Mechanism Of Fluid Flow In Fractured Media Under Electric Fields

It is a new technology to enhance oil recovery by electric field methods. Mechanism of fluid flow in various porous media under electric fields is one of contents in this subject. In this paper, mechanism of one- and two-phase fluid flow in fractured media with different structures under electric fields was systematically investigated by finite element method (FEM).Based on electroosmosis-electrophoresis theory, the mathematical models of one- and two-phase fluid flow in fractured media under electric fields were established. They were solved by FEM. The error between the results of numerical simulation in this paper and the experimental data in literatures is less than 5.14%. It is shown that mathematical models are correct.Nine models of fractured media were designed, which are different in fracture aperture, fracture density and fracture connectivity, respectively. One- and two-phase fluid flow in these fractured-media models under electric fields were numerically simulated by FEM. When an electric-field strength ranging from 0 to 4.5V/cm was applied, the velocity of single-phase fluid flow in fractured-media models is 1 to 8.2 times bigger than that without electric field; and in the case of two-phase fluid flow in fractured models, water saturation in fractured-media model was reduced by 0 to 27.3%. On the condition of the same pressure gradient and electric-field strength, the influence of electric fields on one- and two-phase fluid flow in fractured media model is more remarkable if the absolute permeability of this fractured media model is smaller.The conclusions in this paper are the theoretical basis of enhancing oil recorvery of fractured reservoir by electric field methods. And it is very important to direct the enhancing oil recovery of fractured reservoir by electric fields.