New Search

Export article

Assessment of Design Collapse Equations for OCTG Pipes Under Combined Loads

Published: 1 September 2021

Abstract: The objective of this paper is to evaluate the design collapse equations presented in chapter 8 and Annex F of the current standard ISO TR 10400 for casings under external pressure and axial tension. A nonlinear numerical model has been developed to analyze the performance of these equations to predict casing collapse under combined loads. Experimental tests have been performed with different diameters, d/h ratio and steel grade to calibrate the numerical model. The KT model has been assessed previously against different models by API Work Group and it has shown to be reliable to be used as design equations. However, the API Work Group included the KT model in the appendix F of the code as informative. The work done in this paper has confirmed the better performance of KT model for most of the cases analyzed. For combined loading, the API collapse equation results in a simple strength de-rating method, whilst the KT model has achieved similar behavior for low values of axial tension when comparing the experimental results. The axial tension for the casings into the well is likely to be lower than 40% of yield strength. Therefore, the KT model has shown to be more convenient to well design than API equations.
Keywords: model / equations / collapse equation / combined loads / axial tension / behavior

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

Share this article

Click here to see the statistics on "Journal of Pressure Vessel Technology" .
Back to Top Top