Experimental Investigation on the Dissociation Behavior of Methane Gas Hydrate in an Unconsolidated Sediment by Microwave Stimulation

The technique of recovery of methane from a hydrate reservoir by microwave stimulation was experimentally verified for a laboratory scale. The stimulation was carried out in the unconsolidated sediment from the South China Sea by applying 2.45 GHz microwave with the average radiation densities ranging from 3 to 19 kW/m(2). We observe that the far-field hydrate layer, which exceeds the microwave penetration depth, dissociated at equilibrium. The hydrate saturation (15.5-54.5%), water saturation (40.7 and 70.4%), freezing and combining with depressurization affect the heating and gas production behaviors, as well as the production efficiency. The formation of ice reduces the gas production efficiency for the frozen sediment but boosts the gas production for the unfrozen sediment combining with depressurization.