HR: 1340h
AN: H33A-1371    [Abstracts]
TI: Drainage and Imbibition Measurements of Interfacial Area per Volume in Micro-Models
AU: * Chen, D
EM: chen36@purdue.edu
AF: Department of Earth & Atmospheric Sciences, 550 Stadium Mall Drive , West Lafayette, IN 47907-2051
AU: Pyrak-Nolte, L
EM: ljpn@physics.purdue.edu
AF: Department of Physics, 525 Northwestern Avenue, West Lafayette, IN 47907-2036
AU: Pyrak-Nolte, L
EM: ljpn@physics.purdue.edu
AF: Department of Earth & Atmospheric Sciences, 550 Stadium Mall Drive , West Lafayette, IN 47907-2051
AB: Drainage and imbibition measurements were performed on micro-models to quantify interfacial area per volume (IAV) for a known pore geometry as a function of fluid pressure and saturation. The micro-models are completely transparent and measure 600 æm x 600 æm with an aperture of 1.08 æm. Because the micro-models are transparent, full visualization and quantification of the fluid distributions is possible. Initially the micro-models are saturated with decane (wetting phase). Nitrogen (non-wetting phase) is invaded into and withdrawn from the system in small pressure increments. At each increment, the system is allowed to equilibrate and then digital images of fluid distributions within the pore structure are acquired. The pressure were controlled such that breakthrough was not allow to occur. Approximately, four hundred images per micro-model resulted from the drainage scanning and imbibition scanning experiments. The images were analyzed to determined fluid saturations and interfacial areas per volume. From comparison of the drainage data and the imbibition data, interfacial area per volume between non-wetting and wetting fluids lifts the ambiguity associated with the hysteretic relationship between capillary pressure (Pcap) and saturation (S) in porous media. While the surface is unique, an important issue that remains is the invertibility of the Pcap-S-IAV relationship. For the range of capillary pressures (and the resulting saturations) explored in this study, we found that Pcap is a single-valued function of IAV and S; and that IAV is a single-valued function of Pcap and S. However, saturation is observed not to be a single-valued function of Pcap and IAV. At low nitrogen saturation (i.e., high wetting phase saturations), a fixed value of saturation yields the same value of IAV for a range of capillary pressures. However, at higher nitrogen saturation, a single valued relationship is observed. The observed behavior of the Pcap-S-IAV relationship is for prior to breakthrough. Post-breakthrough behavior will affect the invertibility of this relationship. Acknowledgments: LJPN wishes to acknowledge the Geosciences Research Program, Office of Basic Energy Sciences US Department of Energy, the University Faculty Scholar program at Purdue University, and National Science Foundation Grant #0509759-EAR
DE: 1816 Estimation and forecasting
DE: 1839 Hydrologic scaling
DE: 1849 Numerical approximations and analysis
DE: 1859 Rocks: physical properties
SC: Hydrology [H]
MN: Fall Meeting 2005