The Late Devonian Duvernay Formation is an overpressured, organic-rich, siliceous mudstone that has the potential to be a world-class unconventional reservoir. It formed during a marine transgression, when deep basinal sediments were deposited over large areas of the Western Canada Sedimentary Basin (WCSB). It was deposited synchronously with reefal buildups of the Leduc Formation, which formed barriers to ocean circulation and promoted the anoxic conditions suitable for organic matter preservation.
Improved delineation of sweet spots in the exploration phase requires predictions of the reservoir quality and of the type of hydrocarbons expected. Reservoir quality is largely a function of original depositional lithofacies. Because the reservoir is also the source, understanding the burial, thermal, maturation and expulsion/retention history is also important in terms of delineating the right fairways for liquids and gas content.
The petroleum system model (PSM) constructed in this study uses reconstructions of the regional structure, stratigraphy, facies, thermal, burial and erosional histories to identify the most favorable productive fairways. The work presented here also highlights the importance of natural fracturing in this reservoir and how accurate construction of discrete fracture networks is required.
