Effect of Tool Cone angle on Performance of Metal Seal for Expandable casing

Abstract

In order to select the size of the expansion cone angle suitable for the expandable casing joint with metal seal, the elastic-plastic finite element simulation analysis of the expandable casing joint with a typical metal seal structure was carried out, considering the geometric, material and contact nonlinear problems, by using LS/DYNA finite element explicit dynamic analysis software. The magnitude and distribution of the Mises equivalent stress during the expansion and the residual stress after the expansion, the deformation data of the metal seal structure, and the contact force between sealing surfaces were obtained. It is recognized that when the cone angle of the expansion cone is within the range of 5° to 6°, the best expansion effect on the expandable casing joint with metal sealing can be achieved. The expansion cone with the cone angle of more than 7° will make the joint lose its sealing performance after expansion. When the cone angle is less than 5°, the rebound at the end of the male thread after expansion is larger, and the structural integrity of the joint is reduced. The research results of this paper are helpful to provide reference for the optimization design of expansion tools used in expandable casing joints with metal seal.