轴向载荷对套管螺纹连接应力的影响分析

针对深井和大位移井中套管存在很大的轴向拉伸和压缩载荷的情况,采用有限元方法对套管柱中最薄弱的螺纹接头部分进行了分析计算,研究了API长圆螺纹套管在轴向拉、压载荷作用下,螺牙面的接触压力和应力分布规律,结果表明:API长圆螺纹套管接头最大接触压力出现在公扣的根部,并且前4扣的接触压力和应力较大,最有可能发生粘扣和屈服破坏。对在深井、大位移井中正确选用API长圆螺纹套管,减少套管连接部位失效事故的发生具有重要意义。

EFFECT OF AXIAL LOAD ON CASING THREADS CON-NECTION STRESS

There are very big axial tension and compression in th casing under the deep well and large displacement well. the paper analyzed the weakest threads joint of the casing string bthe finite element method (FEM), and studied the contac pressure and the stress distribution under the API LTC axia tension and compression. the results shows that the maximu connection pressure of API LTC casing joint located in the mal threads root, the contact pressure and stress of the front fou threads is greater than any others. The threads gluing an yielded failure possibly occurred. It has an important signifi cance to select the API LTC casing correctly for the deep wel and large displacement well.