Capillary Desaturation Tendency of Hybrid Engineered Water-Based Chemical Enhanced Oil Recovery Methods

Several studies have shown the synergetic benefits of combining various chemical enhanced oil recovery (CEOR) methods with engineered waterflooding (EWF) in both sandstones and carbonate formations. This paper compares capillary desaturation tendency hybrid combinations water (EW) CEOR their conventional counterparts. coreflood experiments were conducted, including EW-surfactant flooding (EWSF), EW-polymer (EWPF), EW-alkali-surfactant (EWASF), EW-surfactant-polymer (EWSPF), EW-alkali-surfactant-polymer (EWASP). Capillary numbers (Nc) corresponding residual saturation (Sor) for each scenario are compared curves (CDC) from literature. The results indicate that EW–CEOR higher to methods. obtained by standalone polymer (PF) usually range 10−6 10−5, which not sufficient cause a significant reduction Sor. However, approach considerably reduced Sor same Nc values, proving effectiveness investigated method. EWASP caused highest (23%) against values 8 × 10−2, while ASP relatively (3 10−3 10−1). Overall, 30–70% more efficient terms recovering oil, EWF can be attributed combination different mechanisms such as wettability modification EW, ultralow interfacial tension alkali surfactant, surfactant adsorption addition, favorable mobility ratio polymer. Based on promising results, these techniques effectively implemented formations harsh reservoir conditions high salinity temperature.