3D Electromagnetic Inversion over a Near Surface Oil Contaminated Model

The paper summarizes the primer (frequency-dependent components of electric and magnetic field intensity) and secondary (frequency-dependent complex resistivity, component of the impedance tensor, phase of the impedance, etc.)electromagnetic (EM) field characteristics and analyses their applicability in the environment examination and environmental protection. An own-developed 3D hybrid-integral equation electromagnetic field modeling method and a software system as well as an inversion algorithm based on global optimization (Simulated Annealing) using the forward modeling procedure are presented. The horizontal and vertical contour maps of EM field characteristics were produced by the 3D hybrid-integral equation EM modeling method in case of a subsurface oil contamination. By means of these parameter images, the borders of the contaminated volumes can be determined (basement, cover, lateral extension) and the optimal frequency domain of the field measurements can also be projected. For the integrated visual and numerical analysis of EM field characteristics an Intergraph GeoMedia GIS based geoinformatical system was developed. The operation of this system is shown in case of a GIS database created by model computation of a subsurface oil contamination.