Estimating hydrate formation and decomposition of gases released in a deepwater ocean plume

Oil wells in the deep ocean contain a mixture of oil and gas. If gases are released from such water depths due to an accident, the gases can undergo p hase changes as they travel through the water column. Based on previous exp eriments that were mostly done in the laboratory for gases in pipelines, it is known that under such high-pressure conditions, natural gases will be c onverted to hydrates. As the hydrates travel upwards, the reduced pressure conditions may change the hydrates to free gas. The impact assessment due t o these deepwater releases requires a jet/plume hydrodynamics model with an integrated module to simulate gas hydrate formation and decomposition. In this paper, a model for calculating the rate of the gas hydrate formation a nd decomposition is developed based on the work of Englezos et al. [Chem. E ng. Sci. 42 (1987) 2647] and Kim et al. [Chem. Eng. Sci. 42(7) (1987)]. The model is then used to calculate the fate of gas bubbles as they travel tho ugh the water column. The calculations are useful for understanding the fat e of a gas bubble released in the deep ocean and for eventual integration i nto a jet/plume model. (C) 2001 Elsevier Science B.V. All rights reserved.