微小盆地倾斜煤层采空区瞬变电磁法探测

Detection of Mine Tunnels in Inclined Coal Seam of Small Coal Bearing Basin Using TEM

为研究微小含煤盆地倾斜煤层采空区的瞬变电磁法探测效果,以云南省新近系向斜盆地采空区为研究对象,从数值模拟与现场实测两方面对瞬变电磁探测效果展开研究。首先,针对研究区微小盆地构造条件建立倾斜煤层地电模型,以正演模拟和电阻率计算论证理论可行性;其次,根据模拟结果设置工作参数进行现场数据采集,以倾斜含煤段作为电性标志层追踪电阻率异常并推断采空区分布范围;最后,采用井下超前钻探对推断的采空区进行验证。结果表明,瞬变电磁法适用于探测微小盆地的构造变化而引起的地电结构的改变,探测结果清晰显示盆地倾斜含煤地层的起伏变化,能准确反映采空区的分布。

In order to study the effect of TEM on the detection of mine tunnels in small coal bearing basin inclined coal seam,mine tunnels of a syncline basin in Yunnan Province is taken as the research object,and research is carried out from numerical simulation and field measurement.First of all,the inclined coal seam electricity section model is set up based on geological conditions of the study area,one dimensional forward modeling and resistivity calculation are used to demonstrate the feasibility of the theory;Secondly,TEM network is arranged according to the conditions of the field,optimum working parameters are set up according to the simulation results,field data with high signal-to-noise ratio are collected,resistivity anomaly is identified according to take coal bearing section as electrical marker layer,and distribution and geological causes of mine tunnels are analyzed and deduced.Finally,the inferred mine tunnels are exposed by advance drilling undermine.The results show that TEM is adapted to the change of geoelectric section structure by inclined strata,the fluctuation of the inclined coal seam in the coal bearing basin,location and scope of mine tunnels are clearly identified by the detection results,and TEM is suitable for application in Neogene coal bearing basin inclined coal seam.