Researchers from the University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS) and University of Western Australia say they have observed how oil droplets are formed and have measured their size under pressure.
Their study simulated how the atomized oil from the Macondo well, off the Louisiana coast in the U.S., reached the ocean's surface during the 2010 Deepwater Horizon accident in the Gulf of Mexico. Results suggest that the physical properties in deep water create a natural dispersion mechanism for oil droplets that generates a similar effect to applying chemical dispersants at the source of an oil spill.
"These results support our initial modeling work that the use of toxic dispersants at depth should not be a systematic oil spill response," says Claire Paris, associate professor of Ocean Sciences at RSMAS. "It could very well be unnecessary in some cases."
To conduct this study, oil was placed in a high-pressure chamber and monitored using a high speed, high-resolution camera to watch and analyze how droplets form under varying turbulent conditions.
"This is the first time that we've been able to visually monitor how droplets break up and coalesce at up to 120 times atmospheric pressure," says Zachary Aman, associate professor of mechanical and chemical engineering at the University of Western Australia. "When paired with the high pressures and flow rates of Macondo, the results suggest a natural mechanism by which oil is dispersed into small droplets."
The paper, “High-pressure visual experimental studies of oil-in-water dispersion droplet size," will appear in the May edition of the journal Chemical Engineering Science.