AHTS are truly multi-purpose vessels, and the Bourbon Liberty 215 has proven that once again. A few months after conducting a reservoir stimulation operation, this anchor handling vessel is now engaged in quite a different kind of operation, again off Congo. The objective: to ensure the development of the production unit (FPU) Alima, for Total Congo, over the Moho Bilondo Nord, field, which officially went into production on December 11, 2015. Report.
The missions follow one another, but they are not alike for the Bourbon Liberty 215 and her crew!
First challenge, towing a barge on which 2 modules are stored weighing 200 tons each, from Pointe-Noire to the Moho Bilondo field. This movement alone actually was three operations in one, since it was first necessary to tow the barge alongside it as a pair in order to get out of the harbor, and then tow it more traditionally on the open sea, and finally to pair up again once at the destination.
On site, the Lewek Crusader, a hotel-barge equipped with a 400 ton crane, took up position near the Alima, and moored on the other side of the barge. The barge's powerful lifting equipment was then brought into play, and it performed the subsequent unloading of the two modules, which were then placed on the FPU (Floating Production Unit). Beforehand, stowage of 3 units would have required about three weeks of risk assessment analysis before the operation, dealing with issues such as the ballasting of the barge, emergency towing resources, the type of cables used, etc. "Paired towing is anything but trivial, especially when three elements are concerned," explains Adrien Richaud, 32, captain of the Bourbon Liberty 215. "The equipment is tested, weather conditions can change quickly, the vessel must not be underpowered, in order to ensure optimum safety. The upstream preparation, in collaboration with the captain of the barge and the teams in charge of the project is paramount, as is the choice of the vessel by the client, in this case a Bourbon Liberty for this operation."
"Despite the lack of visibility for divers and a fairly strong current, we were able to complete this mission and connect two tubes in less than a week without the slightest incident, which is our priority."Adrien RICHAUDcaptain of the Bourbon Liberty 215
I-tube placement in full DP
A choice then confirmed by a second operation, a week later, which was to perform the placement of I-tubes, over the same field, this time directly connected to the FPU, in order to supply the latter with sea water. An operation in "full DP" - i.e., managed entirely using Dynamic Positioning - with, firstly, the positioning of the Bourbon Liberty 215 within 10 meters of the FPU, followed by connecting the cables working together with the barge. An operation again preceded by a thorough risk analysis and conducted under the supervision of divers from the FPU, in order to better assess the strength of the current and make sure the installation could take place under maximum safety conditions.
"Despite the lack of visibility for divers and a fairly strong current, we were able to complete this mission and connect two tubes in less than a week," says Adrien Richaud. "And above all, without the slightest incident, which is our priority." Now it's time for feedback: "After an operation, I always generate feedback in order to share it with the vessels and crews who in turn have to deal with similar situation..." he concludes.