A Numerical Study of the Influence of Rock Mineralization on CO2 Storage

Abstract

One of the anthropogenic greenhouse gases that significantly affects the climate is CO2, and it may be possible to lower its emission by sequestering it in an appropriate geological subsurface formation. For secure and effective sequestration, it is necessary to answer questions relating to enhancing the reaction rates of rock minerals to speed up sequestration, understanding the critical reservoir parameters involved with geochemically induced changes and how they affect mineralization, and the affinity of rock minerals for dissolution or precipitation in the presence of CO2 and reservoir brine. Therefore, in this paper, a case study of CO2 sequestration in a saline aquifer was investigated by using a numerical simulator to examine the impacts of injection period, temperature, pressure, and salinity on the CO2 mineralization trapping mechanism during the sequestration process. Nine intra-aqueous and seven mineral reactions were modeled to investigate the dissolution and precipitation of formation minerals. The results of this work can provide the appropriate mineralization temperatures at which each of the simulated minerals can either dissolve or precipitate. Calcite and dolomite mineralize more effectively at medium and lower temperatures, despite the fact that the reaction of other minerals such as illite, kaolinite, K-feldspar, and quartz will be more favored at high temperatures. Porosity and pH showed only slight variations, but they were sufficient to show how the dynamics of mineral reactivity and mineralization trapping efficiency had changed.