Ultrasonic Cavitation-Induced Erosion of Gypsum: Insights from High-Speed Imaging, Modelling and Experiments

Scale deposition remains a significant obstacle in oil pipelines, impeding flow and necessitating labor-intensive remediation. Gypsum, among the most prevalent and resilient scale types, is particularly challenging due to its low solubility in conventional chemical treatments. Mechanical enhancement has shown promise in improving removal efficiency. In this study, we investigate the role of ultrasonically induced cavitation in the mechanical disruption of gypsum deposits. High-speed imaging is employed to visualize bubble dynamics and interactions at the solid interface, revealing direct evidence of cavitation-induced fragmentation in select samples. A physics-based model is developed to characterize pressure fields, bubble evolution, and fluid-structure interactions, with erosion rates quantified through imaging and experimental data. Results show pronounced material degradation, with cavitation preferentially nucleating at microfractures. These findings highlight the potential of acoustic cavitation as a targeted, non-invasive method for enhancing scale removal in subsurface flow systems.