DEVELOPMENT OF TRANSPARENT POROUS-MEDIA WITH PERMEABILITIES AND POROSITIES COMPARABLE TO SOILS, AQUIFERS, AND PETROLEUM RESERVOIRS

Model porous media made from glass beads and matched refractive index liquids have made it possible to visualize displacement processes in heterogeneous porous media and to obtain in situ concentration profiles to validate flow codes. However, glass beads produce porous media that are translucent rather than transparent. Thus, these models cannot be used to observe 3-D effects. Furthermore, the current necessity of using relatively large glass beads results in permeabilities that are several orders of magnitude larger than natural porous media. This paper describes a new approach for making transparent porous media by consolidating suspensions of amorphous silica in matched refractive index liquids. The resulting porous media can be made to have porosities and permeabilities comparable to a very wide range of soils and reservoir materials by the appropriate choice of particle size and/or consolidation pressure. Because these porous media are truly transparent and not merely translucent, relatively simple optical techniques can be used to map variations in porosity and to measure 3-D flow processes.