Geometric 3D inversion application for recovering the polarizability of geoelectric-heterogeneous geological media

The paper presents the 3D-inversion computational scheme for recovering the boundaries of 3D anomalous polarizable objects and their polarizability in a 3D conductive heterogeneous medium with the use of electric field measurements on the Earth's surface. In order to solve a direct problem, we use a special computational scheme which allows presenting the induced polarization (IP) field as superposition of fields induced by each polarizable subdomain. This makes it possible to increase the computational efficiency of both forward and inverse problems. In order to solve the inverse problem, the volume being investigated is divided into subdomains so that each survey profile should cross one row of subdomains. The unknown parameters in 3D-inversion are subdomains boundaries along profiles and their polarizability, but boundaries along the axis orthogonal to profiles are fixed. The numerical results obtained with the use of synthetic IP data show that, if the conductivity of 3D medium is known, the approach developed enables us to define with high accuracy the polarizability of 3D objects and their boundaries along profile, even if the recovered polarizable subdomains boundaries along the axis orthogonal to profiles do not coincide with the boundaries of real objects.