Forward Modeling Study on the Characteristics of the Frequency-domain Response of Borehole-Surface Electromagnetic Method

The Borehole-Surface electromagnetic method(BSEM) is considered as a very sensitive and effective electromagnetic method. In this paper, forward modeling research was conducted to analyze the characteristics of the frequency-domain response of BSEM.The forward modeling results show that the BSEM anomalies of the targets at excited layer are obvious, but exceptionally complex, also rapidly decrease with increasing the distance from the targets to the borehole. The target with a distance to the borehole generate anomaly near borehole, also trend anomaly in the periphery; the relative anomaly of the target being away 1000m to the borehole is less than 1% in the forward test.