Against the backdrop of the continuous growth of global energy demand, heavy oil, as an important unconventional resource, and its efficient exploitation are of great significance for ensuring national energy security. Electric field-enhanced oil recovery technology has broad prospects for development in the green exploitation of heavy oil. However, at present, few studies have comprehensively considered these mechanisms and established a microscopic numerical simulation model for electric field-assisted hot water flooding for oil recovery from heavy oil reservoirs. This paper considered the mechanism of direct current electric field in reducing crude oil viscosity, interfacial tension, wetting angle, and electroosmotic flow. A fully coupled mathematical model of flow field–temperature field–direct current electric field was established. The model was solved by the finite element method and verified through previous experiments. Using this model, the effects of the potential difference at both ends of the porous medium, the direction of the electric field, the wetting angle, and the interfacial tension on the degree of heavy oil recovery were studied. Finally, the hot water flooding and the direct current (DC) electric field-assisted hot water flooding technology for enhanced oil recovery were compared. The research results show that as the potential difference between the two ends of the porous medium increases, it will inhibit the premature breakthrough of water and prolong the water breakthrough time. As a result, the water will be displaced along the smaller pore throat, thereby playing a role in expanding the volume of water displacement waves. The degree of recovery is the greatest when the direction of the electric field is consistent with the displacement direction. The smaller the wetting angle and interfacial tension, the greater the degree of heavy oil recovery. Compared with hot water flooding, the direct current electric field-assisted hot water flooding can significantly increase the recovery degree of heavy oil.
Zhang et al. (Sun,) studied this question.