Low Interfacial Tensions Involving Mixtures of Surfactants

Abstract

The interfacial tension of surfactant mixtures with hydrocarbons obeys a simple scaling rule. Many apparently inert surfactants give low tensions when in mixtures; the scaling rule still applies to these mixtures. The influence of surfactant structure and molecular weight on low-tension behavior zs examined, and the application of these results to the optimization of surfactant flooding systems is discussed.

Characterization of Crude Oil Equivalent Alkane Carbon Number (EACN) for Surfactant Flooding Design

“…[7][8][9][10] With proper design and advances in new surfactant chemistry in the last decade, new generation surfactant chemical flooding has provided much more cost attractive and provided strong economic incentive for site owners to explore it as a viable EOR alternative in recent years. [11][12][13][14] During laboratory screening phase, investigating solution phase behaviors of brine/oil/surfactant mixture is one of the key steps that could reveal the potential outcome of the recovery and the size of chemical slug required. On the other end, early EOR efforts in the literature had also shown that the optimal brine salinity developed for a specific brine/oil/surfactant mixture was largely related to the alkane carbon number (ACN, the number of carbons in a straight alkane chain) for normal alkanes, or so called equivalent alkane carbon number (EACN) for a mixture of hydrocarbons or non-alkyl hydrocarbons.…”

“…Equilibrium IFT as a function of electrolyte concentration (salinity scan) for the systems of extended surfactant for hexane (C6), octane (C8), decane (C10) and dodecane(12).…”

Studies of Synergism/Antagonism for Lowering Interfacial Tensions in Alkyl Benzene Sulfonate Mixtures

“…The model system introduced by Cayias et al, [5][6][7][8][9] in which a pure n-alkane replaces the crude oil, has proven to be a useful tool for examining low IFT behavior in EOR. Development of the alkane model began when a study of the IFT of a series of pure n-alkane drops against a petroleum sulfonate saline solution revealed that only one alkane gave a really low IFT.…”

Microemulsions for Cleaning Applications

“…They are blends of molecules with a distribution of molecular weights and molecular configurations. It is determined experimentally by comparing its phase behavior with that of a well-defined linear hydrocarbon in the same surfactant-oil-water system [5,[14][15][16]48]. In this case the EACN is used instead [15].…”