Abstract
The main objective for this project was to develop a protocol for conducting bench-top effectiveness testing of subsea injection of dispersants. The dispersant effectiveness is quantified as a shift in oil droplet size distribution for the chemically dispersed oil compared to the untreated oil. The new test method is designed for continuous monitoring of an oil plume generated by a turbulent jet. Shift in droplet sizes are monitored as a function of turbulence levels, different injection techniques and different dispersant dosage. The test also includes an option for dispersibility testing of surfaced oil slicks resulting from subsea injection (re-dispersion). The capabilities of this new bench-scale method is documented by testing a selection of commercial products (3), with different oil types (4), turbulence levels (2), injection techniques (2) and dispersant dosages (3). The new test protocol is documented by comparing results with large-scale testing in the SINTEF TowerBasin (6 m high containing 42 000 litres of natural sea water) with the same oil types and dispersants. This report covers SINTEF's part of a comparative study performed both at CEDRE and SINTEF.