Pre-prepared Microemulsion Flooding in Enhanced Oil Recovery: A Review

Abstract

It is evident that one of the important applications of microemulsions is in enhanced oil recovery (EOR) process due to its unique properties such as ultra-low interfacial tension. The injection of microemulsion slug reduces the interfacial tension between the crude oil and reservoir brine, which leads to mobilization of substantial fraction of residual oil. In general microemulsion flooding is classified into two distinct categories, pre-prepared and in situ prepared, depending on its preparation method. The authors present a detailed discussion of microemulsion preparation and summarizes major articles on pre-prepared microemulsion flooding in EOR processes. Their review opens new horizons for the future researches on pre-prepared microemulsion flooding in EOR processes by organizing the literature data and comparing them.

Microemulsion-enhanced displacement of oil in porous media containing carbonate cements

“…[13][14][15] The presence of both surfactant and co-surfactant has a dual effect on lowering the IFT. 16,17 The hydrocarbon phase (also called carrier fluid) could be C 6 -C 18 alkanes, 18 biodiesel, 19 or natural oils such as pine oil, 20 palm oil, 21 and terpenes like d-limonene, 22,23 which are usually preferred for their solvent qualities and biodegradability. 24 The surfactant should be able to create stable microemulsions when used in specific proportions.…”

“…The most commonly used ones are biodegradable nonionic surfactants with an HLB number between 8 and 18. Examples include linear alcohol ethoxylates with various ethylene oxide numbers (EON), 23,25 alkyl polyglucosides, 21 as well as those from the tergitol family, 18 and polysorbate (or tween) family. 19 The co-surfactant consists of short or medium chain primary, secondary and tertiary alcohols with 1-20 carbon atoms such as 2-propanol, 18,23 isoamyl alcohol, 26 and glycerol monooleate.…”

Dynamic and static radiation scattering in a microemulsion as a function of dispersed phase concentration

“…In materials science they have been used to obtain both organic and inorganic nanoparticles [3][4][5][6] and some systems have successfully been used in enhanced oil recovery [7]. In environmental applications (more specifically in soil remediation), they can be used to wash out polycyclic aromatic hydrocarbons [8] and have intensely been used/suggested for pharmaceutical formulations destined to controlled release of bioactive agents [9].…”

Nanoparticle-stabilized microemulsions for enhanced oil recovery from heterogeneous rocks

“…12 Various water-soluble surfactants with hydrophilelipophile balance (HLB) between 8 and 18 have been applied as emulsifiers; examples are linear alcohol ethoxylates and alkylpolyglucosides. [12][13][14][15] Co-surfactants on the other hand often consist of short or medium chain alcohols such as 2-propanol. 13,14,16 These formulations are able to carry surfactant molecules deep into the formation and minimize losses due to adsorption on rock surfaces.…”