Influence of alumina nanofluids on wettability and capillary sealing of organic-aged shale substrates for H2 geological storage
Author Identifier (ORCID)
Alireza Keshavarz: https://orcid.org/0000-0002-8091-961X
Abstract
The increasing concentration of carbon dioxide in the atmosphere, primarily driven by the combustion of fossil fuels, poses serious risks to global climate stability and public health. As a cleaner alternative, hydrogen (H2) offers promising potential; however, its widespread adoption is hindered by challenges related to its low density, high reactivity, and safe storage, especially under subsurface conditions. Shale formations are crucial for retaining H2 underground for geological hydrogen storage. A critical factor influencing this storage potential is wettability, which directly affects H2 trapping efficiency. Organic contaminants, such as stearic acid, can degrade caprock sealing capacity, whereas nanofluids may offer a solution to mitigate this effect. This study investigates the influence of alumina (Al2O3) nanofluids on the wettability of stearic acid-contaminated shale samples under simulated reservoir conditions. Shale cores from the Eagle Ford, Marcellus, and Barnett formations were artificially aged with stearic acid (10−2 mol/L) to replicate subsurface contamination. Wettability was assessed using the sessile drop method by measuring the brine advancing and receding contact angles on pure, organic-aged, and nanofluid-aged (at Al2O3 nanofluid concentrations of 0.05, 0.1, 0.25, and 0.75 wt%) substrates, across a pressure range of 01–16 MPa at a fixed temperature of 323 K. Various characterization techniques were employed to monitor mineralogical and morphological changes. The results indicate that stearic acid and elevated pressure promoted H2-wet conditions, increasing the brine contact angle and reducing the H2 column height, which implies decreased capillary trapping. Treatment with Al2O3 nanofluids, particularly at 0.25 wt%, reversed the wettability to an intermediate state, increasing the H2 column height and capillary trapping. These findings underscore the potential of nanofluid-based wettability alteration to enhance H2 storage security in shale formations, contributing to a broader transition toward sustainable energy systems.
Document Type
Journal Article
Date of Publication
11-7-2025
Volume
186
Publication Title
International Journal of Hydrogen Energy
Publisher
Elsevier
School
School of Engineering
RAS ID
88118
Funders
King Abdullah University of Science and Technology (10876-kaust-2023-KAUST-C-4-1-SE-)
Copyright
subscription content
Comments
Ali, M., Ahmad, T., Kumar, N., Usman, M., Kobaisi, M. A., Keshavarz, A., & Hoteit, H. (2025). Influence of alumina nanofluids on wettability and capillary sealing of organic-aged shale substrates for H2 geological storage. International Journal of Hydrogen Energy, 186, 152079. https://doi.org/10.1016/j.ijhydene.2025.152079