| 摘要: |
| 目的 厘清新疆油田稠油火驱某采出井N80油管的腐蚀失效原因，明确腐蚀主控因素和腐蚀机理。方法 分析了火驱井油管服役井史和宏观腐蚀形貌，检验了失效油管的化学成分、金相组织和力学性能，利用扫描电镜、能谱仪、X射线衍射仪对腐蚀产物进行物相分析。结果 失效油管的化学成分、力学性能均符合相关标准要求，金相组织无异常；油管以局部腐蚀为主，服役仅1年油管外径减少了1.89 mm；腐蚀产物层厚度达96 μm，主要由Fe2O3、FeCO3和FeOOH组成。结论 失效油管发生了高温环境下的CO2腐蚀和O2腐蚀，O2和Cl–的协同作用是导致油管局部腐蚀发展的主要原因，建议采用铝合金牺牲阳极短节进行防护，研究成果为火驱环境油管柱的腐蚀与防护提供了借鉴。 |
| 关键词: N80油管 火驱 CO2腐蚀 O2腐蚀 失效分析 |
| DOI：10.3969/j.issn.1007-3426.2024.06.014 |
| 分类号: |
| 基金项目:国家自然科学基金“静载、振动与腐蚀作用下H2S/CO2气井完井管柱螺纹密封面的力化学损伤机制研究”（51774249） |
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| Corrosion failure analysis of N80 tubing in heavy oil fire-drive production well in Xinjiang oilfield |
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CHEN Dengya1, ZOU Jungang2, YU Chengxiu3, SUN Jianghe1, XIANG Hong1, ZENG Dezhi3
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1.Oil Production Technology Research Institute, PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang, China;2.No.1 Oil Production Plant of PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang, China;3.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan, China
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| Abstract: |
| Objectives To clarify the corrosion failure causes of N80 tubing in a production well of heavy oil fire flooding in Xinjiang oilfield, and to identify the main control factors and corrosion mechanism. Methods The service history and macroscopic corrosion morphology of the fire-drive production well tubing were analyzed. The chemical composition, metallographic structure and mechanical properties of the failed tubing were analyzed. The corrosion products were analyzed by SEM, EDS and XRD. Results The chemical composition and mechanical properties of the failed tubing were in line with the relevant standards, and the metallographic structure was normal. The oil pipe was mainly corroded locally, and the outer diameter of the oil pipe was reduced by 1.89 mm after only 1 year of service. The corrosion product layer has a thickness of 96 μm and is mainly composed of Fe2O3, FeCO3 and FeOOH. Conclusions CO2 corrosion and O2 corrosion have occurred in the failed tubing at high temperatures, and the synergistic effect of O2 and Cl- was the main cause leading to the development of local corrosion in the tubing. It is recommended that Al alloy sacrificial anode short sections be used for protection, and the research results provide a reference for the corrosion and protection of tubing string in fire-drive environment. |
| Key words: N80 tubing fire-drive CO2 corrosion O2 corrosion failure analysis |
