Cross-well electromagnetic imaging in three dimensions

Abstract

In this paper we develop a new technique for 3-D cross-well electromagnetic imaging based on the localized quasi-linear (LQL) approximation introduced by Zhdanov and Tartaras, 2002. This approximation was specially designed for modelling the electromagnetic field generated with a moving transmitter. Using the LQL approximation, which is independent on the source position, one can model and invert the EM data for all transmitter and receiver positions at once. This remarkable property of the LQL approximation makes it a practical tool for 3-D imaging of the cross-well EM data. In the numerical inversion algorithm we implement the options for smooth or focusing regularized imaging, which helps generating a clear focused image of the geological target. The numerical examples demonstrate effectiveness of this technique in 3-D cross-well electromagnetic data interpretation for imaging both conductive and resistive targets.