This paper describes the formulations for a three-phase, fully implicit, parallel, EOS compositional chemical flooding simulator with comprehensive compositional phase behavior model as a function of salinity. Presented formulation assumes that the reservoir is isothermal and no free gas or alkali is present. The improved simulator can handle the full transition from Type I to Type III to Type II microemulsion phase behavior. The parallel processing capability combined with fully implicit time stepping allows high-resolution full field scale chemical flooding simulations. The fully implicit simulation results are validated against an IMPEC chemical flooding simulator. This generalization required a substantial reformulation of the equations and extending the three phase water/oil/gas to up to four phases of water/oil/gas/microemulstion with corresponding physical property models. The full coupling of chemical with EOS model will provide a general framework to model the effect of live oil and pressure on surfactant phase behavior.
This paper presents a fully implicit, chemical-EOS compositional simulator with a comprehensive surfactant phase behavior that can take into account the effect of salinity and the resulting two- or three-phase flow with efficient parallel scalability.