Two-section separation based SAGD produced fluid treatment method and device

The invention relates to the technical field of SAGD circulating preheating stage produced fluid treatment, in particular to a two-section separation based SAGD produced fluid treatment method and device. The method is characterized in that high-pressure under-pressure separation and low-pressure flash-evaporation separation are performed on the SAGD produced fluid, and follow-up treatment is thenperformed. A secondary gas-liquid separating process of under-pressure separation and flash-evaporation separation is adopted, wherein the first stage is under-pressure gas-liquid separation with relatively high control pressure, and is mainly used for separating a gas phase carried in the produced fluid, and stabilizing the front end pressure of a collecting and transport system; and the secondstage is used for performing flash-evaporation separation on a first liquid phase, wherein the control pressure is relatively low, the produced fluid is sufficiently subjected to flash-evaporation, the liquid phase is partiall