Conductor Shield and Prospecting for Water-rifled Goaf in Multilayer

摘要

With coal mines in deep mining,prospecting for water-filled goaf in multilayer have become very important task of transient electromagnetic (Transient Electromagnetic,TEM) exploration of coal field hydrogeololgy.Generally,the thickness of coal layer is much smaller than buried depth.Coal layer and goafs with none water,the goafs with water form resistive and conductivity thin layers.It is different from prospecting for single conductive thin layer that in prospecting for water-filled goafs of multilayer,upper conductive layers will shield the bottom layers and need more long time window.Besides,the conductive layer makes responses of the bottom layer too weak to be identified.Therefore,the length of time window necessary to prospecting for water-filled goaf in multilayer first,than start from horizontal layered earth model,the behavior of conductive shield and coal measure thin layers have been analyzed directly using induction electromotive force curves.The result of prospecting for water-filled goafs of multilayer in Dazigou coal field,Datong Coal Mine show that it is feasible for prospecting water-filled goaf in multilayer together with Geophysical conditions.