Simulation And Application Of Temporary Plugging Agent Flow Based On CFD-DEM Method

With the increasing consumption of oil and gas resources,the secondary development of old wells and unconventional reservoir development are becoming more and more important.Due to the complex reservoir environment and difficult development,fracturing is an important means to achieve effective development.Temporary plugging reorientation fracturing is currently a more efficient fracturing technology,which is very suitable for repeated fracturing of old wells and multistage fracturing of unconventional reservoirs,which is conducive to the construction of complex seams and increase production.In the current temporary plugging steering fracturing construction,the research on the parameters of temporary plugging agent mainly stays in the field experience stage,but the theoretical research is less.In this paper,the optimal temporary plugging agent materials are studied by laboratory evaluation test and liquid-solid two-phase flow simulation of temporary plugging agent-fracturing fluid.The specific contents are as follows:(1)Learning the action mechanism of temporary blocking agent,according to the principle and working environment,select the temporary blocking agent material,carry on the performance evaluation test,determine the strength,solubility,blocking property and harmfulness of the temporary blocking agent,respectively.It is proved that the selected temporary plugging agent is suitable for temporary plugging steering fracturing construction.(2)Analyzing the temporary plugging agent migration process,establishing the wellbore physical model and the wellbore-crack physical model,and perform meshing and local mesh encryption.(3)Using computational fluid dynamics(CFD)and discrete element mathod(DEM)coupling methods to numerically simulate the migration of temporary plugging materials in the wellbore and the temporary plugging process in the fracture,and optimize the the construction parameters.(4)Field application implementation.The condition of the well casing is complicated,and the mechanical segmentation and fracturing cannot be realized.The temporary plugging reorientation fracturing is adopted,and the amount of temporary plugging agent is optimized,and the result is good.