材料形变强化和摩擦系数对圆螺纹接头滑脱性能的影响

Influence of Material Deformation Strengthening and Friction Coefficient on Round Thread Connection Pull-out

API圆螺纹接头套管滑脱强度受多种因素影响,本文基于材料非线性、大变形及摩擦接触,应用有限元方法对API圆螺纹滑脱进行了研究,分析了材料形变强化和摩擦系数对API圆螺纹套管滑脱强度的影响。研究成果为提高API圆螺纹接头滑脱强度,充分发挥其性能,节约油气开发成本提供了技术支持。

Many factors influence the pull-out strength of round thread casing. During the full scale tests of Φ177.8×8.05mm N80 long round thread connection, it is found that even if the thread and geometrical parameters, material yield and ultimate strength meet the API standard requirements, the pull-out strength of connection gets below API 5C2 specification value. The pull-out strength of API round thread, and the influence of various material deformation strengthening curves and friction coefficients to round thread connection pull-out strength, are investigated with finite element analysis(FEA) method. It is concluded that the pull-out strength of round thread varies more than 10% with different material deformation strengthening curves, and the pull-out strength can be improved by eliminating yield plateau; the pull-out strength linearly depends on the friction coefficient, the greater the friction coefficient, the higher the pull-out strength.