InterPore2026

Pore structure and fluid occurrence in flexible shale nanocomposites: decoupling the role of pressure, inorganic matter and fluid content

Not scheduled

1h 30m

Poster Presentation (MS20) Special Session in Honor of Jun Yao Poster

Speaker

Mr Tianhao Li (China University of Petroleum (East China))

Description

Organic-clay composite nanoporous media play critical roles in unconventional oil/gas extraction, geological carbon sequestration, underground hydrogen storage, and nuclear waste disposal. However, the changing patterns of the pore structure and fluid distribution of organic clay complexes under the influence of organic-inorganic composition, fluid content, and pressure remain unclear. In this study, flexible shale nanoporous models with varying kerogen-montmorillonite ratios were constructed. We evaluated how organic-inorganic composition, fluid content, and pressure collectively govern pore structure and fluid distribution. Our results show that increasing inorganic content promotes mesopore formation while reducing micropores and surface-area-to-pore-volume ratios, except in pure organic systems. In the latter, kerogen self-aggregation suppresses micropore development compared to composite systems containing minor clay fractions. A higher inorganic content increases the free phase proportion, improving recovery potential, while pure organic systems exhibit slightly less adsorbed fluid than composites with trace inorganic content. Fluid content exerts a stronger influence on pore structure and fluid distribution than pressure. Decreasing fluid content or increasing pressure diminishes mesopores but enhances micropores and surface-area-to-pore-volume ratios. The sensitivity of pore structure changes to fluid variations is more pronounced in organic-rich systems. Reducing fluid content elevates the adsorbed phase proportion, particularly in organic-rich systems, and simultaneously deteriorates pore connectivity, thereby hindering extraction. In pure inorganic systems, collapsed clay inter-layer pores squeeze adsorbed oil into isolated free clusters that appear mobile but remain trapped and difficult to produce. Higher pressure minimally affects fluid distribution but enhances reservoir energy, benefiting extraction. This work provides molecular-level insights into pore structure and fluid behavior in organic-clay composites.