Abstract
Currently, Enhanced Oil Recovery (EOR) processes are monitored using gas analysis, geophysical logging, observation wells (P&T), well testing methods, seismic velocity tomography, or inversion of deformation measurements. These methods each have their strengths and weaknesses. Most EOR processes involve massive changes in the formation resistivity because of the introduction of a fluid phase with a different conductivity, or a large change in temperature. Threedimensional electrical resistivity tomography may be a way of tracking propagation of fluid fronts with time. We present general requirements for resistivity tomography in EOR, typical electrode installations to reduce noise and seasonal variations, requirements for a general inversion of a 3-D resistivity problem in EOR, sensitivity analyses for a shallow reservoir case subjected to EOR, and a method of rapid design evaluation of resistivity monitoring. We believe that analysis tools and the technology is now adequate to reevaluate and develop electrical monitoring for EOR applications.
