Influence of fracturing fluid rheology on proppant transport and elbow erosion: A comparative CFD-DEM study

To enable the precise prediction and control of erosion in hydraulic fracturing pipelines, this study employs a CFD-DEM method coupled with a wear model to quantitatively analyze the influence of shear-thinning fracturing fluids on proppant transport and elbow erosion. The study reveals a critical, non-monotonic effect of fluid concentration on erosion. Compared to the water baseline, the low-concentration (0.2%) fluid, by enhancing particle impact kinetic energy, counter-intuitively caused the maximum elbow erosion rate to surge by approximately 40%. However, as the concentration was further increased to 0.4%, the fluid's effective viscosity became dominant, causing the maximum erosion rate to plummet relative to the 0.2% case, ultimately falling to a level ∼8% below the water baseline. More importantly, the high-concentration fluid altered particle trajectories, leading to a significant shift of the peak erosion zone from the elbow's midpoint (∼77°) to its outlet (90°). This finding quantifies the complex impact of fracturing fluid rheology on erosion and provides critical data and a new perspective for proactively managing pipeline integrity by optimizing the fluid's non-Newtonian properties.