Subsea 7 IRT Participates in Diverless 1st for Esso Norge

The Integrated Remote Technologies (IRT) division of, Subsea 7, successfully completed its involvement in the replacement of the first out of two stern thrusters on the Balder FPU (Floating Production Unit). Subsea 7 was contracted to perform the subsea ROV (Remotely Operated Vehicle) operations associated with this project. The work was planned and executed by a specialised team from Esso Norge AS and a number of equipment suppliers and contractors including Subsea 7 IRT. The thruster change out was part of the 2004 maintenance program for the Balder FPU.

The work performed by Subsea 7 was executed under an existing frame agreement with Esso and included: active involvement in the design and provision of an ROV operable subsea rigging system for connection of cross hauling lines to the thrusters, cleaning and inspection of the thruster connections, and close monitoring during cross hauling and lifting of the thruster to surface. Subsea 7 IRT was responsible for all underwater ROV execution tasks, utilising the Warrior workclass ROV and Seaeye Tiger observation ROV systems during the removal and reinstallation of the replacement thruster. Each step of the operation required close coordination to avoid potential damage to the thruster or vessel.

Subsea 7 IRT's Vice President, Ian Cobban, commented, "Subsea 7 IRT performed safely and efficiently in the execution of this project and with no ROV stoppage time, which earned us great praise from our client. We feel that this work is a major achievement for Subsea 7 IRT as similar operations in the past have required the vessel in question to be relocated to an inshore location for assistance by divers, diver assistance in the field (offshore) or performance in dry dock. The methods and equipment designed for the operation on Balder, however, made it possible to do the work without divers on location which proved to be a safer, lower risk procedure as well as cost-effective for the client."