Abstract: In the fire flooding development process of multi-layer reservoirs, in the early stage of ignition and combustion in the wellbore, there exists some problems such as low longitudinal effective producing degree of the reservoirs, and difficulty in tracking and controlling reservoir dynamics. In response to these problems, combined with indoor experimental data and field test data, by using reservoir engineering analysis methods, it was clarified that the essential feature of fire flooding is high temperature oxidation reaction, that the most critical parameter ensuring high temperature oxidation was the gas injection intensity at different stages, and that fire flooding development mode was a last mode for oil recovery. Applying the above research results to the design of a fire flooding development plan for a multi-layer reservoir, and the results show that the fire flooding development plan for multi-layer reservoirs should subdivide the development formation, that the total thickness of the target layer should be less than 30 m and the thickness of the oil-bearing sublayer should be less than 20 m, and that stable production can be achieved by layer-by-layer return and replacement from bottom to up. The research content is of great significance for the fire flooding development of multi-layer reservoirs to maximize the recovery rate and reduce engineering risks.

Key words: fire flooding, multi-layer reservoir, high temperature oxidation, development mode, gas injection intensity, strata division, heavy oil reservoir