Alkyl polyglycoside surfactants for improved oil recovery

Many surfactants have been evaluated for their ability to recover incremental oil; this paper focuses on alkyl polyglycosides (APG) as candidates for this IOR application. These nonionic carbohydrate-based surfactants have become in recent years a large, significant volume (over 80,000 tons/year) commercial product that sees widespread use in household and agricultural products. This laboratory study determined the characteristics of many APG surfactant formulations, in particular for their capability to create low interfacial tensions (IFT) with n-alkane hydrocarbons. Formulations explored included a wide range of alcohol and Sorbitan-based surfactants as cosurfactants with these APG surfactants. Some APG-cosurfactant combinations did exhibit low IFT values of 0.01 dyne/cm or less versus n-octane. Laboratory testing did confirm the useful properties that the IFT for these APG formulations can be largely independent of both salinity and temperature. Preliminary studies also suggest some APG products will have only modest adsorption onto kaolinite clay.