HR: 10:35h
AN: H32A-02    [Abstracts]
TI: Interfacial Area per Volume: The link between capillary pressure and saturation
AU: * Chen, D
EM: chen36@purdue.edu
AF: Deparment of Earth & Atmospheric Sciences, Purdue University , 550 Stadium Mall Drive , West Lafayette, IN 47907-2051
AU: Cheng, J
EM: cjt0610@yahoo.com
AF: Department of Geology & Geophysics, Texas A&M University, College Station, TX 77843-3115
AU: Nolte, D D
EM: nolte@physics.purdue.edu
AF: Deparment of Physics, Purdue University , 525 Northwestern Avenue, West Lafayette, IN 47907-2036
AU: Giordano, N
EM: ng@physics.purdue.edu
AF: Deparment of Physics, Purdue University , 525 Northwestern Avenue, West Lafayette, IN 47907-2036
AU: Pyrak-Nolte, L J
EM: ljpn@physics.purdue.edu
AF: Deparment of Physics, Purdue University , 525 Northwestern Avenue, West Lafayette, IN 47907-2036
AU: Pyrak-Nolte, L J
EM: ljpn@physics.purdue.edu
AF: Deparment of Earth & Atmospheric Sciences, Purdue University , 550 Stadium Mall Drive , West Lafayette, IN 47907-2051
AB: Measurements were performed on micro-models to quantify interfacial area per volume 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 the system by the application of pressure in increments. At each increment, the system is allowed to equilibrate and then digital images of fluid distributions within the pore structure are acquired. The images are analyzed to determined fluid saturations, interfacial areas per volume and curvature of the interfaces. The curvatures of the interfaces are calculated using level set methods Pressure measurements are also made with pressure transducers during the experiment. From the data, we have established that the interfacial area per volume between non-wetting and wetting fluids lifts the ambiguity associated with the hysteretic relationship between capillary pressure and saturation in porous media. The interface between the non-wetting and wetting phases is composed of two subsets: one with a unique curvature determined by the capillary pressure, and the other with a distribution of curvatures dominated by disjoining pressure. This work provides experimental support for theoretical predictions that the capillary-dominated subset plays a role analogous to a state variable. Any comprehensive description of multiphase flow properties must include this interfacial area with the traditional variables of pressure and fluid saturation. Research is continuing to examine the role of pore structure on the relationship among capillary pressure, saturation and interfacial area per volume. Acknowledgments: Geosciences Research Program, Office of Basic Energy Sciences US Department of Energy. LJPN and DDN wish to acknowledge University Faculty Scholar program at Purdue University
DE: 5112 Microstructure
DE: 5114 Permeability and porosity
DE: 5139 Transport properties
DE: 5194 Instruments and techniques
DE: 3210 Modeling
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting