Figure 7
From: A comprehensive review of viscoelastic polymer flooding in sandstone and carbonate rocks
Schematic of charge-screening mechanism in porous media: (a) low-salinity condition, where polymers are stretched due to repulsive forces causing the higher flow resistance, (b) addition of salt cations to the brine creates a barrier for electrostatic interactions between the polymer chains, preventing polymer stretching and reducing its flow resistance. Herein, polymers are shown with blue curves, while cations are illustrated with solid green circles.
