Phase Behaviour Methods for the Evaluation of Surfactants for Chemical Flooding at Higher Temperature Reservoir Conditions

Abstract

Abstract Accurate laboratory screening of surfactants for their ability to give ultra-low interfacial tensions in oil/brine systems is important as a pre-cursor to laboratory core flow tests and surfactant flooding processes in the field. Screening is usually judged by visualisation of middle-phase micro-emulsions in oil/brine systems. Three laboratory methods are described which enable the phase behaviour of oil/water systems containing surfactants to be more safely visualised and measured in glassware at higher temperatures. Higher temperature test conditions result in significant vapour pressures from crude oil and water, and some glass tube test methods currently used in the industry may not be appropriate from a laboratory safety standpoint. The new methods have been verified in our laboratories for higher temperature use and provide useful screening methods for higher temperature reservoirs (up to 150°C).