Assessment of methane gas production from Indian gas hydrate petroleum systems

The effectiveness of the electro-thermal and depressurisation based techniques applied to three marine gas hydrate reservoir settings of India is modeled and simulated using MATLAB and TOUGH + HYDRATE reservoir modeling software. The results indicate that the depressurisation technique (with an achievable ΔP of >90 bar) will be effective in dissociating gas hydrates up to 145 m from a well bore in the Krishna Godavari (KG) reservoir. The technique when applied to the Andaman and Mahanadi reservoirs is found to produce a maximum ΔP of 64 and 70 bar against the minimum required threshold of 134 and 152 bar, and hence, found to be less effective for hydrate dissociation. The in-situ electro-thermal technique will be effective in the KG and Andaman reservoirs; and in the Mahanadi reservoir, if the gas hydrate saturations are >17%. The depressurization technique when applied to a hypothetical sandy reservoir in the KG basin shows that the spatial pressure drop is nearly double that in a clayey setting, which is conducive for hydrate dissociation.