Application of viscoelastic surfactant in acid stimulation

Viscoelastic surfactant is a new type of surfactant developed in recent years. Its viscosity becomes very high when it is exposed to salt solutions. On the contrary. when it is in contact with hydrocarbons, it degrades and its viscosity lowers, thus it is easy to flowback Therefore, it has been successfully used as a fracturing fluid in dydraulic fracturing treatment In recent years, utilization of viscoelastic surfactant has been gradually extended into acid stimulation, including selective acidizing, diversion in matrix acidizing and filtration control.