Methodology for assessing CO₂ storage potential of organic-rich shale formations

The United States Department of Energy's National Energy Technology Laboratory (DOE-NETL) is developing a volumetricbased methodology for calculating prospective CO₂ storage resource of organic-rich shale formations. Similar to natural gas, carbon dioxide (CO₂) can be stored in organic-rich shale as free-gas within fractures and pores and as a sorbed component on organic matter and clays. The proposed methodology includes three screening criteria to serve as guidelines for assessing CO₂ storage. The absence of thorough, comprehensive geologic and petrophysical data for unconventional shale reservoirs is noted as a significant limitation and source of uncertainty in estimating CO₂ storage resource. Future work is aimed towards analyzing geologic data from organic-rich shale in order to refine the methodology and reduce the uncertainty associated with CO₂ storage in these complex formations.