摘要
针对双厚组合坚硬顶板厚煤层工作面开采过程中的强矿压显现问题,本文提出了定向长钻水力压裂方案,并基于压力实测、瞬变电磁及钻孔窥视方法从孔内、孔外、动态、静态四个方面对定向长钻水力压裂裂缝扩展进行可视化监测评价。研究成果表明:压裂过程包括钻孔周围微裂隙发育扩展,出现宏观裂缝,宏观裂缝周围微裂隙发育,出现新的宏观裂缝,直至压裂完成;钻孔径向20m范围内岩层电阻率较低,大裂缝较为发育;设计的3个钻孔压裂后影响范围基本可以覆盖整个顶板治理区域;长钻孔内各压裂段裂隙可以实现贯通,钻孔内纵裂隙、横裂隙交替发育形成三维裂隙网络;压裂后顶板微震事件总能量和总次数都显著降低,压裂层位顶板能量提前释放,表现为“高频低能”显现,工作面来压强度明显改善。
Aiming at the problem of strong mine pressure in the mining process of thick coal seam working face with double thick combined hard roof,this paper proposes a directional long drilling hydraulic fracturing scheme,and based on the pressure measurement,transient electromagnetic and borehole peeping method,the visual monitoring and evaluation of directional long drilling hydraulic fracturing crack propagation is carried out from four aspects:inside and outside the hole,dynamic and static.The research results show that the fracturing process includes the development and expansion of microcracks around the borehole,the emergence of macrocracks,the development of microcracks around macrocracks,and the emergence of new macrocracks until the completion of fracturing.The resistivity of the rock layer is low within the range of 20 m in the radial direction of the borehole,and the large cracks are more developed;the influence range of the three designed boreholes after fracturing can basically cover the whole roof control area.The fractures of each fracturing section in the long borehole can be connected,and the longitudinal and transverse fractures in the borehole develop alternately to form a three-dimensional fracture network.After fracturing,the total energy and total number of roof microseismic events are significantly reduced,and the roof energy of the fractured horizon is released in advance,showing“high frequency and low energy”,and the pressure intensity of the working face is obviously improved.
作者
杨欢
王泽阳
郑凯歌
李彬刚
李延军
杨森
王豪杰
戴楠
王林涛
YANG Huan;WANG Zeyang;ZHENG Kaige;LI Bingang;LI Yanjun;YANG Sen;WANG Haojie;DAI Nan;WANG Lintao(Lanzhou Resources&Environment Voc-Tech University,Lanzhou 730030,China;Xi’an Research Institute of China Coal Technology Engineering Group Corp,Xi’an 710077,China;School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China)
出处
《中国矿业》
2024年第1期163-169,共7页
China Mining Magazine
基金
中煤科工西安研究院(集团)有限公司科学创新基金项目资助(编号:2022XAYJS04)
新锐博士基金项目资助(编号:2021XAYXR01)。
关键词
坚硬顶板
矿压治理
压裂弱化
评价方法
瞬变电磁
hard roof
mine pressure control
fracturing weakening
evaluation method
transient electromagnetic
