Ahuroa gas field converts to underground storage

Jan. 30, 2009
The Origin Energy-Contact Energy partnership's Ahuroa gas field in New Zealand's onshore Taranaki basin is undergoing the first stage of its transition to a gas storage facility.

Rick Wilkinson
OGJ Correspondent

MELBOURNE, Jan. 29 -- The Origin Energy-Contact Energy partnership's Ahuroa gas field in New Zealand's onshore Taranaki basin is undergoing the first stage of its transition to a gas storage facility.

The $120 million (Aus.) transformation project is receiving most of its gas through Origin's Waihapa production station. The aim is to achieve minimum operational pressure in the Ahuroa reservoir by August this year.

Stage 2, which will include full injection and extraction functionality with three injection wells and two extraction compressors, is scheduled for completion before the June winter of 2010. At that point Contact will be able to inject or extract as much as 100 terajoules/day (93 MMcfd) of gas.

The field will then play a critical part in enabling Contact to store gas during periods when it has access to lower-cost power generation alternatives such as hydro and geothermal electricity. The more expensive gas option will be used to operate fast-start plants to cope with peak loads.

The plan is for Contact to store gas from a number of sources, including near-shore Pohokura field as well as potential future LNG imports.

Origin bought Ahuroa field among a number of other New Zealand gas assets in 2008 for a total of $136 million (Aus.) from Swift Energy. Contact contributed $43 million of that sum for the right to own and develop Ahuroa as New Zealand's first underground gas storage facility and towards purchase of the field's remaining gas.