A Counter-current Heat-exchange Reactor for the Thermal Stimulation of Hydrate Bearing Sediments

Since huge amounts of methane are bounded in natural gas hydrates occurring at all active and passive continental margins and in permafrost regions, the production of natural gas from hydrate bearing sediments becomes more and more of interest. Three different methods for the release of methane gas from destabilized hydrate are discussed in principle: thermal stimulation, depressurization and chemical stimulation. This study focusses on the thermal stimulation using a counter-current heat-exchange reactor for the in situ combustion of methane. The heat of the flameless, catalytic oxidation of methane was used for the decomposition of hydrates in sand in a pilot plant scale within a large reservoir simulator (LARS). The promising results of the latest reactor test for which LARS was filled with sand, and ca. 80 % of the pore space was saturated with methane hydrate are presented in this study. The data analysis showed that 15 % of the methane gas released from hydrates would have to be used for the successful dissociation of all hydrates in the sediment using catalytic combustion of methane.