Study on the ability of transient electromagnetic method to identify low-resistance thin layer

Abstract

Based on the different field source theory of transient electromagnetic method, the transient electromagnetic response expression of electric dipole is given, and the transient electromagnetic response of long-line source and loop line source is calculated by the superposition principle of electromagnetic field. Based on the definition of the whole area apparent resistivity, the apparent resistivity of the three-layer model was calculated by the binary search, and the apparent resistivity curve was plotted. By comparing the apparent resistivity curves of different models, the resolution limits of transient electromagnetic methods for low-resistance thin layers under different conditions are analysed and discussed. The identification and resolution of low-resistance thin layers by transient electromagnetic method are summarized. Transient electromagnetic working devices are of great significance.