摘要
随着我国煤炭开采深度的不断增加,冲击地压等煤岩动力灾害日益加剧,严重影响到煤矿安全生产。综合采用理论分析、装备研发,技术开发、工程实践等方法,研究了厚煤层综放开采的覆岩运动特征、动静叠加载荷作用下冲击动力灾害发生原理,提出了坚硬顶板多点拖动式分段水力压裂冲击防治方法,并在神东布尔台煤矿开展了工程应用。结果表明:综放开采中-低位关键层破断方式逐渐由悬臂梁式过渡为砌体梁式,控制采掘扰动形成的动载荷,改造覆岩破断形式是解决冲击动力灾害的关键。通过顶板分段水力压裂弱化技术实施,压裂最高压力30.7 MPa,破裂压降最大达10.0 MPa,出现3.0 MPa以上压力降200余次。单个压裂钻场弱化影响范围达走向300m,倾向230m;压裂后顶板来压步距、动载系数、最高压力较未压裂段分别降低了20.00%~69.70%、5.79%~7.90%、13.44%~18.37%,验证了顶板弱化的有效性。
With the increasing of mining depth,the coal mine safety production is seriously affected by coal-rock dynamic disasters such as rock burst which is increasingly intensifying.The characteristics of overburden movement in mechanized top caving mining of thick coal seams and mechanism of coal-rock dynamic disasters caused by the superposition of static and dynamic loads have been studied through theoretical analysis,equipment research and development,technological development and engineering practice.Based on these,the control methods for preventing rock burst of multi-point drag hydraulic fracturing of rigid roof have been proposed,and the engineering application has been carried out in Buertai coal mine.The results have shown that the rupture pattern changes from cantilever beam to masonry beam by middle-low key stratum.The key to solve the coal-rock dynamic disaster is the dynamic load controlling the formation of mining disturbance and the form of reforming overburden fracture.The maximum hydraulic fracturing pressure is 30.7 MPa,the maximum fracture pressure drop is 10.0 MPa,and the pressure drop above 3.0 MPa is more than 200 times by implementing the roof section hydraulic fracturing weakening technology.The weakening influence range of a single fracturing drilling strike length reaches 300 m,with a tendency of 230 m.Compared with the un-fractured sections,the pressure step,dynamic load coefficient and maximum pressure reduced by 20.00%~69.70%,5.79%~7.90%,13.44%~18.37%respectively,and the effectiveness of weakening roof fracturing is verified.
作者
杨俊哲
郑凯歌
YANG Junzhe;ZHENG Kaige(Shenhua Shendong Coal Group Corporation Limited,Shenmu,Shaanxi 719315,China;Xi’an Research Institute of China Coal Technology&Engineering Group Corp,Xi’an,Shaanxi 710077,China;School of Earth and Environment,Anhui University of Science and Technology,Huainan,Anhui 232001,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2020年第4期750-758,共9页
Journal of Mining & Safety Engineering
基金
“十三五”国家科技重大专项项目(2016ZX05045002-002)
关键词
冲击矿压
动力灾害
分段水力压裂
破断方式
来压步距
动载系数
impulsion pressure
dynamic disaster
staged hydraulic fracturing
rupture pattern
pressure step
dynamic load coefficient
