Polymer adsorption isotherms with NaCl and CaCl2 on kaolinite substrates

Abstract

During polymer injection in enhanced oil recovery processes, polymeric molecules are attached to the rock surface as a result of a series of interactions between both components, leading to concentration decrease on the injected batch. This phenomenon, known as adsorption [18], can be estimated by analytical models and depends on several factors like the type of rock, degree of hydrolysis and polymer concentration, reservoir temperature, salinity of formation water, among other aspects. This paper shows the results of 144 statics tests where salinity (NaCl and CaCl2) and polymer concentration were taken as the parameters to be changed in order to determine which analytical model is the most accurate for the prediction of experimental results. The abnormal adsorption tendency with NaCl, indicates that the grater salinity value, the lesser adsorption value concentrations. This is mainly due to the response of the kaolinite substrate to flocculation.