The integrity of flexible risers is often addressed by monitoring the condition of the annulus. This is because most degradation mechanisms in the layers of flexible riser often start with the ingress of water in the annulus. Annulus testing and increasingly flooded annulus detection are standard assessment methods to obtain this information. Methods for direct detection of defects in the steel components of the pipe are a rather emerging method.
This paper presents a novel method to detect cracks in the armour layers of flexible riser. The method consists of scanning the riser externally with a crawler deployed by ROV. The full length of the riser can be inspected. For flowlines on the sea bottom short sections are inspected which are selected by assessing the likeness for the formation of cracks.
Experience from actual offshore inspection projects is presented including the technical aspects of the tool deployment and defect detection capabilities. The implication for the integrity assessment of flexible riser is discussed.

Remark for the technical committee:
This presentation is a succession of last year’s presentation. The presented method and the technical content are completely different. The results presented were not available in May 2025.