Study On The Coupling Mechanissm Between Electromagnetic Field And Elastic Wave Field In Multi Phase Saturated Porous Media

The mutual coupling information between electromagnetic field and elastic wave field of seismoelectric effect in porous media has important significance for improving the level of geophysical exploration and studying the new methods of geological exploration and well logging.While the existing studies on the seismoelectric theory in porous media are mostly concentrated on water saturated condition,there are few studies on the case of saturated by multi phase,and it restricted the promotion and application of related technologies.Therefore this article combines the elastic wave theory in unsaturated porous media and Maxwell's electromagnetic theory,using the electrokinetic coupling theory and the coupling theory of current field and seepage field in gas-water saturated porous media,in order to establish the mathematical models of describing the seismoelectric effect,the complex resistivity effect in gas-water saturated porous media and oil-water saturated porous media respectively.Then the microscopic mechanism and influence factors are analyzed by quantitative simulation respectively.First,considering the case of the porous media saturated by gas and water based on the elastic wave theory in the unsaturated porous media by other authors,derive the propagation theory of the elastic wave in gas-water saturated porous media.Quantitatively simulate the propagation characteristics of the elastic wave,and inquire the influence of frequency and water saturation on it.Thus the foundation of further study on the seismoelectric effect in gas-water saturated porous media is established.Second,the electrokinetic coupling theory and the established elastic wave theory in gas-water saturated porous media and Maxwell's electromagnetic theory are combined to establish the mathematical model describing the seismoelectric effect in gas-water saturated porous media.Quantitatively simulate the response characteristics of plane seismoelectric wave field,and inquire the influence of porous media parameters on the propagation characteristics of seismoelectric wave.Third,transforming the elastic wave theory in gas-water saturated porous media to the case of saturated by oil-water,combine the electrokinetic coupling theory and the elastic wave theory in oil-water saturated porous media and Maxwell's electromagnetic theory,in order to estabilish the mathematical model describing the seismoelectric effect in oil-water saturated porous media.Quantitatively simulate the propagation characteristics of seismoelectric wave,and inquire the influence of porous media parameters on it.Last,based on the study of the seismoelectric effect in oil-water saturated porous media,according to the two-electrod method,derive the mathematical model describing the complex resistivity in oil-water saturated porous media,and quantitatively simulate the frequency dispersion characteristics of complex resistivity,inquire the influence of porous media parameters on it.And try to quantitatively simulate and analysis the frequency dispersion characteristics of complex resistivity in gas-water saturated porous meida with this method.