Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining
The pressure-relief gas drainage in longwall mining goaf is an important part of the simultaneous extraction of coal and gas in the green mining technology system. The horizontal-directional long boreholes arranged in overlying strata for pressure-relief gas drainage have been widely used in recent...
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Editorial Office of Journal of China Coal Society
2023-10-01
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| Series: | Meitan xuebao |
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| Online Access: | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.1379 |
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| author | Mingjie GUO Wenbing GUO Gaobo ZHAO Ruifu YUAN Yusheng WANG Erhu BAI |
| author_facet | Mingjie GUO Wenbing GUO Gaobo ZHAO Ruifu YUAN Yusheng WANG Erhu BAI |
| author_sort | Mingjie GUO |
| collection | DOAJ |
| description | The pressure-relief gas drainage in longwall mining goaf is an important part of the simultaneous extraction of coal and gas in the green mining technology system. The horizontal-directional long boreholes arranged in overlying strata for pressure-relief gas drainage have been widely used in recent years. The boreholes in mining overburden are different from the high drainage roadway and ordinary high-level boreholes. When the pressure-relief gas is extracted from the overburden of goaf, the boreholes response and sensitivity to the mining overburden damage and gas migration have some significant particularities. Through theoretical analysis, numerical simulation and engineering example verification, the position characteristics and pressure-relief gas drainage mechanism of horizontal-directional long boreholes in mining overburden were studied. The technical principle of extracting pressure-relief gas by horizontal-directional long boreholes was described. Combined with laboratory tests and numerical simulation, three position characteristics of hori-zontal-directional long boreholes were analyzed. The gas accumulation degree at the borehole area is high, which provides the concentration conditions for borehole gas drainage. The fractures at the borehole area are relatively developed, which provides gas source guarantee for borehole drainage. The stratum at the borehole area is less affected by mining, which provides stability conditions for the borehole. On this basis, the drainage mechanism of horizontal-directional long boreholes was revealed from three aspects: the degree of gas accumulation in mining fractures, the permeability of mining strata and the stability of mining boreholes. The theoretical criteria for determining the position of horizontal-directional long boreholes was proposed, and the method for determining the position of the boreholes drainage was given, which were verified by numerical simulation and engineering examples. The research results show that according to the borehole position criteria, the maximum pure volume of gas drainage of the borehole arranged is 2.59 m3/min, which is 2.56 times that of other comparative boreholes. Affected by horizontal-directional long boreholes drainage, the maximum gas volume fraction in return airway is 0.11%−0.72%, and the gas volume is 0.69−2.79 m3/min, which verifies the reasonability of pressure-relief gas drainage based on the position determination method of horizontal-directional long boreholes. The research results can provide a technical basis for the layout of horizontal-directional long boreholes to extract the pressure-relief gas in goaf, thereby improving the pres-sure-relief gas extraction rate and promoting the development of green mining technology of the mine. |
| first_indexed | 2024-03-11T17:15:52Z |
| format | Article |
| id | doaj.art-c4b3f7315dea4199ab65013d2c61d3e2 |
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| language | zho |
| last_indexed | 2024-03-11T17:15:52Z |
| publishDate | 2023-10-01 |
| publisher | Editorial Office of Journal of China Coal Society |
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| series | Meitan xuebao |
| spelling | doaj.art-c4b3f7315dea4199ab65013d2c61d3e22023-10-20T01:57:45ZzhoEditorial Office of Journal of China Coal SocietyMeitan xuebao0253-99932023-10-0148103750376510.13225/j.cnki.jccs.2022.13792022-1379Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall miningMingjie GUO0Wenbing GUO1Gaobo ZHAO2Ruifu YUAN3Yusheng WANG4Erhu BAI5School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, ChinaSchool of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, ChinaDepartment of Mining Engineering, West Virginia University, Morgantown WV 26506, USASchool of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, ChinaJiulishan Coal Mine, Henan Coking Coal Energy Co., Ltd., Jiaozuo 454100, ChinaSchool of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, ChinaThe pressure-relief gas drainage in longwall mining goaf is an important part of the simultaneous extraction of coal and gas in the green mining technology system. The horizontal-directional long boreholes arranged in overlying strata for pressure-relief gas drainage have been widely used in recent years. The boreholes in mining overburden are different from the high drainage roadway and ordinary high-level boreholes. When the pressure-relief gas is extracted from the overburden of goaf, the boreholes response and sensitivity to the mining overburden damage and gas migration have some significant particularities. Through theoretical analysis, numerical simulation and engineering example verification, the position characteristics and pressure-relief gas drainage mechanism of horizontal-directional long boreholes in mining overburden were studied. The technical principle of extracting pressure-relief gas by horizontal-directional long boreholes was described. Combined with laboratory tests and numerical simulation, three position characteristics of hori-zontal-directional long boreholes were analyzed. The gas accumulation degree at the borehole area is high, which provides the concentration conditions for borehole gas drainage. The fractures at the borehole area are relatively developed, which provides gas source guarantee for borehole drainage. The stratum at the borehole area is less affected by mining, which provides stability conditions for the borehole. On this basis, the drainage mechanism of horizontal-directional long boreholes was revealed from three aspects: the degree of gas accumulation in mining fractures, the permeability of mining strata and the stability of mining boreholes. The theoretical criteria for determining the position of horizontal-directional long boreholes was proposed, and the method for determining the position of the boreholes drainage was given, which were verified by numerical simulation and engineering examples. The research results show that according to the borehole position criteria, the maximum pure volume of gas drainage of the borehole arranged is 2.59 m3/min, which is 2.56 times that of other comparative boreholes. Affected by horizontal-directional long boreholes drainage, the maximum gas volume fraction in return airway is 0.11%−0.72%, and the gas volume is 0.69−2.79 m3/min, which verifies the reasonability of pressure-relief gas drainage based on the position determination method of horizontal-directional long boreholes. The research results can provide a technical basis for the layout of horizontal-directional long boreholes to extract the pressure-relief gas in goaf, thereby improving the pres-sure-relief gas extraction rate and promoting the development of green mining technology of the mine.http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.1379longwall mininghorizontal-directional long boreholesposition characteristicspressure-relief gasdrainage mechanism |
| spellingShingle | Mingjie GUO Wenbing GUO Gaobo ZHAO Ruifu YUAN Yusheng WANG Erhu BAI Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining Meitan xuebao longwall mining horizontal-directional long boreholes position characteristics pressure-relief gas drainage mechanism |
| title | Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining |
| title_full | Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining |
| title_fullStr | Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining |
| title_full_unstemmed | Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining |
| title_short | Position characteristics of horizontal-directional long boreholes in overlying strata and drainage mechanism of pressure-relief gas in longwall mining |
| title_sort | position characteristics of horizontal directional long boreholes in overlying strata and drainage mechanism of pressure relief gas in longwall mining |
| topic | longwall mining horizontal-directional long boreholes position characteristics pressure-relief gas drainage mechanism |
| url | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.1379 |
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