LiDAR Data Applied for 3D Printing of Subsea Well Part

Fugro and 3D at Depth, a provider of subsea LiDAR systems and solutions, have used subsea LiDAR data to 3D-print an accurate 1:1 physical model of a damaged well part.

The subsea part fabrication was part of a larger project conducted in early 2016, using 3D at Depth’s subsea LiDAR SL 2 technology and point cloud software.

3D at Depth was contracted by Fugro to perform subsea laser scanning services on a well abandonment project in Oceania, Australia. The Plugged and Abandoned (P&A) wells located in a water depth of circa 110 meters, were drilled decades earlier and suspended at the time of drilling.

An SL2 Subsea LiDAR laser, manufactured and operated by 3D at Depth, was mounted on the crash bar of the Fugro FCV3000 WROV sending near real-time data to the operator on the vessel via a fibre optic multiplexor.

Data Collection
Approximately 44 million data points were collected at the well in 13.5 hours. The LiDAR laser data was processed using point cloud processing tools to compute the spatial relationships, measurements and orientations of the seabed structures. The resulting deliverables included a 3D point cloud database, a dimensional report for each well, CAD files and a 360° animation of each well, modelled from the point cloud.

In addition to subsea LiDAR data, physical measurements were collected by the Fugro ROV using different sizes of V-gauges and rulers. Cross-referencing of the physical and LiDAR measurements with the original drawings helped identify discrepancies in existing drawing dimensions.

3D Print Process (Additive Manufacturing)
To create a 1:1 model for the design of an appropriate ‘hot tap’ connector, a 3D print of the top of the well, with its damaged stub, at full scale was required. As the large size of the well cap structure made the cost prohibitive, a hybrid Computer Numeric Control (CNC) machining process, combined with a 3D print of the damaged part, was proposed by 3D at Depth as a viable alternative solution.

The first step was to re-processes the point cloud data from the top of the well and then create 3D CAD models of the separate parts. However, this process proved more challenging than first thought due to the complexity of the shape. For this particular part the auto meshing algorithms which convert point clouds into surfaces did not perform well and as a result the CAD model was developed manually, which is also common when modelling complex shapes from terrestrial laser scans.

The part was then 3D printed by means of Fused Deposition Modelling (FDM) technology using Acrylonitrile Butadiene Styrene (ABS) thermoplastic material. One of the other two CNC machined parts was made from Acetal and the well cap from ultra-high-molecular-weight polyethylene (UHMWPE).

“While the individual sector scans provide millimeter accuracies, the wide area point cloud can provide a 3D dataset of centimeter accuracy across an entire drill center,” said Adam Lowry, MD of 3D at Depth Pty Ltd. “Wide area point clouds, when used for planning, have proven to avoid costly surprises which are otherwise only discovered after the intervention vessel is actually on location. Cost savings can be realised from almost any situation where accurate spatial data would be beneficial to planning intervention operations.”

Source: 3D at Depth