Coupling Effect Of Electric Field And Fluid Flow In Porous Media

Coupling effect of electric field and fluid flow in porous media, which is also called streaming potential, is one kind of coupling flow phenomena accompy with flow process.The study of this effect is helpful to recognize fluid flow process in reservoir, to decide formation heterogeneity, to monitor injected water flow, to evaluate productivity of hydraulic fractures.This method has the potential to become a new dynamic monitoring tool. The thesis began with fundamental theory of the coupling electric effect, from electrical charge absorbed by solid surface of rock and structure of electrical double layer to the measurement and numerical simulation method of streaming potential; analysed how each physical parameter affect electric potential, established fundamental numerical model of coupling flow of fluid flow and electric current, deduced simplified model in different conditions; then simulated coupling electrical effect according to different condition,including 1D and 2D single phase flow model,3D water-oil flow model,calculated electric potential signal transmiting characteristics in multi-layer formation with different properties which not only include the whole source-reservoir-seal combination also include layers from deep earth to surface weathered layers, analysed the electric potential attenuation character in different depth,simulated electrical data during production of water drive in one quarter of five point well pattern model, the result shows electric potential vary with the water cut and position of oil-water front,analysed potential data scale with injector-producer borehole flowing pressure difference, permeability and coupling flow coefficient; designed and assembled the equipment to measure coupling electric potential in laboratory condition, measured coupling coefficient of NaCl solution in different concentration flow in sand pack with different grain size,compared the data with theoretical and experiment data in literature,checked stability of equipment set and data validity. Measured electric potential data of water/oil single phase flow and water drive in 1D sand pack model, got the potential data of water drive production in 2D cementing sand model for five point well pattern,compare the experiment data with numerical simulation data.Finnally,build the real model according to field production data,analysed three possible scheme in field test include evaluating injection water front in different layers by vertical heterogeneity and distribution of interlayer,monitoring production performance of hydraulic fractures,monitoring electric potential during CO₂ sequestration.The result has the enlightment meaning to the application of this method to production in future.