A New Approach to Simulation of LNG Spills in the Ocean

Spills of LNG can pose a safety risk to people and structures in proximity to such spills. Methodologies to assess risk from either accidental or intentional spills must include a component to estimate the fate and transport of spilled LNG. LNGMAP is a fully integrated, geographic information based modular PC-based system that predicts the fate and transport of marine spills of LNG from vessels. The model is organized as a discrete set of linked algorithms that represent the processes affecting LNG once it is released into the environment. The model includes a time dependent release rate, spreading, transport on the water surface, evaporation from the water surface, transport and dispersion in the atmosphere, and, if ignited, burning and associated radiated heat fields. A major feature of LNGMAP is its ability to account for the movement of the vessel and the currents onto which the LNG was spilled. This ability allows more realistic pool shapes, vapor clouds and radiated heat zones. To illustrate the model predictive capability for realistic emergency scenarios, simulations were performed for three cases: the first assumes the vessel continues on course after the spill starts, the second that the vessel stops as soon as practical after the release begins, and the third that the vessel grounds at the closest site practical