Gas–Water Flow Behavior during Hydrate Dissociation Using a Developed 2.5D Microfluidic Chip

With the emergence of natural gas hydrates (NGHs) as a crucial transition energy, understanding the gas–water flow mechanisms is essential for the exploitation of NGHs. A 2.5D microfluidic chip device was used to visualize the real-time dissociation process of methane hydrate and methane–tetrahydrofuran hydrate. This allowed us to perform a morphological analysis of the in situ dissociation process of hydrate. We quantitatively analyzed the distribution of dissociated methane bubbles to describe the hydrate dissociation behavior, and the results found that the initial distribution of formed hydrates and the denseness of hydrates are critical for the formation of gas–water flow channels. The initial distribution of the gas–water channels determines the dissociation priority and speed. Hydrate dissociation and secondary formation in the methane–tetrahydrofuran system significantly differ from those in the methane–pure water system. This work provides a new approach to study the microscopic control mechanism of fluid flow during the phase change of NGHs.