A deep isolated working face roadway and super-deep large-diameter drilling arrangement method

Abstract

The application discloses a kind of deep island working face roadway and ultra-deep large-diameter borehole arrangement method, negative coal pillar roadway is arranged along floor in low stress area in adjacent two sides goaf of island working face, and impact risk of roadway is eliminated to realize no impact ground pressure risk of two sides roadway;Since stress concentration phenomenon can exist in island working face coal wall, the application is arranged by implementing ultra-deep large-diameter borehole in stress concentration area of island working face coal wall, and the construction parameters of borehole are determined according to stress distribution, and after completion, pressure relief protection zone is formed, which effectively plays a pre-unloading effect on island working face coal wall, and the construction of ultra-deep large-diameter borehole plays a role in risk detection for subsequent to-be-mined coal seam, which effectively relieves pressure on the whole island working face through the above-mentioned manner, so that it is in a low stress environment, facilitating subsequent mining of island working face, providing a safe and effective method for strip mining pillar recovery in deep impact ground pressure mine.

Description

Technical Field

[0001] This invention belongs to the field of coal mine safety production technology, specifically a method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes. Background Technology

[0002] With the continuous development of coal resources, underground mining is becoming increasingly deeper. Due to factors such as geological conditions and mining technology, deep isolated working faces may form during the mining process, such as when using strip mining or an unreasonable mining sequence. The increased stress in the coal and rock mass at deep mines, coupled with stress concentration at the isolated working faces, makes them more susceptible to rockbursts.

[0003] In the mining of deep isolated working faces, there may be situations where two or three sides are mined out. If coal pillar mining is adopted, the risk of rock bursts will increase due to the influence of the geological structure and burial depth, which makes mining of isolated working faces strictly prohibited.

[0004] Therefore, the research direction of this invention is to provide a new method for the layout of roadways and decompression boreholes that can effectively decompress isolated working faces, placing them in a low-stress environment to facilitate subsequent mining of isolated working faces. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for arranging roadways and ultra-deep large-diameter boreholes in deep isolated working faces. By arranging negative coal pillar roadways in the goaf areas on both sides of the isolated working face and constructing ultra-deep large-diameter boreholes on the coal wall of the isolated working face, the synergistic effect of these methods can effectively relieve the pressure on the isolated working face, placing it in a low-stress environment, which facilitates subsequent mining of the isolated working face.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes, the specific steps of which are as follows:

[0007] Step 1: Based on mine pressure theory and numerical simulation, and combined with the layout of goaf areas on both sides of the isolated working face, determine the stress distribution in the goaf areas on both sides of the isolated working face.

[0008] Step 2: In the low-stress areas of the goaf on both sides of the isolated working face, arrange the negative coal pillar roadways of the isolated working face along the bottom plate of the goaf on both sides, so as to form the return air roadway and the transport roadway of the isolated working face in the goaf on both sides respectively. The distance between the return air roadway of the isolated working face and its nearest coal pillar is L1, and the distance between the transport roadway of the isolated working face and its nearest coal pillar is L2.

[0009] Step 3: In order to better reduce stress and create a larger plastic zone between the pressure relief boreholes, a single row of ultra-deep large-diameter boreholes is designed on the coal wall of the isolated working face. The distance between each ultra-deep large-diameter borehole and the roof is L3, and the distance between each borehole and the floor is L4. The diameter D of the ultra-deep large-diameter borehole is determined. Then, based on the physical and mechanical parameters of the coal seam in the isolated working face and the dip length of the coal wall, combined with the single-row borehole construction method and the diameter D, the borehole spacing L5 of the ultra-deep large-diameter boreholes is determined.

[0010] Step 4: Obtain measured stress data of the coal body in the isolated working face, determine the stress distribution of the coal wall, and carry out ultra-deep large-diameter drilling in the stress concentration area of ​​the coal wall in the isolated working face according to the drilling method and drilling parameters determined in Step 3; and according to the stress distribution in the stress concentration area, design the ultra-deep large-diameter drilling depth in the stress-high area to be greater than the ultra-deep large-diameter drilling depth in the stress-low area.

[0011] Step 5: Simultaneously construct all the ultra-deep, large-diameter boreholes designed on the coal face of the isolated working face; and during the construction of each ultra-deep, large-diameter borehole, judge the stress of the coal and rock mass in real time according to the drill cuttings method, so as to adjust the depth and spacing of each ultra-deep, large-diameter borehole in a timely manner, to ensure that the depth of the ultra-deep, large-diameter borehole in the high-stress area is always greater than the depth of the ultra-deep, large-diameter borehole in the low-stress area (that is, if the stress at one ultra-deep, large-diameter borehole is greater than the stress at another ultra-deep, large-diameter borehole, then the depth of the first ultra-deep, large-diameter borehole must be greater than the depth of the second ultra-deep, large-diameter borehole). After the construction of all boreholes is completed, an effective pressure relief protection zone is formed.

[0012] Furthermore, the diameter D is selected to be as large as possible within the range of 200mm to 300mm, based on the actual conditions of the mine.

[0013] Furthermore, the drilling spacing L5 in step three is calculated using the following formula:

[0014] L5=εD / 2

[0015] In the formula: ε is the fracture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

[0016] Furthermore, the fifth step of simultaneous construction specifically involves: designing mine maintenance shifts for drilling construction according to the mine's production schedule, determining the maximum number of personnel for each maintenance shift, and arranging as many personnel as possible to participate in drilling construction within each maintenance shift; thereby achieving simultaneous construction of ultra-deep, large-diameter boreholes.

[0017] Furthermore, in step five, if the amount of coal dust exceeds the threshold or a stuck drill occurs during the construction of a certain ultra-deep large-diameter borehole, the drilling spacing between adjacent ultra-deep large-diameter boreholes will be reduced, and the borehole arrangement will be densified to ensure the required pressure relief effect.

[0018] Furthermore, the depth of ultra-deep, large-diameter boreholes shall not be less than 30m.

[0019] Compared with existing technologies, this invention arranges negative coal pillar roadways along the floor in the low-stress areas of the goaf on both sides of the isolated working face, placing the roadways in a low-stress environment and eliminating the risk of roadway impact, thus achieving a rockburst-free roadway on both sides. After solving the roadway impact risk, stress concentration may still occur in the coal wall of the isolated working face. To address this phenomenon, this invention arranges ultra-deep, large-diameter boreholes in the stress concentration areas of the coal wall of the isolated working face, and determines the construction parameters of the boreholes according to the stress distribution. After completing the construction of all boreholes, a pressure relief protection zone is formed, which effectively pre-depressurizes the coal wall of the isolated working face. Furthermore, the construction of ultra-deep, large-diameter boreholes plays a role in risk detection for subsequent coal seams to be mined. Through the above methods, the entire isolated working face is effectively depressurized, placing it in a low-stress environment, which facilitates the subsequent mining of the isolated working face and provides a safe and effective method for the recovery of coal pillars left over from strip mining in deep rockburst mines. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall layout of the present invention;

[0021] Figure 2 for Figure 1 Cross-sectional view along the AA direction;

[0022] Figure 3 This is a diagram showing the layout of ultra-deep, large-diameter boreholes in this invention.

[0023] In the diagram: 1. First goaf; 2. Second goaf; 3. Return airway of isolated working face; 4. Transport roadway of isolated working face; 5. Fine sandstone; 6. Mudstone; 7. Medium sandstone; 8. Sandy mudstone; 9. Ultra-deep large-diameter borehole in high stress area; 10. Ultra-deep large-diameter borehole in low stress area. Detailed Implementation

[0024] The present invention will be further described below.

[0025] like Figure 1 and 2 As shown, the specific steps of this invention are as follows:

[0026] Step 1: Based on mine pressure theory and numerical simulation, and combined with the layout of goaf areas on both sides of the isolated working face, determine the stress distribution of the goaf areas on the adjacent sides of the isolated working face. The two goaf areas are the first goaf area 1 and the second goaf area 2, respectively.

[0027] Step 2: In the low-stress areas of the goaf on both sides of the isolated working face, arrange the negative coal pillar roadways of the isolated working face along the bottom plate of the goaf on both sides, thereby forming the return air roadway 3 and the transport roadway 4 of the isolated working face in the goaf on both sides respectively. The distance between the return air roadway 3 and its nearest coal pillar is L1, and the distance between the transport roadway 4 and its nearest coal pillar is L2.

[0028] Step 3: To better reduce stress and create a larger plastic zone between the pressure-relief boreholes, such as... Figure 3 As shown, a single row of ultra-deep, large-diameter boreholes is designed on the coal face of the isolated working face. Each ultra-deep, large-diameter borehole is L3 from the roof and L4 from the floor. The diameter D of each ultra-deep, large-diameter borehole is determined, and the maximum value within the range of 200mm to 300mm is selected based on the actual mine conditions. Then, based on the physical and mechanical parameters of the coal seam in the isolated working face and the dip length of the coal face, combined with the single-row borehole construction method and the diameter D, the borehole spacing L5 is determined. The specific formula is as follows:

[0029] L5=εD / 2

[0030] In the formula: ε is the fracture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

[0031] Step 4: Obtain measured stress data of the coal face in the isolated working face, determine the stress distribution of the coal wall, and carry out ultra-deep large-diameter drilling in the stress concentration area of ​​the coal wall in the isolated working face according to the drilling method and drilling parameters determined in Step 3; and according to the stress distribution in the stress concentration area, design the depth of ultra-deep large-diameter borehole 9 in the high stress area to be greater than the depth of ultra-deep large-diameter borehole 10 in the low stress area; and the depth of ultra-deep large-diameter borehole is not less than 30m.

[0032] Step 5: Simultaneously construct all the ultra-deep, large-diameter boreholes designed on the coal face of the isolated working face. Specifically, based on the mine's production schedule, design mine maintenance shifts for drilling construction and determine the maximum number of personnel for each maintenance shift (according to the "Limit on the Number of Personnel Entering the Mine (Pit) for a Single Shift" regulation, the maximum number of personnel for a maintenance shift in a mine working face with severe disasters is 40, and the maximum number of personnel for a maintenance shift in a mine working face with other mines is 30). Arrange as many personnel as possible to participate in the drilling construction within each maintenance shift; thereby achieving simultaneous construction of ultra-deep, large-diameter boreholes; and during the construction of each ultra-deep, large-diameter borehole, use the drill cuttings method to judge the stress of the coal and rock mass in real time, thereby adjusting the depth and spacing of each ultra-deep, large-diameter borehole in a timely manner, ensuring that the depth of ultra-deep, large-diameter borehole 9 in the high-stress area is always greater than the depth of ultra-deep, large-diameter borehole 10 in the low-stress area, and forming an effective pressure relief protection zone after all borehole construction is completed. In addition, if the amount of coal dust exceeds the threshold or a stuck drill occurs during the construction of an ultra-deep, large-diameter borehole, the drilling spacing between adjacent ultra-deep, large-diameter boreholes will be reduced, and the borehole layout will be densified to ensure the required pressure relief effect.

[0033] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for arranging deep, isolated working face roadways and ultra-deep, large-diameter boreholes, characterized in that, The specific steps are as follows: Step 1: Based on mine pressure theory and numerical simulation, and combined with the layout of goaf areas on both sides of the isolated working face, determine the stress distribution in the goaf areas on both sides of the isolated working face. Step 2: In the low-stress areas of the goaf on both sides of the isolated working face, arrange the negative coal pillar roadway of the isolated working face along the bottom plate of the goaf on both sides, so as to form the return air roadway and the transport roadway of the isolated working face in the goaf on both sides respectively. The distance between the return air roadway of the isolated working face and its nearest coal pillar is L1, and the distance between the transport roadway of the isolated working face and its nearest coal pillar is L2. Step 3: Design a single row of ultra-deep, large-diameter boreholes on the coal face of the isolated working face. The distance between each ultra-deep, large-diameter borehole and the roof is L3, and the distance between each borehole and the floor is L4. Determine the diameter D of the ultra-deep, large-diameter boreholes. Then, based on the physical and mechanical parameters of the coal seam in the isolated working face and the dip length of the coal face, combined with the single-row borehole construction method and the diameter D, determine the borehole spacing L5 of the ultra-deep, large-diameter boreholes. Step 4: Obtain measured stress data of the coal body in the isolated working face, determine the stress distribution of the coal wall, and carry out ultra-deep large-diameter drilling in the stress concentration area of ​​the coal wall in the isolated working face according to the drilling method and drilling parameters determined in Step 3; and according to the stress distribution in the stress concentration area, design the ultra-deep large-diameter drilling depth in the stress-high area to be greater than the ultra-deep large-diameter drilling depth in the stress-low area. Step 5: Simultaneously construct all the ultra-deep, large-diameter boreholes designed on the coal face of the isolated working face; and during the construction of each ultra-deep, large-diameter borehole, judge the stress of the coal and rock mass in real time according to the drill cuttings method, so as to adjust the depth and spacing of each ultra-deep, large-diameter borehole in a timely manner, ensuring that the depth of the ultra-deep, large-diameter borehole in the high-stress area is always greater than that in the low-stress area, and form an effective pressure relief protection zone after the construction of all boreholes is completed.

2. The method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes according to claim 1, characterized in that, The diameter D is selected as close to the maximum value as possible within the range of 200mm to 300mm, based on the actual conditions of the mine.

3. The method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes according to claim 1, characterized in that, The drilling spacing L5 in step three is calculated using the following formula: L5=εD / 2 In the formula: ε is the fracture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

4. The method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes according to claim 1, characterized in that, The fifth step of simultaneous construction specifically involves: designing mine maintenance shifts for drilling construction based on the mine's production schedule, determining the maximum number of personnel for each maintenance shift, and arranging as many personnel as possible to participate in drilling construction within each maintenance shift; thereby achieving simultaneous construction of ultra-deep, large-diameter boreholes.

5. The method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes according to claim 1, characterized in that, In step five, if the amount of coal dust exceeds the threshold or a stuck drill occurs during the construction of a certain ultra-deep large-diameter borehole, the drilling spacing between adjacent ultra-deep large-diameter boreholes will be reduced, and the borehole arrangement will be densified to ensure the required pressure relief effect.

6. The method for arranging deep isolated working face roadways and ultra-deep large-diameter boreholes according to claim 1, characterized in that, The depth of the ultra-deep, large-diameter borehole is not less than 30m.

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