Analysis and application of the detection depth of electrical source Short-offset TEM
XUE Jun-Jie1, CHEN Wei-Ying2, WANG He-Yuan1
1. College of Sciences, Liaoning University of Technology, Jinzhou 121001, China; 2. Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing 100029, China
Abstract：There are several concepts of depth in transient electromagnetic method, including diffusion depth, limit detection depth, effective detection depth and apparent detection depth. In this paper, we conducted the calculation, analysis and application to these different depths based on the method of SOTEM. The diffusion depth represent the diffusion and propagation of the underground transient EM field, the limit detection depth reveals the detectability of SOTEM and the results indicate that the greatest depth will be obtained when the offset approximately equal to the 0.7~1 times of buried depth of targets, and the apparent detection depth can give a estimation of the actual detection depth for a given recording time which have a significant meaning to the field work designing. At last, we proposed a synthetic model and a filed example to verify the feasibility and accuracy of using apparent detection depth to estimate the actual detection depth of SOTEM.
