Abstract: In response to the problems that the controlling countermeasures of steam flooding in middle and deep heavy oil are greatly influenced by the dynamic characteristic parameters of the development stage and it is difficult to clearly divide the development stage of steam flooding, taking the steam injection in Qi 40 Block as an example, the dynamic and static monitoring data analysis, reservoir engineering calculation, numerical simulation and other means were comprehensively used according to the analysis of variation law of steam chamber to define the recovery law of different development stages of steam flooding, and select the dynamic parameters such as injection pore volume, recovery percent of recoverable reserves, water content and temperature as the limit parameters for the division of steam flooding stages. The results of the study showed that the injection pore volume at the steam breakthrough in Qi 40 Block was linearly related to the oil saturation before the flooding conversion; the injection pore volume multiplier was a second-order function with zero intercept with the recovery percent of recoverable reserves. The study results are highly operational in the classification of steam flooding development, and provide a reference for the development of control countermeasures for different types of steam flooding well clusters.

Key words: steam flooding, development stage, dynamic characteristics, tracking and control, medium and deep heavy oil