Gas supplies to industrial consumers look set to be partially restored this afternoon as workers repair the damaged Maui pipeline in north Taranaki.
Acting Energy and Resources Minister Hekia Parata told a media conference in Auckland this morning there were adequate gas supplies already in the pipeline north of the breach to allow some major gas users – including dairy factories – to be brought back on line.
”But this will rely on as moderate use of the gas as possible – we still need to conserve it,” she said.
Engineers worked through last night carefully excavating the site of the damaged section of pipeline, digging in increments of just 300mm to ensure no further damage would be caused to the Maui line or to a small Vector gas line just 5m away.
Vector CEO Simon McKenzie said it was hoped the excavation work will be completed this afternoon, at which time work can start on replacing the damaged section of line.
The leak appears to have been the result of a failed weld, he said.
”But it is far too premature to come to any conclusions as to why this happened,” Mr McKenzie said, adding that there have been no issues with the Maui line in its 30-year history.
Gas industry experts face a frantic mission today to find and fix a gasline rupture crippling industry in the top half of the North Island.
The Maui gas pipeline, which runs from the Maui production station at Oaonui and feeds gas to much of the North Island, was closed early yesterday morning when a leak was discovered near White Cliffs north of Urenui.
By noon the closure of the line forced 15 of Fonterra’s northern factories reliant on gas to shut down or only partly operate, and Waikato dairy farmers last night began dumping milk.
Other industries also began to suffer and Employers and Manufacturers Association manufacturing manager Bruce Goldsworthy described the situation as “a bloody disaster”.
At this stage residential supplies are not affected.
Hekia Parata, the acting Energy Minister, travelled to New Plymouth for briefings on the crisis.
Last night pipeline operator Vector could not say when gas would be turned back on. Although the leak has been isolated to a section of pipe near White Cliffs, spokeswoman Sandy Hodge did know the extent or type of damage suffered by the pipe.
“For safety reasons a full excavation of the pipe cannot be undertaken until a detailed site evaluation has been carried out. We need to have a careful look at the pipeline before we bring diggers in,” Ms Hodge said.
She said engineers were working on “every scenario they can come up with” on what type of fix the pipe will need so repairing can begin as soon as the fault is understood.
Ms Hodge said the leak had not posed an explosion risk and as far as she knew it was the first time the pipeline had been compromised.
Yesterday residents near the pipeline on Pukearuhe Rd reported hearing a huge roar of gas being vented but little else.
“They were blowing stuff through there today. It made a hell of a noise. A big roar,” said Ian Besley.
“There was a message on my phone from Vector to say they were doing something. They had some sort of problem.”
Mr Besley said he had heard the pipeline being vented in the past and did not think it unusual.
Neighbor Michael Kuriger said Vector called his wife in the morning to say there had been a major leak and they might be flaring off some gas. But it was only the appearance of a Taranaki Daily News car on Pukearuhe Rd that made him think anything unusual might be going on.
“And I saw a truck go down the end of the road with a steel cage arrangement that they might use to protect men working in a hole. But I didn’t think anything of it. I didn’t link that with what my wife said about work from Vector,” Mr Kuriger said.
The high pressure pipeline was opened in 1978 and is owned by Maui Development Ltd.
The section containing the leak has been isolated from production supplies in Taranaki.
The Maui pipeline is the largest-capacity high pressure gas pipeline in New Zealand.
Commissioned in 1973, it runs from the Maui production station at Oaonui to Huntly. At Huntly it is connected to other pipelines that feed gas to thousands of consumers throughout northern North Island.
It is 84cm in diameter, opened in 1978, and is owned by Maui Developments Ltd.
It is operated by gas transmission company Vector.
It does not only carry Maui gas, but gas from all Taranaki’s fields.