Production was halted in late November as a precaution following discovery of a crack during a scheduled inspection in one of the wellhead platform’s 12 horizontal struts.
Air divers installed three clamps last month as an intermediate solution, with Fitzroy Engineering and NZ Diving and Salvage managing the repair. This secured the damaged strut on level 3, roughly 4 m (13 ft) below the waterline.
Lloyds verified the repair, both during the design phase and post-installation.
OMV has also completed a full electromagnetic inspection of all nodes (strut and leg connections) on level 3 and also commissioned an ROV inspection of the entire platform structure, which stands in 100 m (328 ft) of water.
Two options for a permanent solution are under investigation by AMOG and Worley Parsons (Melbourne). The work should be completed this month and a preferred concept selected, with a permanent repair likely completed by mid-2017.
During the interim repair period OMV resumed planned shutdown maintenance program that had been scheduled to start on Dec. 5, 2016. This included completing replacement of a water injection flowline, using two support vessels supplied by Maersk and DOF.
Maintenance work on the field’s production risers (connected between the wellhead platform and the floating production vessel Raroa) was also completed during the shutdown.
According to Cue, regulatory agencies WorkSafe, Maritime New Zealand and the Environmental Protection Authority were consulted on an ongoing basis throughout the campaign.