Thickened oil cold production viscosity reduction method for improving fluidity and application

The invention discloses a thickened oil cold production viscosity reduction method for improving fluidity. The method comprises the steps that 1, a hydraulic vibration source is installed in an oil well, wherein the installation depth of the hydraulic vibration source roughly corresponds to the depth of an oil layer; 2, a nitrogen foam slug is injected into the oil well to block formation water; 3, the hydraulic vibration source is started to generate continuous hydraulic oscillation pulse flow, and meanwhile a viscosity reducer is injected into the oil well, wherein the injection speed of the viscosity reducer is 5-6m < 3 >/h, the vibration frequency of the hydraulic vibration source is 30-40Hz, and the amplitude is 6-10MPa; and 4, soaking is conducted, the hydraulic vibration source is pulled out, and oil pumping operation is recovered. According to the thickened oil cold production viscosity reduction method for improving fluidity, a low-frequency hydraulic oscillator is adopted for conducting hydraulic os