The disassembled rig arrived at Port Taranaki aboard the 6037-tonne Umiavut vessel earlier this week, after a delivery journey from Houston, and is now being readied for transportation to the Maui A platform about 50km off the Taranaki coast.
The specially modified drilling rig is to drill two wells, one an extended reach well, effectively each side of the Ihi fault that runs through part of the northern Maui A lobe.
Drilling is scheduled to start in late January and finish about five months later.
Ihi has been a possible drilling target for the Maui partners – Shell New Zealand, OMV and Todd Petroleum Mining – for years and is just one of several bypassed pockets of gas in the Maui field. It could contain up to 90 billion cubic feet of carbon dioxide-rich gas from the main Maui producing formation, the Eocene-aged Kapuni D sands.
While CO2 is usually an unwanted by-product of gas exploration, it can be useful to global methanol giant Methanex in helping methanol production at its Taranaki plants.
Methanex NZ used to use CO2-rich Kapuni gas at its Motunui and Waitara Valley plants. However, the twin-train Motunui complex is now mothballed, though the valley plant is scheduled to reopen next Friday, for at least two months, using the remainder of Methanex’ contracted Maui gas.
However, gas at Ihi, and any other pockets, will deemed to be new production and outside the ERR (economically recoverable reserves). As such, it is likely to fetch substantially more than gas priced under the existing Maui contract.
The Nabors rig has been specially strengthened for working from a platform in the earthquake-prone Taranaki region. The rig itself weighs about 800 tonnes, the derrick about 617 tonnes, and there is about 900 tonnes of associated equipment.
The Maui support vessel Pacific Chieftain and the newly arrived Pacific Runner will take all equipment out to the Maui A platform. The Pacific Runner arrived from Geelong last month to help with further offshore work for the possible US$600 million (A$816 million) Pohokura project.
The more northern near-shore Pohokura gas-condensate field is now New Zealand’s largest known petroleum resources, with about 900 bcf of gas and 50 million barrels of condensate. It is only a third the size of the original Maui field.
