A mathematical model for estimating electric osmose effect on water displacing oil process in porous media and its application

摘要

A mathematical model based on Darcy' s law and electric - osmosis equation in porous media was developed and two parameters named electric osmose coefficient K{sub}e and relative electric osmose coefficient K{sub}(re) were used to calculate the curves of K{sub}e and K{sub}(re) vs. water saturation which were employed to estimate the effect of electric osmose on water displacing oil process in sandstone cores . Under the conditions of constant injection rate displacement and constant electrical potential gradient, the method to calculate parameters K{sub}e and K{sub}(re) at different water saturation was developed and unsteady-state displacement experimental data under the effect of electric osmese were used to determine the parameters' value. The results show that K{sub}e and K{sub}(re) were increased firstly with increasing water saturation and then decreased This trend show the inter - relationship between electric - osmosis and the water displacing oil process. Finally application of the model to ECMP mechanics studies and actual reservoirs was analyzed in this paper.