Demonstrating the Value of Combining Geologic Carbon Dioxide Sequestration with Enhanced Oil Recovery: Powder River Basin, Wyoming and Montana

Melick, Jesse J.¹, Michael H. Gardner¹ (1) Montana State University, Bozeman, MT

Gigaton-scale CO2 sequestration requires basin-scale storage solutions. Balancing significant costs associated with developing sufficient infrastructure to transport, inject and monitor geologic storage of carbon could be mitigated linking it to enhanced oil recovery (EOR) practices. Geologic models of Powder River Basin (PRB) will test feasibility of this approach, characterizing a suite of potential CO2 and EOR intervals. Dynamic fluid flow simulation of permeability pathways will be interrogated at pore, field, and basin scales.

Four principal basin reservoirs determine CO2 migration and storage. The Mississippian carbonates and Pennsylvanian eolian units, capped by 50m of impermeable Goose Egg Fm., representing 0.2% of the 80,000 km3 PRB volume, are attractive CO2 storage targets. Lower Cretaceous valley fills encased in thick shales, but aligned with structural lineaments, represent critical lateral permeability pathways that could focus and promote rapid eastward escape. However, if vertical seepage in western PRB reaches upper Cretaceous shoreface sandstones, CO2 could rapidly rise through permeable exposed Tertiary units. Constructing simulation models of a mature petroleum basin can be used to generate multiple realizations of fluid-flow scenarios. Each of these pathways corresponds to hydrocarbon reservoirs with significant EOR potential.

This approach identifies potential sequestration sites, characterizes fracture connectivity and permeability pathways, and predicts migration within the basin's plumbing system. Assessing the PRB, where nine power plants rim the basin, will highlight the enormous capacity, infrastructure and financial requirements needed to reach zero emission targets. This pragmatic approach to sequestration research utilizes petroleum technology and engages an industry with built in EOR incentives.