VISUALIZATION OF STEAM DISPLACEMENT OF HEAVY OILS IN A HELE-SHAW CELL

Experimental visualization of steam injection was performed at low pressure in a transparent Hele-Shaw cell. Synthetic (Dutrex 739) and natural heavy oils were displaced by steam under a variety of conditions. The results demonstrate the significant interplay between steam injection, steam condensation, viscous fingering, heat transfer, gravity and steam distillation effects. The experiments reveal that steam fronts may be neither smooth nor flat, but undergo constant rearrangements as a result of condensation and injection. These dynamics are substantially different from typical immiscible displacement processes. The injected steam was generally found to follow the path of the condensed water. The latter set the general displacement pattern, which was highly fingered. Also identified was a rather unusual viscoelastic response of the displaced heavy oils. Although novel and interesting, these results should be extrapolated with care to account properly for field effects of heat losses.