Improving basalt wettability to de-risk co₂ geo-storage in basaltic formations

CO₂ geo-storage in basaltic formations has recently been identified as a viable option to rapidly dispose large quantities of CO₂, hence mitigating anthropogenic CO₂ emissions. However, it has been shown that basalt is weakly water-wet or intermediate-wet at typical storage conditions, which reduces capillary trapping capacities and increases lateral and vertical spreading of the CO₂ plume; and these effects increase project risk. We thus propose here to prime basalt surfaces with anionic surfactant (here we used sodium dodecyl benzene sulfonate), and demonstrate that such priming is highly efficient, and renders the basalt completely water-wet even at high pressures and minute sodium dodecyl benzene sulfonate concentrations. Such a wettability alteration can therefore significantly de-risk storage projects. This work aids in the improvement of CO₂ storage in basaltic formations and supports implementation of industrial-scale CO₂ geo-sequestration and climate change mitigation.