TOOLS FOR PREDICTING SERVICE LIFE OF DYNAMIC FLEXIBLE RISERS

A cooperative analytical and experimental technical program involving three organisations is described which is leading to the capability to predict the service life of dynamic flexible risers. Zentech Consultants is encoding the degradation model as a module auxiliary to the riser analysis program Flexriser 4 so that a life prediction can be made as an output for a given riser design study, for the expected lifetime current and wave excitation spectrum. Wear of the plastic barrier layer and of the other plastic layers as a result of flexure is also being addressed, and algorithms for predicting plastic degradation will be added to the model. A joint industry program is in progress which will establish wear coefficients through bench scale wear experiments. Several flexible pipes will be subjected to dynamic tests. In the interim, available public domain wear data is being used.