This session explores key challenges and advancements in subsurface storage and well integrity. Topics include the geochemical reactivity of hydrogen with sandstone for underground storage, 2D modeling of fault instability due to cold fluid injection, and brine management for CO2 storage in offshore aquifers. We'll also cover X-ray microtomographic studies of Portland cement in harsh conditions, well impairment from halite precipitation, the economic viability of enhanced CO2 storage and gas recovery, and wellbore integrity challenges during the energy transition.