Electromagnetic characterisation of terrain for unconventional petroleum exploration

Abstract

A method to characterize the electromagnetic (EM) signature of barefaced terrain using 3D computer electromagnetic models (CEM) for radar applications is presented. Five barefaced terrain types with different electrical, physical and chemical properties were investigated. They include both homogeneous and heterogeneous terrain types particularly beach sand, gravel and pebble acquired locally and oil sands from Nigeria. The approach develops CEMs using reflectance spectroscopy and dielectric permittivity data. First geochemical signatures were determined using reflectance spectroscopy in the Near Infrared region while dielectric properties were experimentally determined at L-, C- and X-band for multi-frequency radar. Both viscous and hard oil sand indicated resonance effects in the upper C-band. The results provide new information on the complex electrical permittivity ε*(co) and loss tangent, tan ö. Finally a laboratory based approach to measure the relationship between sensor configuration and terrain backscatter for 0.013m3 of terrain samples using microwave measurement techniques in an anechoic chamber is outlined.