高温高产井油管屈曲对特殊螺纹性能的影响

为研究高温高产井中油管发生屈曲对特殊螺纹性能的影响，借助ABAQUS有限元软件建立了某特殊螺纹的三维有限元模型，结合实际屈曲工况，并综合考虑了温度、内压、轴向力等因素，得到了屈曲后油管特殊螺纹的应力分布以及密封结构上的接触压力分布。结果表明：屈曲后特殊螺纹环向上应力分布不均，表现为受压缩一侧Von Mises应力及接触压力明显大于受拉伸一侧，且正弦屈曲段相比于螺旋屈曲段接头环向上的应力集中更突出；屈曲后，受压一侧的台肩以及管体大端外螺纹第一扣处的Von Mises应力值超过了材料的屈服强度，结构发生塑性变形；受拉一侧的密封面以及台肩面上的接触压力为零，密封结构失去密封能力。

Research on the Influence of Buckling of Tubing in High Temperature and High Production Wells on the Properties of Premium Threads

In order to study the effect of buckling of tubing on the properties of special threads in high temperature and high production wells. A three-dimensional finite element model of a special thread is established with the help of ABAQUS finite element software. Combined with the actual buckling conditions, and comprehensively consider factors such as temperature, internal pressure, and axial force. The stress distribution of the special thread of the tubing after buckling and the contact pressure distribution on the sealing structure are obtained. The results shows: After the tubing is buckled, the stress distribution on the special threaded ring is uneven. It is manifested that the Von Mises stress and contact pressure on the compressed side are significantly greater than those on the tensile side. And the stress concentration in the joint ring is more prominent in the sinusoidal buckling section than in the helical buckling section. After buckling, the Von Mises stress value of the shoulder on the compression side and the first buckle of the external thread of the large end of the pipe body exceeds the yield strength of the material, and the structure undergoes plastic deformation. The contact pressure on the sealing surface on the tension side and on the shoulder surface is zero, and the sealing structure loses its sealing ability.