TY - JOUR

T1 - The development of novel nanofluid for enhanced oil recovery application

AU - Khoramian, Reza

AU - Kharrat, Riyaz

AU - Golshokooh, Saeed

N1 - Publisher Copyright: © 2021 Elsevier Ltd

PY - 2022/3/1

Y1 - 2022/3/1

N2 - Recently, nanofluids’ application in enhanced oil recovery (EOR) studies has been severely confined in low salineenvironments due to instability. In this study, a novel nanofluid was developed by conjugating an anionic surfactantto graphene oxide nanosheets (GONs) through electrostatic forces and compared with negatively chargedcolloidal silica nanoparticles. The surfactant conjugation on target GONs was confirmed by transmission electronmicroscopy, Fourier transforms infrared spectrometry and zeta potential. The developed nanofluid preserved ahigh salinity of 6 wt% NaCl and built more stable dispersions than bare silica nanofluid. The nanofluids’ potentialin recovering oil was comparatively studied by performing the viscosity, wettability, Pickering emulsion, andinterfacial tension (IFT) experiments. Even though a tangible improvement of 1.48 cp was observed in the viscosityof Janus-GONs fluid after the dissolution of NaCl, this figure became negligible for silica fluid, by 0.07 cp.From the wetting values (θ), Janus-GONs changed the oil-wet wettability toward neutral-wet (89.9◦), and silicananoparticles toward partially water-wet (66.4◦). Oil-in-water Pickering emulsions stabilized with the reinforcednanofluid remained fully stable compared to those of silica, which rapidly grew unstable. The reinforcednanofluid lowered interfacial tension by just under a third, which was attributed to its higher surface energy. Incontrast, silica nanoparticles did not change interfacial tension sensibly. Micromodel experiments revealed thatJanus-GONs yielded a considerable oil recovery of 79 % by restoring wettability to mixed-wet and reducing theviscous fingering phenomenon, compared to that of 53 % for silica. Based on the core flooding experiments, thepercentage of oil recovered for Janus-GONs fluid was twice the silica nanofluid due to the higher capillarynumber (1 × 10 4) compared to the silica (8.7 × 10 6). Viscosity improvement was proposed as a new EORmechanism next to wettability alteration and IFT reduction. Overall, the Janus nanofluid can be a groundbreakingnanomaterial for EOR.

AB - Recently, nanofluids’ application in enhanced oil recovery (EOR) studies has been severely confined in low salineenvironments due to instability. In this study, a novel nanofluid was developed by conjugating an anionic surfactantto graphene oxide nanosheets (GONs) through electrostatic forces and compared with negatively chargedcolloidal silica nanoparticles. The surfactant conjugation on target GONs was confirmed by transmission electronmicroscopy, Fourier transforms infrared spectrometry and zeta potential. The developed nanofluid preserved ahigh salinity of 6 wt% NaCl and built more stable dispersions than bare silica nanofluid. The nanofluids’ potentialin recovering oil was comparatively studied by performing the viscosity, wettability, Pickering emulsion, andinterfacial tension (IFT) experiments. Even though a tangible improvement of 1.48 cp was observed in the viscosityof Janus-GONs fluid after the dissolution of NaCl, this figure became negligible for silica fluid, by 0.07 cp.From the wetting values (θ), Janus-GONs changed the oil-wet wettability toward neutral-wet (89.9◦), and silicananoparticles toward partially water-wet (66.4◦). Oil-in-water Pickering emulsions stabilized with the reinforcednanofluid remained fully stable compared to those of silica, which rapidly grew unstable. The reinforcednanofluid lowered interfacial tension by just under a third, which was attributed to its higher surface energy. Incontrast, silica nanoparticles did not change interfacial tension sensibly. Micromodel experiments revealed thatJanus-GONs yielded a considerable oil recovery of 79 % by restoring wettability to mixed-wet and reducing theviscous fingering phenomenon, compared to that of 53 % for silica. Based on the core flooding experiments, thepercentage of oil recovered for Janus-GONs fluid was twice the silica nanofluid due to the higher capillarynumber (1 × 10 4) compared to the silica (8.7 × 10 6). Viscosity improvement was proposed as a new EORmechanism next to wettability alteration and IFT reduction. Overall, the Janus nanofluid can be a groundbreakingnanomaterial for EOR.

KW - Janus-graphene oxide nanosheet

KW - Silica nanoparticle

KW - Stability

KW - Viscosity

KW - Wettability

KW - Pickering emulsion

UR - http://www.scopus.com/inward/record.url?scp=85119587295&partnerID=8YFLogxK

U2 - 10.1016/j.fuel.2021.122558

DO - 10.1016/j.fuel.2021.122558

M3 - Article

VL - 311.2022

JO - Fuel

JF - Fuel

SN - 0016-2361

IS - 1 March

M1 - 122558

ER -