Numerical simulation study of freezing barrier enhanced depressurization of hydrate exploitation

Abstract:

With the increase in global energy demand， marine natural gas hydrates have received widespread attention as a potential source of clean energy. However， methane leakage and marine ecological damage during hydrate extraction remain pressing challenges. In this study， a novel natural gas hydrate extraction method based on a freezing barrier is proposed， which aims to enhance the extraction efficiency and reduce the environmental risks. Through the formation of a solid ice barrier over the hydrate reservoir， the freezing barrier can effectively inhibit gas diffusion， enhance reservoir stability， and prevent seawater intrusion， while avoiding the ecological damage caused by traditional extraction methods. Numerical simulations comparing the SH7 site and the AT1 site show that in the low-permeability SH7 site， the freezing barrier increases the methane recovery rate by 16% and gas production by 17.89%， while the AT1 site does not show the same effect due to the difference in the barrier location. The results of the study show that the rational configuration of the freezing barrier provides effective technical support for the safe and environmentally friendly exploitation of natural gas hydrates and has good application prospects.