Viscous Fingering and Static/Dynamic Heterogeneity Induced Instabilities in Porous Media
Abstract
This dissertation addresses different aspects of flow instability in non-isothermal miscible displacements
through media with static and dynamic permeability distributions. The research
is conducted in three steps. In the first step non-isothermal flows in homogeneous media are studied by numerical simulation of the displacement process in a Hele-Shaw cell. The results show that the stability of the process highly depends on the strength of interactions between the two fronts determined by the thermal lag coefficient. The relative rate of diffusion of heat in the medium can magnify the effect of lag between the two fronts or compensate for
it depending on the considered scenario.
Miscible displacements with adverse mobility ratios are analyzed in the second part of
this study for layered heterogeneous media. The effects of the flow parameters and the heterogeneity characteristics of the domain are examined. Qualitative and quantitative analysis of the results lead to characterization and unification of four distinct regimes that govern the flow displacement for different parameters. The unification allows to distinguish between the
flows in which the instability is dominated by heterogeneity and those with viscous fingering dominant instability.
Finally in the last two chapters of this dissertation, the changes in the porosity and
permeability in melting porous media are modeled. The effects of the melting arameters
on the amount of melted material and the rate of melting are analyzed. In addition, the heat transfer mechanisms in presence of the bypassing flow around frozen blocks of different geometries are analyzed and their melting rates are unified based on the shape factor and initial porosity of the block. In study of the flow displacements prone to instability, the dominant mechanisms that affect the growth and patterns of instability for different melting
parameter values are recognized and their contribution to enhancement or attenuation of fingers are determined analytically. The study shows that instabilities in general enhance melting but the enhancement is limited for displacements with small melting potentials.
Description
Keywords
Engineering--Chemical, Engineering--Mechanical, Engineering--Petroleum
Citation
Sajjadi, M. (2015). Viscous Fingering and Static/Dynamic Heterogeneity Induced Instabilities in Porous Media (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28644