REDUCING SURFACTANT ADSORPTION IN CARBONATE RESERVOIRS

This paper compares the adsorption of anionic and cationic surfactants on carbonate minerals. It shows that, in general, cationic surfactant s may exhibit significantly less adsorption on carbonate minerals than that exhibited by anionic surfactants. It is also shown that cationic surfactant adsorption on carbonates may be reduced dramatically by th e presence of divalent cations, an environment in which the precipitat ion of anionic surfactants might make their use impractical. It is rec ommended that cationic surfactants be considered for use in miscible f looding with CO2.