Influence of multiple mining of outburst coal seam group on gas extraction of cross-layer borehole

doi:10.16265/j.cnki.issn1003-3033.2020.05.011

Abstract

Abstract: In order to reveal influence of multiple mining of coal seam group on gas extraction efficiency of cross-layer borehole in bottom extraction roadway, Flac software was used to simulate and study pressure relief characteristics of roadway roof and expansion features of plastic area of surrounding rock during downward mining of No. 3, 4, 5 coal seam of Shaqu No.2 mine. Then, site measurement was conducted for borehole gas extraction efficiency. The results show that pressure relief degree of No.3 coal seam mining is more than 59%, indicating the most obvious pressure relief effect and largest increase rate of gas extraction concentration and purity. Along with increase of mining times, pressure relief degree and increase rate decrease. During mining of the No.4 coal seam, plastic area of surrounding rock reaches 3.1 m, exceeding borehole sealing length, and amount of gas mixture in borehole begins to increase gradually. As mining times increase, plastic area and gas mixture increase. Meanwhile, gas extraction concentration and purity of cross-layer borehole show a gradual downward trend.

Key words: coal seam group, downward mining, cross-layer borehole, pressure relief gas, extraction efficiency

CLC Number:

X936
TD712

YANG Zhengkai, CHENG Zhiheng, LIU Yanqing, WANG Hongbing, YANG Peng, SUN Fulong. Influence of multiple mining of outburst coal seam group on gas extraction of cross-layer borehole[J]. China Safety Science Journal, 2020, 30(5): 66-73.

References

[1] 马国强,陈如忠,崔刚,等. 近距离突出煤层群上保护层瓦斯综合治理技术[J]. 煤炭科学技术,2015,43(3): 52-55.
MA Guoqiang,CHEN Ruzhong,CUI Gang,et al. Gas comprehensive control technology of upper protective seam in contiguous outburst seams[J]. Coal Science and Technology,2015, 43(3): 52-55.
[2] 冀超辉.单一低透突出煤层底抽巷煤气共采技术及实践[J].矿业安全与环保,2015,42(3): 86-98.
JI Chaohui.Application and practice of coal-gas co-extraction technology by floor drainage roadway in single low-permeability outburst seam[J].Mining Safety & Environmental Protection, 2015,42(3): 86-98.
[3] 赵宁,戴广龙,张瑞.底抽巷一巷两用瓦斯治理技术实践[J].煤炭科学技术,2014,42(2):44-46,62.
ZHAO Ning, DAI Guanglong, ZHANG Rui. Practice on gas control technology of floor drainage gateway with two uses[J].Coal Science and Technology, 2014,42(2):44-46,62.
[4] 周红星,程远平,刘洪永,等.突出煤层群穿层钻孔孔群增透技术及应用[J].煤炭学报,2011,36(9): 1 515-1 518.
ZHOU Hongxing,CHENG Yuanping,LIU Hongyong,et al. Permeability improvement technology of array crossing boreholes and its application in outburst coal seam[J].Journal of China Coal Society,2011, 36(9): 1 515-1 518.
[5] 袁亮.卸压开采抽采瓦斯理论及煤与瓦斯共采技术体系[J].煤炭学报,2009,34(1): 1-8.
YUAN Liang. Theory of pressure relieved gas extraction and technique system of integrated coal production and gas extraction[J].Journal of China Coal Society, 2009,34(1): 1-8.
[6] 季文博,齐庆新,李宏艳,等. 近距离被保护卸压煤体透气性变化规律实测研究[J]. 煤炭学报,2015,40(4):830-835.
JI Wenbo,QI Qingxin,LI Hongyan,et al. Research on permeability characteristics of depressured protective layer in close-distance seam group[J]. Journal of China Coal Society, 2015,40(4): 830-835.
[7] 程志恒,齐庆新,李宏艳,等.近距离煤层群叠加开采采动应力-裂隙动态演化特征实验研究[J].煤炭学报,2016,41(2): 367-375.
CHENG Zhiheng,QI Qingxin,LI Hongyan,et al. Evolution of the superimposed mining induced stress-fissure field under extracting of close distance coal seam group[J]. Journal of China Coal Society,2016,41(2): 367-375.
[8] 薛东杰,周宏伟,孔琳,等.采动条件下被保护层瓦斯卸压增透机理研究[J].岩土工程学报,2012,34(10): 1 910-1 916.
XUE Dongjie,ZHOU Hongwei,KONG Lin,et al. Mechanism of unloading induced permeability increment of protected coal seam under mining[J]. Chinese Journal of Geotechnical Engineering,2012, 34(10): 1 910-1 916.
[9] 张勇,张春雷,赵甫. 近距离煤层群开采底板不同分区采动裂隙动态演化规律[J]. 煤炭学报,2015,40(4): 786-792.
ZHANG Yong,ZHANG Chunlei,ZHAO Fu. Dynamic evolution rules of mining-induced fractures in different floor area of short-distance coal seams[J]. Journal of China Coal Society,2015, 40(4): 786-792.
[10] 王伟,程远平,袁亮,等.深部近距离上保护层底板裂隙演化及卸压瓦斯抽采时效性[J]. 煤炭学报,2016,41(1): 138-148.
WANG Wei,CHENG Yuanping,YUAN Liang,et al. Floor fracture evolution and relief gas drainage timeliness in deeper underground short-distance upper protective coal seam extraction[J]. Journal of China Coal Society,2016,41(1): 138 -148.
[11] 刘洪涛,赵志强,张胜凯,等. 近距离煤层群围岩碎裂特征与裂隙分布关系[J]. 煤炭学报,2015,40(4): 766-773.
LIU Hongtao,ZHAO Zhiqiang,ZHANG Shengkai,et al. Relationship between failure characteristics and fracture spacing of surrounding rock of short-distance coal seams group[J]. Journal of China Coal Society,2015,40(4): 766-773.
[12] 毕瑞卿,程五一,陈学习.基于Hoek-Brown准则的底抽巷围岩松动圈分析[J].工业安全与环保,2019,45(2): 6-8.
BI Ruiqing, CHENG Wuyi, CHEN Xuexi. Analysis of surrounding rock loose zone of bottom pumping roadway based on Hoek-Brown criterion[J].Industrial Safety and Environmental Protection,2019,45(2): 6-8.
[13] 林海飞,李树刚,赵鹏翔,等.我国煤矿覆岩采动裂隙带卸压瓦斯抽采技术研究进展[J].煤炭科学技术,2018,46(1):28-35.
LIN Haifei,LI Shugang,ZHAO Pengxiang,et al.Research progress on pressure released gas drainage technology of miningcracking zone in overburden strata of coal mine in China[J].Coal Science and Technology,2018,46(1):28-35.
[14] 刘志伟,张帅.高瓦斯突出煤层底抽巷合理布置研究[J]. 煤炭科学技术,2018,46(10): 155-160.
LIU Zhiwei,ZHANG Shuai. Study on rational layout of floor gas drainage gateway in high gassy-outburst seam. [J]. Coal Science and Technology, 2018,46(10): 155-160.
[15] 程志恒,苏士龙,汪昕.近距离煤层采动裂隙场BBM-DEM模拟研究[J].煤炭科学技术,2019,47(12):1-9.
CHENG Zhiheng,SU Shilong,WANG Xin.Study on mining-induced fracture field of contiguous coal seam with BBM-DEM simulation[J].Coal Science and Technology,2019,47(12):1-9.
[16] 刘志伟,张帅.高瓦斯突出煤层底抽巷合理布置研究[J].煤炭科学技术,2018,46(10):155-160.
LIU Zhiwei,ZHANG Shuai.Study on rational layout of floor gas drainage gateway in high gassy-outburst seam[J].Coal Science and Technology,2018,46(10):155-160.
[17] 李树刚,徐培耘,赵鹏翔,等.采动裂隙椭抛带时效诱导作用及卸压瓦斯抽采[J].煤炭科学技术,2018,46(9):146-152.
LI Shugang,XU Peiyun,ZHAO Pengxiang,et al.Aging induced effect of elliptic paraboloid zone in mining cracks and pressure released gas drainage technique[J]. Coal Science and Technology, 2018,46(9):146-152.
[18] 程志恒.底抽巷穿层钻孔封孔深度与布孔间距优化研究[J].煤炭科学技术,2017,45(2): 76-82.
CHENG Zhiheng. Study on optimization of strata passing borehole sealing depth and borehole layout space in floor gas drainage gateway[J].Coal Science and Technology,2017, 45(2): 76-82.
[19] 田世祥,马瑞帅,邹义怀,等.钻孔瓦斯连续流量法测定煤巷卸压带宽度研究[J].中国安全科学学报,2020,30(3): 82-86.
TIAN Shixiang,MA Ruishuai,ZOU Yihuai,et al.Measurement of stress-relief zone width of roadway by borehole gas continuous flow method[J].China Safety Science Journal,2020,30(3):82-86.
[20] 王雨虹,刘璐璐,付华,等.基于声发射多参数时间序列的瓦斯突出预测[J].中国安全科学学报,2018,28(5): 129-134.
WANG Yuhong,LIU Lulu,FU Hua,et al.Research on acoustic emission multi-parameter time series based prediction of gas outburst[J].China Safety Science Journal,2018,28(5):129-134.
[21] 林海飞,田佳敏,刘丹,等.SDBS与CaCl₂复配液对煤体瓦斯解吸抑制效应研究[J].中国安全科学学报,2019,29(11): 149-155.
LIN Haifei,TIAN Jiamin,LIU Dan,et al.Inhibitory effect of SDBS and CaCl₂ compound solution on gas desorption of coal[J].China Safety Science Journal,2019,29(11): 149-155.
[22] 马树俊,王兆丰,任浩洋,等.低温变温条件下煤吸附瓦斯过程研究[J].中国安全科学学报,2019,29(10): 124-129.
MA Shujun,WANG Zhaofeng,REN Haoyang, et al. Study on gas adsorption process of coal at low and variable temperature[J].China Safety Science Journal, 2019,29(10): 124-129.
[23] 年军,高巍,李润芝,等.以孔代巷瓦斯抽采布孔间距模拟及试验研究[J].中国安全科学学报,2019,29(5): 117-123.
NIAN Jun,GAO Wei,LI Runzhi,et al.Simulation and experimental study on space between boreholes for gas drainage instead of roadway[J].China Safety Science Journal, 2019,29(5): 117-123.
[24] 高魁,乔国栋,刘健,等.构造复杂矿区煤与瓦斯突出瓦斯地质分析[J].中国安全科学学报,2019,29(1): 119-124.
GAO Kui,QIAO Guodong,LIU Jian,et al.Gas-geology action analysis of coal-gas outburst in complicated geological structure coal mine[J].China Safety Science Journal,2019,29(1): 119-124.