Erosion-corrosion effect in the low-temperature heavy oil annular flow transportation

Abstract According to statistics, proven reserves of heavy oil account for approximately 70% of the remaining crude oil resources in the world. As an important alternative energy source, the technology of pipeline transportation of high-viscosity heavy oil has rapidly advanced. Among available methods, water loop transportation characterized by its low-cost and operational simplicity, has emerged as the most promising. However, the exceptionally high viscosity of heavy oil exacerbates entrainment of sand particles in the wellbore, significantly reducing the effectiveness of sand removal. Moreover, the erosion of the pipe wall by sand particles, combined with the electrochemical corrosion environment created by the water annulus, poses serious safety risks to the pipeline infrastructure. To investigate the evolution of erosion and corrosion rate during heavy oil water loop transportation, an optimized multi-factor erosion rate model is developed and coupled with heat transfer and multiphase flow models for simulation. Additionally, a CO2 corrosion experiment under the actual engineering conditions is conducted to account for key influencing factors such as sand particle size, water content, flow velocity, and the thermal effects of heavy oil. This study aims to identify the governing trends of erosion and corrosion rates under optimized transport conditions that promote viscosity reduction and drag minimization. The findings provide valuable insights for future research and practical applications related to erosion and corrosion management in heavy oil water-loop transportation systems.