Lawrence Berkeley National Laboratory

We determined the composite thermal conductivity (ktheta) of a porous methanehydrate sample (composedof hydrate, water, and methan e gas) as a function of density using iTOUGH2. X-ray computed tomography (CT) was used to visualize and quantify the density changes that occurred during hydrate formation from granular ice. The composite thermal conductivity was estimated and validated by minimizing the differences between the observed and the predicted thermal response using history matching. The estimated density-dependent composite thermal conductivity ranged between 0.25 and 0.58 W/m/K.