Numerical simulation of proppant transport in hydraulic fracture with the upscaling CFD-DEM method

摘要

In this study, the coupled CFD (Computational Fluid Dynamics)-DEM (Discrete Element Method) method is employed to simulate the proppant transport process in a hydraulic fracturing system. The particle particle and particle-wall interactions can be captured precisely in the DEM, which could not be fully considered in other methods. However, the DEM is time-consuming if every single proppant particle is considered as a discrete element. In order to reduce the computational efforts, the representative particle model (RPM) is adopted in this work for upscaling the CFD-DEM. Dynamic packing problems of both the uniform and bi-density cases are designed to illustrate the advantage of simulating proppant transport behaviors with the CFD-DEM, and the upscaling cases are performed with the RPM for comparison. In addition, upscaling issues regarding validation and large-scale applications of the RRM are also discussed. After upscaling, the main characteristics of the packing patterns can be captured, while the time cost is greatly reduced. (C) 2016 Elsevier B.V. All rights reserved.