高酸性气田地面用国产双金属复合管现场腐蚀评价

On-site corrosion assessment of bimetal composite pipe used in high sour gas fields

关键词:  双金属复合管  环境开裂  电化学腐蚀

Key words:  bimetal composite pipe  environmental cracking  electrochemical corrosion

摘要:

在高酸性气田开发过程中,由于腐蚀环境恶劣,双金属复合管耐蚀材料成为研究热点,但研究主要集中在室内实验,缺少现场应用案例,限制其进一步应用。为考察双金属复合管在高酸性气田地面管线应用的可能性,利用高含硫先导试验基地天东5-1井在线腐蚀试验装置开展了双金属复合管应用于高酸性气田地面管线的现场腐蚀性能评价,形成了双金属复合管腐蚀评价试验方法,并开展了X52/825冶金复合管和L245/825机械复合管两种管材的耐蚀层及焊缝在天东5-1现场腐蚀环境中的抗电化学腐蚀性能和抗环境开裂性能评价试验。试验结果表明,国产X52/825冶金复合管和L245/825机械复合管的耐蚀层及其焊缝在现场试验环境中具有良好的抗环境开裂性能和良好的抗电化学腐蚀性能,形成的双金属复合管腐蚀评价方法为今后开展复合材料现场应力腐蚀评价奠定了基础。 

Abstract:

Due to the severe corrosion environment, materials like bimetal composite pipes have become the research hot topic in the exploitation of high sour gas fields. The research of bimetal composite pipes mainly focuses on lab experiments, and the wide application has been limited due to the lack of on-site application cases. In order to assess the possibility of bimetal composite pipes applying to the surface pipelines in high sour gas fields, field corrosion behavior evaluation was carried out, and then the evaluation method has formed by using online corrosion test device in Tiandong 5-1 high sulfur gas pilot Test base. The electrochemical corrosion and sulfur corrosion cracking experiments of X52/825 metallurgical composite pipe and L245/825 mechanical composite pipe have been conducted. Field test results indicate that the corrosion resistant layer and weld of X52/825 and L245/825 have good environmental cracking resistance and good electrochemical corrosion resistance. The corrosion evaluation method of bimetal composite pipe has laid a foundation for the field stress corrosion evaluation of composites in the future.