Steam-Zone Electrical Characteristics for Geodiagnostic Evaluation of Steamflood Performance

Abstract

Summary An essential part of the development of electrical geodiagnostic techniques for mapping thermal recovery processes is understanding the relationship of formation resistivity to the thermal recovery process. As a result of laboratory measurements of a 1D steamflood, a preliminary understanding of some of the mechanisms of the electrical resistivity change has been gained. The theory of electrical resistivity of a steamflood is reviewed and used to evaluate the resistivity changes expected. A conceptual electrical model of a steamflooded porous reservoir, based on a qualitative description of the fluid zones of an ideal heavy-oil steamflood, is presented. The model assumes that salinity, temperature, and saturation are the important factors controlling resistivity changes and that Archie's law applies. We found that the characteristics of each individual reservoir must be considered before the in-situ resistivity changes are predicted and that in-situ resistivity can either increase or decrease as a result of steamflooding.