Controls on East Shale Basin reservoir distribution within the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin

Abstract

The Duvernay Formation accumulated as an organic-rich basinal mudrock concurrent with shallow marine platform carbonates of the Leduc and Grosmont formations. Historically classified as a major source rock to conventional hydrocarbon production, the Duvernay evolved into an unconventional shale reservoir across Alberta, Canada much like other source rock intervals worldwide. Distributions of the Duvernay Formation are partitioned into the West and East Shale basins by a narrow, linear Leduc Formation reef complex known as the Rimbey-Meadowbrook trend. Since 2011, development has focused on the West Shale Basin, but thermal maturity trends suggest the potential for expanded shale reservoir development within the southern portion of the East Shale Basin. This study characterizes sedimentologic and stratigraphic controls on Duvernay reservoir potential to identify development “sweet spots” within the East Shale Basin. Duvernay geologic attributes mapped within this study include: oil thermal maturity, thick restricted basin facies association occurrence (at least 5-10m thick), high average TOC values (greater than 2.0 wt.%), and high net carbonate thickness (greater than 40m). The geologic attributes are predictive of production potential within horizontal wells, and the distribution of their co-occurrence suggests the potential for expanded development within the southern portion of the East Shale Basin.