Murphy's Seal asset in Peace River Oil-sands renders a strong incentive for application of EOR techniques. A combination of primary depletion and thermal/non-thermal EOR techniques (polymer flood, Cyclic Steam Stimulation (CSS), and Vertical Steam Drive (VSD)) are currently being pursued or evaluated by Murphy Oil to increase Seal's production. High oil viscosity in Seal's Cadotte does not allow for primary development and non-thermal EOR schemes in this area. Hence, Cadotte has been considered for application of CSS and VSD. This study highlights the opportunities and challenges of Cadotte's CSS development using pilot results, history-match/forecast, optimization and uncertainty analysis.
The impacts of reservoir features that complicate Cadotte's CSS development are quantified through history-match/optimization, sensitivity analysis and uncertainty assessment. These features include a presence of multiple PVT regions and water pockets, varying rock dilation, fracturing, and pay-zone thickness variation. Reservoir simulation, Latin hypercube designs, and response surface methodology are used to conduct the history-match, optimization, sensitivity analysis and uncertainty assessment.
Because the underlying geology in Seal is complex, one focus of this study is to isolate the effect of geological complexities on CSS development by conducting the history-matching/forecast using a layer-cake model updated by 3-D seismic and log analyses.
By accounting for geological and reservoir/operation variances, this integrated study helps determine optimum CSS development in Cadotte. It also sheds light on how to screen reservoir/operation parameters for successful application of CSS in geologically-complex reservoirs with a varying PVT behavior.