Duvernay Formation sequence stratigraphy: integrating sedimentology, geochemistry, and petrophysics

Summary Prediction of reservoir properties using sequence stratigraphic analysis is well demonstrated in conventional reservoirs, but similar applications of sequence stratigraphy to self-sourced reservoirs are much less common. The Duvernay Formation of the Western Canadian Sedimentary Basin is an organicrich mudstone that has come into intense focus as a self-sourced resource play, and the growing volume of cores and data available make it a prime candidate for studying fine-grained, organic-rich strata. This study demonstrates how a sequence stratigraphic model was created for the Duvernay formation. The model was grounded in detailed lithofacies analysis, supplemented with organic and inorganic geochemistry, and correlated through an extensive database of wireline logs. Sequence stratigraphic analysis of organic rich mudstones is based on traditional sequence stratigraphic methods but requires an awareness of pitfalls that may lead to incorrect interpretations. Facies analysis and integration of multiple datasets is critical in understanding the dynamic environment responsible for the deposition and preservation of organic-rich mudstones. High resolution examination of rock properties is vital in planning well locations, choosing horizons to land horizontal wells, carrying out an appropriate hydraulic fracturing program, and predicting flow rates and draw down curves.