Impact of Mineral Spatial Distribution on CO ₂ Dissolution Rates in Multimineral Carbonate Rocks

Understanding the reactive dissolution of carbonate rocks in ‐rich brine environments is critical for optimizing carbon capture and storage (CCS). This study integrates flow experiments with high‐resolution micro‐CT imaging and pore‐scale simulation to analyze the interplay between physical and chemical heterogeneity during reactive transport. By examining two carbonate samples comprised principally of dolomite and calcite with anhydrite also present, we quantify how the initial distribution of minerals and permeability variations influence flow patterns, dissolution dynamics, and the increase in permeability. The results show that reaction rates decrease with increasing flow heterogeneity due to enhanced mass transfer limitations. Furthermore, the proximity of minerals to fast‐flow channels impacts their effective reaction rates and alters their hierarchy, highlighting the interplay between transport processes, mineral spatial distribution and mineral dissolution. Both samples displayed dissolution patterns with localized channel widening and formation. The study provides key insights into mineral‐specific reaction behavior and flow‐dependent dissolution patterns, further evaluating a detailed framework for improving predictive models of subsurface storage.