Wormlike Micelles for Mobility Control - A Comparison with Different EOR Techniques

Polymers can be used for EOR operations to improve the mobility, however a major problem is its sensitivity to shear stress. An alternative method could be wormlike micelles, which are self assembled surfactant molecules, that show a similar behaviour than polymers in term of viscosity increase and have the advantage of breaking and reforming in the porous medium when shear stress is modified. We started this study by a complete characterization of a wormlike micelles solution prepared with betaine molecules. Micellar characterization, for different surfactant concentration, salinities and temperatures showed that that the kraff point decreases when the salt and surfactant concentration increase. This means that this system stability increases with temperature. Rheological experiments showed a classical shear thinning behavior. Experiments in porous media consist in one phase and two phase flow in sandstone cores. One phase flow has been performed to determine surfactant adsorption and permeability reduction. Two phase flow displacements were conducted to show the ability of wormlike micelles to improve oil recovery. Experimental data obtained with wormlike micelles displacement are compared with standard reference experiments using polymer and Alkaline Surfactant Polymer. Results show that, despite adsorption, wormlike micelles have a positive effect on mobility control.