3D computational modeling of sand erosion in gas-liquid-particle multiphase annular flows in bends

In the oil and gas industry, predicting sand particle erosion damage is a challenging task as many factors have profound effects on the material losses. In this study, a computational modeling approach was used, and the sand erosion in gas-liquid-solid annular three-phase flows in pipe bends was analyzed. The Volume of Fluid (VOF) and the hybrid Eulerian-Eulerian methods were used to simulate the 3D transient annular air-water flows, and the results were verified with comparisons with the available experimental data. The performed erosion simulation validation also indicated that the DNV erosion model predicts realistic results. The three-phase computational model (VOF and Lagrangian Particle Tracking) was used, and the effects of liquid film thickness, gas and liquid velocities, pipe orientation, sand mass flow rate, liquid viscosity, and bend angle on erosion in a standard elbow were investigated. The results showed that the liquid film cushioning effect in gas-liquid-solid flows significantly reduces the bend erosion compared with the gas-solid flows. Moreover, the gas velocity does not noticeably affect the liquid film thickness in the bend; however, a higher gas velocity causes a higher particle impact velocity and increases erosion. In contrast, higher liquid velocity enhances the film cushioning effect and leads to less erosion.