Research on in-situ combustion oxidation model based on different diameter particle accumulation

In-situ combustion has the advantages of high oil displacement efficiency and obvious improvement of residual oil quality, which has been widely used in heavy oil thermal recovery. The effect of in-situ combustion in the porous media of the reservoir is not only affected by the nature of oxidation reaction, but also by the porous media. At present, there is little research on the in-situ combustion oxidation model involving porous media, and mainly based on the equal diameter model, which makes the in-situ combustion field and the expected effect have a large gap. Firstly, particle size composition and accumulation mode is analyzed and screened in this paper. And then, combining with the morphological changes of different diameter fuel oxidation geometric model and the reaction of crude oil oxidation stages, a geometric model of different diameter fuel oxidation is constructed, which conforms the actual in-situ combustion formation. Furthermore, according to Arrhenius equation and fuel surface reaction rate formula, the in-situ combustion oxidation mathematical model based on the porous media accumulation is established combined with geometric parameter derivation. Finally, the oxygen consumption and oxidation characteristics of each oxidation stage are analyzed, which can provide a reference for the in-situ combustion development theoretical research.