定向井造斜段管柱屈曲分析

摘要

定向井造斜段井眼轨迹呈下凹状态,位于其中的管柱在重力与井眼的约束下必然存在初始下凹弯曲。这就使造斜段管柱的屈曲性质和井眼轨迹为直线时管柱的屈曲性质有很大的不同。为此,运用最小势能原理推导出造斜段管柱屈曲载荷计算公式,并研究了井斜角、造斜段井眼曲率半径对管柱屈曲载荷的影响。算例分析结果表明,随井斜角的增大与井眼曲率半径的减小,管柱屈曲临界载荷增加,即管柱的纵向稳定性提高。%Because of the downward bend in the deflecting part of directional well,there must be initial downward bend of tubular string due to gravity and well bends.The difference of the buckle characteristics between the string which was placed in deflecting part and the erect or horizontal well may be tremendous.Because of this,the buckle formula of the string in the deflecting part was deduced by the principle of the minimum potential energy,and the influences of the deviation angle and the radius on buckling loads were researched.The result showed that tubular string＇s stability can be advanced by increasing deviation angle or decreasing radius of well trajectory.