Enhanced Oil Recovery in High Salinity and Elevated Temperature Conditions with a Zwitterionic Surfactant and Silica Nanoparticles Acting in Synergy

Abstract

Novel SiO2 nanoparticles (NPs) costabilized by a low-molecular-weight ligand (steric stabilization) and a zwitterionic surfactant (electrostatic stabilization) were developed for enhanced oil recovery purpose in sandstone reservoirs with high salinity and elevated temperatures. According to our experiments, the proposed NPs were not sensitive to either monovalent or divalent cations, whose size remained around 10.0 nm in API brine within 8 weeks at 25 °C and 4 weeks at 60 °C. Using the zwitterionic surfactant with NPs reduced the NP dosage required to induce wettability alteration and the possibility of severe permeability damage. The presence of NPs in return effectively decreased the surfactant adsorption loss on rocks, reduced the surfactant concentration needed to produce a low interfacial tension, and rendered the oil-wet solid surface toward a more water-wet condition beneficial for water imbibition and oil displacement. Core flooding tests showed that the nanofluid composed of 800 mg/L of zwitterionic surfactant and 2000 mg/L of lab-synthesized SiO2 NPs was able to recover extra 3.12 and 5.39% original oil-in-place from Berea sandstone cores in the tertiary recovery mode after surfactant flooding or pure NP flooding, respectively. In addition, thanks to the weak interactions between the zwitterionic surfactant and the surface-modified SiO2 NPs, flexible adjustments can be made to their concentration ratios to customize the desirable nanofluid formulas intended for specific applications.

Wettability alteration agents to promote spontaneous imbibition in tight reservoirs: Achievements and limitations

“…However, the applications of nanofluids in HTHS conditions are still limited and nanofluids with higher thermal and salt resistance should be developed. To improve the stability of NPs, ligands with dendritic structure or copolymers can be used (Zuniga et al, 2016;Zhong et al, 2020), but particle size should be carefully screened, and smaller particles are better preferred. 4) Structural disjoining pressure is proposed as the underlying mechanism in most studies to explain the wettability alteration by nanofluids by simply drawing a schematic diagram without compelling substantial evidence.…”

Synergistic Efficiency of Zinc Oxide/Montmorillonite Nanocomposites and a New Derived Saponin in Liquid/Liquid/Solid Interface-Included Systems: Application in Nanotechnology-Assisted Enhanced Oil Recovery

“…Xu et al, Cheraghian et al, Haeri et al, Songolzadeh and Moghadasi, Zhao et al, and Zhong et al. have shown that the combinations of silica nanoparticles with different surfactants have a good potential to alter wettability from oil-wet to water-wet. − Suleimanov et al showed that nonferrous metal NPs can reduce IFT/surface tension . Mohajeri et al, by combining ZrO 2 NPs with sodium dodecyl sulfate and CTAB, showed that the nanofluids optimize IFT/surface tension and alter wettability …”

“…Mohajeri et al, by combining ZrO 2 NPs with sodium dodecyl sulfate and CTAB, showed that the nanofluids optimize IFT/surface tension and alter wettability Table S2 summarizes the studies on the synergistic effects of nanosurfactants. − …”

Mechanism of Nano-depressurization and Injection-Augmenting Technology and Its Application in China’s Oilfields: Recent Advances and Perspectives

“…prepared hydrophobic silica nanoparticles by surface modification of silica nanoparticles with dimethyldichlorosilane. The result showed that the modified silica nanoparticles are adsorbed on the surface of the core and form a hydrophobic layer, changing the wettability of the sand surface from water wet to oil wet, thereby decreasing the flowing pressure . Gao et al established a set of biological nanomaterial depressurization and injection-augmenting numerical simulation technology water flooding models that consider the adsorption characteristics and reservoir physical properties.…”