TITLE      : MODELING FLOW IN VUGGY POROUS MEDIA

SPEAKER    : Todd Arbogast, The University of Texas at Austin

Time and space: Monday May 19, 3:30pm at REC 112


ABSTRACT:
Sedimentary rocks sometimes contain void regions called vugs that are
much larger than the usual intergranular pores.  We consider the
problem of large-scale simulation of flow through vuggy carbonate
reservoirs.  We address the question of determining the effective
permeability of single-phase flow at the grid-block scale, using the
theory of homogenization and direct multiphysics computations.  At the
micro-scale, the system is governed by Darcy's law in the rock matrix
and Stokes' equations in the vugs, with the Beavers-Joseph-Saffman
boundary condition on the interface between the two
regions. Homogenization predicts that on the macro-scale, Darcy's law
holds everywhere with an effective permeability that can be readily
computed.  To assess the validity of this prediction, we need to test
it computationally.  We first develop a numerical method and code
capable of simulating the Darcy-Stokes system in a medium with
irregular and ubiquitous vugs. We then obtain micro-scale computations
of flow in such vuggy media on very fine grids that resolve the
geometry of the vugs, and also a code to determine the homogenized
permeability.