Effects of Cooling Process on Formation of Methane Hydrate in Coarse Sand

Abstract The research on the formation and dissociation of methane hydrate in porous media is very important for understanding the natural gas hydrate in permafrost regions. Ten times of experiments were conducted to study the effects of the cooling process on the formation of methane hydrate in coarse sand. The results show that the cooling process affected the formation of methane hydrate in the coarse sand very much. About 90% of the methane hydrate had been formed before the temperature inside the pressure vessel decreased to 0°C which means that little methane hydrate was formed during the frozen process. And the slower the temperature decreased, the greater the converting rate from the water to the hydrate was. When the frozen sand began to melt, the formation of methane hydrate was observed.