Abstract 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.
Introduction Background Surfactant enhanced oil recovery (EOR) has been for many years, particularly in the 1970's and 1980's when the technology was put on a sound scientific basis. Unfortunately, the economic reality of the process performance in field trials has precluded widespread deployment of this technology, at least in the United States.
This study considers alkly polyglycosides (APG), one class of surfactants largely ignored as candidates for EOR applications. This is due at least in part because APG surfactants were not available as a large volume commercial product during this earlier period of intense interest in chemical EOR in the United States.
APG were described initially over 100 years ago, first recognized as a potentially useful surfactant type in 1936, and then largely ignored until the 1980's. APG has gained favor as economical processes were developed to manufacture them on a large scale, ands also because there has been an increased drive to use surfactants with favorable, low toxicity characteristics like APG for many purposes. This surfactant now sees widespread use in household detergents, cosmetics, and agricultural products. A recent (1999) estimate for worldwide capacity for APG surfactants is 80,000 tons/year. APG has been considered only briefly for EOR applications, with one U.S. patent issued on this topic