In the framework of 2019 offshore asset inspection program, a detailed visual inspection with 3D reconstruction of two subsea wellheads installed in the Mediterranean Sea close to Crotone coast (approx. 180 m water depth) was carried out, in addition to the standard pipeline inspection tasks (acoustic, general visual, cathodic protection, leak detection).
The two wellheads (and the auxiliary structure located close to one of them) were mapped using stills and video; topside part was also laser scanned. About 110000 Ultra HD images were acquired in few hours of operation (between Oct 13 and 14 2019) and used to build a 3D digital model of the structures.
Thanks to the complete digital model of the assets obtained, it is now possible to make a detailed and accurate comparison between the actual situation and previous ones (or even the as-built project data), and consequently identify changes at an early stage and plan the most suitable remedial actions; thanks to the high resolution image quality and dense data sets, even the smallest variations in structural dimension or height differences can be detected (millimetre resolution achievable with laser).
The application here presented provides a significant example of the results obtainable using advanced underwater robotics and digital techniques in support to oil&gas activities (including, but not limiting to, asset inspection). In fact, a complete 3D digital reconstruction of underwater assets is outside capabilities of traditional inspection techniques, and this is the first time this technique has been used in an Eni subsea plant. This experience makes now possible to evaluate the advantages and opportunities offered by this new technique and the role it may play in Eni digital transformation.
In 2019 ENI DIME needed to verify the integrity of its offshore structures to comply with the regulatory programme. For this purpose (and following the previous successful experiences of 2015 and 2017) Clean Sea was selected again, being the most economical and advanced solution available and with the additional advantage that it is a technology fully owned and managed by Eni. Additionally, being operated by Enimed team, the tool is easily available and usable.
