| 摘要: |
| 目的 页岩气田场站金属排污管线腐蚀失效时有发生，亟须明确排污管线高矿化水-细菌-CO2腐蚀环境下非金属复合管的防腐适用性能。方法 开展纤维增强复合管、钢骨架复合管在模拟气田排污腐蚀工况下的加速老化实验，通过试样宏观微观形貌、表面邵氏硬度、红外光谱、氧化诱导以及环向拉伸力学测试，研究其耐腐蚀性能和损伤规律，再基于强度性能和时温等效原理构建寿命预测模型，评估其长期服役性能。结果 两种非金属管试样宏观和微观形貌均未发现缺陷的产生；表面硬度无显著变化；红外光谱和氧化诱导分析发现材质存在分子链交联结构的破坏以及新的官能团羟基、羰基的引入。随着老化时间的延长，材料强度出现了明显的降低，且钢骨架复合管性能降低更显著。纤维增强复合管预测寿命可达到28年，钢骨架复合管预测寿命为23年。结论 非金属管对排污工况介质均具有良好的耐腐蚀性能，随着服役时间的增大，管材的老化敏感性增加，主要体现在分子结构逐步出现降解、抗氧化能力和强度下降。纤维增强复合管对于页岩气田排污工况具有更好的适用性。 |
| 关键词: 页岩气田 纤维增强复合管 钢骨架复合管 腐蚀老化 适用性 寿命预测 |
| DOI：10.3969/j.issn.1007-3426.2024.06.012 |
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| Anticorrosion performance evaluation of non-metallic composite pipes for shale gas field drainage conditions |
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DAN Xia1, LUO Yanli1, YU Zhiming2, YANG Liu1, WEN Zhan1, YANG Jianying1, WU Guiyang2
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1.Sichuan Changning Natural Gas Development Co., Ltd, Yibin, Sichuan, China;2.Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu, Sichuan, China
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| Abstract: |
| Objective Drainage steel pipes frequently fail due to corrosion in shale gas field station, especially in drainage condition,where they are exposed to high-mineral water, bacteria and CO2, seriously affecting safety production. Non-metal pipes offer benefits like corrosion resistance and lower costs, but their applicability for anti-corrosion purposes requires further clarification. Methods Accelerated aging tests were conducted on fiber-reinforced composite pipes and steel skeleton composite pipes under conditions of simulated gas field drainage corrosion at 90 ℃ for varying durations. The study investigated corrosion resistance and performance damage characteristics through macro and micromorphology of specimens, Shore hardness of surfaces, infrared spectroscopy, oxidative induction, and circumferential tensile mechanical testing. Subsequently, a lifespan prediction model based on strength performance and the time-temperature equivalence principle was constructed to assess their long-term operational performance.Results Under simulated drainage corrosion conditions, no defects were observed in the macro and micro morphology of specimens. Surface hardness showed no significant changes. Analysis of infrared spectroscopy and oxidative induction revealed damage to the material's molecular chain cross-linking structure and the introduction of new functional groups such as hydroxyl and carbonyl. With prolonged aging time, a noticeable reduction in strength occurred, with steel skeleton composite pipes exhibiting more pronounced effects. The predicted service life of fiber-reinforced composite pipes reached 28 years, while that of steel skeleton composite pipes was 23 years. Conclusions Non-metal pipes have good corrosion resistance to the media under the drainage conditions. However, as service time increases, the pipes become more susceptible to aging, reflected in the gradual degradation of their molecular structures, reduced antioxidant capability, and declined mechanical strength. Fiber-reinforced composite pipes are more suitable for shale gas field drainage conditions. |
| Key words: shale gas field fiber-reinforced composite pipes steel skeleton composite pipes corrosion aging applicability life prediction |
