Utilizing Hydrocarbon Yield Determinations to Evaluate Source/Reservoir Relationships in the Bakken/Three Forks of the Williston Basin, ND

The Bakken/Three Forks Petroleum System hosts variable source/reservoir r elationships throughout different portions of the Williston Basin. While some of these relationships are easily discernible from production and wireline log data, others become evident by comparing production results to geochemical data of the Upper and Lower Bakken shales. In order to better identify and characterize these relationships a series of “Hydrocarbon Yield” maps were created for the Upper and Lower Bakken shales using a method recently described by Ruble and Lewan (2013). The method computes a volume of hydrocarbon yield (MBOE/640 acres) by multiplying the thickness of the shales by the amount of S2 that has been converted into hydrocarbons. The generated yields are then compared to production data for both the Middle Bakken and Three Forks f ormations. Distinct trends have been identified that appear to be related to reservoir and seal quality, generation poten tial and thickness of the shales, and presence of fractures and other structural features. While this approach d oes provide a new understanding of the Bakken/Three Forks source/reservoir relationships, it can also prove ben eficial when used in the evaluation of other basins and formations.