We were recently approached by a marine contractor to carry out 3D scanning on a subsea template in the Norwegian sector of the North Sea. Although they were a returning customer, whom we had worked with on two previous retro-fit campaigns, this was our first time carrying out 3D scanning for the operator of the field.
There was a requirement to understand the template geometry in order to ascertain the required dimensions for designing and fitting a well enhancement tool. They needed an answer to the question: how do we ensure it fits first time?
The work scope was huge, particularly given the tight timescale. With the template measuring 25m x 15m, the sheer volume of data was something of a challenge in and of itself. The process was also slightly more complex than usual as we had to scan certain areas using video (for low-accuracy), and other areas using digital stills (for high-accuracy), and then merge the information together as a single 3D dataset.
Despite the volume of data required, there was absolutely no compromise in relation to its quality. It was imperative that the well enhancement tool fitted perfectly, and therefore there was no margin for error during the entire scanning, processing and reporting procedure. For example, the inclination of the Christmas tree in reference to the template had to be captured accurately to ensure the tool fitted first time.
As this was a remotely-managed capture, we spent time bringing both the personnel on the support vessel and those operating the ROVs up to speed on the detail of the procedure.
The way in which we carried out the capture was flexible, in that two Work-Class ROVs were scanning different parts of the same structure at the same time, using two different imaging load-outs.
As the data began to arrive with us, we tweaked the methodology of the capture to optimise its quality.
Once all the data had been collected, we processed it into 3D outputs in line with our customer’s request.
Thanks to the quality of the point cloud scan and the density of the data that we were able to provide, the coverage of the template was excellent – revealing a complete picture of the structure which the responsible engineers could analyse from their desks.
Having such an accurate digital copy of what was offshore gave the marine operator, the client and their design house the opportunity to rapidly change their ideas as the project progressed, whilst ensuring they were able to successfully design and fit the well enhancement tool first time. This was verified by a thank-you note received from the customer soon after.
375m2 – the ‘footprint’ of the template
243 million – number of points in final 3D cloud
886Gb – quantity of data collected subsea
1 – number of attempts required to get the new hardware to fit