Inversion of magnetotellurics data with enhanced structural fidelity

Abstract

The magnetotelluric method has been successfully used as a complementary tool in the exploration of foothill plays but its intrinsic non-uniqueness and its reduced structural fidelity, with respect to a seismic section, make its interpretation more complex. Since the solution of a non-unique inverse problem is heavily dependent on its starting point, a traditional method to tackle the non-uniqueness relies on the careful definition of the starting model, used as a tool for injecting the available a-priori information into the inverse problem. We present an alternative approach to the exploitation of the a-priori knowledge that, instead of embedding it into the starting model, relies on the continuous assimilation of the structural/geological information into the resistivity volume. The method we propose for the inversion of the MT soundings tries to maximize, simultaneously, the data-fit and the structural fidelity. We discuss the advantages deriving from the application of this technique by mean of a synthetic example representative of a foothills play.