Application of a novel natural surfactant extracted from Avena Sativa for enhanced oil recovery during low salinity water flooding: Synergism of natural surfactant with different salts

Review on Potential Application of Saponin-Based Natural Surfactants for Green Chemical Enhanced Oil Recovery: Perspectives and Progresses

“…There are numerous reports on improved oil recovery from 29,32,33,50,72,109,130,136,137,141,143,144 SBNS and SBNS-hybrid flooding contribute to incremental oil recovery by 6.223% to 56% of OOIP, which is analogous to that attained by synthetic surfactants (Figure 27). In sandstone samples, SBNSs led to an oil recovery ranging from 7.52% to 36% after waterflooding, while in carbonate rocks, 6.23% to 56% of recoverable oil was produced after waterflooding.…”

“…The IFT reduction is also controlled by the cations where there is a greater integrated effect between salt and the SBNS for cations with lower positive surface charges. Low positive surface charge cations enhance the accumulation/adsorption of surfactant molecules at the oleic–aqueous phase interface, while high positive surface charge cations strongly repel surfactant molecules and prevent their adsorption at the interface. − The order of surface charge from the highest to the lowest of some commonly employed cations is Mg 2+ , Ca 2+ , Na + , and K + . Also, Ca 2+ and Mg 2+ have stronger affinities for asphaltene and resins, respectively. , The findings of Razzaghi-Koolaee et al contradict the proposition by Sami et al, although the former agrees with the latter on the surface charge of the cations as stated above.…”

“…The oil recovery when 48 and 135 h of soaking times were allowed was 5.4% of the OOIP (from 77.8% to 83.2%) and 4.5% of the OOIP (from 77.67% to 82.17%), respectively, and this was greater than similar surfactant flooding with no soaking period. 72,130 The incremental oil recovery by SBNS injection from the various experiments reported in the literature is attributed to both the reduction of IFT and the modification of wettability by the SBNS employed. Thus, the main mechanism responsible for the observed incremental recovery by SBNS injection is not clearly defined.…”

“…Laboratory studies have revealed that saponin-based natural surfactants (SBNSs) can reduce IFT, modify the wettability of oil-wet rock samples, and improve oil recovery. Alkalis, polymers, , smart and low-salinity water, , and nanoparticles ,,,,− have shown to improve SBNS performance in EOR processes. These additives lower the oil–aqueous phase IFT to ultralow levels (close to that provided by synthetic surfactants), significantly reduce the contact angle, enhance emulsion stability, and minimize surfactant adsorption rate, which are beneficial for improved oil recovery.…”

“…267,268 There are inconsistent reports in the literature relating to the most efficient salt/ion for IFT minimization and wettability alteration. 33,72,110 Moradi et al 32 assessed the impact of active ions in a Tribulus terrestris-derived SBNS solution. The hybrid SBNS−smart water slug, which comprised 2.5 times the concentration of sulfate ions (0.6005 wt %) and 0.3 wt % (CMC) of the SBNS, resulted in the highest IFT and contact angle optimizations.…”