Subsea 7, one of the world's leading subsea engineering and construction companies, recently completed the VIC/P44 Stage 2 Development (Henry) Project, offshore Australia, which involved the installation of a 21.7km long / 12-inch rigid pipeline to connect the subsea production trees at the Henry-2 and Netherby locations, together with 4 rigid spool pieces. The project also included the installation of a 22km long electro-hydraulic umbilical from Casino-4 to Pecten East locations.
Awarded to Subsea 7 in August 2009 by Santos Limited, the work scope required the Henry and Netherby fields to be tied back to the existing Casino field, located offshore Victoria in the Otway Basin. The engineering was completed by a dedicated project team with offshore operations commencing in December 2009.
One of Subsea 7's rigid reeled pipelay vessels, the Seven Navica, arrived in Singapore in late November 2009 before commencing its journey to the project's spoolbase in Crib Point, Victoria. The Seven Navica successfully installed the 21.7km of 12-inch rigid pipe complete with two in-line tee skids, over two trips returning to the spoolbase in the interim. The Seven Navica was supported by Subsea 7's Dive Support Vessel, Rockwater 2, which installed four sections of umbilical, electrical and hydraulic flying leads, three pipeline end manifolds, associated subsea infrastructure and 650 stabilisation mattresses to complete the tie-ins and freespan rectification. Over 2000 lifts were performed by the Rockwater 2's 300t active heave compensated crane. The umbilicals ranged from 3.3km to 6.5km in length and were installed utilising an in-line tensioner and a reel drive system. The vessel also installed rigid spools; performed the associated metrology and assisted Santos with field commissioning and start-up activities.
Craig Broussard, Vice President Asia Pacific stated: "We are delighted to have successfully completed this workscope for Santos, which builds upon Subsea 7's established track record in the region of delivering projects safely, efficiently and on time. Both vessels performed well on the project and the utilisation of the Seven Navica from Subsea 7's global fleet of vessels, demonstrates our long term commitment to the Asia Pacific region."
The Henry and Netherby fields, located in 56 - 72 metres of water, are operated by Santos Limited on behalf of a joint venture it has with AWE Limited and Mitsui E&P Australia Pty Ltd. Subsea 7 was also involved in the original Casino development in 2005, installing mattresses, jumpers and structures and also completing the tie-ins.