(661c) Comparison of Numerical Simulators for Methane Production From Hydrate Reservoirs

Several numerical simulators for methane hydrate dissociation in porous media such as ToughFx, Tough+Hydrate, HydrateResSim, FLUENT, COMSOL, CMG STARS, MH-21, and STOMP-HYD are available. These simulators are useful in developing a fundamental understanding of complex hydrate dissociation systems in which heat, mass, and momentum transports interact with the hydrate kinetics and or thermodynamics. Particularly, HydrateResSim is a free open-source numerical reservoir simulator software available from the National Energy Technology Laboratory.

We have investigated the dissociation and production of methane induced by depressurization of hydrate sediment in a laboratory-scale reactor using four numerical simulators namely HydrateResSim, ToughFx, Tough+Hydrate, and FLUENT. Our predictions show that the free HydrateResSim software interfaced with PetraSim can produce, with some modifications, comparable results obtained using the commercial software ToughFx, Tough+Hydrate, and FLUENT. Furthermore, experimental data of methane production in the open literature compare reasonably well with HydrateResSim predictions as well as with the commercial codes tested.

The effects of radiative heat transfer and coordinate systems on hydrate dissociation are investigated. Our simulations show that neglecting the thermal radiation (Stefan-Boltzmann law) lead to negligible variation on the hydrate production. Predicted two-dimensional results using the Cartesian coordinates differ from simulated methane production using the Cylindrical coordinates.