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

This study investigates the effects of polymer treatment on relative permea bility curves. Capillary pressure curves and relative permeability curves b efore and after polymer treatment are compared to understand the interactio n of adsorbed polymer with porous rocks. Capillary pressure curves before a nd after polymer treatment were obtained using an ultracentrifuge. Centrifu ge 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 pol ymer on non-wetting phase relative permeability is different in different r ocks. A decrease in non-wetting phase relative permeability was observed in Elgin sandstone (Elgin SS), whereas an increase was observed in Okesa sand stone (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 th is study provide useful insights into the interaction of adsorbed polymer w ith clays and the resultant effects on relative permeability curves. This s tudy also suggests a useful way of using centrifuge data to study the effec ts of polymer treatment on capillary pressure characteristics of porous roc ks. (C) 2001 Elsevier Science B.V. All rights reserved.