WETTABILITY EFFECTS ON OIL-WATER-CONFIGURATIONS IN POROUS-MEDIA - A NUCLEAR-MAGNETIC-RESONANCE RELAXATION STUDY

H-1 spin-lattice relaxation and other physical properties are compared to study the oil-water-surface interplay in suitably chosen and prepared natural porous media of different wettability. Whereas the water-oil arrangement is well established for both strongly water wet and strongly oil wet porous media, the problem is still open for intermediate wettability surfaces. Relaxation behavior reflects the pore space geometry and shows wettability effects on sweeping efficiency and on immiscible liquid arrangement in well-defined equilibrium situations. A simple picture at the pore-length scale is verified for strongly water wet samples, whereas a more complex picture arises for intermediate wettability samples.