Ahuroa Gas Storage Hero

Ahuroa Gas is New Zealand’s first underground natural gas storage facility. Gas is injected into underground storage facilities and then withdrawn during periods of high demand.

In 2007, Australian-based Origin Energy bought the Ahuroa gas field (east of Stratford in Taranaki) from Swift Energy. The intention was to build New Zealand’s first underground natural gas storage facility. As part of the deal, Contact paid for the right to own and operate Ahuroa as the underground storage facility and to buy the remaining gas and LPG reserves in the Ahuroa reservoir.

The first phase of the project: to inject gas into the depleted Ahuroa reservoir, 3 kilometres underground, commenced in December 2008. A joint-venture comprising Hawkins and Transfield Worley was awarded the contract for the turnkey design, procurement, construction and commissioning of the second stage of this project – designed to extract the gas from the reservoir as and when required and to improve the existing facility and systems. 

 

ORIGIN ENERGY AND CONTACT'S AIMS

  • To create a more flexible supply of gas: allowing it to be stored in the reservoir during periods of low demand (such as summer) and extracted in times when it is most needed or when the cost of gas is high.
  • To help ensure the security of electricity supply and to better manage that supply during dry years.

WHAT WE DID

We were involved in the treatment of gas and in ensuring the safe operation of the plant by improving the existing facility and systems. Our contract was for the turnkey design, procurement, construction and commissioning of the second stage of this project.

Integrating the Hawkins and Transfield Worley people into a cohesive team to deliver the project was the first task. We opened a project office and gave people opportunities to get to know one-another professionally and socially.

This was a fast-track project, which included procuring and installing:

  • All process equipment and materials across all disciplines. Good planning was vital as we  had to factor in long lead delivery as a result of needing to procure processing equipment internationally.
  • Civil, building, mechanical, electrical and instrumentation works, including environmental controls and compliance with the resource consent.

UNIQUE CHALLENGES

  • The original contract was extended by the addition of a gas vent and flare system. As a result there were more people working within a congested site over the Christmas and New Year period. We achieved this with a superb health & safety record (no serious incidents or accidents)
  • The brownfield gas production site located within the hilly Taranaki terrain, has a water table 1 metre below ground surface with varying summer/winter levels. This complicated the earthworks, which required 1000m³ of cut to fill, 5000m³ of cut to waste and 1000m³ of imported fill.

THE OUTCOME

New Zealand’s first underground natural gas storage facility was opened in May 2011. It enables Contact to store gas during periods of low demand and extract it when demand or the price of gas is high.