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

Abstract

The United States Department of Energy's National Energy Technology Laboratory (DOE-NETL) is developing a volumetric- based 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.