Numerical simulation of sand production experiment using a coupled Lattice Boltzmann-Discrete Element Method

In this study, a coupled numerical approach based on Lattice Boltzmann Method (LBM) and Discrete Element Method (DEM) is employed for two-dimensional simulation of fluid flow in deformable particulate media comprising of movable circular particles. The developed LB-DE code is validated against the results of a bi-axial shear test as well as two well-known benchmark problems including settling of a circular particle under gravity force inside a viscous fluid, and motion of a neutrally buoyant particle released in a Poiseuille flow. The verified code is then utilized for simulation of “Sand Production” phenomenon which is of importance for oil producing wells in weakly cemented sandstone reservoirs. Although a full numerical simulation of the sand production phenomenon in real large scale is impractical by current computational resources, the developed numerical tool proved to be capable of capturing the basic mechanisms involved in sand production in laboratory scale. The numerical results show that the magnitude of sand production strongly depends on the flow rate and also on the confining pressure (in-situ stresses). For all confining pressures, flow rates above a critical rate results in significant increase of the rate of sand production. Also, it has been shown that for a specific flow rate, the cumulative sand production decreases as the confining pressure increases.