The CSEM Response in Horizontal Steel Casing for Geological Advance Forecast

Abstract

Water inrush is a prevalent geological hazard that poses a significant threat to human safety and property in underground mining operations. As deep mines are being rapidly exploited through tunnel construction, accurately predicting and detecting water inrush has become increasingly crucial. The land-based controlled source electromagnetic method (CSEM) is commonly employed to identify water-bearing structures. In order to enhance its sensitivity, we have proposed a novel measurement approach for CSEM, which involves deploying electromagnetic sensors within horizontally positioned steel-cased wells embedded in the coal seam. To evaluate the feasibility of this new approach, numerical modeling was conducted using COMSOL to address the challenges posed by the casing. The influence of the steel casing was investigated, and the results demonstrated that it has minimal impact on the measured magnetic field amplitude. Moreover, the magnetic field distribution along the horizontal casing well provided straightforward indication of any anomalous bodies surrounding the coal seam. Through numerical simulations, we have validated the proposed method as a viable and effective technique for detecting water-bearing structures during deep mineral exploration.