| In this study, it was attempted to develop a mathematical model for electrically assisted oil transport in porous media. The main implementation of the model would be in predicting the oil recovery in electrically enhanced oil recovery method. First, the contributing factors to the electrically assisted oil transport in porous media were investigated through laboratory experiments. Some of these contributing factors were found to be (i) viscous drag of oil with electro-osmosis of the water phase, primarily controlled by the oil/water ratio and the hydraulic and electro-osmotic permeability of the formation; (ii) reduction of oil-water interfacial tension due to electrochemical transformation of oil that affect its viscosity, hence increases its mobility, and (iii) increase in the permeability of the formation rock under applied electric field. A mathematical model that couples the pressure and electric gradients applied to the porous medium and incorporates the viscous drag of water on the oil phase under applied electric gradient was developed. Implicit Pressure Explicit Saturation (IMPES) solution strategy was used to solve the set of governing equations and Finite Volume Method (FVM) was used to solve the model numerically and to run several simulations. One of the most important constitutive relationships necessary for solution of the model, relative permeability coefficients as a function of water saturation, were introduced and evaluated under applied electric field in this study. Although it was attempted to capture the most important parameters in the development of the mathematical model, to have a model that more realistically represent the electrically assisted oil recovery phenomena in reservoir scale, the transient change in the viscosity of formation oil and the non-isothermal effects should also be considered in the model for future researches. |
