Research On The Mechanism Of Direct Current Electric Field Increasing Two-phase Seepage

As a new oil recovery technology,the application of an electric field to increase the recovery factor has been a research direction that cannot be ignored because of its advantages of zero pollution,low cost,and ease of use.The external electric field also has important research significance for the high-efficiency development of low-permeability reservoirs.Based on the theory of Electric phenomenon and reservoir porosity,a mathematical model of two-phase flow in porous media under the action of electric field is established.Through the study of the finite element solution method,the pressure finite element model and the porosity finite element model during two-phase seepage are deduced.Since the change of porosity will affect the flow velocity of the fluid in the reservoir,the effect of the applied electric field on the seepage flow is studied from the perspective of porosity.It is solved using the COMSOL Multiphysics software,and the curve of External electric field-flow rate is obtained.On the basis of the above research,three different pairs of pore radius models are designed in this paper,and electric fields are applied to the two ends of the two,respectively,to simulate the two-phase seepage of these porous media models.When both the pressure and the applied electric field are constant,the seepage velocity increases with the increase of the applied electric field,and the smaller the pore radius,the more obvious the flow velocity increases with the voltage difference.In the range of 0-30 k V,the best effect potential difference is 25 k V.At this time,the seepage velocity in the model tends to be gentle with the increase of the applied electric field,and its value tends to the maximum.By comparing and choosing the voltage-stabilized power supply combining Buck voltage feeding topology and positive and negative bidirectional voltage doubler rectification as the power supply for the external electric field,the principle and framework are briefly explained.According to the selected power supply and technical conditions,the feasibility of increasing the two-phase seepage mechanism studied by this paper is analyzed.