The middle and shallow gas reservoirs of Chuanxi oilfield is of typical low-permeability and tight gas reservoir,and fracturing operation is the main exploration method.However,with the exploration developing,the quality of reservoir is getting worse,the normal fracturing fluid system cannot work effectively anymore.A kind of multifunctional synergistic fracturing fluid system is developed that has performances of low surface tension(25 mN/m),fast gel-breaking and high viscosity of flow-back.The comparison result of productivities with two adjacent wells show that the productivity of fractured well is 3.4×104 m3/d,1.8 times of the other well.