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%, which was a substantial increase (154.54–423.07%) compared to that of solid core samples (1.61–4.16%). Total organic carbon was found to influence closed pore formation, while clay, carbonate, and quartz + K-feldspar contributed to open pores. Multifractal analyses comparing pore heterogeneity and complexity between accessible and inaccessible pores demonstrated higher heterogeneity and complexity in the latter, with accessible pores exhibiting simpler characteristics. Pore size distributions of both accessible and total pores (includes both accessible and inaccessible pores) exhibited multifractal behavior. Our findings emphasize the significance of evaluating pore accessibility and heterogeneity in shale-gas analysis, providing fresh insights into the interlinked elements of pore structure, composition, and gas recovery potential, thus advancing reservoir characterization understanding.

本研究调查了在印度 Krishna-Godavari 盆地 2930 至 2987 米深度采集的热成熟 Raghampuram 页岩样品中孔隙通达性和复杂性对天然气储存、运输和采收潜力的影响。我们的研究结果表明，样品性质（粉末状、碎片状或岩心）和评估方法显着影响孔隙可达性评估，凸显了使用不可靠的单分形理论解释页岩孔隙结构的不规则性、复杂性和非均质性方面的研究差距。采用涉及低压N ₂和CO ₂吸附、同步加速器小角散射和He比重测定技术的多尺度方法，我们估计了粉末和岩心样品的可及性。粉末样品的孔隙可达性范围为36.07-106.94%，与固体岩心样品（1.61-4.16%）相比，显着增加（154.54-423.07%）。研究发现总有机碳影响闭孔的形成，而粘土、碳酸盐和石英+钾长石则有助于开孔的形成。比较可通孔和不可通孔之间的孔隙非均质性和复杂性的多重分形分析表明，后者具有更高的非均质性和复杂性，可通孔表现出更简单的特征。可通孔和总孔隙（包括可通孔和不可通孔）的孔径分布均表现出多重分形行为。我们的研究结果强调了页岩气分析中评估孔隙通达性和非均质性的重要性，为孔隙结构、成分和天然气采收潜力等相互关联的要素提供了新的见解，从而推进了储层表征的理解。