Using centrifuge data to investigate the effects of polymer treatment on relative permeability

This study investigates the effects of polymer treatment on relative permeability curves. Capillary pressure curves and relative permeability curves before and after polymer treatment are compared to understand the interaction of adsorbed polymer with porous rocks. Capillary pressure curves before and after polymer treatment were obtained using an ultracentrifuge. Centrifuge data were then used to derive relative permeability curves using Wyllie and Gardner's model. Results of this investigation show a marked reduction in wetting phase relative permeability. However, the effect of adsorbed polymer on non-wetting phase relative permeability is different in different rocks. A decrease in non-wetting phase relative permeability was observed in Elgin sandstone (Elgin SS), whereas an increase was observed in Okesa sandstone (Okesa SS) at the same polymer concentration. An attempt was made to determine if these differences are due to the distribution of clays in the pores and to their interaction with the adsorbed polymer. The results of this study provide useful insights into the interaction of adsorbed polymer with clays and the resultant effects on relative permeability curves. This study also suggests a useful way of using centrifuge data to study the effects of polymer treatment on capillary pressure characteristics of porous rocks. (C) 2001 Elsevier Science B.V. All rights reserved.