Strength Analysis of Transitional Segment of Buckling Tubing Nearby the Packer in Vertical Well

Abstract

The buckling deformation and stress distribution of the tubing nearby the packer would be seriously influenced by the packer constraints. This paper focused on the Strength analysis of transitional segment. The method to calculate the buckling deformation and the equivalent stress of transitional segment were derived considering the tubing boundary and continuity condition, adopting the fourth-order nonlinear ordinary differential equations and helical buckling strength method. This study makes up for the weakness of traditional stress analysis of the buckling tubing nearby the packer in vertical well, improves the pertinence and accuracy of stress analysis of buckling tubing. The results of analysis show that with the axial pressure increasing lead to the length of the transitional segment irregular fluctuations and the maximum equivalent stress increasing. The equivalent stress would gradually reduce and finally approach a constant.