A Model for Gas and Hydrates Plumes in Deep Ocean

A release of methane gas in deepwater undergoes a series of physical chemical processes as it rises from the deep to shallow water in the form of a plume. A key process is the formation of methane hydrate in the deep and the eventual hydrate dissociation when the plume reaches shallower regions of lower pressure and higher temperatures. This paper presents a model to simulate the behavior of methane gas released in deepwater. The model considers all processes that gases undergo when released in deepwater under high pressure and low temperature conditions. In addition to including the complete plume hydrodynamics and thermodynamics in the model, it takes into account the processes like hydrate formation and dissociation, gas dissolution, hydrate dissolution, break-up and coalescence of gas bubbles, and the possible separation of gases from the main plume. Scenario simulations using the model are also presented in this paper. The model is suitable for environmental impact assessment and contingency planning.