Abstract
Extraction of oil trapped after primary and secondary oil production stages still poses many
challenges in the oil industry. Therefore, innovative enhanced oil recovery (EOR) technologies are required
to run the production more economically. Recent advances suggest renewed application of surfacefunctionalized nanoparticles (NPs) for oil recovery due to improved stability and solubility, stabilization of
emulsions, and low retention on porous media. The improved surface properties make the NPs more
appropriate to improve microscopic sweep efficiency of water flood compared to bare nanoparticles,
especially in challenging reservoirs. However, the EOR mechanisms of NPs are not well understood. This
work evaluates the effect of four types of polymer-functionalized silica NPs as additives to the injection water
for EOR. The NPs were examined as tertiary recovery agents in water-wet Berea sandstone rocks at 60 °C.
The NPs were diluted to 0.1 wt. % in seawater before injection. Crude oil was obtained from North Sea field.
The transport of NPs though porous media, as well as nanoparticles interactions with the rock system, were
investigated to reveal possible EOR mechanisms. The experimental results showed that functionalized-silica
NPs can effectively increase oil recovery in water-flooded reservoirs. The incremental oil recovery was up to
14% of original oil in place (OOIP). Displacement studies suggested that oil recovery was affected by both
interfacial tension reduction and wettability modification, however, the microscopic flow diversion due to
pore plugging (log-jamming) and the formation of nanoparticle-stabilized emulsions were likely the relevant
explanations for the mobilization of residual oil
challenges in the oil industry. Therefore, innovative enhanced oil recovery (EOR) technologies are required
to run the production more economically. Recent advances suggest renewed application of surfacefunctionalized nanoparticles (NPs) for oil recovery due to improved stability and solubility, stabilization of
emulsions, and low retention on porous media. The improved surface properties make the NPs more
appropriate to improve microscopic sweep efficiency of water flood compared to bare nanoparticles,
especially in challenging reservoirs. However, the EOR mechanisms of NPs are not well understood. This
work evaluates the effect of four types of polymer-functionalized silica NPs as additives to the injection water
for EOR. The NPs were examined as tertiary recovery agents in water-wet Berea sandstone rocks at 60 °C.
The NPs were diluted to 0.1 wt. % in seawater before injection. Crude oil was obtained from North Sea field.
The transport of NPs though porous media, as well as nanoparticles interactions with the rock system, were
investigated to reveal possible EOR mechanisms. The experimental results showed that functionalized-silica
NPs can effectively increase oil recovery in water-flooded reservoirs. The incremental oil recovery was up to
14% of original oil in place (OOIP). Displacement studies suggested that oil recovery was affected by both
interfacial tension reduction and wettability modification, however, the microscopic flow diversion due to
pore plugging (log-jamming) and the formation of nanoparticle-stabilized emulsions were likely the relevant
explanations for the mobilization of residual oil