Simulation of Big Muddy Surfactant Pilot

Summary An improved compositional chemical-flood simulator has been used for the study of the low-tension pilot project at the Big Muddy field near Casper, WY. Both the tracer injection conducted before injection of the chemical slug and the chemical-flooding stages of the pilot project were analyzed. Using a compositional simulator, we successfully matched not only the oil recovery but also the tracers, polymer, alcohol, and chloride histories. Simulation results indicate that for this freshwater reservoir, the salinity gradient during preflush and the resulting calcium pickup by the surfactant slug played a major role in project success. In addition, the analysis of the effects of crossflow on the performance of the pilot project indicate that for the well spacing of the pilot, crossflow does not play as important a role as it might for a large-scale project.