ABSTRACT
Research experiments were completed to determine the viability of using chemical dispersants on two crude oils in very cold water conditions. Tests were completed at Ohmsett (the National Oil Spill Response Test Facility in Leonardo, New Jersey) in late February and early March of 2002. Ohmsett is a large outdoor, above-ground concrete tank (203 m long by 20 m wide by 3.4 m deep) filled with 9.84 million gallons of salt water. The tank has a wave-generating paddle, a wave-dissipating beach, and mobile bridges that transport equipment over its surface. A refrigeration unit was installed to ensure that the water was kept at near freezing temperatures during the entire test program. A total of twelve large-scale tests were completed. Corexit 9500 and Corexit 9527 were applied to fresh and weathered Hibernia and Alaska North Slope crude oils, on cold water (-0.5 to 2.4 °C), at dispersant-to-oil ratios (DORs) ranging from 1:14 to 1:81. The average wave amplitude for the tests ranged between 16.5 and 22.5 cm and the average wave period was between 1.7 and 1.9 seconds. The effectiveness of the dispersant in each test was documented through extensive video records and by measurement of the residual oil remaining within the containment boom at the end of each test. The results clearly show that both dispersants were effective in dispersing the two crude oils tested in cold-water conditions.