基于超声波传感器阵列的变径管段高压多相流冲刷腐蚀机理研究

High pressure erosion-corrosion (HP E-C) is the major harm in oil and gas production. The HP E-C of pipeline in oil and gas industry is not only the key problem of the security of oil and gas production, but also the interdisciplinary problem of corrosion science. E-C is accelerated due to the synergistic effect of corrosion and mechanical effect induced by temperature, pressure and mechanical erosion. However, how temperature, CO2 partial pressure and hydrodynamic characteristics affect E-C behavior and structural characteristics of corrosion product film is not clear. E-C tests under HP conditions are conducted to investigate the correlation between E-C mechanism and corrosion electrochemical mechanism of gradual expansion/contraction pipes and growth evolution and damage mechanism of corrosion product film combining ultrasonic sensor array, in situ dynamic high pressure electrochemical measurements in loop and microscopic characterization analysis. CFD simulation calculation is performed to characterize flow field, solid particle concentration, velocity and trajectory of solid particle, impact force exerted on the wall by particles and erosion rate in gradual expansion/contraction pipes. Combining E-C tests, electrochemical measurements and CFD simulation, the correlation between E-C mechanism of gradual expansion/contraction pipes and temperature，CO2 partial pressure and hydrodynamics is illuminated and a E-C predictive model of gradual expansion/contraction pipes is built. It is anticipated that this research would provide theoretical guidance for the protection of multiphase flow E-C under HP environment.

高压冲刷腐蚀已逐渐成为油气田生产的主要危害，不仅是油气田安全生产的关键问题，也是多学科知识领域交叉与综合的腐蚀科学问题。温度和压力引起的腐蚀及力学效应与固体颗粒的机械冲刷存在耦合作用，而温度、CO2分压和流体动力学特征是如何影响冲刷腐蚀行为及腐蚀产物膜的结构特征并不清楚。本项目拟结合超声波传感器阵列、高压环路中的动态原位电化学测试和微观表征，研究高压下碳钢变径管段冲刷腐蚀行为和腐蚀电化学行为，阐明变径管段高压冲刷腐蚀机理和腐蚀电化学机理与腐蚀产物膜生长演化及损伤机制的关联性。应用CFD模拟计算变径管段内流体流速、固体颗粒的浓度、速度和运动轨迹、固体颗粒对壁面的冲击力及冲刷速率分布。结合冲刷腐蚀试验、电化学测试和CFD模拟计算，揭示变径管段冲刷腐蚀机理与温度、CO2分压和流体动力学特征的相关性，建立高压多相流下碳钢变径管段的冲刷腐蚀预测模型，为油气输送管道高压冲刷腐蚀与防护提供理论依据。

高压CO2环境流动加速腐蚀已逐渐成为油气田生产的主要危害，不仅是油气田安全生产的关键问题，也是多学科知识领域交叉与综合的腐蚀科学问题。CO2分压和流体动力学特征是如何影响流动加速腐蚀行为及腐蚀产物膜的结构特征并不清楚。本项目结合高压环路中的阵列电极技术、动态原位电化学测试和微观表征，研究高压下碳钢变径管段流动加速腐蚀行为，阐明变径管段高压流动加速腐蚀机理与腐蚀产物膜生长演化及损伤机制的关联性。应用CFD模拟计算变径管段内流体流速、壁面剪切应力及湍流动能分布。结合电化学测试和CFD模拟计算，揭示变径管段流动加速腐蚀机理与CO2分压和流体动力学特征的相关性；研究咪唑啉类缓蚀剂对高压CO2环境变径管段流动加速腐蚀的缓蚀机理；建立高压多相流下碳钢变径管段的流动腐蚀预测模型，为油气输送管道高压冲刷腐蚀与防护提供理论依据。