Gas Production From Hydrates Dissociation in Marine Sediments

The quantity of gas accumulated as gas hydrates has been estimated as more than the half of the total fossil energy and it is considered as the most prominent, energy resource to cover the requests of natural gas to future. Due to the limited data available, important efforts in the harvesting of real data have being carried out and additional simulation studies for this not conventional reservoir like gas hydrates accumulations are considered. The main two mechanisms to define the exploitation strategic are depressurization and thermal stimulation, and reservoir numerical simulation, is considered an important tool to get characterization and evaluation of the optimize production mechanism. A three-dimensional commercial numerical simulator, is used to model the gas production from gas hydrates dissociation considering the thermodynamic equilibrium and the kinetic intrinsic, both simultaneously. Depending on the deposit configuration defined, gas hydrates accumulations can be associated to a biphasic zone with gas free layer below the gas hydrates zone (deposits Class 1), and for this configuration gas production by depressurization is the most favorable one. The initial production from the free gas layer drives the process of dissociation of methane hydrates zone. In the case where the configuration includes the presence of an aquifer or water zone in a biphasic zone below to the gas hydrates zone (deposits Class 2); the mechanism evaluated more often is hot water or steam injection and thermal XIX International Gas Convention AVPG 2010, May 24th 26th Caracas, Venezuela Page 2 stimulation behave like an acceptable alternative for gas production, the rise in temperature promotes the dissociation of the upper hydrates reaching temperatures to that of equilibrium. Gas production is associated with important quantity of water.