An evaluation of models that estimate droplet size from subsurface oil releases

Droplet size substantially affects the fate of oil released from deep subsea leaks. A baseline dataset of volume-median droplet diameters (d(50)), culled from similar to 250 laboratory observations, is used to validate seven dropletsize models. Four models compare reasonably well, having 95% confidence limits in d(50) of similar to +/- 50%. Simulations with a near-field fate model (TAMOC) reveals that the four best-performing models, with d(50) of 1.3-2.2 mm, agree similarly with observed fractionation of petroleum compounds in the water column during June 4-July 15, 2010. Model results suggest that, had a higher dose of dispersant been applied at the wellhead during Deepwater Horizon oil spill (DWH), the d(50) would have dropped by an order of magnitude, reducing surfacing C-1-C-9 volatiles by 3.5x. Model uncertainty is found to be substantial for DWH-like blowouts treated with chemical dispersants, suggesting the need for further droplet-size model improvement.

Automated summary

The study found that droplet size significantly affects the fate of oil released from deep-sea leaks, with model predictions of droplet size being in good agreement with observed results. Simulation results suggest that a higher dose of dispersant may significantly reduce the release of volatiles in oil spills.