Research on sealing performance of special thread of tubing under complex load

Abstract

Abstract In order to study the performance of a special threaded joint of a tubing under severe well conditions, a two-dimensional finite element model of this joint was established in the finite element software, and the mechanical properties and sealing performance of the special threaded joint under different working conditions were analyzed and studied. The results of the study indicate: under different make-up torques, the Mises stress value on the thread has a small difference, and there is a significant difference at the shoulder. When subjected to complex loads, the Mises stress on the load-bearing surface of the thread head and tail ends is high, the overall maximum Mises stress exceeds the yield limit of the material, but the stress level in most areas is low, there is no plastic penetration part and structural damage on the thread teeth. The sealing index of the threaded joint is greater than the critical sealing performance index. This shows that this threaded joint can meet the requirements of use.