A Multi-Parameter Correction Model for Predicting IFT and MMP of CO₂–Oil Systems

The full-parameter correction gave lower IFT and MMP than correction of only critical temperature and critical pressure. For CO₂–C8 at 80 °C in a 5 nm pore, the IFT at 6 MPa decreased from 2.52 to 0.613 mN/m, and the MMP decreased from 12.75 to 11.48 MPa after all parameter shifts were included. The correction effect became stronger in smaller pores, at higher temperatures, and for longer-chain hydrocarbons.

Mechanistic analysis showed that pressure and stronger confinement promote gas–liquid compositional homogenization, whereas temperature regulates miscibility non-monotonically. The workflow is most suitable for comparing pore-size, temperature, pressure, and composition effects in CO₂-alkane and simplified mixed-hydrocarbon systems. Extension to complex crude oils requires reliable compositional and thermodynamic inputs.