Features of apparent resistivity anomaly of CSAMT and prospects of oil shale in Tongchuan area of southern Ordos basin, China

Abstract

Four CSAMT (Controlled Source Audio-frequency Magnetotelluric) profiles were conducted in early 2011 in order to investigate the distribution rules of oil shale in Tongchuan area of southern Ordos basin. After terrain correction, we high-pass filtered the resulting images to prepare the 2D CSAMT apparent resistivity profiles for further analysis. Specifically, we correlated the high-pass filtered apparent resistivity anomalies to the distribution of oil shale seen in three available wells. The results show a close relationship between the oil shale distribution and the anomalously high apparent resistivity belt-like anomalies in the Tongchuan area. Our analysis indicates two prospective areas with different depths for oil shale within the study area.