Short note: A simple interpretation aid for downhole time?domain electromagnetic anomalies

Abstract

The transient magnetic fields in a borehole near a plate-like conductor can be simulated with a simple current loop in the plane of the conductor. The shape of the response with depth in the hole is related to the position and orientation of the current loop, so that characteristics of the response such as the zero-crossing separation can be used to predict the location of the current loop and therefore the location of the conductor in which the current circulates. Physical model results verify the application of the characteristics in this way.