Page 209 - Fundamentals of Enhanced Oil and Gas Recovery

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6.2.5 Application of Nanoparticles in Enhanced Oil Recovery Schemes
Ahmadi and Shadizadeh [79] studied first the effect of nanoparticles on the adsorption
of surfactant on to reservoir rock, particularly carbonates. They pointed out that add-
ing nanoparticles could reduce the surfactant loss due to adsorption on to reservoir
rock; they concluded that the performance of hydrophobic nanosilica was higher than
hydrophobic ones. The main mechanism was hydrophobic between hydrophobic
groups in nanosilica and surfactant [79]. Ahmadi and Shadizadeh [80] examined the
effect of nanoparticles on the adsorption behavior of a surfactant on to reservoir rock.
They employed hydrophilic and hydrophobic nanosilica in their adsorption
experiments. They concluded that hydrophilic nanosilica could significantly reduce
the surfactant adsorption on to sandstones; the main mechanism behind this reduction
was hydrogen bond between hydroxyl groups in nanosilica and head of surfactant as
depicted in Fig. 6.6.
Ehtesabi et al. [81] conducted core-displacement experiments, contact angle
measurements, scanning electron microscopy, and energy-dispersive spectrometry on
titanium oxide nanoparticles to figure out its performance on oil recovery. According

Figure 6.6 Adsorption mechanism of a natural surfactant onto a sandstone rock in presence of
(A) hydrophobic nanosilica and (B) hydrophilic nanosilica [80].