Abstract We simulate supercritical carbon dioxide (scCO2 ${text{scCO} }{2}$) dissolution in water in nano/submicron pore‐throats (14.3–21.5 nm) using a multi‐component, multiphase pseudopotential lattice Boltzmann model closed by a Peng–Robinson equation of state. Phase coexistence, interfacial tension and contact angle are calibrated, and scCO2 ${text{scCO} }{2}$ solubility is matched to Henry’s law at representative reservoir conditions. By varying pore‐throat size and wettability, we identify two dissolution regimes. Narrow throats with weakly hydrophilic walls generate highly curved convex hulls of scCO2 ${text{scCO} }{2}$ that create quasi‐miscible water–CO2 ${text{CO} }{2}$ pockets and yield markedly higher dissolved fractions than wider or more strongly hydrophilic cases. In contrast, wider throats or strongly hydrophilic walls support continuous water films, suppress curvature hot spots and produce nearly uniform dissolution. Both regimes are quantified in this study by means of the space correlation between the local curvature of scCO2 ${text{scCO} }_{2}$ clusters with neighboring solubilities.