Effect of the SiO₂ Nanoparticle Size on Application of Enhanced Oil Recovery in Medium-Permeability Formations

Abstract

Nanoparticles (NPs) have been applied in enhanced oil recovery (EOR) successfully over the last couple of decades, due to their unique property inherited by the small size (most of the studies focused on sizes smaller than 50 nm) and abundant surface functional groups. The important mechanism of EOR using a NP-based nanofluid is the change of interfacial properties. However, the effect of the nanoparticle size on the same type of oil recovery has not been systematically studied, especially the larger size. Therefore, in this research, SiO 2 NPs of different sizes, namely, ∼60, ∼100, ∼200, and ∼300 nm, were synthesized using the Stober method and the properties of the NP-based nanofluids were investigated, including interfacial tension (IFT), contact angle, viscosity, capillary pressure, and the ability to extract oil. The experimental results showed that as the SiO 2 NP size decreased, there was a little increase in the IFT, oil contact angle, viscosity, and capillary pressure. With a NP concentration of 0.3 wt % in 3 wt % NaCl brine, the ∼60 nm SiO 2 NP-based nanofluid was the most efficient oil-displacing agent to recover oil from the mediumpermeability core sample of Daqing Oilfield. Therefore, according to the discussion of the selective preference for SiO 2 NP sizes, the developed nanofluid is a promising new material in medium-permeability reservoirs for enhanced oil recovery.

Nanoparticle-Assisted Surfactant/Polymer Formulations for Enhanced Oil Recovery in Sandstone Reservoirs: From Molecular Interaction to Field Application

“…The performance of SiO 2 and TiO 2 NPs was attributed to the higher surface area and large size, respectively . It was reported by Zhou et al that, as the nanoparticle size increased, the IFT between the oil and nanofluid decreased. Furthermore, when nanoparticles become larger, the more contribution to oil and aqueous phase interactions leads to lowering of IFT.…”

“…IFT reduction based on the concentration and size of nanoparticles. This figure was reproduced with permission from ref . Copyright 2023 American Chemical Society.…”

“…Also, Bera et al conducted a study on how silica nanoparticles affect the viscosity of the guar gum solution, behavior of the crude oil–nanofluid phase, and more oil recovery. It was discovered that silica nanoparticle addition increases guar gum solution viscosity, further noting that viscosity is a function of the nanoparticle concentration …”