Abstract
We study thermal stimulation and huff and puffin a homogeneous model with a single heterogeneous layer using numerical simulation. This included investigating the response of the dissociation front and the volume of dissociated methane to variations in the depth of the injector well and the permeability of the heterogeneity during thermal stimulation. The sensitivity analysis around the permeability of the heterogeneity demonstrated that the vertical extent of the dissociation front was maximum when the permeability of the heterogeneity matched the permeability of the background medium. Reducing the permeability of the heterogeneity below the background permeability compromised overall fluid flow whereas increasing the permeability, redirected the fluid flow radially into the lateral heterogeneity. The sensitivity analysis for well depth was conducted for a permeable heterogeneity as well as a relatively impermeable heterogeneity. For the permeable case, it was found that maximum radial extent of the dissociated front was observed when the injector well was placed within the heterogeneous layer. For the impermeable case, a significant reduction in radial extent was observed at well depths close to the heterogeneity, and the highest dissociated volumes were recorded for well depths away from the heterogeneity. Subsequently, production was simulated within the reservoir using huff and puff to study the performance of the reservoir during production. Interestingly, it was observed that the case with a permeable heterogeneity underperformed the other cases with respect to the production of gas.
NSTL