Tracking Fluid Flow from All Scales Using Self-Potential Tomography
The self-potential tomography is a new method to image non-intrusively ground water flow at all scales. When water moves through a porous material, it creates a small electrical current of electrokinetic nature. This source current is responsible of an electrical field that can be measured in boreholes or at the ground surface of the Earth or at the sea floor. The forward problem corresponds to the modeling of this electrical field associated with the numerical solution of the ground water flow problem. This is done using the finite element code Comsol Mutiphysics 3.4. The petrophysical model has been extended to multiphase flow and accounts for the deformation of the rocks. The inverse problem corresponds to the deer;ination of the permeability of the geological system under consideration or the pattern of ground water flow using the self-potential data, auxiliary data for resistivity, and possibly a prior information. Various cases will be shown showing the usefulness of the methods at various scales. They include pumping/injection tests and the inversion of the permeability strcuture at the scale of a gothermal system.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009