The stability of saline foams

If one drills for oil, the extraction process should be as efficient as possible. Yet, the technology for extracting crude oil from reservoirs beneath the ground involves an inherently unstable step: that is, the pumping of the less viscous water into a more viscous medium. This results in the “viscous fingering instability” which leaves islands of unrecoverable oil behind.

In this talk, you will see an examination of the stability (in saline, reservoir conditions) of foams of bubbles which can suppress this instability. In order to study foam collapse on multiple lengthscales, we constructed an imaging setup to study the foam simultaneously on the macroscopic scale and the bubble scale, and automated the analysis to enable studies that span days instead of minutes. We find results that are consistent on macro and bubble scales. Our results suggest that reservoir foams are special and that bubble scale results provide early warning of macroscopic foam collapse.