Dynamic Adsorption of Functionalized Zwitterionic Copolymers on Carbonate Surfaces under Extreme Reservoir Conditions

Abstract

The injection of aqueous polymer solutions into reservoirs for enhanced oil recovery has attracted considerable interest in the petroleum industry. Polymers increase the viscosity of the fluids and thereby improve the volumetric sweep efficiency. However, significant polymer retention in reservoirs by adsorption to surfaces limits the propagation through the reservoir and can reduce the efficiency of the polymer flooding. To explore the structure-property relationships that can direct improvements in future polymer designs, we have investigated the dynamic adsorption of a model system of five zwitterionic copolymers using a quartz crystal microbalance with dissipation and core-flooding experiments at high temperatures and salinities. The results indicate that the degree of dynamic polymer retention is sensitive to a low percentage of functional comonomers on the polymer backbone. The concept of using a small fraction of comonomers to tune the adsorption of polymers is an attractive cost-effective method for modifying the properties of the polymers employed in the oil and gas industry.