Load-in & load-out
When Nabors was building a drilling module (DM) for its client Chevron, Mammoet was asked to transport over 120 components from one construction yard to another for further assembly.
Mammoet took on the challenge but proposed a much faster approach. Instead of shipping the DM as individual elements, Mammoet suggested assembling, transporting, and lifting the 2,268-ton module onto the platform in one piece.
This allowed construction on another part of the platform to continue while the DM was built. Mammoet’s plan saved 30 days of rebuilding and another 30 days of hook-up time.
Nabors chose its original approach of transporting the DM in individual pieces because it was under the impression it simply could not be shipped in one go. First, the road from the fabrication yard to the load-out area was too narrow to carry the module.
Secondly, there was a height difference between the barge and the load-out quay, which was supposedly too steep to load out the tall DM. Finally, the customer assumed the shallow waters of the shipping route would not be able to handle a barge with the weight of the full DM either. But transport aside, the DM wasn’t designed to be lifted in one piece, to begin with.
After close examination, Mammoet came up with an approach that took away all bottlenecks. We began by building a special support frame to allow the DM to be lifted onto the offshore platform. In order to overcome the issue of the narrow road, Mammoet proposed to move the separate DM components to an alternative yard near the load-out area and assemble it there.
From there, it was possible to transport the DM in its entirety to its final destination. A custom ramp offsets the height difference between the barge and the quay at the load-out location. Mammoet successfully loaded the DM onto a barge with enough draught to make it through the shallow waters.
To make sure the shipping route could in fact handle the barge with the weight of the complete DM, a sonar survey was conducted and a dive team was employed to double-check the water depth.
Mammoet’s alternative solution proved highly advantageous for Nabors and Chevron. By allowing construction on the ETLP to continue while the DM was built in another construction yard, Mammoet helped Nabors deliver the DM 60 days ahead of schedule.