Drag reduction and degradation behavior of polyethylene oxide (PEO) solutions in hydraulic fracturing applications

Abstract This study systematically investigates the rheological properties, drag reduction performance, and degradation behavior of polyethylene oxide (PEO) solutions under turbulent flow conditions relevant to hydraulic fracturing. Using Particle Image Velocimetry (PIV) and Dynamic Light Scattering (DLS), complemented by rheological testing, we analyzed the flow characteristics of PEO solutions at various concentrations. Results show that a 150 ppm PEO solution achieved a maximum drag reduction (DR) rate of 52% at a Reynolds number (Re) of 5085, significantly lowering frictional resistance and enhancing fluid transport efficiency. PIV analysis revealed that PEO effectively suppresses turbulent eddies and reduces velocity fluctuations, leading to a more stable flow profile and decreased energy dissipation. DLS measurements quantified the molecular degradation, demonstrating that under continuous turbulent shear, the average hydrodynamic radius of PEO molecules decreased from approximately 351 nm to 211 nm within 10 min, representing a 39.8% size reduction. Most importantly, this reduction in molecular size strongly correlates with the decline in drag reduction efficiency ( R 2 = 0.95), providing evidence that the reduction of molecular‑scale hydrodynamic size is strongly correlated with impaired drag‑reduction performance, consistent with polymer mechanical chain scission. By integrating macroscopic flow visualization with microscopic structural analysis, this study establishes a quantitative relationship between molecular-scale degradation and macroscopic performance loss, offering valuable insights for the development of high-performance, shear-resistant drag reducers in hydraulic fracturing applications.