Dissociation and transport modeling of methane hydrate in core-scale sandy sediments: A comparative study

Better understanding of the dissociation and transport mechanism of methane hydrate in sandy sediments contributes to the future commercial extraction of hydrate. This paper presents a comparative study on the dissociation and transport modeling of methane hydrate in core-scale sandy sediments. The mathematical model is established considering the heat and mass transfer in the hydrate dissociation and the migration process of gas-water flow. The permeability model of the core is modified based on the lab test on the Berea sandstone, which is more feasible and physical than those by historical matching. The theoretical model is verified by comparing with experiments. The following improvements are achieved: 1) The distribution of the synthetic hydrate within the core in the lab is not uniform even when assuming the core is homogeneous. 2) Better agreements are acquired between the simulation and experimental data using the simulated initial distribution of the hydrate, water and methane in Masuda's experiment. 3) As the first effort in literature, the mini peak of the far-field pressure and the temperature fluctuation in Masuda's experiments are investigated by simulation, which reveals the physical reason for the phenomena. Moreover, this paper provides new insight into the modeling validation using Masuda's experiment for numerical simulation benchmarking.