Interfacial phenomena: Reservoir wettability in oil recovery

This paper presents the importance of wettability in the petroleum industry , and more particularly in reservoir engineering. It starts from the problem of reservoir wettability: how this wettability i s evaluated. It shows how microscopic scale studies help to a better understanding of ma croscopic observations made in the laboratory on multiphase flows in reserv oir porous material. Finally, it presents results on actual reservoir material concerning the ro le of mineralogy (presence and nature of clays) and pore-size distribution (particularly in the case of carbonates) in the coexistence of two networks (water-wet and oil-wet) in so-called mixed wettability systems.