As we all know, depressurization is considered as the most promising method to release natural gas from hydrate reservoirs. In this study, we study methane hydrate dissociation behavior in porous media under different production pressure. The experimental results show that the process of methane hydrate dissociation can be divided into the depressurization stage (DS) and the constant pressure stage (CPS). In DS, the heat required for hydrate dissociation is from the sensible heat of hydrate-bearing sediments. As the production pressure decreases, the total amount of gas production and water production increase. In CPS, the required heat for hydrate dissociation is transferred from surroundings. With the decrease of the production pressure, the rising rate of average temperature in hydrate-bearing sediments increases, and the gas production rate increases.
Keywords methane hydrates, dissociation behavior, production pressure, gas production