History matching of hydrate formation and dissociation experiments in porous media

Gas hydrates are crystalline, ice-like compounds of gas (e.g., methane) and water molecules that are formed under high pressure and low temperature. Many of the transport properties of porous media containing hydrates are unknown and difficult to measure experimentally. The goal of this work is to match laboratory experiments of hydrate formation and dissociation in cores to estimate some of these transport properties. An implicit, thermal, compositional simulator is used which accounts for four components (hydrate, water, methane and salt) and five phases (hydrate, aqueous, gas, ice, and salt precipitate). The transformation of methane and water to hydrate is modeled by a reaction with the kinetics controlled by the hydrate surface area. The key unknown is the variation of permeability within the core. Permeability and its spatial variation are used as parameters to match the experimental results.