A resolved CFD-DEM investigation into sand production under water flooding in unconsolidated reservoir

Excessive sand production in the wellbore can impede oil production from unconsolidated reservoirs. The study reports an investigation of numerical simulation of sand production in oil-water two-phase flow. The interaction between fluid and particles is achieved by coupling the discrete element method (DEM) with resolved computational fluid dynamics (CFD). By harnessing the advantages of the method, the numerical model can capture the movement of particles and the changes in fluid field at a scale smaller than fine particles. The model reveals the water flooding process in the granular matrix and effectively visualizes the microscopic mechanisms of particle migration. The results indicate that the model with water flooding exhibits higher produced mass compared to the model without water flooding. Parametric analysis shows that there is a critical fines content, which leads to the maximum sand production. With the increase of viscosity and the decrease of interfacial tension, the sand production increases. [Display omitted] •Resolved CFD approach is used to reveal the variation of fluid field at mesoscale.•Volume of fluid method is employed to reproduce two-phase flow of oil and water.•The sand production mechanism under two-phase flow of water and oil is revealed.•Influences of fines content, fluid viscosity and interface tension are revealed.