Interaction of Cationic Surfactants with Anionic Polymers for Improving Oil Production

Surfactants used for chemical flooding were usually anionic surfactants such as sulfate, sulfonates and carboxylates with different hydrophobic chains (Hirasaki et al. 2011, Negin et al. 2017). This is due to most chemical flooding applications were in sandstone reservoirs (Sheng 2010, Guo et al. 2018, Alvarado and Manrique, 2010). Sandstone is composed of quartz (SiO2) grains cemented together with a variety of minerals. As a result, the rock surface of sandstone is negatively charged. The adsorption of anionic surfactants on sandstone is low due to electrostatic repulsion. Polymers used were also negatively charged such as partially hydrolyzed polyacrylamides (Needham and Doe 1987, Zhu et al. 2015) and sulfonated polyacrylamides (Moradi-Araghi et al. 1987, Levitt et al. 2008).