Methane gas hydrates are naturally occurring gas hydrates found in permafrost regions and on the seafloor. This natural gas hydrate holds a very large carbon reserve, almost twice that of conventional fossil fuels. Because of their huge energy reserves, gas hydrates have gained attention in the past few decades. This Project, in collaboration with IOCL via the Centre of Excellence in Oil, Gas & Energy, IIT Bombay, aims to understand the thermodynamics and mechanistic aspects of the CH4-CO2 replacement process in the hydrate reservoir. Both MD and MC techniques are used in this study, and post-processing is done using in-house codes. The findings of simulations will be validated through experiments at the IOCL R&D facility.