Modified cell-to-cell method for slim tube test simulation considering the porous media effect

This study estimates the minimum miscibility pressure (MMP) for a hydrocarbon gas injection project using integrated laboratory and simulation approaches. The MMP was first determined experimentally via a slim tube displacement test. Concurrently, a modified cell-to-cell simulation (CCS) model was developed, incorporating key corrections to account for porous media effects. These modifications included: adjusting the Peng–Robinson equation of state for a porous medium, improving the critical properties shift equation, incorporating capillary pressure into vapor–liquid equilibrium calculations, and refining fluid transfer criteria. The simulation used the permeability-to-porosity ratio to represent the porous medium’s influence on phase behavior. Results demonstrate that a decreasing permeability-to-porosity ratio reduces the MMP. This effect is particularly significant in tight reservoirs (with ratios below 10), indicating that miscibility can be achieved more readily in such formations compared to conventional reservoirs. The modified CCS method provides an efficient and reliable tool for MMP estimation.