Eimund Gilje

The effect of inorganic salt on the solubilization of alcohols in aqueous surfactant solutions

Solubilization studies in micellar systems have been carried out at 298.2 K in pure and commercial aqueous surfactant systems with and without inorganic salt added. The solubilizates were medium chain length alcohols, butanol to heptanol. For all studied systems the solubilization capacity decreased when salt was added. Sodium chloride was more efficient than lithium chloride in this respect. The effect of added salt was more pronounced for the longer alcohols. At 0.2 and 0.4 m NaCl the maximum amount of alcohol that could be solubilized was much less above the critical micelle concentration than the amount dissolved below. The results have been discussed in terms of changes in the solubilization mechanism and the precipitating phases upon addition of salt.

Coreflood experiments with surfactant systems for IOR: Computer tomography studies and numerical modelling

This paper addresses the dynamic behaviour of surfactant systems for IOR-applications in terms of phase behavior and coreflood recovery processes. Extensive measurcments of phase behaviour have provided a good characterization of the phase diagram of abrine, surfactant and heptane system. The surfactarit system does not require any cosurfactant to obtain middle phase microemulsions. Tertiary recovery surfactant coreflood experiments have been perforrned and the dynamic process in the core have been studied using computer tomography (CT). Effluent analysis have also been performed. A new phase-behavior-model based on direct interpolation of experiment al data combined with correlations has been developed and used for the modelling of the phase bchaviour of this overall three-cornponent system (brine, heptane and surfactant). A tertiary coreflood recovery test have been simulated using a compositional chemical flooding simulator with the new phase-behaviour model.