Nanoscale Visualization of Gas Shale Pore and Textural Features

Abstract

URTeC 1581981 Characterization of gas shale pore topology and composition supports efforts to produce methane as well as assess the feasibility of using depleted organic-rich shale reservoirs for carbon dioxide sequestration. Imaging performed with Full-field Transmission X-Ray Microscopy technology to characterize gas shale structure and heterogeneity was conducted on a set of Barnett and Haynesville gas shale samples to help determine how the physical and chemical processes associated with CO2 in organic-rich shales affect injectivity and storage capacity (over long periods of time), and the ability of the shale to sequester CO2 (as both a free and adsorbed phase). The images show the presence of density-differentiated areas that might be an indication of predominantly organic and inorganic matter matrices, along with lowest-density lineal pathways that point to the potential presence of micro cracks. Using an innovative imaging technique at the nanoscale, high X-ray contrast gas was applied to the sample and the images obtained show visual enhancement of particular rock features, such as available porous space and microcracks.