Enhancement Of Oil Recovery Via Direct Current

Direct current(DC) electric field is a new, enhanced oil recovery technique in recent years. As the shortage of crude oil resources is a major matter facing the world, enhanced oil recovery is an effective way to alleviate the problem. However, as the high permeability reservoirs enteringin to the stage of high water cut, the fractured-vuggy low permeability reservoirs become a major bottleneck in oil exploration. Using conventional methods to deal with fractured-vuggy low permeability reservoirs, nearly50-70%of the crude oil can not be mined. Therefore, the enhancement of oil recovery via direct current has abroad development prospects. The main work has four parts as shown:Mathematical models are established to describe single-phase fluid flow in fractured-vuggy media under the influence of an electric field. The finite element equations of numerical models are derived. The fluid flow mechanism in fractured-vuggy media under the influence of electric field is systematically investigated using COMSOL Multiphysics software. The distributions of velocity, in the fracture and vugare studied. The results show that the electric field effectively increases fluid flow. The distributions of isobarand equipotential line can be affected by the fractureand vug.Different width-diameter ratio and different number of fracture-hole models are built to make depth research of the impact of the external DC electric field on the single-phase fluid flow in the different structure of media. There suits show that the external DC electric field can effectively increase the flow fluid in the fractured-vuggy media; a larger width-diameter ratio results in a larger seepage velocity. The significant influence of the electric field on the lower penetrance of the fracture-vuggy model is observed; a greater number of holes results in smaller seepage velocities. A conspicuous effect of an electric field apply on lower number of holes in the fractured-vuggy model is observed.On analysis, the most obvious effect occur when the value of DC electric field is about150V in the range of0-300V, the seepage velocity in single-phase mathematical models reache a maximum value, and the enhanced oil recovery effects are the most obvious too.According to the numerical simulation conclusion, with150V DC electric field as a standard,150V Regulated DC Power supply are initially designed around center on LM317voltage regulator, and then Multisim simulation software is applied, the steady DC field is obtained.