Interaction of Shale Gas Production and Potential CO2 Sequestration Sites

Carbon sequestration may be seen as a needed bridge technology between the current energy portfolio with high carbon emissions and a future portfolio based on low-carbon energy sources. A path to the low-carbon future would also include exploration and production of unconventional gas reserves, especially shale gas. However, the production of shale gas could interact with potential CO2 storage because the shale formations that are fractured could otherwise act as caprock formations in CO2 storage operation. Because of the large zone of influence resulting from the pressure perturbation associated with large-scale CO2 injection, there is potential for a large spatial extent of CO2 storage interaction with unconventional gas production. For this presentation we identify areas where shale gas production occurs in formations that are suitable for use as caprock formations in CO2 storage operations. We subsequently discuss the interaction of gas production activity and a CO2 sequestration project, in an area such as the Barnett Shale. We then examine concentrated leakage pathways in the caprock to simulate a localized increase in permeability, due to induced fractures, of an otherwise confining unit. Furthermore, we examine how a CO2 plume would encounter a hydraulic zone perturbed by exploration, and if there would be direct interruption of both the CO2 storage program and gas production.