IN-PLACE BURNING OF PRUDHOE BAY OIL IN BROKEN ICE1

Abstract

ABSTRACT Small-scale and large-scale experiments were performed at the U.S. Environmental Protection Agency's Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) facility to explore the range of conditions in which oil slicks of Prudhoe Bay crude can be burned in broken ice and to determine the efficiencies of such burns. In laboratory experiments, the minimum slick thickness supporting combustion was found to be 2.5 mm on brackish water at temperatures from 2° to 6.5° C. Minimum slick thickness to support combustion on brackish water at temperatures from 18° to 22° C was found to be 2 mm. The wicking agent was found to vary in effectiveness as a burn-enhancing agent. Decreases in burn efficiencies and burn rates were observed with decreasing water temperatures. Four burn tests were performed in the OHMSETT tank with varying ice cover, volume of oil, and wave conditions. The brackish tank water ranged from 3.8° to 7.7° C during testing. One test was performed using lightly weathered (topped) Prudhoe Bay crude oil. Burn effectiveness ranged from 85 to 95 percent by mass. Flame spread rates ranged from 1.3 to 2.4 m/min based on discrete measurements. The slicks were ignited along the downwind edge, and in all tests the flame was not significantly inhibited by the ice from spreading throughout the test area. This program was sponsored by the OHMSETT Interagency Technical Committee (OITC), which includes the U.S. Minerals Management Service, U. S. Coast Guard, Canadian Environmental Protection Service, U.S. Environmental Protection Agency, and the U.S. Navy.