Résumé : Enhanced oil recovery typically relies on injection of seawater mixed with chemicals to increase reservoir pressure. A polymer such as partially hydrolyzed polyacrylamide (HPAM) is often added to increase viscosity. In this work, an oilfield biofilm consortium was found to utilize a commercial HPAM-based polymer. The polymer at 1000 ppm (w/w) promoted the growth of planktonic cells and sulfate reducing bacteria sessile cells in an artificial seawater medium during a 30-day incubation period in anaerobic vials. The polymer utilization led to 34.5% viscosity loss and more severe microbiologically influenced corrosion weight loss and pitting against C1018 carbon steel.