A Study of Branched Alcohol Propoxylate Sulfate Surfactants for Improved OilRecovery

摘要

This investigation considers one class of anionic surfactant, arnseries of branched alcohol propoxylate sulfate surfactants, asrncandidates for chemical EOR applications. This experimentalrnresults show that these surfactants may be preferred candidatesrnfor EOR as they can be effective at creating low interfacialrntension (IFT) at dilute concentrations, and without requiringrnan alkaline agent or cosurfactant. In addition, some of thernformulations exhibit a low IFT at several percent sodiumrnchloride concentrations, and hence may be suitable for use inrnmore saline reservoirs.rnAdsorption tests onto kaolinite clay indicate that the loss ofrnthese surfactants can be comparable to or greater than otherrntypes of anionic surfactants.rnSurfactant performance was evaluated in oil recovery corernflooding tests. Selected formulations could displace most ofrnthe waterflood residual oil in place even with dilute, 0.2 wt%rnsurfactant solutions from Berea sandstone cores.