Subsea Release of Oil & Gas – A Downscaled Laboratory Study Focused on Initial Droplet Formation and the Effect of Dispersant Injection

Abstract

ABSTRACT This article describes the SINTEF Tower Basin (located in Trondheim, Norway) and its use for examining droplet formation and the effectiveness of dispersant injection. The Tower Basin is 6 m high and 3 m in diameter, containing 42 m3 of natural sea water. Oil is injected from the base of the basin and oil droplets are monitored by laser diffraction and in-situ camera techniques. Size distributions of oil droplets formed in deep water oil & gas blowouts have a substantial impact on the fate of the oil in the environment. However, very limited data on droplet size distributions from subsurface releases exist. The objective of this study has been to establish a laboratory facility to examine droplet size versus release conditions (flow rates and nozzle diameters), oil properties and injection of dispersants (injection techniques and dispersant types). Changes in the size of oil droplets that result from injection of dispersant are used to assess the effectiveness of the dispersant application (dosage and injection method). This comprehensive dataset is used to develop and calibrate existing algorithms to predict droplet sizes from subsurface releases, and the effect of dispersant treatment. The improved algorithms are implemented in current operational models where they are used to describe subsurface use of dispersant and fate of the dispersed oil in the water column.