OIL MIGRATION AND MODIFICATION PROCESSES IN SOLID SEA ICE

Abstract

ABSTRACT The migration of Prudhoe Bay crude oil and diesel fuel through first year sea ice and the effect of entrained oil on sea ice growth rates were examined. Physical and chemical changes within the oils were examined during and after the entrainment process. Several crude oil and diesel fuel injections beneath solid sea ice were conducted off Prudhoe Bay during the winter of 1979/1980. Oil layers of 2.5, 15, and 30 centimeters (cm) were formed under 15, 30, and approximately 60 cm of sea ice. The sea ice growth under the injected oils was monitored. At the end of the ice growing season the individual oil injection sites were excavated from the ice. Each site was studied to determine the extent of vertical oil migration. The field results are compared to laboratory salt water ice growth experiments with entrained oil layers. The laboratory test results include oil migration as a function of ice temperature and the effect of various oil layer thicknesses upon the ice growth rates. Direct heat flux measurements are included from which the thermal conductivity of oil layers is obtained as a function of the oil layer thickness. These data illustrate the relationships among oil layer thickness, temperature gradient across the oil layer, oil viscosity, and convective motion occurring within the oil layer.