Methane gas hydrates are naturally occurring gas hydrates found in permafrost regions and seafloor. This natural gas hydrate holds a very high amount of carbon reserve, almost twice of conventional fossil fuel. Because of such a huge amount of energy reserve in it, 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.