BRANDVIKP.J., FAKSNESS L.G., SINGSAAS I., DALING P.S.,S0RHEIM K.R.

The University centre in Svalbard (UNIS), Norway, SINTEF Materials and Chemistry, Norway

The knowledge regarding weathering processes in Arctic oil spills and especially with ice is limited. Experimental studies have been performed in laboratories, but only to a limited degree in the field. This paper summarizes and compares results from field experiments performed in Norway in 1989, 1993 and 2003-06.

Field measurements from experimental oil releases in Norway are used to compare the behavior of oil spilled in open water and in an Arctic broken ice scenario. Similar oil types and amount (25 - 30 m3) were used in an experimental oil release in open water at Haltenbanken (65°N) in 1989 and in dynamic broken ice at Svalbard (75°N) in 1993. Results from small-scale field experiments performed later (2003 - 2006) on Svalbard are also discussed and compared to the earlier field data. Several weathering properties for the oil spill in broken ice are strongly influenced by the low temperature, reduced oil spreading and reduced wave action caused by the high ice coverage. Reduced water uptake, viscosity, evaporation and pour point extend the operational time window for several contingency methods compared to oil spills in open waters. This could open up for dispersant treatment and in-situ burning even after an extended period of weathering for an oil spill in broken ice.

In the period of 2003-06 SINTEF and the University Centre at Svalbard (UNIS) initiated a research program to study selected weathering processes in Arctic oil spills for a wide range of oil types. This program was funded by Norwegian authorities and oil companies. The objective with this program is to focus on weathering processes; biodegradation, release of water-soluble components to the seawater and photo oxidation. Results from field experiments to study oil behavior with different ice conditions (slush ice, 30% and 90% ice coverage) are also presented in this paper.

OIL AND GAS OF ARCTIC SHELF 2006 (PROCEEDINGS OF INTERNATIONAL CONFERENCE)