(274c) Brine-Soluble Zwitterionic Polymers with Tuneable Adsorption on Carbonates

Injection of aqueous fluids into reservoirs for enhanced oil recovery (EOR) has been of great interest in petroleum engineering. EOR using viscous polymer solutions increases the fluid viscosity and reduces its relative permeability in the reservoir, therefore improving volumetric sweep efficiency for EOR and oil recovery. However, significant polymer adsorption on the rock surface and in the pores reduces fluid viscosity and increases the overall cost of EOR as more materials are required to compensate for the lost polymers. Polymer retention in high salinity and high temperature reservoir conditions is one of the greatest challenges in polymer flooding EOR. Here we report the dynamic adsorption and retention studies of five brine-soluble zwitterionic polymers using a Quartz Crystal Microbalance (QCM-D) and core flooding at high temperatures. Our results indicate that the dynamic adsorption of the polymers on carbonates correlates to their structure variation. QCM-D coupled with core flooding experiments help to understand the dynamic adsorption behavior of these polymers with clear insight on the mechanisms and the kinetics of adsorption. This work presents a unique way of correlating the structural variations of polymers to the dynamic retention on carbonate surfaces under extreme reservoir conditions.