The relevance of the kozeny-carman coefficient for the processes of fluid flow,electric current conduction,and seismic wave (acoustic signal) propagation and attenuation through porous media

摘要

Flow of fluid(s),conduction of electric surrent,and propagation and attenuation of sound vibrations (seismic waves and acoustic signals) throgh porous media are complicated processes governed by several lithophysical characteristics of the composite solid particles (grains),fluid molecules,and pore spaces,as well as the interactions among them.Some of the influences that considerably affect the three processes (fluid flow,electric current conduction,and propagation and attenuation of sound vibrations) are: type,size and shape of grains; clay content; porosity; permeability; tortuosity (geometry of pore channels or capillary tubes); degrees of compaction,consolidation and cementation; viscosity,density, compressibility and temperature of saturant; and degree of saturation.In this study,emphasis is placed on the Kozeny-Carman coefficient (K_(infinity)) of the Kozeny-Carman equation and its relevance for the three processes,as K_(infinity) is affected by properties of the composite grains,pore fluid(s),and pore spaces,as well as by the overall lithophysical characteristics of porous media.The K_(infinity) is defined as tortuosity (#tau#) times shape factor (S_(hf)),and thus,it varies with variations of #tau# and/or S_(hf),of the Kozeny-Carman equation (Kozeny,1927;Carman,1937, 1938) is analogous to the Archie cementation factor (m) of the Archie-Winsauer equation (Archie,1942; Winsauer et.al.,1952), because both parameters (S_(hf),m) account for the same influences (shape and type of grains and pores,specific surface area,tortuosity,anicotropy,and overburden pressure). It is also shown that the Kozeny-Carman coefficient, K_(infinity) is analogous to the acoustic coupling factor (structure factor,#kappa#) of the Biot's theory of elasticity (Biot,1956a,b; 1962a,b).For a porous medium,the analogy between K_(infinity) and #kappa# is due to the fact that both parameters account for the same influences [sinuosity of pore channels (expressed in terms of tortuosity,#tau#); and shape of pore channels,pores and grains (expressed in terms of the shape factor,S_(hf))].