Sammendrag
The project has been a co-operation between SINTEF and Cedre. Some “holes” in the data still extist. However, some preliminary findings can be drawn: Russian Export Blend Crude Oil (REBCO):1. REBCO is a crude oil that shows to be dispersible when using oil spill dispersants, both at summer and winter conditions. However, no systematic studies for estimating the “time window” for effective use of dispersant, due to the weathering, was performed within this project. 2. OSR 62 showed to be the overall most effective dispersant of the two dispersants tested under various sea salinities, and is less sensitive to salinity variation 3. Compared to two other Russian crude oils from the Murmansk area (hereafter called Murm. A and B) that recently has been investigated at SINTEF, REBCO shows the following properties (using 1 day weathering at 5oC sea temperature and 10 m/s wind, as an example): the REBCO crude will have a slightly higher evaporative loss: approx. 30 % evaporation (versus 22 to 26% for Murm. B and A, respectively) will emulsify water significantly faster: approx. 75% water uptake (versus 20% and 70% water for Murm. A and B respectively) the viscosity of emulsion will be slightly lower: around 35 000 cP (versus 53 000 and 45 000 cP for Murm. A and B, respectively) there will be a high density of the REBCO and Murm. B emulsions, in the range 0,99 5 - 1,0 kg/L, fairly close to the seawater density an intermediate high pour point: around 15oC (versus 30oC and -15oC for Murm. A and B respectively. This indicates a wide span in pour point for the Russian crudes Vysotsk IFO-380 bunker fuel oil:4. Vysotsk IFO-380 oil showed to be dispersible at a low weathering stage under summer conditions. The “time window” for effective use of dispersant due to the weathering was not investigated within the project. At very cold winter conditions (0oC) Vysotsk IFO (having viscosity of 174 000 cP) showed very limited dispersability. 5. OSR 62 is the most effective dispersant of