Nanopore Heterogeneity and Accessibility in Oil and Gas Bearing Cretaceous KG (Raghampuram) Shale, KG Basin, India: An Advanced Multi-analytical Study

This study investigated the impact of pore accessibility and complexity on gas storage, transport, and recovery potential in the little-studied thermally mature Raghampuram shale samples collected from 2930 to 2987 m depth of Krishna–Godavari basin, India. Our findings reveal that sample nature (powdered, chipped, or cores) and assessment methods significantly influence pore accessibility evaluation, highlighting a research gap in the interpretation of irregularity, complexity, and heterogeneity of shale pore structure using unreliable monofractal theories. Employing a multiscale methodology involving low-pressure N2 and CO2 sorption, synchrotron small-angle scattering, and He-pycnometry techniques, we estimated accessibility in powder and core samples. Powder samples displayed a pore accessibility range of 36.07–106.94