Adsorption of High-Molecular-Weight EOR Polymers on Glass Surfaces Using AFM and QCM-D

High-molecular-weight (HMW) polyacrylamide and its derivatives are widely used in oilfield applications ranging from drilling fluids, enhanced oil recovery (EOR), and treatment of oil sand tailings. In these applications the adsorption characteristics of these polymers are essential since it would affect their applicability and efficiency. In this study, adsorption of three high-molecular-weight polymers (nonionic (NPAM), partially hydrolyzed (HPAM), and sulfonated (SPAM) polyacrylamides on silica surfaces from 2% KCl) is characterized using a quartz crystal microbalance with dissipation monitoring (QCM-D) and an AFM-based colloidal probe apparatus. QCM-D measurements show that semiequilibrium for adsorption on silica surfaces is reached within 3 h. The adsorbed amount and adsorption rate are highest for NPAM and lowest for SPAM. AFM experiments revealed that after 20 min of incubation in solution, HPAM induced bridging attraction on approach (i.e., compression). On the other hand, only a weak attraction ...