Effect of polymer on surfactant floodings of oil reservoirs

It has been found that addition of hydrophilic polymers in the range 0–10,000 ppm has little effect on surfactant bulk properties in the II(−) state. In some cases, added hydrophilic polymer can reduce the saturation value for surfactant adsorption due to competitive adsorption. Surfactant-polymer interactions, for non-associating systems, have little effect on surfactant/polymer core floods. On a larger scale, polymer will of course provide mobility control and a somewhat higher capillary number due to the increased viscosity. It is concluded that the observed effects of polymer on laboratory surfactant core floods is due to secondary effects that have little relevance at the reservoir scale. This means that in field applications there is a freedom in the choice of surfactant-polymer combination.