Research On Oxidation Model Of In-Situ Combustion Based On Packing Particle In Porous Medium

As a kind of thermal recovery technology with high displacement efficiency,In-situ combustion can improve the quality of remaining oil and achieve high recovery,and has been widely used in heavy oil thermal recovery.In the porous media of oil reservoir,the effect of fire flooding is not only affected by the characteristic of oxidation reaction,but also by the porous media.At present,there is little research on the oxidation model of fire flooding involving porous media,which leads to a large gap between the actual scene of fire flooding and the expected effect,and difficult to implement on site.This paper starts with the geometric model of fuel oxidation,and reconstructs the existing geometric model based on the existing research to construct a new fuel geometric model which takes into account the particle size composition and stacking mode,which closer to the actual stratum.In consideration of the stratum stress,the actual mine field and other conditions,the unequal-diameter varying-fuel geometry model is established.And then based on the new fuel geometry model and multi-step oxidation reaction model,a fire flooding oxidation model based on the accumulation of porous media is established.The results show that the new model can better explain and prove the obvious influence of porous media on the oxidation rate.The oxidation rate of fire flooding not only needs to consider the chemical oxidation,but also needs further analysis combined with the particle size composition of porous media itself.Finally,the relationship between oxygen consumption and particle size in different oxidation stages and fuel deposition is further analyzed.The results show that the overall oxygen consumption in the oxidation stage of fire drive presents three peaks,which proves that porous media has obvious influence on the fire drive practice.The fuel deposition range and heat balance analysis under different particle sizes are discussed,and the large particles with different particle sizes are obtained Under 70 mesh particle size,fuel deposition increased significantly,which can meet the normal heat demand of fire drive.Finally,the simulation of fuel oxidation consumption and the analysis of sensitive parameters by MATLAB programming provide a certain reference value for fire flooding screening.In this paper,the effect of porous media on the oxidation rate of fire drive is preliminarilyexplored,which provides some reference value for the further development of the development theory of fire flooding.