In West Central Saskatchewan the Mississippian/Devonian middle Bakken Formation was deposited as NE-SW trending sand ridges, capable of producing heavy oil. In the Court field, the middle Bakken sand pool has been operated as a heavy oil waterflood for over 15 years with significant success. A review of an earlier field simulation was conducted, an updated model generated, and the potential for reduction in well spacing has been identified.

The lateral continuity of the sand ridge is variable due to post-depositional sinkholes. This structural complexity was mapped based on 3D seismic and well-logs and incorporated into the model. There were also stratigraphic disparities to take into account as discontinuous interbedded siltstones are potential flow barriers that create anisotropy in the permeability. Accordingly, grid orientation was modified to align axially with the main sand ridge permeability trends. Reservoir properties were re-assessed through correlation of cores, well-logs, porosity and permeability maps. Improved resolution was obtained with an increase in the amount of grid blocks used to account for the effect of grid orientation and numerical dispersion on the saturation distribution. A thorough analysis of pressure history, production/injection rates, waterflood performance by pattern interference, and dye injection tests were used to control the history matching process. The simulation model was then used to evaluate the downspacing potential and waterflood optimization of the middle Bakken reservoir.

You can access this article if you purchase or spend a download.