Stability Condition of Methane Hydrate in Fine-Grained Sediment

Stability condition is of critical importance for methane hydrate exploitation, transportation, and reserves. This study measured the stability conditions in fine-grained sediment with different dry densities (ρd = 1.40, 1.50 1.60 g/cm3) various initial water saturations by multi-step heating method. The experimental result showed that formation required lower temperature and/or higher pressure compared to bulk state. At same time, it found deviation degree P–T density saturation are completely from pure water. In addition, according nuclear magnetic resonance technique (NMR), changes NMR signal intensity during decomposition silt were analyzed. Regardless dissociation stages, liquid always distributes small pores. An empirical formula developed address capillary suction respect unhydrated within sediment. Furthermore, a phase equilibrium model proposed predict hydrate-bearing