柔性套管铰链接头力学分析

Mechanical analysis of flexible casing hinge connection

在合适的单元长度和铰链转角下,柔性套管可以较好地适应弯曲的井眼。在套管的提升过程中,由于提升力的作用,铰链接头的失效形式一般表现为铰链拉脱或强度不足。根据柔性套管铰链接头的结构和受力特点,对其受力进行了简化,建立了力学分析模型———受边缘力系作用的长圆筒,并给出了其变形的基本方程,得到了铰链边缘的径向位移和转角的计算公式,形成了完整的柔性套管铰链接头的力学分析模型。当铰链承受196kN的拉力时,铰链外筒的径向位移为051mm,对应的边缘转角为25°,铰链不会拉脱,强度校核满足要求。

With rational unit length and hinge rotating angle, the flexible casing can be adaptable to the buckling borehole. The hinge is apt to be pull apart and the strength of the hinge connection is insufficient owing to the action of the elevating force in the course of casing lifting. According to the construction and load characteristics of flexible casing hinge connection, its mechanical model is simplified as a long thin walled cylinder subjected to edge force and moment, a fundamental equation for its deformation is presented, and the formulae for calculating the radial displacement and rotating angle of the hinge edge are obtained. When the hinge is subjected to an axial tension force of 196kN, the radial displacement of hinge outer edge is 0 51mm, and the edge rotating angle is 2 5°, so the hinge can not be pulled apart, and the strength check is satisfactory.