含水采空区瞬变电磁时空响应特征研究及应用  

Spatiotemporal response characteristics of transient electromagnetic field in water-bearing goaves and their applications

作　　者：宋贵磊 公绪飞 杨富强 崔建廷 李瞻领 刘丽娜[1] SONG Guilei;GONG Xufei;YANG Fuqiang;CUI Jianting;LI Zhanling;LIU Lina(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Ordos Haohua Clean Coal Co.,Ltd.,Ordos 017000,China)

机构地区：[1]山东科技大学能源与矿业工程学院,山东青岛266590 [2]鄂尔多斯市昊华精煤有限责任公司,内蒙古鄂尔多斯017000

出　　处：《煤田地质与勘探》2024年第12期201-212,共12页Coal Geology & Exploration

基　　金：国家自然科学基金项目(52374097);山东省泰山学者工程项目(tstp20221126);山东省自然科学基金项目(ZR2022ME158)。

摘　　要：【目的与方法】为提高矿井瞬变电磁法对煤矿含水采空区的成像精度,基于高家梁煤矿地质条件,通过COMSOL有限元软件模拟不同层间距含水采空区模型的感应电磁场时空响应特征,分析其在视电阻率拟断面图及视纵向电导微分图分布规律;在鄂尔多斯高家梁煤矿开展了实地探测,成功识别出采空区含水情况。【结果和结论】结果表明:感应磁场在含水体内衰减速度慢于岩层内,电压衰减曲线可随时间的推移分为初始稳定衰减、相对缓慢衰减、相对快速衰减和最终稳定衰减4个阶段;层间距越小,初始稳定衰减阶段到相对缓慢衰减的转折点出现时间越早,相对缓慢衰减和相对快速衰减阶段持续时间越长,感应电压越大;磁感应强度最大值通常出现在含水采空区内,且随层间距增大线性减小;视纵向电导二阶微分能有效分辨高阻-低阻交界面,且层间距越小视纵向电导微分幅值越大;在高家梁煤矿20302和20313工作面采空区积水探测中,感应电压衰减转折点分别出现在718.51μs和1 004.31μs,根据相邻测道电压及视纵向电导微分变化,判断出积水横向分别分布在36~120 m和24~168 m,岩-水交界面分别出现在66 m和72 m处,并经钻探得到验证。研究结果可为矿井老空水探测及疏放提供指导,并对矿井安全生产具有重要意义。[Objective and Methods]This study aims to enhance the accuracy of the mine transient electromagnetic method(MTEM)in of imaging of water-bearing goaves.Based on the geological conditions of the Gaojialiang Coal Mine,this study simulated the spatiotemporal response characteristics of the induced magnetic field in the water-bearing goaf model under varying stratigraphic spacings using finite element software COMSOL.Accordingly,this study analyzed the distribution patterns of the induced magnetic field on the apparent resistivity pseudosections and the plots of the differentials of longitudinal apparent conductivity.Using the results,the water-bearing conditions of goaves in the Ordos Gaojialiang Coal Mine were successfully identified during field detection.[Results and Conclusions]The results indicate that the induced magnetic field in water-bearing bodies exhibited lower decay rates than that in rock layers.The time-varying voltage decay curves can be divided into four distinct stages:the initial stable,relatively slow,relatively rapid,and final stable decay stages sequentially.A greater stratigraphic spacing was associated with an earlier turning point between the initial stable and relatively slow decay stages,longer relatively slow and relatively rapid decay stages,and higher induced voltage.The maximum magnetic induction frequently occurred within the water-bearing goaves,decreasing linearly with an increase in the stratigraphic spacing.The second-order differentials of longitudinal apparent conductivity can effectively identify interfaces between high and low resistivity,with a smaller stratigraphic spacing corresponding to a higher amplitude of the second-order differentials.In the water detection of goaves along mining faces 20302 and 20313 in the Gaojialiang Coal Mine,the turning points of induced-voltage decay occurred at 718.51μs and 1004.31μs,respectively.The variations in the voltages between adjacent channels and the second-order differentials of longitudinal apparent conductivity reveal that water a

关 键 词：矿井瞬变电磁法 含水采空区 层间距 时空响应 数值模拟 

分 类 号：P631[天文地球—地质矿产勘探] TD745[天文地球—地质学]