Nanoscale Fluid-Rock Interaction in CO₂ Geological Storage

Continuous growth of atmospheric CO₂ concentration believed to be the major reason for "greenhouse effect", has become a global environmental issue in recent years. CO₂ reduction is a challenge not only for the survival of human society, but also for the development of geosciences and technology. Although there are a variety of approaches to reduce atmospheric CO₂, geological storage is considered as an effective way to reduce CO₂. Understanding CO₂ fluid-rock interaction is the key to successful geological storage of CO₂, because of its effects on CO₂ injection efficiency, and storage capacity, efficiency, safety and stability of the reservoir. Nanoscale materials have extraordinary properties with their abnormally huge amount of surface atoms and surface energy. CO₂ fluid-rock interaction has multi-scale effect, with much higher rate and efficiency at nanoscale than those at other scales, due to substantial differences in surface atoms and surface energy. Therefore, it is critical to reveal the major factors and mechanisms of nanoscale interaction between CO₂ fluid and rock to find some natural cost-effective nano-minerals for capture, storage and conversion of CO₂.