海上某油井测压油管腐蚀失效分析

Analysis of corrosion failure of pressure measuring tubing in the offshore oil well

海上某油井在修井过程中发现测压油管和电缆发生严重腐蚀失效。经过宏观分析、腐蚀产物分析、金相组织分析、微观分析和电化学分析,明确测压油管失效主要原因为电化学腐蚀,同时因与套管接触形成密闭腐蚀环境,形成自催化效应,导致油管与套管接触区域穿孔。

Serious corrosion failure of pressure measuring tubing and cables was found during service work of the offshore oil well.Through macroscopic analysis,corrosion product analysis,metallographic organization analysis,microscopic analysis and electrochemical analysis,it is clear that the main cause of corrosion of pressure measuring tubing is electrochemical corrosion.At the same time,closed corrosion environment is formed due to contact with casing,which is formed the effect of self-catalysis and the intensifying corrosion,leading to perforation in the contact area between tubing and casing.