Numerical Simulation Study of the Gas Hydrate Using Thermal Stimulation Method

There are three production methods for gas hydrate like depressurization method, thermal stimulation method and gas or inhibitor injection method. Among them, thermal stimulation method includes hot water injection method and electrical heating of wellbore method. Reservoir temperature is increased to destabilize the hydrate by the thermal stimulation. Thermal stimulation (hot water circulation) pilot test for the gas hydrate production was excuted at the Mackenzie Delta in the Canadian Arctic in 2002. However, the cumulative gas production was only 468 m3 during 5 days, even with the large energy consumption. Although depressurization method is considered to be the best production method with simple and economic effectiveness, this method can cause considerable subsidence. However, thermal stimulation methods are able to increase geomechanical stability. Accordingly, in this study, numerical simulation study was conducted using thermal stimulation method in the Ulleung Basin of the Korea East Sea. A 3D field scale geological model was constructed using seismic and well logging data from the Ulleung Basin of the Korean East Sea. Grids were refined by I and J direction and the grids near the production well were very small in order to consider realistic hydrate behavior. Various case studies were conducted with how water flooding, huff and puff method and electrical heating of wellbore method.