某气井完井管柱泄漏原因分析

Analysis for One Gas Well's Leakage of Completed String

某水平井完井后试采不到1个月,套压异常升高,不得不实施修井作业。对套压升高原因进行了详细调查,对起出的油管逐根进行了检查,发现许多油管螺纹接头严重腐蚀和变色,几乎所有油管管体内、外表面均有腐蚀,大多数油管粘扣。根据油管失效特征判断,套压升高原因是油管接头泄漏引起的,油管接头泄漏主要是粘扣所致。进一步分析认为油管粘扣主要是操作不当所致,油管腐蚀主要是天然气中含的CO2、Cl-和凝析水所致。

Less than one month of production test after the completion of a horizontal well,workover has to implement for abnormal.By investigating reason of pressure increase of casing in detail and examining the pipeline one by one, it is found that many of tubing nipple to be severe corrosion and discoloration,almost all the tubing tube body,the outer surface of both are of corrosion and most of the oil pipe are gluing.According to characteristics of pipeline failure,the reason of increased case pressure is due to leakage of pipe joints,the pipe joint leakage is mainly caused by gluing.Further analysis shows that pipeline galling is mainly caused by improper operation,and tubing corrosion mainly caused by CO2,Cl-and condensate water of the natural gas.