Numerical Simulation Of Electroosmotic Flow In Porous Medium Based On OpenFOAM

Due to the presence of an electric field,the electrodynamic effect of electroosmosis in rock layers has the potential to regulate the direction of oil displacement and achieve the function of intelligently searching for oil displacement.In addition,electric energy can be provided by renewable energy such as wind energy and solar energy,so as to reduce the carbon emission in the process of oil production and meet the major national strategic needs such as carbon peaking and carbon neutrality.Further research on the complex fluid flow problems in oil reservoirs is crucial for increasing crude oil output and improving oil recovery.The thesis,on the basis of the mathematical model of porous medium seepage under the electric field,summarizes the characteristics of porous medium,explains the reasons for the formation of diffused double layer and electroosmosis in electromotion phenomena,and derives the slip velocity of electroosmosis.At last,the motion equation of seepage under external electric field and the continuity equation of seepage under external electric field are derived and explained,and calculate and verify the feasibility of electroosmotic flow method in the external electric field.Based on the open-source toolbox Rheo Tool in OpenFOAM,a numerical simulation model of porous media under electric field is constructed using the dynamic interface changes of tracing solvents.It reproduces the physical process of micro porous medium electroosmotic flow,and conducts a series of numerical simulation studies on the flow characteristics of electroosmotic flow in porous medium.Firstly,the influence of external electric field strength,pressure,and electric field position on seepage is studied.The simulation results indicate that applying a certain range of electric fields at the access point of porous medium can promote the displacement of fluid flow and displacement,while applying a certain range of electric fields at or below the access point will significantly hinder the seepage in the porous medium.Adjusting the pressure within a lower range results in a more significant effect of the electric field on the fluid,while gradually increasing the pressure weakens the effect of the electric field on the fluid.Secondly,in order to study the seepage effect of porous medium with different porosity,10 groups of operating modes with different porosity are designed to carry out the research.With the increase of porosity,the time of fluid to reach the designated area shows a trend of increasing overall.However,due to the closeness of the model pore size and the randomness of the distribution in the solid region,the time of the fluid reaching the designated area is affected to a certain extent,and there are haphazard fluctuations in the relation curve between the two.Thirdly,through summarizing and analyzing the factors that affect seepage in the external electric field,an improved design and optimization are proposed for the current displacement seepage conditions,and multiple sets of flow field comparison analysis are designed.At last,the most efficient transport condition is evaluated and selected.The research results of this thesis can not only provide a certain theoretical basis for the directional control of seepage using the electric field method to improve oil recovery,but also offer a new research approach for the development and application of electric field effect to improve oil recovery technology.