Modelling of the Phase-Partitioning Behaviors for CO2-Brine System at Geological Conditions

Abstract An improved phase-partitioning model is proposed for the prediction of mutual solubility in CO2-brine system containing Na+, K+, Ca2+, Mg2+, Cl-, and SO42-. The correlations are computationally efficient reliable, they primarily designed incorporation into a multiphase flow simulator geology- energy-related applications including CO2 sequestration, CO2-enhanced geothermal systems, oil recovery. relies on fugacity coefficient CO2-rich phase activity aqueous to estimate properties. In model, (i) coefficients simulated by modified Peng-Robinson equation state which incorporates new alpha function binary interaction parameter (BIP) correlation; (ii) estimated unified equilibrium constant Margules expression; (iii) simultaneous effects salting-out compositions corrected Pizter model. Validation calculations against literature experimental data traditional models indicates that capable predicting behaviors with higher accuracy at temperatures up 623.15 K pressures 350 MPa. Using diagram CO2+H2O generated. abrupt change revealed during transfer from vapor liquid or supercritical. Furthermore, preliminary simulation shows effect can considerably decrease water content phase, has not been well experimentally studied so far.