Preparation and Property Evaluation of Anionic Clean Fracturing Fluid

An anionic surfactant clean fracturing fluid was synthesized and its main performance was studied. The viscosity of fracturing fluid increased with increasing dosage of anionic surfactant. And the viscosity of fracturing fluid increased first, and then decreased with increasing concentration of KCl. The viscosity reached maximum 360 mPa•s when the KCl content is 2.7%. The results showed that the fracturing fluid had best temperature resistance and shear resistance performance under the condition of 100°C and at the shearing rate of 170 s-1. The sedimentation velocity of sand in the fracturing fluid are about 11.124, 18.840 mm/min at the temperature of 80°C and 120°C respectively. It indicated that the fracturing fluid has a better sand-carrying performance. The viscosity of fracturing fluid decreased below 5 mPa•s during 70 minutes when the dosage of kerosene was 3%, and the surface tension of the breaker fluid is 26.10 mN/m while the interfacial tension is 0.73mN/m. The low surface tension can meet the requirements of operation. The damage rate to the core is 7.65% and the fracturing fluid has lower damage to core than guar gel.