某油田N80钢级长圆螺纹套管螺纹黏结原因分析

Investigation of Causes for Thread Galling of N80 Long-round Thread Casings as Used in a Certain Oil Field

摘要: 为分析Φ244.48mm×10.03mm规格N80钢级长圆螺纹套管螺纹黏结原因，检测了该批套管螺纹接头加工质量，检验了套管的材料特性，通过套管上卸扣试验，对比不同接箍表面处理特性等。结果证明：套管材料碳含量较低、硬度低、接箍表面磷化层较薄、附着力差是造成此批套管产品抗螺纹黏结性能较差的主要原因。

Abstract: The causes for thread galling of the Φ 244.48 mm×10.03 mm N80 long-round thread casings as used in a certain oil field are investigated by means of inspecting the thread connection processing quality and material characteristics of all the trouble-ridden casings，and comparing the surface processing characteristics of different couplings by means of the make & break test.As a result，it is identified that major elements responsible for the poor anti-galling performance of the very lot of casings include rather low carbon content and hardness of the casing material，and over-thin phosphate coating of the coupling surface that leads to poor adhesion of itself.