We have developed a fully implicit, parallel, compositional reservoir simulator that includes both a cubic equation of state model for the hydrocarbon phase behavior and Hand's rule for the surfactant/oil/brine phase behavior. The aqueous species in the chemical model include surfactant, polymer, and salt. The physical property models include surfactant/oil/brine phase behavior, interfacial tension, viscosity, adsorption, and relative permeability as a function of trapping number. The fully implicit simulation results were validated by comparison with results from our IMPEC chemical flooding simulator (UTCHEM). The results indicate that the simulator scales well using clusters of workstations. Also, simulation results from parallel runs are almost identical to those using a single processor. Field-scale, high-resolution surfactant/polymer flood simulations were successfully performed with over 1,000,000 gridblocks using more than 100 processors.