By Gavin Evans
May 7 (BusinessDesk) - Maintenance work at the country’s biggest gas field is winding up, with China Oilfield Services’ Boss rig expected to start decoupling from the Pohokura production platform by tomorrow.
That process means production from the field’s offshore wells will be stopped for about 12 days. Production from three wells that come ashore near Waitara will continue.
Field operator OMV says most of the work – a mix of well interventions and platform maintenance – has been completed.
“Most of the well intervention equipment has already been demobilised from the COSL Boss rig and preparations to commence decoupling are underway.”
Pohokura, developed by Shell but now owned by OMV and Todd Energy, typically delivers close to 40 percent of the country’s natural gas. Two maintenance shuts last year and the latest work, which started in February, tightened gas supplies and pushed electricity prices higher when the country’s hydro dams were low last spring and again in February and March.
OMV had hoped to complete the latest maintenance campaign last month. Power prices have jumped again this month as intermittent gas shuts at Pohokura have coincided with the onset of cold, still weather that has boosted demand and reduced wind generation.
Wholesale electricity cost an average $152 a megawatt-hour yesterday, more than four-times that a year earlier, according to Electricity Authority data.
Contact Energy last month restarted its 377 MW Taranaki Combined Cycle plant with gas contracted from operators of other less efficient plants in order to help meet demand heading into winter.
It shut its own gas-fired peakers, while production from Nova Energy’s McKee plant and Genesis Energy’s dual-fuel Rankine units has also dropped since TCC resumed production, according to EnergyLink data.
OMV says that, once clear of Pohokura, the Boss rig will return to Admiralty Bay in the Marlborough Sounds where it will be loaded on to a heavy lift vessel and leave New Zealand waters.