直连型套管螺纹接头偏心原因分析

Cause Analysis on Off-centre of Integral Joint Casing

直连型套管螺纹接头比接箍式套管的加工难度大,常见的问题是螺纹接头偏心。在现场对某油田到货的直连型套管接头台肩壁厚进行检验,发现套管接头偏心严重。对该批套管检测结果进行了统计分析,认为套管接头偏心与管端弯曲有关。通过统计分析,认为该批套管接头产品过程能力指数不足。为了从根本上解决直连型套管接头偏心问题,提出了订货补充技术条件。该技术条件不仅使油田到货验收有了技术依据,而且也对工厂质量控制具有指导作用。

The threading of integral joint casing is more difficult than that of coupling connection casing,and joint off-centre is common quality problem of integral joint casing. The connection end thickness for the integral joint casing in one oil field is inspected and it is found that the integral joint casings were off-centre. It is considered that the casing process capability index is not enough per statistics analysis. The complementary delivery technical conditions for integral joint casing is given in order to prevent casing joint from being off-centre. It is not only on the basis of technique for check and accepted by user, but also the guidance for manufactory to control product quality.