University of New Hampshire
Mentor: Dr. Nancy Kinner
Determining the Factors that Cause Submerged Oil to Become Re-Suspended in the Water Column
The success of sunken oil recovery is limited and highly dependent on its transport and fate about which little is known. Re-suspension of sunken oil under various wave and current conditions has previously been observed (e.g., Tank Barge DBL-152, Kalamazoo River spill), but the corresponding current conditions that mobilized the oil from the bottom are unknown. Better predictive modes of the transport and fate of sunken oil would greatly assist spill responders in location and recovery for a spill incident involving heavy oil. One of the crucial inputs necessary to enhance such models are the critical shear stresses that mobilize sunken heavy oils at different temperature and salinity regimes.
The objective of this research is to estimate the critical bed shear stresses needed to mobilize Alberta bitumen and a California Kern River crude (API gravities < 15) at 5o and 20oC in freshwater and saltwater (35 ppt). Three dimensional water velocity measurements are being made using a Nortek Vectrino Profiler in a flume from which bed shear is estimated.
For spill responders, knowing the types of conditions at which oils will mobilize on the bed and re-mobilize into the water column is crucial. This laboratory study will be one of the first to provide critical shear stresses for two common heavy oils at four distinct environmental conditions, which will help calibrate predictive models of the transport of sunken oil.