Short subsea pipelines when subjected to high internal pressures and high operational temperatures (HP/HT) might experience displacements of the whole line that may accumulate cyclically over their operational lifetime resulting in a phenomenon known as “pipeline walking”.
Three different mitigation strategies for this phenomenon have been investigated for a specific pipeline, which also had PLETs with sliding foundations at both ends, and results of this investigation were published recently — Castelo et al. (2012). The aforementioned strategies, however, have included only suggestions of different ways to anchor the pipeline subjected to the “pipeline walking” phenomenon.
This recent publication has presented the conclusion that it is advantageous to anchor the pipeline at an intermediate position along its length in order to try to cancel out the friction forces by having them occur in opposite directions, also considering the presence of the unbalanced forces caused by the sloped seabed.
In practical terms determining this intermediate position is not just choosing the pipeline midpoint because of forces built into the pipeline during installation and it is reminded also that no suggestions had been made on how to anchor.
In this paper, therefore, the authors have decided to provide some insight on how to investigate the position where the anchoring should take place in order to minimize the unbalanced forces and also on what structural details are more adequate to perform this anchoring.
