Wettability of hydrogen-rock-brine systems: Parametric analysis and knowledge gaps
Author Identifier
Stefan Iglauer: https://orcid.org/0000-0002-8080-1590
Document Type
Journal Article
Publication Title
Fuel
Volume
401
Publisher
Elsevier
School
Centre for Sustainable Energy and Resources / School of Engineering
Abstract
Underground hydrogen storage (UHS) has emerged as a vital component of the green energy transition. The wettability of the hydrogen-rock-brine system is crucial to the UHS process as it affects the storage capacity, containment security, and hydrogen recovery. However, the wettability of the hydrogen-rock-brine system has not been fully explored and a significant variation exists in the available data. This article provides a review of the published datasets on the wettability of hydrogen-rock-brine system to better consolidate knowledge and enhance the fundamental understanding in this area. In particular, the recently published datasets for H2-contact angle were reviewed and analysed for various rock systems, and parameters that have a significant impact on hydrogen-rock-brine wettability were identified and critically evaluated. This includes the effect of temperature, pressure, brine salinity, rock mineralogy, and the presence of organic acids. Furthermore, we compared the wettability of hydrogen-rock-brine systems with that of the CO2 analogues, and discussed the implications for hydrogen structural and residual trappings as well as knowledge gaps in this review. Our analysis shows that organic surface concentrations led to dramatically higher contact angles (more H2-wet systems). Also, the contact angles increased with increasing pressure due to the higher H2 density and the consequently higher H2-rock affinity due to the increased Van der Waals interactions between rock and H2. Temperature effects are complex, showing non-monotonic trends. For example, with the increase in temperature, most of the contact angle (CA) data shows a decrease at a constant pressure of 20 MPa, while it shows an increase at 10 MPa. Additionally, organic acids substantially raise contact angles, which can compromise capillary sealing. Our analysis reveals that sandstone systems predominantly exhibit water-wet conditions, whereas carbonate rocks tend to exhibit weakly water-wet behaviour. Comparative analysis indicates that hydrogen-brine-rock systems are generally more wetting than CO2-brine-rock systems, implying potentially higher storage containment but lower recovery efficiency. This article, therefore, provides essential data along with an overall overview and critical assessment of relevant parameters, thus aiding in the large-scale implementation of UHS and energy decarbonization.
DOI
10.1016/j.fuel.2025.135821
Access Rights
subscription content
Comments
Adila, A., Aboushanab, M., Raza, A., Mahmoud, M., Iglauer, S., Armstrong, R. T., & Arif, M. (2025). Wettability of hydrogen-rock-brine systems: Parametric analysis and knowledge gaps. Fuel, 401, 135821. https://doi.org/10.1016/j.fuel.2025.135821