Low salinity surfactant alternating gas/CO2 flooding for enhanced oil recovery in sandstone reservoirs

Surfactant alternating gas/CO 2 (SAG) flooding is a promising enhanced oil recovery (EOR) technology, which has the potential to improve production beyond primary and secondary water methods. However, performance of SAG restricted due instability under high salinity reservoir conditions excessive surfactant adsorption. One convenient relatively low-cost option overcome limitations use low (LSW). In this study, an innovative effective approach in form (LSS) system was developed suitably enhance efficacy immiscible sandstone cores. The impact LSS solutions on various mechanisms responsible for EOR including surface interfacial tension (IFT), wettability alteration, CO -foam stability, adsorption were investigated. initial IFT measurements revealed that oil-water could be lowered using formation (FW), however more reduction possible only when surfactants introduced such solutions. Similarly, reductions contact angle (from 122° 45°) achieved with demonstrated favorable alteration rock from oil-wet water-wet conditions. Foam stability experiments half-life -foams generated appreciably higher, thus indicating positive foam stability. Additionally, anionic displayed reduced behavior onto cores, whereas cationic values comparatively higher exhibited reverse trend decreasing salinity. Finally, core illustrated significantly residual mobilized recovered through tertiary (LSSAG) flooding. Nearly 23% original place (OOIP) produced by employing solution as chemical slug during LSSAG similar experimental conditions, about 16 %OOIP despite its better performance. summary, constitute means • Low prepared diluted water. favorably altered IFT. Anionic most stable crude oil. Oil improved surfactants.