Numerical studies of gas hydrate formation and decomposition in a geological reservoir

Numerical modeling of gas hydrates can provide air integrated understanding of the various process mechanisms controlling methane (CH4) production front It hydrates and carbon dioxide (CO,) sequestration (is a gas hydrate in geologic reservoirs. This work, describes a new unified kinetic model which, when coupled with a compositional thermal reservoir simulator; can simulate the dynamics of CH4 and CO2 hydrate formation and decomposition in a geological information. The kinetic model contains two mass transfer equations: one equation converts gas and water into It hydrate and the other equation decomposes hydrate into gas and water. The model structure and parameters were investigated in comparison with a previously published model. The proposed kinetic model was evaluated in two case studies. Case 1 considers a single well within a natural hydrate reservoir for studying the kinetics of CH4 and CO2 hydrate decomposition and formation. A close agreement was achieved between the present numerical simulations and results reported by Hong and Pooladi-Darvish (2003, "A Numerical Study on Gas Production Front Formations Containing Gas hydrates," Petroleum Society's Canadian International Petroleum Conference, Calgary, AB, Jun. 10-12, Paper No. 2003-060). Case 2 considers multiple wells within a natural It hydrate reservoir for studying the unified kinetic model to demonstrate the feasibility of CO2 sequestration in a natural hydrate reservoir with potential enhancement of CH4 recovered The model will be applied in future field-scale simulations to predict the dynamics of gas hydrate formation and decomposition processes in actual geological reservoirs.