Fluid Injection Experiments in Two-dimensional Porous Media

摘要

A series of injection experiments were conducted in a Hele-Shaw cell-like radial flow device filled with fine sands to better understand the fundamental failure/flow mechanisms when dense granular media is invaded and displaced by a fluid. Both aqueous glycerin solutions and polyacrylamide solutions were used as the invading fluids. The experimental findings suggest that there is a transition from the solid-like (fracturing) to fluid-like (fingering) behavior in the injection process. Based on the gain displacements and fluid flow patterns, four distinct failure/flow regimes can be identified from the experiments, namely, 1) the simple radial flow regime, 2) the leakoff-dominated regime, 3) the grain displacement-dominated regime, and 4) the viscosity fingering-dominated regime. These failure/flow patterns emerge as a result of competition among various forms of energy dissipation, i.e., viscous dissipation through flow in porous media, dissipation through mechanical deformation, and viscous dissipation through flow in thin channels.