Maari oil field closed after wellhead platform crack discovered
The Maari oil field off the coast of Taranaki has been shut down after a crack was found on its wellhead platform.
The 1.4 metre crack was discovered this week in one of the platform's 12 horizontal struts following a scheduled underwater check.
Although there is no risk to people or the environment, oil field operator OMV New Zealand has ceased production and is taking more than 30 staff off the platform, 80 kilometres off the Southern Taranaki coast, while it undergoes repairs.
"The issue is that we have bad weather approaching this weekend, and New Zealand also has a heightened earthquake risk, so we are taking a precautionary approach," OMV's senior vice-president for Australasia, Gabriel Selischi, said.
After scheduled underwater checks began on November 1, the company discovered damage caused by "fatigue" and "combined action of wind and wave".
"The crack was caused by fatigue on level 3, exactly where the wave and wind pressure is greatest," an OMV spokesperson said.
OMV said it was not possible to determine if the platform damage was exacerbated by the massive 7.8 earthquake which rattled much of the country and saw major damage in parts of South Island and Wellington.
Taranaki's oil and gas sector seemed to have escaped unscathed.
Petroleum Exploration and Production Association of New Zealand (PEPANZ) chief executive Cameron Madgwick said the industry's installations were built to high standards and designed to withstand strong quakes.
"Cracks are not common but do they occur," he said.
"You wouldn't expect something like this to happen.
Madgwick said he was pleased to hear of the quick response OMV took.
A 15-day shutdown of the Maari platform was due to begin on December 5, to allow for the completion of a water injection flowline installation.
But when the damage was discovered the pipeline was closed immediately.
The company had yet to determine how long the platform would remain shut.
However the spokesperson said they would need to wait "for the duration of the expected bad weather".
OMV said 34 platform staff were being removed by helicopter. Thirteen left on Wednesday, more were scheduled to leave Thursday and the remainder Friday, Selischi said.
"Production ceased yesterday and the wells were shut-in."
While OMV could not say how much financial loss the company would endure, contracted employees would continue to receive their salary.
The company said "staff and securing the facilities" were its top priority.
Selischi said support vessels and equipment would be on hand shortly.
"Work has started on stabilising the crack and we are actively monitoring it in the meantime.
"We've engaged specialist advisors to assist in this work, and have been keeping both WorkSafe and Maritime New Zealand fully informed," he said.
Selischi said the platform was flexible and had a high level of built-in redundancy.
"There are 12 horizontal struts and the six levels of the structure are supported by four structural legs, consolidated by 20 vertical cross-members."