High-Resolution Reservoir Characterization of Incised Valley Fills of the Lower Cretaceous Grand Rapids Formation, Upper Mannville Group, East Central Alberta, Canada

Coderre, Adam B.; Pouderoux, Hugo; Pedersen, Per; Leier, Andrew

The complex nature of fluvial to marine-influenced incised valley fills often makes it difficult to predict the internal geometries and heterogeneities of heavy oil bearing sandstone reservoir bodies. Abundant subsurface data from Lower Cretaceous strata in western Canada provide new insights into the 3-D reservoir distribution within incised valley systems. These data help improve reservoir characterization models and serve as important parameters for secondary recovery techniques.

The Lower Cretaceous Grand Rapids Formation of the Upper Mannville Group in east central Alberta, Canada consists of shoreface parasequences that are incised by multiple valleys infilled with fluvial and estuarine sediment. Sandstone bodies within the incised valleys have 65-80% oil saturation and comprise the primary heavy oil reservoirs in the region. These deposits are covered by a dense dataset (e.g., 1 mi2 area with over 20 wells) of wireline logs and cores, which allow for a high-resolution characterization of the sedimentology, stratigraphy, and internal geometry of the incised valley fill sediments. Utilization of standard stratigraphic characterization methods combined with more innovative mapping techniques highlight key differences in reservoir properties. This allows for the generation of a high-resolution model of the distribution and dimensions of reservoir-quality fluvial to marine-influenced sandstones and non-reservoir heterolithic strata within incised valleys that, in turn, enhances predictability of reservoir connectivity and fluid flow pathways.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013