Collapse of Mechanically Joined Composite Pipes: Determining Equivalent Configurations

Abstract

In submarine metallic pipelines used in petroleum extraction, one of the current configurations is the application of metallic steel pipelines that contain a mechanically joined internal Liner. The hydrostatic pressure is one of the critical scenarios of this type of system when the pipeline is empty, which can cause the collapse due to the external pressure. It is of interest to determine a theoretical increment of the backing steel’s thickness due to the addition of the mechanically joined internal liner. For that purpose, a series of numerical simulations are carried out to find an analytical expression that allows us to easily determine the new level of collapse pressure. In this study, the dimensional analysis methodology is used, which makes it possible to identify the parameters that have the most influence in these equivalent configurations. Numerical simulations are performed using the finite element method considering the physical and numerical nonlinearities of the problem studied. Two analytical expressions are proposed, and their applicability is discussed in this work.