediately implemented, the power supply of the coal mining machine is cut off, and the coal mining machine stops working.

[0011] Furthermore, in step S8, the threshold M 0 before the current time T 2 Average value of gas monitoring data in the time period P t 200% of, that is: ; If the current gas monitoring value M t Greater than M 0, an emergency warning of gas exceeding the limit is issued, and the gas-electric interlock operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine.

[0012] Furthermore, the gas concentration range obtained by the single-hole gas precise metering data is 0~100%.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention realizes in-depth mining of mine gas monitoring data and ground stress while drilling monitoring data. Through real-time monitoring and analysis of gas parameters of at least three drilling sites of the advance coal mining machine in the mining face (including the range of 15 m outside the contour lines of the two tunnels), single-hole precise measurement of gas extraction boreholes is realized, and real-time early warning of excessive gas concentration in the mining tunnel is realized, effectively ensuring the production safety of the mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the layout inside the drilling site of Example 1 of the present invention.

[0015] Figure 2 This is a schematic plan view of the hole arrangement of Example 1 of the present invention.

[0016] Figure 3 It is the front view of the hole arrangement of embodiment 1 of the present invention.

[0017] Figure 4 It is a side view of the hole arrangement of embodiment 1 of the present invention.

[0018] Figure 5 This is a schematic diagram of the layout inside the drilling site of Example 2 of the present invention.

[0019] Figure 6 This is a schematic plan view of the hole arrangement of Example 2 of the present invention.

[0020] Figure 7 This is a front view of the hole arrangement of embodiment 2 of the present invention.

[0021] Figure 8 It is a side view of the hole arrangement of embodiment 2 of the present invention.

[0022] in: High-extraction lane 1, drilling site 2, coal seam 3, mining face 4, through-layer drill hole 5, mining face lane 6, single-hole gas precision meter 7, drilling-while-drilling ground stress measuring instrument 8, drilling rig 9, ground stress analysis module 10, gas concentration analysis module 11, gas over-limit warning module 12, bottom extraction lane 13. DETAILED DESCRIPTION

[0023] In order to better understand the technical solution of the present invention, the following will be described in detail in conjunction with the relevant illustrations. It should be understood that the following specific embodiments are not intended to limit the specific implementation of the technical solution of the present invention, and are only implementations that can be adopted by the technical solution of the present invention. It should be noted that the description of the positional relationship of each component in this article, such as component A being located above component B, is based on the description of the relative positions of the components in the illustration, and is not intended to limit the actual positional relationship of the components.

[0024] Embodiment 1: See also Figure 1-Figure 4 , Figure 1 A schematic diagram of the internal layout of a drilling site of a method for early warning of gas concentration in a mine recovery working face based on pre-extraction lane extraction drilling holes is drawn. As shown in the figure, a method for early warning of gas concentration in a mine recovery working face based on pre-extraction lane extraction drilling holes of this embodiment 1 includes the following contents: S1, use high extraction lane 1 to extract the borehole; A drilling rig 9 is used to construct a through-layer borehole 5 from the drilling site 2 of the high extraction roadway 1 to the mining face 4 arranged in the coal seam 3. The hole arrangement position is the entire mining face 4, including the range of 15 m outside the roadway contour line of the two mining face roadways 6 on the mining face 4. The hole arrangement spacing is 2R, R is the drilling extraction radius, and R is 2m in this embodiment 1; A drilling site 2 is arranged every 4 to 6 rows of through-layer drill holes 5, and the spacing between the drilling sites 2 is generally not more than 10 m. In this embodiment 1, one drilling site 2 is arranged every 4 rows of through-layer drill holes 5; S2, installing a single-hole gas precision meter 7 and a drilling-while-drilling ground stress measuring instrument 8; Install a single-hole gas precision meter 7 and a drilling-while-drilling ground stress measuring instrument 8 for all the through-layer boreholes 5 within the range of three drilling sites ahead of the current position of the coal mining machine; the single-hole gas precision meter 7 is set in the middle of the through-layer borehole 5, and the drilling-while-drilling ground stress measuring instrument 8 is set on the mining working face 4; S3, installing a gas concentration analysis module 11, a ground stress analysis module 10 and a gas over-limit warning module 12; The drilling rig 9 is connected to the gas over-limit warning module 12, and the gas over-limit warning module 12 is respectively connected to the ground stress analysis module 10 and the gas concentration analysis module 11, the ground stress analysis module 10 is connected to each drilling ground stress measuring instrument 8, and the gas concentration analysis module 11 is connected to each single-hole gas precision meter 7, thereby obtaining real-time gas single-hole precise metering data and ground stress drilling measurement data while extracting gas.

[0025] The single-hole gas precision meter 7 and the drilling ground stress measuring instrument 8 are data acquisition modules, which collect borehole gas parameter data (i.e., gas extraction drilling single-hole precision metering data) and ground stress drilling measurement data during the working face recovery process; the gas concentration analysis module 11 and the ground stress analysis module 10 perform corresponding fitting analysis on the collected gas extraction drilling single-hole precision metering data and ground stress drilling monitoring data to obtain gas and ground stress early warning indicators; the gas over-limit early warning module 12 coordinates the early warning of gas over-limit accidents during the recovery process based on the fitting results.

[0026] The data acquisition module is used to collect monitoring data, provide basic early warning data for other modules, and connect with the corresponding analysis module through wireless sensors; The gas concentration analysis module 11 is mainly used to analyze the changes in the gas concentration characteristics of the mining face in real time, and predict the gas concentration sequence of the mining face in the future, obtain the real-time change curve of the ultra-low gas concentration and the predicted curve of the gas concentration change and the maximum value of the future gas concentration, and obtain the prediction index of the gas concentration; the gas concentration analysis module 11 can use the YZC6 gas drainage pipeline multi-parameter measuring instrument software (2023SR1201469) on the market; The geostress analysis module 10 is mainly used to analyze the changes in the geostress of hard and soft rocks, and calculate the in-situ geostress of soft and hard rocks by combining the output energy of the drilling rig, the amount of drill cuttings and the particle size distribution of drill cuttings during the drilling process, so as to obtain the in-situ geostress change curve and the prediction curve as well as the maximum value of the future geostress, and obtain the prediction index of the geostress while drilling; the geostress analysis module 10 can adopt the YZC6 gas drainage pipeline multi-parameter measuring instrument software (2023SR1201469), and can also refer to a downhole geostress measurement system while drilling provided by Chinese patent CN202322197718.1; The gas over-limit warning module 12 performs gas over-limit risk identification based on the gas concentration analysis module 11 and the ground stress analysis module 10 and provides a warning result of the gas over-limit risk.

[0027] S4. Obtain gas monitoring data of at least three drilling sites of the leading coal mining machine in the mining face (including the 15 m range outside the two tunnel contours) in real time; the gas concentration range of the single-hole gas precise measurement data is 0~100%; S5. Extract the current gas monitoring value M t Before the current time T 1 , T 2 Gas monitoring data for a certain period of time; The time period T1 is 10~15 min; time period T 2. Determined according to the advancing speed of the working face; S6. According to T Gas monitoring data for a period of time, gas concentration analysis module calculation indicators N t ; index N t is the average value of the gas monitoring data in the T1 period before the current moment, and the calculation method is: ; Gas short-term over-limit warning threshold N 0 Get the time before the current time T 1 Indicators for time periods N t If the indicator N t Greater than threshold N 0, a 10-15 minute short-term warning of gas exceeding the limit is issued; this step is repeated continuously. If there are two or more consecutive short-term warnings of gas exceeding the limit, the gas electric interlock operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine; S7. According to T Gas monitoring data for 2 time periods, gas concentration analysis module calculates the calculation index P t ; index P t Before the current time T 2 The average value of gas monitoring data in a time period is calculated as follows: ; in, y i for T 2. Gas monitoring data of the working face at different times within a time period; v is the working face advancement speed; l The working face advancement distance is generally 15~30 m; S8, when the indicator N t Greater than threshold N 0:00, a short-term warning of gas exceeding the limit is issued; when the gas monitoring value M t Greater than threshold M At 0:00, an emergency warning for gas exceeding the limit is issued; Threshold M 0 before the current time T 2Average value of gas monitoring data in the time period P t 200% of, that is: ; like M t Greater than M If the gas exceeds the limit, an emergency warning is issued, and the gas-electric interlock operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine; S9. As the working face advances, repeat steps S5 to S8 to issue dynamic real-time warnings for excessive gas concentrations at the working face.

[0028] In this embodiment 1, T 1 Take 15min, T 2 Take 3 days and calculate N t =17.8%, P t =19.55%, M t =15.1%, M 0=39.1%.

[0029] The early warning of geostress measurement while drilling includes the following contents: S1. Drill holes in the coal seam high-drawn lanes to obtain real-time ground stress monitoring data Z of at least three drilling sites of the leading coal mining machine in the mining working face (including the 15m range outside the two lane contours), and extract the data before the current time. T 1. T 2. Monitoring the in-situ stress of the coal seam roof strata during the time period while drilling, and collecting drill cuttings; T 1 is 10~15 min; time period T 2. Determined according to the advancing speed of the working face; S2, as the mining face advances, step S2 is continuously repeated; according to T 2 The in-situ ... α t and send the above indicators to the ground for backup; When the in-situ ground stress monitoring data Z of the rock formation to be measured is greater than the threshold α 0, carry out emergency warning of gas exceeding limit. After the warning is triggered, the gas-electric interlocking operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working; α t and α 0The calculation method is: ; in,z i for T 2 In-situ ground stress monitoring data of rock formations in different boreholes over a period of time; v is the working face advancement speed; l The distance of the working face advancement.

[0030] In this embodiment 1, α t =12.1 MPa, α 0=24.2 MPa.

[0031] During the mining process of the working face, the layout of the extraction drill holes is the entire mining working face (including the 15 m range outside the contour lines of the two tunnels). The installation position of the intelligent early warning system for excessive gas limit in this embodiment is all the through-layer drill holes within the range of 3 drilling sites ahead of the current position of the coal mining machine. When the coal mining machine advances past the drilling site, the intelligent early warning system for excessive gas limit in this embodiment can be removed and moved to the drilling site behind, so that the intelligent early warning system for excessive gas limit always covers all the through-layer drill holes within the range of 3 drilling sites ahead of the current position of the coal mining machine.

[0032] Embodiment 2: See also Figure 5-Figure 8 , Figure 5 A layout diagram of the inside of a drilling site of a method for early warning of gas concentration in a mine recovery working face based on pre-extraction lane extraction drilling holes is drawn. As shown in the figure, the method for early warning of gas concentration in a mine recovery working face based on pre-extraction lane extraction drilling holes of this embodiment 2 is different from that of embodiment 1 in that: In the present embodiment 2, a bottom extraction tunnel 13 is used for extraction drilling, and a drilling rig 9 is used from the drilling site 2 of the bottom extraction tunnel 13 to construct a through-layer drilling hole 5 toward the recovery working face 4 arranged in the coal seam 3.

[0033] Working principle: The present invention provides a method for warning gas concentration of a mine recovery working face based on pre-extraction drilling holes, which uses single-hole gas metering data to coordinate warning of gas over-limit accidents in the recovery working face; through-layer drilling is constructed from a high-extraction lane or a bottom-extraction lane (gas pre-extraction lane) to the recovery working face, and a single-hole gas precision meter is installed; the single-hole gas data of the recovery working face is acquired in real time, and the gas over-limit threshold is fit-analyzed by a gas concentration analysis module and compared with the real-time monitoring data, and then the gas over-limit warning module is used to coordinate warning of gas concentration over-limit accidents in the mine recovery working face.

[0034] The above are only specific application examples of the present invention and do not constitute any limitation on the protection scope of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the present invention.

Claims

1. A method for early warning of gas concentration in a mine working face based on pre-extraction drilling, characterized in that: Includes the following: S1, using the pre-extraction tunnel to extract the borehole; Use a drilling rig to drill through the coal seam in the drilling field of the high extraction roadway or the bottom extraction roadway. The drilling position is the entire extraction working face, including the 15m outside the roadway contour line of the two extraction working face roadways on the extraction working face; S2. Install single-hole gas precision meter and drilling ground stress measuring instrument; Install single-hole gas precision meter and drilling ground stress measuring instrument for all through-layer boreholes within 3 drilling sites ahead of the current coal mining machine location; S3, install gas concentration analysis module, ground stress analysis module and gas over-limit warning module; The drilling rig is connected to the gas over-limit warning module, which is respectively connected to the ground stress analysis module and the gas concentration analysis module, which is connected to each while-drilling ground stress measuring instrument, and the gas concentration analysis module is connected to each single-hole gas precision meter, thereby obtaining the gas single-hole precision metering data and the while-drilling ground stress measurement data in real time while extracting gas; S4. Obtain gas monitoring data of at least three drilling sites of the leading coal mining machine in the entire mining face in real time, including the 15 m range outside the contour lines of the two tunnels; S5. Extract the current gas monitoring value M t Before the current time T 1 , T 2 Gas monitoring data for a certain period of time; S6. According to T Gas monitoring data for a period of time, gas concentration analysis module calculation indicators N t ; index N t is the average value of gas monitoring data in the T1 period before the current moment. N t The calculation method is: ； Gas short-term over-limit warning threshold N 0 Get the time before the current time T 1 Indicators for time periods N t ; S7. According to T Gas monitoring data for 2 time periods, gas concentration analysis module calculation indicators P t ; index P t Before the current time T 2 Average value of gas monitoring data in a certain period of time, index P t The calculation method is: ； in, y i for T 2. Gas monitoring data of the working face at different times within a time period; v is the working face advancement speed; l is the working face advancement distance; S8, when the indicator N t Greater than threshold N 0:00, a short-term warning of gas exceeding the limit is issued; when the gas monitoring value M t Greater than threshold M At 0:00, an emergency warning for gas exceeding the limit is issued; S9. As the working face advances, repeat steps S5 to S8 to issue dynamic real-time warnings for excessive gas concentrations at the working face.

2. A method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1, characterized in that: In step S1, the spacing of the through-layer drilling holes is 2R, where R is the drilling extraction radius.

3. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized in that: In step S1, a drilling site is arranged every 4 to 6 rows of through-layer drilling holes, and the distance between the drilling sites does not exceed 10 m.

4. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized in that: The single-hole gas precision meter described in step S2 is set in the middle of the through-layer borehole, and the drilling stress measuring instrument is set on the mining working face.

5. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized in that: The time period in step S5 T 1 is 10~15 min; time period T 2 Determined according to the advancement speed of the working face.

6. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized by: In step S6, this step is repeated continuously. If the indicator N t Greater than threshold N 0, a short-term warning of gas exceeding the limit for 10 to 15 minutes is issued; If there are two or more consecutive short-term gas over-limit warnings, the gas-electric interlock operation will be immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working.

7. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized by: In step S8, the threshold M 0 before the current time T 2 Average value of gas monitoring data in the time period P t 200% of, that is: ； If the current gas monitoring value M t Greater than M 0, an emergency warning of gas exceeding the limit is issued, and the gas-electric interlock operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine.

8. The method for early warning of gas concentration in a mine working face based on pre-extraction drilling according to claim 1 is characterized by: The gas concentration range of the single-hole gas precise metering data is 0~100%.

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