Abstract
SINTEF received Rev condensate in December 2008. Talisman wanted SINTEF to perform Oil weathering characterisation of the condensate, Chemical and toxicological characterization of the Water Accommodated Fraction (WAF) and an Oil drift and spreading study. These studies are covered in three separate reports. Rev field is positioned close to the British sector in the North Sea, as seabed frames producing to Armada on the British sector. The light components of Rev will evaporate fast after a spill at sea. The low viscosity and density contribute to a fast spreading at the sea surface. The formation of a thin oil film facilitates further evaporation in addition to natural dispersion. The predicted mass balances show that Rev is expected to have a very short lifetime at sea at high wind speeds (approx. 3 hours at 10 m/s wind, both at summer and winter conditions). At low wind speeds and no breaking waves, the oil sheet could live longer. Rev will, in any case, exist as a sheen at the sea surface and not a thick oil layer. The temperature of the oil will be cooled to ambient water temperature within a short time after a spill. The fire hazard will be greatest as long as the flash point of the oil is below the sea temperature. The flash point will be above the sea temperature within a few minutes at winter conditions and nearly half an hour at summer, even at low sea states (5 m/s wind). Some vessels have a flash point limit of 60°C for liquids to be stored onboard. At low wind speed (2 m/s) this limit will be reached in approximately 5 hours at winter conditions and 3 hours during summer time for Rev. The flash point limit will be reached considerably faster at higher winds. Due to high spreading and low viscosity of Rev, mechanical recovery will be difficult, and the low viscosity will cause the condensate to escape the boom during towing. Use of chemical dispersants will not be a relevant combat method, because Rev will form a thin oil film at the sea surface.
