Study on the Relationship between Lithological Differences and Electromagnetic Changes during Mine Water Inrush

Abstract To address the issue of low detection and identification accuracy of water sources and channels under mine water inrush conditions. The effects of lithology, water saturation, and salinity on the conductivity of five kinds of coal and rock were studied. The results show that the resistivities of coking coal, fine sandstones, and coarse sandstones increase with decreasing water saturation and formation water salinity, but those of mudstone and sandy shale are not affected. Sandy shale exhibits abnormally high resistivity under low- and medium-salinity conditions and low resistivity under high-salinity conditions; the resistivity does not change with increasing water salinity, and mudstone is basically not affected. The electromagnetic response characteristics identified for various coal and rock samples can increase the precision of geophysical detection and identification pertaining to mine water filling sources and channels.