Investigation and application of the transient electromagnetic method for assessing water richness in the goaf of overburden coal seams at the 9104 working face

To ensure the safe extraction of the 9104 working face, this study identifies water-rich zones within the goaf of the overlying coal seam using a combination of geological analysis, transient electromagnetic (TEM) detection, and drilling verification. The methodology proceeds in distinct stages, systematically addressing the identification, delineation, and validation of potential water hazards. First, a hydrogeological analysis of the 9104 working face is conducted based on existing geological data. This analysis reveals that the primary latent water hazard originates from water accumulation in the goaf of the overlying No. 4-1 coal seam. Subsequently, tailored geophysical methods are selected based on the specific characteristics of the identified water hazards, enabling the design of an optimized detection strategy. Using detection data collected from the return air and transport channels, this study elaborates on the process of constructing apparent resistivity isoline slices for the No. 4-1 coal seam. This approach facilitates the precise delineation of anomalous water accumulation zones. Finally, the results demonstrate that integrating geological analysis, TEM detection, and drilling verification provides a robust framework for identifying and managing water hazards, thereby enhancing the safety of mining operations at the 9104 working face.