直流电场提高水驱油效率的数值模拟方法

从毛细管双电层理论出发，结合孔隙介质的电渗流理论，建立了直流电场作用下油水两相的渗流方程。在恒压降注水条件下，利用有限差分法对假定油藏进行了数值模拟计算。结果表明，在直流电场的作用下，水相渗透率降低，油相渗透率提高；在水驱油过程中，直流电场使含水率下降，产油量上升；在含水率为２０％～７０％时用直流电场处理水驱油藏，控水效果好。用直流电场处理高含水油藏，增产效果明显，在含水８０％时用１００Ｖ／ｍ的直流电场对油藏作用３个月，采收率可提高１．６％左右，且采收率的提高与渗透率无关。

NUMERICAL SIMULATION METHOD FOR ENHANCING WATERFLOODING EFFICIENCY USING DIRECT CURRENT ELECTRIC FIELD

Based on the theory of electric double layer and electric osmosic theory of porous media, a mathematical model for electrokinetic waterflooding was developed. A reservoir was simulated by using finite difference approach. Under the action of direct current electric field on the reservoir, oil mobility increased and water permeability reduced. The water percentage is reduced under the action of direct current electric field when water percentage is in the range of 20% to 70%. The oil production is improved by applying direct current electric field in high water percentage. The increase of oil recovery is about 1.6% under action of a direct current field of 100 V/m for 3 months. The increase of oil recovery has nothing to do with permeability.