A dynamic foam method for the estimation of critical micelle concentrations at elevated temperatures and pressures

We have developed a new method for the estimation of critical micelle concentrations (cmcs) that is suitable for use at high temperatures and pressures; is much more rapid than the surface tension method; and is applicable to a wide range of surfactant classes, including both ionic and amphoteric (zwitterionic) surfactants. The method involves conducting surfactant titrations and monitoring the presence of foaming in a dynamic foam height apparatus. Typical plots of dynamic foam height versus solution surfactant concentration yield sharp inflections. Below the cmc there is little or no foam production while beginning at the cmc there occurs a sharp increase in foaming. The method is suitable for the estimation of cmcs needed for improved oil recovery process development and optimization, wherever micelle-controlled surfactant reactions are important, and can be applied at realistic reservoir conditions of temperature and pressure.