Rheology and Interfacial Tension of Internal Olefin Sulphonate Coated Nano-silica for Enhanced Oil Recovery
Nano-materials have shown great potential for enhanced oil recovery (EOR) applications. They are
environmentally amiable and cost-effective especially in challenging temperature pressure reservoirs. Rheology and
interfacial tension are the fluid properties that are required to be critically studied before eventual field deployment.
However, un-stability caused by nanoparticles’ suspension might pose a significant obstacle for their wide EOR applications.
The present study examines rheological properties of surface modified nano-silica using anionic surfactant (IOS20-24).
Surface modification effect over stability of colloidal solution, colloidal dispersibility and interfacial tension (IFT) were
inspected. The developed surface modified nano-silica was characterized using Field Emission Scanning Electron
Microscope (FESEM) technique. Then, TurbiScan Classic was used to determine the optimal nano-silica concentration
where comprehensive analysis using light transmission through the brine solution containing modified nano-silica was
carried out. Afterwards, relationship between shear stress, shear strain and temperature were analysed using HPHT
Rheometer. It was found that the stability of the modified suspensions could be improved considerably with their shear
thinning behaviour. Both surfactant coated nano-silica and increasing silica concentration caused reduction in the IFT.
These results seemed to conclude that surfactant coated nano-silica has potential for EOR applications.
Keywords - Nano-silica, Surfactant Coating, Dispersion Stability, IFT reduction, enhanced oil recovery, rheology.