HR: 1340h
AN: H33F-0522    [Abstracts]
TI: Upscaling Relative Permeabilities in a Structured Porous Medium
AU: * Gasda, S E
EM: sgasda@princeton.edu
AF: Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544 United States
AU: Celia, M A
EM: celia@princeton.edu
AF: Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544 United States
AB: Upscaling of multi-phase flow problems for a heterogeneous porous medium requires modification of constitutive functions at the grid-block scale. A particular type of heterogeneity that has important environmental consequences involves thin, continuous streaks of high permeability through lower-permeability background rocks. These streaks, which may correspond to features like abandoned wells in mature sedimentary basins, can become preferential flow paths for an invading fluid. Quantification of flow through these types of heterogeneities in deep, geological formations is necessary to estimate the migration and possible leakage of injected fluids such as hazardous liquid wastes, municipal liquid wastes, and, possibly, carbon dioxide. One of the important constitutive functions for proper estimation of flow through these flow paths is the relative permeability function. In the simple case of a single high-permeability streak in a uniform rock matrix, with both materials having identical (local) relative permeability functions, the upscaled relative permeability must be changed significantly to capture the proper leakage due to the nonlinear coupling with phase saturation. Standard petroleum reservoir pseudo functions for relative permeability capture the general features of the upscaled function, but they still produce errors of several hundred percent in the leakage estimation. Detailed three-dimensional numerical simulations and associated upscaled calculations demonstrate the proper form for the upscaled relative permeability, and provide a new derivation of pseudo functions to capture the leakage behavior in larger-scale models.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1869 Stochastic processes
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting