Preparation and Properties of Potassium N-Lauroylglutamate/Potassium Erucate Composite Anionic Surfactant Wormlike Micelles

The effect of different counterions, including inorganic salt(KCl) and different organic salts, on the properties of solutions of potassium N-dodecanoyl glutamate (KLAD), potassium erucate (KEU) and their mixed system (KAU) was studied respectively, then three viscoelastic wormlike micelles systems were obtained, including KLAD/KCl, KEU/benzyltripropylammonium chloride(BTAC) and KAU/BTAC/KCl. The temperature (T) and shear resistance of the three systems were compared by viscosimetry method, and their sand-carrying performance and gel breaking property were also investigated. The results showed that the apparent viscosity (η_a) of systems of KLAD/KCl and KEU/BTAC were 19.2mPa·s and 37.7mPa·s at 100℃, but the η_a of KAU/BTAC/KCl solution was up to 82.5mPa·s. After shearing 60 min incessantly at 100℃, the η_a of solutions of KLAD/KCl and KEU/BTAC decreased to 14.0mPa·s and 19.3mPa·s respectively, however, the η_a of KAU/BTAC/KCl solution still maintained at 52.9mPa·s. When the sand carrying ratio was 10%, the sedimentation rates of the seeds in the three systems were about 0.294cm·min^-1, 0.113cm·min^-1 and 0.067cm·min^-1 at 30℃, respectively. For all systems, the viscosity of the gel breaking liquid without residue decreased below 5mPa·s within 2 hours. The better temperature and shear resistance of KAU/BTAC/KCl system indicated that BTAC and KCl produced a synergistic effect on the wormlike micelles with high viscosity.