Φ127mm×9.19mm IEU S-135钻杆腐蚀失效分析

Analysis on Corrosion-caused Failure of φ127mm × 9.19mm IEU S -135 Drill Pipe

对发生管体刺穿、外壁腐蚀的Φ127mm×9.19mm IEU S-135钻杆进行了失效分析。结果表明,钻杆的化学成分、金相组织、机械性能均符合API标准及订货技术条件。钻杆管体刺穿是由于内壁发生严重H_2S腐蚀+氧腐蚀造成的。钻杆管体外壁腐蚀是由氧腐蚀引起的。

The analysis involves the failures of the φ127 mm × 9.19 mm IEU S -135 drill pipe, including piercing-corrosion and outer surface corrosion of the pipe body. The result shows that the chemical composition, metallographic structure and mechanical properties etc. of the drill pipe are all up to applicable specification of API Standard and the technical requirements as specified in the order, and that the said piercing-corrosion failure is caused by the severe combined corrosive effect on the pipe inner surface by H2S and oxygen, while the said outer surface corrosion is merely caused by oxygen.