During an ‘as-laid’ inspection of a recently installed flexible riser in the Norwegian North Sea, the operator’s marine contractor found a small section of the riser to be mis-shapen, thought to be caused by the installation equipment.
In collaboration with an international marine contractor, Viewport3 performed a high-accuracy 3D scanning operation aimed at recording the ‘new’ shape of that particular section of riser.
The capture was organised in a ‘remotely managed’ configuration, whereby the imaging equipment was issued to the marine contractor, alongside a guidance procedure and 3D guidance animation.
With no opportunity to excavate around the site of the anomaly, it was crucial that the image set also captured the interface between flexible and the seabed as accurately as possible.
A virtual meeting was held to ‘walk’ the ROV team through the operation, whilst highlighting best-practice in terms of collecting technically valuable images.
The data was then reconstructed in 3D. As well as standard geometric analysis reporting, Viewport3 also provided 2D ‘slices’ of the riser profile at pre-defined intervals, helping the riser manufacturer to understand the shape and magnitude of the damage.
After completing virtual analysis and effect simulations based on the Viewport3 provided data, the riser manufacturer advised that the hardware was serviceable, and would remain so if the riser could be retained in its new shape and not allowed to ‘relax’ with the passage of time.
Subsequently, the Viewport3 data was deployed a second time and used as a basis to manufacture a clamp for the riser, which would hold the item in a manner that matched the non-primitive geometry at the area of the anomaly. Two black lines on the flexible were also transformed and represented as CAD entities, helping the customer organise a correct method of aligning the clamp during installation.
Viewport3 were glad to hear that the field was subsequently brought into production in Q3 of 2022.
It is estimated that the cost of replacing the flexible riser would run into the millions of pounds, dwarfing the cost of applying a fit-first-time retaining clamp, based on real-world 3D geometry extracted by the Viewport3 process.
