An experimental study on the gas production from gas hydrate reservoir by depressurization scheme

Because of containing a large amount of methane, hydrates have been considered as a future energy resource. The recovery of gas from hydrate reservoir was described through laboratory measurement. An experimental apparatus was designed and set up to analyze the dissociating phenomena of hydrate in porous rock. Experiments with the depressurization scheme were conducted to investigate the dissociation characteristics of methane hydrates and the productivities of dissociated gas and water. The flowing behavior of the dissociated gas and water in porous rock and the efficiency of the production were studied. In the measurement of hydrate formation, when hydrate started forming, the pressure decreased rapidly and the temperature increased. Exothermic temperature increased 0.2 K during hydrate formation. In the experiment of dissociation, the time of coinciding with inlet and outlet pressure, i.e., the dissociating time takes shorter and the productivity becomes higher as the outlet pressure is closer to equilibrium pressure. Pressure decrease in depressurization scheme should be considered as significant factor affected on the gas production rate in a hydrate reservoir. This is an abstract of a paper presented at the International Gas Union 23rd World Gas Conference (Amsterdam, The Netherlands 6/5-9/2006).