Behavior of Viscous Fingering of Miscible Two-Phase Flow in 3D Porous Media

Carbon dioxide flooding, which is one of enhanced oil recovery schemes, improves oil recovery due to the miscibility between supercritical carbon dioxide and oil. When a less viscous fluid displaces a more viscous one, however, viscous fingering reduces oil recovery. In this study, the there-dimensional development of viscous fingering in miscible two-phase flows in porous media is visualized using an X-ray CT scanner. Interaction among the fingers such as shielding, merging, and tip splitting is observed. Three-dimensionally involved structure of the fingers results in low sweep efficiency compared with two-dimensional viscous fingering.