NMR measurements and numerical simulation of fluid transport in porous solids

Pulsed magnetic field gradient stimulated echo NMR measurements are performed for diffusion and flow of an aqueous phase both within a sample of packed spherical beads and within a 25% porosity Fontainebleau sandstone. The stimulated echo dependence on the gradient pulse area q is used to derive the displacement probability distributions P-Delta(X) for fixed observation times Delta. The shape of P-Delta(X) as a function of Delta is simulated for computer-generated porous media, and a good agreement is obtained between the experimental NMR data and the simulations.