Formation, characteristics and oil industry applications of nanoemulsions: A review

Nanoemulsions are kinetically stable homogeneous dispersions of immiscible liquids with droplet sizes in the order of 500 nm. The nano-size droplets are advantageous in enhancing nanoemulsion properties such as sturdy stability, large surface area per unit volume, improved interfacial and wetting behavior and configurable rheology. Nanoemulsions are widely prepared by high energy or Brute Force comprising ultrasonication and high pressure homogenization (HPH) and by low energy or Persuasion methods comprising phase inversion temperature (PIT) and phase inversion composition (PIC). Bubble bursting, microfluidization and evaporative ripening are the newly developed nanoemulsions preparation techniques. From pharmaceuticals, drug delivery, cosmetics, material synthesis to food, agriculture and nanoscale colloidal dispersions understanding nanoemulsions have found a diverse industrial applications. Recent investigations discovered nanoemulsions to be beneficial in oil and gas industry operations for instance in enhanced oil recovery (EOR) applications. This review article summarizes methods of nanoemulsions formation, its properties and significant research on nanoemulsions in oil and gas industry. • Formation, characteristics and investigations of nanoemulsions in petroleum industry. • Recently introduced nanoemulsions have proved to be beneficial in EOR operations. • Brute Force and Persuasion are the two most widely nanoemulsion formation techniques. • Sturdy stability, enhanced surface properties with tunable rheology are advantageous.