Movement and Accumulation of Methane in Marine Sediments: Relation to Gas Hydrate Systems

Abstract

Hydrates may occur where thermodynamic conditions permit and where methane concentration in the water exceeds a threshold level, but they will only concentrate where gas flow is focused. Existing models of submarine gas hydrate occurrence encapsulate the system of transport and reactions into a one dimensional model (e. g. Rempel and Buffet 1998, Zatsepina and Buffett 1998, Xu and Ruppel 1999). With this simplification we can constrain key parameters, but it is difficult to capture the geological complexity of real systems. To predict the spatial distribution of hydrates we need to account for the range of mechanisms by which methane can move though the sediments.