Kinetic Behaviors of Methane Hydrate Formation with Bubble Seeping at Conditions of "Haima" Cold Seep

Marine methane sequestration pattern and potential play significant roles in climate change mitigation. It is essential to study the fate of methane bubbles migrating from the seafloor, given the widespread occurrence of methane seeping in the seafloor. We investigated the kinetics of methane hydrate formation in bubble flow, including the mass transfer of the CH4 gas and water molecules at different flow patterns, morphological evolution and gas consumption during hydrate formation in the reactor, at 277.2 K and 12 MPa corresponding to temperature and pressure in "Haima" cold seeping surroundings. We found that a critical-state flow rate existed between steady and unsteady flow patterns, which sharply shortened nucleation time in induction processes. Moreover, hydrates might be found not to form under high driving forces of pressure. This work can help to explore the hydrate formation mechanism and the assessment of the carbon content under the surrounding of the sub seafloor.