Verification of Slopover Phenomenon in the Fire Fighting Strategy On Offshore Installations

Adoption of temperatures above 100°C in heavy crude oil separation on offshore installations required process safety studies with focus on possible occurrence of undesirable phenomena.

Slopover is the phenomenon provided of water spray over the oil surface at temperature above water boiling point, causing foam formation and expulsion of material. In fire situations the scattering of the burning oil could occur, promoting fire propagation beyond initial limits of the pool fire.

Water application systems (manual or automatic) are a commonly used solution to fire fighting on offshore production installations. Due to possibility of oil spills above 100ºC, the possibility and magnitude of slopover phenomenon had to be studied to support fire fighting strategies. Tests were conceived to simulate hot oil spilling with and without fire in containment basin, followed by water application.

Slopover occurrence was not verified in tests without fire. In fire tests the phenomenon was occurred but in a reduced magnitude: the scattering area of the burning oil was minimal. This fact can be explained by small thickness of oil present in containment basins of offshore production installations.