Polymer flooding represents a key chemical enhanced oil recovery (EOR) technique to improve displacement efficiency in heterogeneous carbonate reservoirs, where residual oil is trapped by capillary forces and early water channeling reduces sweep efficiency. This study evaluates a high-molecular-weight acrylamide-maleic anhydride-styrene terpolymer for EOR in challenging reservoir environments, focusing on its rheological stability, viscoelastic behavior, and displacement performance under controlled micromodel flooding experiments. Micromodels, fabricated from CT scans of carbonate cores to replicate reservoir heterogeneity (porosity 58.97%, average pore radius 14.16 μm, total pore volume 0.230 cm³), were used to assess polymer solutions at concentrations of 500, 750, and 1000 ppm. Experiments varied injection rates (0.005–0.02 mL/min) to examine front stability and sweep efficiency, salinity levels (seawater, 2×SW, 3×SW) to simulate ionic strengths of reservoir brines, and temperatures (25°C, 50°C, 80°C) to evaluate thermal stability and viscosity retention in reservoir-like conditions. Results demonstrate the terpolymer's ability to maintain performance across these parameters, enhancing macroscopic sweep and oil mobilization while addressing limitations of conventional polymers in high-temperature, high-salinity heterogeneous reservoirs.
Ahmed et al. (Mon,) studied this question.