Study of the formation kinetics of natural gas hydrates in the South China Sea using calcite and quartz sand

The abundant natural gas hydrates stored on the seabed determine their potential commercial value. Combining the characteristics of hydrate deposition and accumulation in the South China Sea with the composition of sediments, this study reports on the formation rate and gas storage capacity of natural gas hydrates under 270.65 K and 6.08 MPa when calcite and quartz sand of different particle sizes interact with sodium dodecyl sulfate (SDS) solution. The study also investigates the impacts of different porous media combined with SDS on the rapid formation of hydrates and changes in gas storage performance and provides a mechanistic analysis of these processes. The results indicate that the gas storage capacity of hydrates formed by the synergistic interaction of calcite and quartz sand with SDS is superior to that of pure SDS solution. Among these, calcite is significantly more effective than quartz sand in promoting nucleation and enhancing gas storage capacity. The dimensions of the medium’s particles affect the final gas storage capacity of the hydrate. Changes in the surface properties and physical-chemical characteristics of the medium alter the medium environment and spatial steric hindrance, leading to differences in gas consumption and gas storage.