Experimental investigation on the spatial differences of hydrate dissociation by depressurization in water-saturated methane hydrate reservoirs

•Spatial differences of hydrate dissociation in the reservoir were investigated.•Factors affecting spatial differences of hydrate dissociation were investigated.•Factors controlling hydrate dissociation were analyzed.•The vacating of pore spaces is the controlling factor of hydrate dissociation.•A new method to enhance gas production from marine gas hydrate was proposed.