HR: 17:15h
AN: H44D-06    [Abstracts]
TI: Drainage and Imbibition Simulations in Realistic Porous Media Based on the Level Set Method
AU: * Prodanović, M
EM: masha@ices.utexas.edu
AF: University of Texas at Austin, Center for Petroleum and Geosystems Engineering, 1 University Station, C0304, Austin, TX 78712, United States
AU: Bryant, S L
EM: steven_bryant@mail.utexas.edu
AF: University of Texas at Austin, Center for Petroleum and Geosystems Engineering, 1 University Station, C0304, Austin, TX 78712, United States
AB: Knowledge of the geometrical distribution of immiscible fluids during displacement in porous media could significantly improve predictions of capillary pressure - saturation curves, interfacial areas and relative permeability. Slow displacement can be modeled as a quasi-static, capillarity-controlled process. At constant pressure and interfacial tension, pore scale fluid-fluid interfaces are modeled as constant mean curvature surfaces, which are not easy to calculate. Further, tracking the topological changes of the interface, such as splitting or merging, is nontrivial specifically due to the irregular pore spaces in natural porous media. We apply the level set method for propagating interfaces in order to robustly handle topological changes and to obtain geometrically correct interfaces. We describe a simple but robust model for simulating both drainage and imbibition in general porous media. Though set up for quasi-static displacements, the model nevertheless captures both reversible and irreversible behavior (Haines jump, pore body imbibition). The pore scale grain boundary conditions are extracted from model porous media and from imaged geometries in real rocks. The method gives quantitative agreement with measurements and with other theories and computational approaches. Our simulations establish the exact position and shape of the interface in porous geometries, from which fluid volumes, contact areas and interface curvatures can be obtained. We show examples of 2D and 3D displacements in individual pores and throats, simulated and imaged porous samples as well as artificially and naturally fractured media. Investigative power of the method is shown on a study of non-wetting phase snap-off in a suite of doubly constricted geometries. We also show preliminary results on the method extension to allow for nonzero fluid-fluid-solid contact angles.
DE: 1009 Geochemical modeling (3610, 8410)
DE: 1828 Groundwater hydraulics
DE: 1832 Groundwater transport
DE: 1847 Modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting