Host-rock and caprock wettability during hydrogen drainage: Implications of hydrogen subsurface storage
Document Type
Journal Article
Publication Title
Fuel
Volume
351
Publisher
Elsevier
School
School of Engineering
RAS ID
58443
Funders
Iran National Science Foundation
Abstract
Underground hydrogen storage (UHS) is an integral part of H2 economy value chain, essential for industrial-scale actualization of global decarbonization objectives. UHS in depleted hydrocarbon reservoirs is considered a safer and promising storage technique due to presence of large porous formation and impermeable seal, but its effectiveness depends on precise estimation of rock wettability, a crucial parameter in reservoir characterization, which controls pore-scale gas distribution, H2 containment safety and withdrawal efficiency. Several recent studies have provided contact angles data for host rock-water-H2 (quartz and sandstone) and caprock-water-H2 (mica and shale) measured through sessile drop method. However, the contact angle datasets for carbonate rock-water-H2 measured via captive bubble method, which can reflect the wettability of the rock during imbibition and drainage are largely unknown. The present work characterized the wettability of carbonate-water-H2 systems for various rock types, prepared from five different lithologies with different mineral assemblages. The contact angle was measured using the captive bubble method at two different temperatures of 303 K and 348 K, and three different pressures (3.44, 10.34, and 17.23 MPa). Experimental results showed that all rocks remained intrinsically strongly water-wet ( ranged between 17° – 30°) at all experimental conditions. Furthermore, no significant change in contact angles occurred with changing temperature and pressure. For instance, at 17.23 MPa, contact angle of H2/brine on anhydrite (S-4) rock were measured as 19° and 20° at 303 K and 348 K respectively, suggesting that H2 remains the non-wetting phase with increasing storage depth and at warmer reservoirs. The study suggests that the pore-scale flow and fluid connectivity of H2 may not be influenced by changing wettability in pure storage rocks/caprocks. Thus, the wettability of carbonates storage rocks and caprocks may not be over-predicted by assuming strongly water-wet conditions for the non-contaminated rock surfaces during UHS.
DOI
10.1016/j.fuel.2023.129048
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Comments
Aghaei, H., Al-Yaseri, A., Toorajipour, A., Shahsavani, B., Yekeen, N., & Aldmann, K. (2023). Host-rock and caprock wettability during hydrogen drainage: Implications of hydrogen subsurface storage. Fuel, 351, article 129048. https://doi.org/10.1016/j.fuel.2023.129048