Effect of Molecular Structure on the Viscosity and Viscoelasticity of Anionic Gemini Surfactant Solution

In order to construct high-temperature novel clean fracturing fluid, the viscosity and viscoelasticity of anionic Gemini surfactant solution were measured by the rheometer and investigated through changing the molecular structure and temperature. The results indicate that when the length of spacer chain s is 2, with the length of carbon chain m increasing, the viscosity of carboxylate anionic Gemini surfactants solution increases; the viscosity of sulfonate anionic Gemini surfactants solution decreases; the viscosity of sulfate anionic Gemini surfactant solution changes slightly and lower than 1.5mPa.s. Viscous modulus (G") and elastic modulus (G') of sulfonate/carboxylate anionic Gemini surfactants solution increase, while the date of G' is more than G", and the solution shows elastic characteristics. With s decreasing at m=10 or 16, the viscosity of sulfonate/carboxylate anionic Gemini surfactants solution increases. Moreover, DS-10-2-10 and DC-16-2-16 exhibit prominent viscosifying ability. The viscosity of DS-10-2-10 and DC-16-2-16 solution decrease with the temperature increasing, but the viscosity of DS-10-2-10 solutions till reaches 30.8mPa.s at 90°C and is more than the viscosity of DC-16-2-16 solution. The temperature has no effect to G' and G" of solution below 45°C. The increasing amount of G" is more than G above 45°C, and elastic effect of the solution decrease with raising temperature.