Patent ID: 8482287
Filing Date: 2013-07-09
Classification: G01V

Abstract:
1. A method of determining electrical anisotropy in a subsurface formation, comprising the steps of: providing electromagnetic field data from a multi-offset electromagnetic survey obtained by using an electromagnetic source and a plurality of electromagnetic receivers at varying offset distances from the source, the electromagnetic source and plurality of electromagnetic receivers being located above the subsurface formation, the electromagnetic field data comprising a first set of multi-offset response signals received at each receiver with the electromagnetic source emitting at a first frequency, and at least one additional set of multi-offset response signals received at each receiver with the electromagnetic source emitting at a different frequency; comparing the first set and the at least one additional set of multi-offset response signals; determining the presence of electrical anisotropy in the subsurface formation from the comparison of the first and at least one additional sets of multi-offset response signals; wherein comparing the first set and the at least one additional set of multi-offset response signals comprises comparing both electric field amplitude attributes and phase attributes of the multi-offset response signals.