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Coal Geology & Exploration

Abstract

The hard roof is a difficult problem in rock stratum control. The breaking and instability of high hard rock strata often induces strong coal pressure disasters, seriously threatening the safety production in coal mines. Hard roof control is one of the major problems in coal mine safety production. In response to the problems of large thickness, high hardness of the coal seam roof and its difficulty in collapse in Buertai Coal Mine in Shendong Mining Area, the hydraulic fracturing mechanism and technical advantages of directional long borehole segmented hydraulic fracturing are analyzed. The location of boreholes is determined based on the key layer theory. The effects of fracturing injection time and injection velocity on fracture propagation are analyzed and calculated by using the pseudo three-dimensional fracture model. The layout of the roof fracturing boreholes of 42108 working face in Buertai Coal Mine is determined, where three holes are arranged in parallel along the inclined direction of the working face. As the half length of the fracture is 41 m, the fracturing control area covers the whole working face. The practice shows that after the application of segmented hydraulic fracturing, the end cycle resistance of normal support in working face decreases by 3.33% in 42108 working face. During the period of cyclic pressure, the end cycle resistance of the support decreases by 6.81%. The dynamic load coefficient reduces by 10.88% on average. It weakens the strong coal pressure behavior of the mine, ensuring the mining safety of the working face.

Keywords

long borehole directional drilling, hydraulic fracturing, hard roof weakening, mine pressure, Buertai Coal Mine of Shendong Coal Group

DOI

10.12363/issn.1001-1986.21.03.0119

Reference

[1] 牟宗龙,窦林名,张广文,等. 坚硬顶板型冲击矿压灾害防治研究[J]. 中国矿业大学学报,2006,35(6):737−741. MU Zonglong,DOU Linming,ZHANG Guangwen,et al. Study of prevention methods of rock burst disaster caused by hard rock roof[J]. Journal of China University of Mining & Technology,2006,35(6):737−741.

[2] 牟宗龙,窦林名. 坚硬顶板突然断裂过程中的突变模型[J]. 采矿与安全工程学报,2004,21(4):90−92. MU Zonglong,DOU Linming. The cusp type catastrophic model of the fracture process of hard rock roof[J]. Journal of Mining & Safety Engineering,2004,21(4):90−92.

[3] 王金安,尚新春,刘红,等. 采空区坚硬顶板破断机理与灾变塌陷研究[J]. 煤炭学报,2008,33(8):850−855. WANG Jin’an,SHANG Xinchun,LIU Hong,et al. Study on fracture mechanism and catastrophic collapse of strong roof strata above the mined area[J]. Journal of China Coal Society,2008,33(8):850−855.

[4] 朱德仁,钱鸣高,徐林生. 坚硬顶板来压控制的探讨[J]. 煤炭学报,1991,16(2):11−20. ZHU Deren,QIAN Minggao,XU Linsheng. Discussion on control of hard roof weighting[J]. Journal of China Coal Society,1991,16(2):11−20.

[5] 魏锦平,靳钟铭,杨彦风,等. 坚硬顶板控制的数值模拟[J]. 岩石力学与工程学报,2002,21(增刊2):2488−2491. WEI Jinping,JIN Zhongming,YANG Yanfeng,et al. Numerical simulation of hard roof control[J]. Chinese Journal of Rock Mechanics and Engineering,2002,21(Sup.2):2488−2491.

[6] 李新元,马念杰,钟亚平,等. 坚硬顶板断裂过程中弹性能量积聚与释放的分布规律[J]. 岩石力学与工程学报,2007,26(增刊1):2786−2793. LI Xinyuan,MA Nianjie,ZHONG Yaping,et al. Storage and release regular of elastic energy distribution in tight roof fracturing[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(Sup.1):2786−2793.

[7] 潘岳,顾士坦,戚云松. 周期来压前受超前隆起分布荷载作用的坚硬顶板弯矩和挠度的解析解[J]. 岩石力学与工程学报,2012,31(10):2053−2063. PAN Yue,GU Shitan,QI Yunsong. Analytic solution of tight roof's bending moment and deflection under swelling distributive supporting pressure[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(10):2053−2063.

[8] 靳钟铭. 坚硬顶板长壁采场的悬梁结构及其控制[J]. 煤炭学报,1986(2):71−79. JIN Zhongming. The hanging beam structure of hard roof in longwall workings and its control[J]. Journal of China Coal Society,1986(2):71−79.

[9] 伍永平,郭振兴,马彩莲,等. 坚硬顶板大采高采场支架阻力的确定[J]. 西安科技大学学报,2010,30(2):127−131. WU Yongping,GUO Zhenxing,MA Cailian,et al. Study on supports’ resistance of high mining height face based on simulation experiment[J]. Journal of Xi’an University of Science and Technology,2010,30(2):127−131.

[10] 王家臣,潘卫东,李诚. 葛泉矿坚硬顶板综放开采三维数值模拟[J]. 采矿与安全工程学报,2008,25(3):272−276. WANG Jiachen,PAN Weidong,LI Cheng. 3D numerical simulation of top coal caving with hard roof in Gequan mine[J]. Journal of Mining & Safety Engineering,2008,25(3):272−276.

[11] 谭诚.煤层巨厚坚硬顶板超前深孔爆破强制放顶技术研究[D].淮南: 安徽理工大学, 2011.

TAN Cheng.Research on advance deep hole loose blasting technology in coal seam thick hard roof[D].Huainan: Anhui University of Science & Technology, 2011.

[12] 王开,康天合,李海涛,等. 坚硬顶板控制放顶方式及合理悬顶长度的研究[J]. 岩石力学与工程学报,2009,28(11):2320−2327. WANG Kai,KANG Tianhe,LI Haitao,et al. Study of control caving methods and reasonable hanging roof length on hard roof[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(11):2320−2327.

[13] 邓广哲,郑锐,徐东. 大采高综采端头悬顶水力切顶控制机理[J]. 西安科技大学学报,2019,39(2):224−233. DENG Guangzhe,ZHENG Rui,XU Dong. Control mechanism of hydraulic roof cutting for end suspended roof of fully−mechanized mining face with large mining height[J]. Journal of Xi’an University of Science and Technology,2019,39(2):224−233.

[14] 李方立,王成,段长寿. 超前深孔预爆破处理坚硬顶板的应用[J]. 采矿与安全工程学报,2001(3):72−74. LI Fangli,WANG Cheng,DUAN Changshou. Using advanced deep hole pre−blasting to deal with hard roof[J]. Journal of Mining & Safety Engineering,2001(3):72−74.

[15] 闫少宏,宁宇,康立军,等. 用水力压裂处理坚硬顶板的机理及实验研究[J]. 煤炭学报,2000,25(1):32−35. YAN Shaohong,NING Yu,KANG Lijun,et al. The mechanism of hydrobreakage to control hard roof and its test study[J]. Journal of China Coal Society,2000,25(1):32−35.

[16] 邓广哲,王世斌,黄炳香. 煤岩水压裂缝扩展行为特性研究[J]. 岩石力学与工程学报,2004,23(20):3489−3493. DENG Guangzhe,WANG Shibin,HUANG Bingxiang. Research on behavior character of crack development induced by hydraulic fracturing in coal−rock mass[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(20):3489−3493.

[17] 黄炳香,程庆迎,刘长友,等. 煤岩体水力致裂理论及其工艺技术框架[J]. 采矿与安全工程学报,2011,28(2):167−173. HUANG Bingxiang,CHENG Qingying,LIU Changyou,et al. Hydraulic fracturing theory of coal–rock mass and its technical framework[J]. Journal of Mining and Safety Engineering,2011,28(2):167−173.

[18] 冯彦军,康红普. 定向水力压裂控制煤矿坚硬难垮顶板试验[J]. 岩石力学与工程学报,2012,31(6):1148−1155. FENG Yanjun,KANG Hongpu. Test on hard and stable roof control by means of directional hydraulic fracturing in coal mine[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(6):1148−1155.

[19] 靳钟铭, 徐林生.煤矿坚硬顶板控制[M].北京:煤炭工业出版社, 1994.

[20] 孙守山,宁宇,葛钧. 波兰煤矿坚硬顶板定向水力压裂技术[J]. 煤炭科学技术,1999,27(2):51−52. SUN Shoushan,NING Yu,GE Jun. Directional hydraulic fracturing technology for hard roof in Polish coal mines[J]. Coal Science and Technology,1999,27(2):51−52.

[21] 黄小朋,张鹏鹏,闫耀飞. 矿井坚硬顶板定向水力压裂技术研究[J]. 中国煤炭,2017,43(7):55−57. HUANG Xiaopeng,ZHANG Pengpeng,YAN Yaofei. Research on directional hydrofracture technology in handling mine hard roof[J]. China Coal,2017,43(7):55−57.

[22] 张帆,马耕,刘晓,等. 煤岩水力压裂起裂压力和裂缝扩展机制实验研究[J]. 煤田地质与勘探,2017,45(6):84−89. ZHANG Fan,MA Geng,LIU Xiao,et al. Experimental study on initiation pressure and mechanism of fracture propagation of hydraulic fracturing in coal and rock mass[J]. Coal Geology & Exploration,2017,45(6):84−89.

[23] 郑凯歌. 碎软低透煤层底板梳状长钻孔分段水力压裂增透技术研究[J]. 采矿与安全工程学报,2020,37(2):272−281. ZHENG Kaige. Permeability improving technology by sectional hydraulic fracturing for comb−like long drilling in floor of crushed and soft coal seam with low permeability[J]. Journal of Mining and Safety Engineering,2020,37(2):272−281.

[24] 陈冬冬,孙四清,张俭,等. 井下定向长钻孔水力压裂煤层增透技术体系与工程实践[J]. 煤炭科学技术,2020,48(10):84−89. CHEN Dongdong,SUN Siqing,ZHANG Jian,et al. Technical system and engineering practice of coal seam permeability improvement through underground directional long borehole hydraulic fracturing[J]. Coal Science and Technology,2020,48(10):84−89.

[25] 郭超奇,赵继展,李小建,等. 中硬低渗煤层定向长钻孔水力压裂瓦斯高效抽采技术与应用[J]. 煤田地质与勘探,2020,48(6):103−108. GUO Chaoqi,ZHAO Jizhan,LI Xiaojian,et al. Technology and application of high efficiency gas extraction by directional long borehole hydraulic fracturing in coal seams of medium hardness and low permeability[J]. Coal Geology & Exploration,2020,48(6):103−108.

[26] 王建利,陈冬冬,贾秉义. 韩城矿区碎软煤层顶板梳状孔水力压裂瓦斯抽采工程实践[J]. 煤田地质与勘探,2018,46(4):17−21. WANG Jianli,CHEN Dongdong,JIA Bingyi. Practice of gas drainage by hydraulic fracturing of roof pectination boreholes in broken soft coal seam in Hancheng mining area[J]. Coal Geology & Exploration,2018,46(4):17−21.

[27] 杨俊哲,吕清绪,郑凯歌,等. 浅埋特厚硬煤层过沟谷开采超前区域弱化控制技术[J]. 中国煤炭,2021,47(6):13−20. YANG Junzhe,LYU Qingxu,ZHENG Kaige,et al. Weakening control technology in advanced region during mining through gully area in shallow buried extra–thick and hard coal seam[J]. China Coal,2021,47(6):13−20.

[28] 杨俊哲,郑凯歌,赵继展,等. 浅埋近距离上覆遗留煤柱应力集中灾害压裂治理技术研究[J]. 矿业安全与环保,2020,47(4):82−87. YANG Junzhe,ZHENG Kaige,ZHAO Jizhan,et al. Research on fracturing treatment technology of concentrated stress disaster by the overlying coal pillar in close distance shallow seam[J]. Mining Safety & Environmental Protection,2020,47(4):82−87.

[29] 杨俊哲,郑凯歌,王振荣,等. 坚硬顶板动力灾害超前弱化治理技术[J]. 煤炭学报,2020,45(10):3371−3379. YANG Junzhe,ZHENG Kaige,WANG Zhenrong,et al. Technology of weakening and danger−breaking dynamic disasters by hard roof[J]. Journal of China Coal Society,2020,45(10):3371−3379.

[30] 杨俊哲,郑凯歌. 厚煤层综放开采覆岩动力灾害原理及防治技术[J]. 采矿与安全工程学报,2020,37(4):750−758. YANG Junzhe,ZHENG Kaige. The mechanism of overburden dynamic disasters and its control technology in top–coal caving in the mining of thick coal seams[J]. Journal of Mining & Safety Engineering,2020,37(4):750−758.

[31] NASIRISAVADKOUHI A. A comparison study of KGD,PKN and a modified P3D model[EB/OL]. (2015−07−30) [2021−08−01]. https://www.Researchgate.net/publication/280568251.

[32] 赵睿,范涛,李宇腾,等. 钻孔瞬变电磁探测在水力压裂效果检测中的应用[J]. 煤田地质与勘探,2020,48(4):41−45. ZHAO Rui,FAN Tao,LI Yuteng,et al. Application of borehole transient electromagnetic detection in the test of hydraulic fracturing effect[J]. Coal Geology & Exploration,2020,48(4):41−45.

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