Salinity, temperature and pressure effect on hydrogen wettability of carbonate rocks

Hydrogen had been injected into the geologic formations, and the geologic formation wettability would influence the hydrogen storage. Hydrogen wettability of sandstone res-ervoirs (quartz), mica and other rocks have been explored in the previous study. However, the research on hydrogen wettability of carbonate rocks was lacked. In this study, we studied the carbonate rock wettability alteration when exposed to the hydrogen environ-ments. Salinity, temperature and pressure effect on H2/carbonate rock/brine wettability were explored. When the solutions ions concentration increased, the advancing/receding contact angle would increase, and divalent ions could make the contact angle higher than monovalent ion, which was because ions could compress the electric double layer. The carbonate rock powder in brine showed negative charge, and the zeta potential increased with higher ions concentration. When temperature increased and the pressure decreased, the contact angle would decrease, which was related to the H2 gas density and molecular interactions.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.