CFD-DEM modeling and analysis study of proppant transport in rough fracture

Hydraulic fracturing is essential in unconventional oil and gas extraction, with a critical role in the effectiveness of proppant transport. This study employs Synfrac software to simulate rough fractures and real rock fracture morphology. Using the combined approach of Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM), we investigate essential proppant transport features in rough fractures. The model's validity is confirmed by comparing present experimental results with characteristic parameters over time. The model contrasts planar and rough fractures analyzes dune properties under various velocities and fractal dimensions, and introduces a new pressure drop diagram for understanding proppant transport. A novel multiple regression equation for predicting proppant dune height is introduced, leveraging pressure drop curves. Its effectiveness is validated comprehensively. An optimized strategy is developed for graded proppant injection considering sequence and size ratio. The study enhances understanding of proppant transport and pump pressure drop improvement in rough fractures.