From Bureau of Economic Geology, The
University of Texas at Austin (www.beg.utexas.edu).
For more information, please contact the author.
Bureau Seminar, February 06, 2009
Pore-to-Reservoir Up-scaling of Transport Processes: Applicable to
Sand Reservoirs, Shale Systems, and Naturally Fractured Media
Bureau of Economic Geology
The dynamics of transport phenomena in random porous media, e.g., sand reservoirs, shale systems and naturally fractured reservoirs are modeled with a set of differential equations corresponding to pore scale and continuum macro-scale. Mass transport at the pore scale includes convective flow, diffusive flow and surface events such as adsorption, desorption, and/or chemical reactions in a unit cell representing the media. A unit cell is the smallest portion of a porous media that can reproduce the porous media by repetition. Inner boundaries in a unit cell are the surfaces of the mineral grains or fracture surfaces. Mass transport at the pore scale is transformed into continuum macroscale by adopting periodic boundary conditions for contiguous unit cells and applying macrotransport theory. Using this theory, the discrete porous system changes into a continuum system within which the propagation and interaction of the fluid molecules of interest with the solid matrix and fracture surfaces are characterized by three position-independent macroscopic coefficients: the mean velocity vector, dispersivity dyadic, and mean volumetric reaction (or adsorption, or desorption) coefficients.