Depositional facies analysis and modeling of the Judy Creek reef complex of the Upper Devonian Swan Hills, Alberta, Canada

Judy Creek, located in west-central Alberta, is one of the largest reservoirs in the Swan Hills oil field. Judy Creek is an isolated reef complex of the Upper Devonian Swan Hills Formation. This mature field has about 350 wells drilled and nearly 6000 m (19,685 ft) of cores and thus provides a good database for depositional facies analysis and testing methods for integrating descriptive and quantitative data in facies modeling. General depositional facies and sequence stratigraphy of Judy Creek have been studied quite extensively. However, no three-dimensional numeric facies model has been built to guide the field development. One of the objectives in constructing such a model for this study was to establish a close linkage between the facies depositional analysis and modeling. As a matter of fact, there have been significant disconnects between descriptive analysis and numeric modeling in the exploration and production. Depositional facies analysis has focused on conceptual understanding for prospect generation and reservoir delineation, whereas facies modeling has emphasized data mining for field development. In this study, a method that integrates the spatial propensity from the depositional conceptual models and facies data from the wells is used to bridge the gap between the depositional analysis and stochastic modeling. Such integration has proven to be critical in building realistic subsurface models in Judy Creek because it helped improve the estimation of subsurface resources.