| abstract
|  Current theories of two-phase flow in
porous media are based on the so-called extended Darcy’s law, and an algebraic
relationship between capillary pressure and saturation. Both of these
equations have been challenged in recent years, primarily based on theoretical
works using a thermodynamic approach, which have led to new governing
equations for two-phase flow in porous media. In this research, these
equations and also other physical aspects of multiphase flow in porous media
are studied. To gain detailed insights into the processes and for quantitative
assessment pore-network modelling has been employed. In this work, we have
developed robust quasi-static and dynamic pore-network models. Several
quasi-static and dynamic pore-networks have been developed to study
relationships between average phase pressures, average capillary pressure, and
specific interfacial area during drainage and imbibition. Other aspects of
flow in porous media such as rapping mechanisms, saturation profile,
non-equilibrium effects in pressure and interfacial area are investigated. In
addition to the investigation of physics of multiphase flow, we have developed
new approaches for better presentation of porous media, which are employed in
quasi-static models. Quasi-static simulations are done in three different
media; a hypothetical porous medium, a two-dimensional micro-model, and a
three-dimensional glass-bead column. Capabilities of the models in simulating
experiments as well as providing more detailed information about the
experiments are shown. This may be impossible and time-consuming in laboratory
experiments. Furthermore, a dynamic pore-network model with improved numerical
features is developed. New algorithms in dynamic pore-network modelling
provide very flexible formulations to simulate the two-phase flow in different
capillary numbers and different viscosity ratios for drainage and
imbibition. |
