STATIC AND DYNAMIC ADSORPTION OF A NONIONIC SURFACTANT ON BEREA SANDSTONE

An experimental study of static and dynamic adsorption of a non-ionic surfactant (Triton X-100) on Berea sandstone was conducted. The effect s of sodium chloride concentration, pH and injection flow rate on the surfactant propagation were examined. A radial flow geometry was used to simulate the fluid flow pattern near a wellbore. Static adsorption isotherms were of the stepped Langmuir type and exhibited good agreeme nt with the hemimicelle model. Experimental results showed that the ad sorption capacity of the solid surface was a strong function of both s olution salinity and pH. Maximum adsorption obtained from dynamic test s was consistently lower than that obtained from static tests. The dif ference increased as the flow rate was increased. The results obtained in this study indicate that the amount of surfactant adsorbed on sand stone decreased under alkaline conditions. This will reduce the amount of non-ionic surfactant required for the application of the alkali/su rfactant process in the field. Also, static adsorption tests will tend to overestimate the amount of surfactant lost due to adsorption, espe cially near the wellbore area.