Fast and accurate selection of surfactants for enhanced oil recovery by dynamic Salinity-Phase-Inversion (SPI)

In conventional chemical Enhanced Oil Recovery (EOR), surfactant mixtures must be optimized to obtain the so-called “optimum formulation” characterized by a three-phase behaviour (WIII) and an ultra-low interfacial tension between crude oil injected water. To attain this condition, discontinuous salinity scans of Surfactant-Oil-Water (SOW) systems are usually performed in series sealed pipettes maintained at reservoir temperature until complete phase separation. Furthermore, some SOW do not give WIII, but instead they form viscous phases which very detrimental for EOR applications. The study herein describes novel method called dynamic Salinity-Phase-Inversion (SPI) quickly accurately determine optimum formulation anticipate whether mixture will provide, static method, WIII or phase. This consists continuously modifying stirred system WOR vicinity 1, order detect inversion emulsion sudden drop conductivity. effectiveness is illustrated seeking two oils presence ionic (sulfated propoxylated n-alcohol) nonionic co-surfactant (ethoxylated i-alcohol), with without alkali. Continuous scan constant allows identification optimal within 30 min. therefore significantly accelerates optimization blends suitable given reservoir.