Coal roadway driving face gas concentration early warning method based on pre-drainage roadway extraction drill hole

Abstract

The invention relates to a coal roadway driving face gas concentration early warning method based on a pre-drainage roadway extraction drill hole. A data acquisition system (single-hole gas accurate metering), a gas concentration analysis module, a ground stress analysis module and a gas over-limit early warning module are included. The method comprises the following steps: acquiring the gas concentration of a coal roadway driving working face in real time, extracting a gas monitoring value Mt at the current moment and gas monitoring data in time periods T1 and T2 before the current moment, and extracting coal seam roof rock stratum crustal stress while-drilling monitoring data; calculating gas monitoring indexes Nt and Pt; and when the index Nt is greater than the threshold value N0, performing short-term early warning on gas overrun. Dynamic intelligent early warning of gas concentration overrun of the coal roadway driving face is achieved, and safe production of a coal mine is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of gas disaster prediction, and in particular to a method for early warning of gas concentration in a coal tunneling working face based on pre-drainage tunnel extraction drilling holes. Background Art

[0002] Affected by factors such as burial depth, high ground stress, and high ground temperature, deep coal mining faces a series of problems such as increased gas outburst, increased gas pressure, and sudden abnormal outburst of local gas, which directly lead to the increased threat of gas disasters to the mine. Coal mine gas outburst accidents mainly occur at the coal tunnel excavation working face. Coal mine gas overlimit is an abnormal phenomenon in which the gas concentration in the underground working environment of the coal mine exceeds the prescribed safety limit. Gas overlimit is likely to cause catastrophic accidents such as coal and gas outburst and gas explosion. Therefore, avoiding underground gas accumulation or gas overlimit is a key link in preventing and controlling coal and gas outburst and gas explosion, 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 concentration in key areas underground, as well as automatic alarm 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, gas disasters are affected by many factors, the causes are complex, and they are prone to coupled disasters. Existing gas concentration monitoring equipment and methods cannot achieve accurate early warning of gas disasters, and there are problems such as single measurement parameters, inaccurate measurements, and untimely responses. Therefore, there is an urgent need for a method to combine various gas monitoring data to intelligently predict the over-limit of gas concentration 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 coal mine excavation working face based on pre-extraction drilling holes. Through intelligent analysis of high-precision low gas flow monitoring data of extraction drilling holes and ground stress drilling monitoring data, non-contact continuous intelligent early warning of the risk of excessive gas concentration in coal mine excavation working face is achieved, 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 method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel extraction drilling, comprising the following contents: S1, using the pre-extraction tunnel to extract the borehole; Use a drilling rig to construct through-layer drilling holes in the excavation tunnel in the coal seam from the drilling site of the high-drawing tunnel or the bottom-drawing tunnel. The hole layout position is the working face of the entire excavation tunnel and the tunnel to be excavated, including the 15m outside the contour line of the two tunnels of the excavation tunnel and the tunnel to be excavated; 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 tunnel boring machine location; S3, install gas concentration analysis module, ground stress analysis module and gas over-limit warning module; The drilling rig is connected to a gas over-limit warning module, which is respectively connected to a ground stress analysis module and a 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 gas single-hole precision metering data and ground stress while-drilling measurement data in real time while extracting gas; S4. Obtain gas monitoring data in the entire coal tunnel excavation working face and at least three advance drilling sites in real time, including the 15 m range outside the two tunnel contours; 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 calculates the calculation index 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 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 excavation working face advances, steps S5 to S8 are repeated to provide dynamic real-time warnings for gas exceeding the limit in the working face.

[0006] Furthermore, the spacing of the through-layer drill holes 5 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 is arranged in the middle of the through-layer borehole, and the drilling stress measuring instrument is arranged on the coal seam.

[0009] Furthermore, in step S5, the time period T 1 is 15~20min; 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 threshold N 0, a short-term warning of gas over-limit will be issued for 10 to 15 minutes; if there are 2 or more consecutive short-term warnings of gas over-limit, the gas electric interlocking operation will be implemented immediately.

[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.

[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, and realizes single-hole precise measurement of gas extraction boreholes and ground stress while drilling monitoring based on the real-time monitoring and analysis of gas parameters and ground stress parameters ahead of at least 3 drilling sites in the working face of the tunnel (including the 15 m range outside the contour lines of the two tunnels). Based on the monitoring data of gas and ground stress, the present invention coordinates the monitoring of gas flow in the tunnel, realizes real-time early warning of gas exceeding the limit in the tunnel, and effectively ensures 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 internal layout of a drilling site according to Embodiment 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] in: Excavation tunnel 1, drilling site 2, through-layer drilling 3, tunnel to be excavated 4, high-extraction tunnel 5, advance drilling site 6, coal seam 7, single-hole gas precision meter 8, while-drilling ground stress measuring instrument 9, directional drilling rig 10, ground stress analysis module 11, gas concentration analysis module 12, gas over-limit warning module 13, bottom extraction tunnel 14. DETAILED DESCRIPTION

[0022] 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. Example 1

[0023] 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 coal tunneling working face based on pre-extraction tunneling drilling holes is drawn. As shown in the figure, a method for early warning of gas concentration in a coal tunneling working face based on pre-extraction tunneling drilling holes of this embodiment 1 includes the following contents: S1, use high extraction lane 1 to extract the borehole; A directional drill rig 10 is used in the drilling site 2 of the high-extraction tunnel 5 to construct a through-layer borehole 3 in the excavation tunnel 1 in the coal seam 7. The hole arrangement position is the entire excavation tunnel 1 and the tunnel to be excavated 4, including a range of 15m outside the contour lines of the two tunnels of the excavation tunnel 1 and the tunnel to be excavated 4. The hole arrangement spacing is 2R, R is the drilling extraction radius, and R is 2.5m in this embodiment 1.

[0024] A drilling site 2 is arranged every 4 to 6 rows of through-layer drill holes 3, 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 3; S2, install a single-hole gas precision meter 8 and a drilling-while-drilling ground stress measuring instrument 9; Install a single-hole gas precision meter 8 and a drilling-while-drilling ground stress measuring instrument 9 for all the through-layer boreholes 3 within the range of three drilling sites ahead of the current tunneling machine location; the single-hole gas precision meter 8 is set in the middle of the through-layer borehole 3, and the drilling-while-drilling ground stress measuring instrument 9 is set on the coal seam 7; S3, installing a gas concentration analysis module 12, a ground stress analysis module 11 and a gas over-limit warning module 13; The drilling rig 10 is connected to a gas over-limit warning module 13, and the gas over-limit warning module 13 is respectively connected to a ground stress analysis module 11 and a gas concentration analysis module 12, and the ground stress analysis module 11 is connected to each ground stress measuring instrument while drilling 9, and the gas concentration analysis module 12 is connected to each single-hole gas precision meter 8, thereby obtaining gas single-hole precision metering data and ground stress measurement data while drilling in real time while extracting gas; The single-hole gas precision meter 8 and the drilling ground stress measuring instrument 9 are data acquisition modules, which collect borehole gas parameter data (i.e., gas extraction drilling single-hole precise metering data) and ground stress drilling measurement data during the working face excavation process; the gas concentration analysis module 12 and the ground stress analysis module 11 perform corresponding fitting analysis on the collected gas extraction drilling single-hole precise metering data and ground stress drilling monitoring data to obtain gas and ground stress early warning indicators; the gas over-limit early warning module 13 coordinates the early warning of gas over-limit accidents during the excavation process based on the fitting results.

[0025] The data acquisition module is used to collect monitoring data and provide basic early warning data for other modules; the data acquisition module mainly includes a single-hole gas precision meter 8 and a drilling-while-drilling ground stress meter 9, and is connected to the corresponding analysis module through a wireless sensor.

[0026] The gas concentration analysis module 12 is mainly used to analyze the changes in the gas concentration characteristics of the excavation tunnel in real time, and predict the gas concentration sequence of the excavation tunnel in the future, to obtain the real-time change curve of the ultra-low gas concentration and the gas concentration change prediction curve and the maximum value of the gas concentration that may appear in the future, and to obtain the prediction index of the gas concentration; the gas concentration analysis module 12 can use the YZC6 gas extraction pipeline multi-parameter measuring instrument software (2023SR1201469) on the market.

[0027] The geostress analysis module 11 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 in combination with the output energy of the drill rig, the amount of drill cuttings and the particle size distribution of drill cuttings during the drilling process, 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 11 can adopt the YZC6 gas extraction 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.

[0028] The gas over-limit warning module 13 performs gas over-limit risk identification based on the gas concentration analysis module 12 and the ground stress analysis module 11 , and provides a warning result of the gas over-limit risk magnitude.

[0029] S4. Real-time acquisition of gas monitoring data within the coal tunnel excavation working face (including the 15 m range outside the two tunnel contours) and gas monitoring data of at least three advanced drilling sites 6; advanced drilling site 6 is the drilling site ahead of the current tunneling machine; the gas concentration range of the single-hole gas precise metering data is 0-100%; S5. Extract the current gas monitoring value M t Before the current timeT 1 , T 2 Gas monitoring data for a certain period of time; The time period T 1 is 15~20min; 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 short-term warning of gas over-limit is issued for 10 to 15 minutes; this step is repeated continuously. If there are two or more consecutive short-term warnings of gas over-limit, the gas electric interlock operation is immediately implemented; 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 30~50 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 MAt 0:00, an emergency warning for gas exceeding the limit is issued; Threshold M 0 before the current time T 2 Average value of gas monitoring data in the time period P t 200%, that is, the average gas concentration is 25%, the threshold M 0 takes 50%, threshold M 0The calculation method is: ; like M t Greater than M 0, an emergency warning of gas over-limit is issued and the gas electric interlocking operation is immediately implemented; S9. As the excavation working face advances, steps S5 to S8 are repeated to provide dynamic real-time warnings for gas exceeding the limit in the working face.

[0030] In this embodiment 1, T 1 Take 15min, T 2 Take 2 days and calculate N t =18.8%, P t =20.15%, M t =16.2%, M 0=40.3%.

[0031] The early warning of geostress measurement while drilling includes the following contents: S1. Drill holes in the coal seam high-drawn tunnel to obtain real-time ground stress monitoring data Z in the tunnel to be excavated and the tunnel to be excavated (including the 15 m range outside the contour lines of the two tunnels) and at least 3 drilling sites ahead. Extract the stress 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 15~20 min; time period T 2. Determined according to the advancing speed of the working face; S2, as the tunneling progresses, 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 rock formation stress monitoring data Z to be measured is greater than the threshold α0, carry out emergency warning of gas over-limit, and immediately implement gas electric interlocking operation after the warning is triggered; α t and α 0The calculation method is: ; in, z i for T 2 Rock formation in-situ stress monitoring data of different boreholes within a time period; v is the working face advancement speed; l The distance of the working face advancement.

[0032] In this embodiment 1, it is calculated that: α t =11.1 MPa, α 0=22.2 MPa.

[0033] During the excavation of the working face, the extraction drilling holes are arranged in the entire excavation tunnel 1 and the tunnel to be excavated 4 (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 excavation head. When the tunneling machine passes the location of the drilling site, the comprehensive intelligent early warning and analysis system for excessive gas limit can be removed and moved to the drilling site in front, so that the comprehensive intelligent early warning and analysis system for excessive gas limit always covers all the through-layer drill holes within the range of 3 drilling sites ahead of the current location of the tunneling machine.

[0034] When constructing multiple high-extraction tunnels and drilling through layers to measure ground stress while drilling, the spacing between the boreholes should be large enough to avoid the construction boreholes affecting other adjacent boreholes. ξ Conduct experimental testing and verification independently. Example 2

[0035] See also Figure 5-Figure 7 , Figure 5 A layout diagram of the inside of a drilling site of a method for early warning of gas concentration in a coal tunneling working face based on pre-extraction tunneling drilling holes is drawn. As shown in the figure, the method for early warning of gas concentration in a coal tunneling working face based on pre-extraction tunneling drilling holes of this embodiment 2 is different from that of embodiment 1 in that: In this embodiment 2, a bottom extraction tunnel 14 is used for extraction drilling. A directional drill rig 10 is used in the drilling site 2 of the bottom extraction tunnel 14 to construct a through-layer drill hole 3 in the driving tunnel 1 arranged in the coal seam 7. The hole layout position is the entire driving tunnel 1 and the tunnel to be excavated 4 (including the range of 15 m outside the contour lines of the two tunnels).

[0036] Working principle: The present invention provides a coal tunneling working face gas concentration early warning method based on pre-extraction drilling holes, which combines single-hole gas metering data with drilling ground stress data to coordinately warn of gas over-limit accidents in the coal tunneling working face; through-layer drilling holes are constructed from the high-extraction tunnel or the bottom-extraction tunnel (gas pre-extraction tunnel) to the coal tunneling working face, and the drilling holes are arranged within 15 m on both sides of the tunneling tunnel and at least 3 drilling sites ahead of the tunneling tunnel; the single-hole gas data and drilling ground stress data of the coal tunneling working face are obtained in real time, and the gas over-limit threshold is fit-analyzed by the gas concentration analysis module and the ground stress analysis module and compared with the real-time monitoring data, and then the gas over-limit early warning module is used to coordinately warn of gas over-limit accidents in the coal tunneling working face.

[0037] 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 coal tunneling working face based on pre-extraction tunnel extraction drilling, characterized in that: Includes the following: S1, using the pre-extraction tunnel to extract the borehole; From the drilling site of the high-drawing tunnel or the bottom-drawing tunnel, a drilling rig is used to construct through-layer drilling holes in the excavation tunnel in the coal seam. The hole arrangement position is the working face of the entire excavation tunnel and the tunnel to be excavated, including the range of 15 m outside the contour lines of the two tunnels of the excavation tunnel and the tunnel to be excavated; 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 tunnel boring machine location; S3, install gas concentration analysis module, ground stress analysis module and gas over-limit warning module; The drilling rig is connected to a gas over-limit warning module, which is respectively connected to a ground stress analysis module and a 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 gas single-hole precision metering data and ground stress while-drilling measurement data in real time while extracting gas; S4. Obtain gas monitoring data in the entire coal tunnel excavation working face and at least three advance drilling sites in real time, including the 15 m range outside the two tunnel contours; 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 calculates the calculation index 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 excavation working face advances, steps S5 to S8 are repeated to provide dynamic real-time warnings for gas exceeding the limit in the working face.

2. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel extraction drilling according to claim 1 is characterized by: In step S1, the spacing of the through-layer drill holes 5 is 2R, where R is the drilling extraction radius.

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

4. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel extraction drilling according to claim 1 is characterized by: The single-hole gas precision meter is arranged in the middle of the through-layer borehole, and the while-drilling ground stress measuring instrument is arranged on the coal seam.

5. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel extraction drilling according to claim 3 is characterized by: The time period in step S5 T 1 is 15~20min; time period T 2 Determined according to the advancement speed of the working face.

6. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel 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 2 or more consecutive short-term gas over-limit warnings, the gas electric interlock operation will be implemented immediately.

7. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel 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.

8. The method for early warning of gas concentration in coal tunneling working face based on pre-extraction tunnel 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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