This paper outlines the approach and methodology used for defining annulus line clamp placement. The assessment encompasses load distribution calculations and load sharing between the two pipes for both installation and connected scenarios. A step by step approach is presented with an emphasis on load calculations from self-weight friction from clamp preload, temperature and pressure effects, bending loads from global vessel offsets and environmental loading.

Load calculation and buckling assessment results from this study will be presented. The findings from this study will demonstrate how the installation stage can be more critical for the annulus line compared to the in place connected scenario. Furthermore, a sensitivity analysis is conducted on the friction effects of the clamp and the load sharing attributed from the clamp torque to illustrate its contribution.

This paper will present a comprehensive methodology and load case matrix for establishing clamp placement and clamp design requirements for a high pressure high temperature intervention riser system. The risk of improper design will also be discussed and the importance for HPHT applications highlighted. While the methods presented here are applicable to all types of intervention risers with annulus lines, this study will be especially useful for HPHT systems which are more sensitive to pressure and temperature effects.