The influence of temperature on surface and microscopic properties of surfactant solutions in relation to fluid displacement efficiency in porous media



The surface properties, microscopic structure of foam, and flow through porous media behavior of mixed surfactant solutions (sodium lauryl sulfate plus lauryl alcohol) have been studied at various temperatures in relation to enhanced heavy oil recovery processes. The studies reported here suggest that temperature has a remarkable influence on the microscopic structure of foam and the flow through porous media behavior of the surfactant solutions. The surface tension and bubble size decreased as the temperature increased. The foam volume increased, whereas foam half-life (or foam stability) decreased with increasing temperature. A linear increase in bubble size with time was observed at different temperatures. The rate of change in bubble size increased with temperature. A significant reduction in effective air mobility and an improvement in fluid displacement efficiency were observed with increasing temperature. All measured parameters changed strikingly in the temperature range of 20–40°C, whereas they exhibited small changes between 40 and 80°C for the surfactant system investigated. The effect of temperature on half-life of foam and on the effective air mobility was most pronounced as compared to that on other parameters. An attempt is made to correlate quantitatively the foam volume of surfactant solution with fluid displacement efficiency in porous media.