HR: 14:10h
AN: H43J-03    [Abstracts]
TI: Quasi-Static Pore-Scale Network Models for Studying Pc-Sw-anw Relationship in Drainage and Imbibition
AU: * Joekar-Niasar, V
EM: joekar@geo.uu.nl
AF: Environmental Hydrogeology Group, Faculty of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Hassanizadeh, M
EM: hassanizadeh@geo.uu.nl
AF: Environmental Hydrogeology Group, Faculty of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Pyrak-Nolte, L
EM: ljpn@physics.purdue.edu
AF: Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IND 47907-2036, United States
AU: Berentsen, C
EM: Berentsen@geo.uu.nl
AF: Environmental Hydrogeology Group, Faculty of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Leijnse, A
EM: toonleijnse@gmail.com
AF: Soil Physics, Ecohydrology and Groundwater Quality Group, Wageningen University, Nieuwe Kanaal 11, Wageningen, 6709 PA, Netherlands
AB: We have developed two types of quasi-static pore-scale network models to simulate drainage and imbibition experiments in two-phase in a porous medium. These models are used to study relationship among capillary pressure (Pc), saturation (Sw), and interfacial area (anw). The first one is a standard pore-scale network model consists of pore bodies and pore throats connected to each other in a 3-D regular lattice structure. The second model has an irregular structure with no well-defined pore throat or pore body. It is based on the exact geometry of a 2-D micro-model. Using the first pore-scale network, through simulating primary and scanning drainage and imbibition, we have generated two surfaces fitted to capillary pressure, saturation, and interfacial area (Pc-Sw-anw) points as well as to relative permeability, saturation and interfacial area (kr-Sw-anw) points. The two fitted three-dimensional surfaces show very good correlation coefficients with the data points. We show that interfacial area can be considered as an essential variable for diminishing or eliminating the hysteresis observed in capillary pressure- saturation (Pc-Sw) and the relative permeability-saturation (kr-Sw) curves. The second pore-scale network is used to simulate a set of drainage and imbibition experiments carried out in a micromodel. In order to define boundaries of pores, medial axis transform has been used in the network development. We show the utility of our model by reproducing the observed microscale distribution of the two fluids. We are also able to obtain measured Pc-S, and anw-S curves with a very good accuracy. This network model will be used to design future two-phase flow experiments in the micro model.
DE: 1828 Groundwater hydraulics
DE: 1847 Modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting