Study on the Static Characteristics of Marine Flexible Riser Skeleton Layer under Radial Clamping Loads

Abstract

The radial compression failure of the skeleton layer is one of the main failure modes in marine flexible riser. In order to study the mechanical properties of the skeleton layer of the flexible marine riser under radial clamping load, an ABAQUS-based skeleton layers numerical simulation model was established to define the influences of inter-layer interaction and lock blocks number on the radial compression of skeleton layers, while taking material nonlinearity into account. Calculation results suggest that the inter-layer sliding will increase the radial compression displacement of skeleton layers when the same load is applied. The number of lock blocks is an important factor affecting the radial compression characteristics of skeleton layers; the number of lock blocks will increase the radial compression stiffness of skeleton layers and allowable radial compression force, which will render a smaller allowable radial compression displacement. Once the number of lock blocks is over four, the influence of the number of blocks on radial compression characteristics of skeleton layer reduces gradually. This study demonstrates that the numerical method in this paper can effectively calculate the maximum loading displacement and the maximum clamping force of the flexible riser without excessive deformation when passing through the tensioner with various numbers of lock blocks.

AAPG Datapages/Search and Discovery Article #130004© Petroleum Drilling Techniques, Issue 5, 2018