Pipeline in moving contact over another pipeline 1

[hsoo]

Gents:
During an installation emergency, a riser pipe may be lowered over an existing pipeline on sea floor with the barge still turning. There is a possiblity of the riser dragging over the pipeline and damage the coating and insulation. I want to analysis this problem.
Any info is welcome. Thanks.

 

[Mark62]

Best to avoid this type of situation if at all possible. Is there no other emergency abandonment procedure that could be adopted.

My initial aproach would be to used Orcaflex, or Flexcom 3D, which are both dynamic analysis programs and can both model pipeline laying and clashing between objects.

This should be able to give you an idication of the imapct angle (across the pipe or along it) and the impact force.

You could then talk to the pipeline coating suppliers to see if the predicted impact is high enough to damage the coating.

If it is likely to damage the coating, then do they have any underwater repair procedures. If thy do not then look even harder for a way to avoid the impact.