Tracey J. Mercier Cheryl A. Woodall Heidi M. Leathers-Miller Thomas M. Finn Phuong A. Le Michael E. Brownfield Kristen R. Marra Geoffrey S. Ellis Christopher J. Schenk 2020 <p>Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 290 milllion barrels of shale oil and 7.9 trillion cubic feet of shale gas in the Ordovician Collingwood-Utica Shale Total Petroleum System of the Michigan Basin Province.</p> application/pdf 10.3133/fs20203027 en U.S. Geological Survey Assessment of continuous oil and gas resources in the Ordovician Collingwood Formation and Utica Shale of the Michigan Basin Province, 2019 reports