Taranaki's energy industry is celebrating a big increase in the amount of reserves in the region's gas fields.
The celebrations are because the upwards revisions are the result of a combination of world-leading technology and extensive drilling programmes aimed at extracting the maximum gas out of existing fields.
New information just made public by the Government shows the gas reserves have been revised upwards by 31 per cent to now be at their highest level in 13 years.
It also means that the forward supply of Taranaki gas - the amount of gas remaining if no further discoveries are made - has jumped from last year's estimate of less than 12 years, to 14.5 years.
The new reserves estimate, released by the Ministry of Business, Innovation and Employment, has Taranaki's 21 gas fields now combining to offer so-called 2P (proven and possible) reserves of 2642 petajoules. Last year New Zealand's annual gas consumption was 181 PJ.
The biggest news of the recalculation involves one of the oldest gas producers. When the offshore Maui field was discovered in 1969 and developed 10 years later, it was forecast it would be exhausted in 30 years.
But now its remaining proved reserves have been doubled to 133 PJ and its 2P reserves more than doubled to 466 PJ.
And Taranaki's biggest gasfield, Pohokura off the northern coastline, has also benefited from a spectacular revision of its reserves estimates.
It is now forecast that the field's proved reserves are 943 PJ, and its proved and possible reserves 1017 PJ.
All the major gasfields in the region have had their reserves increased. South Taranaki's Kupe offshore field has had its remaining reserves increased from 281 PJ to 298 PJ, and the Mangahewa onshore field has had its reserves substantially increased 368 PJ as a result of a major drilling campaign.
Rob Jager, the general manager of Shell Todd Oil Services which operates both the Maui and Pohokura fields, yesterday described the reserves recalculation as a "nice result".
He was particularly pleased with the result for the veteran Maui field, where the drilling of a series of wells from its two offshore production platforms to find small pockets of gas has been a success.
"There's been some very good work by our staff, and it's all squeezing that little bit more out of Maui. The reserves increase will add several more years to its life," he said.
"Maui used to produce more than 90 per cent of New Zealand's gas needs 100 per cent of the time. It used to produce up to 140 PJ a year, and now it's around 35 to 40 PJ. But that's still a significant amount of gas from a field that was supposed to have been exhausted by 2009."
Jager said the Pohokura reserves recalculation was also pleasing, because it maintained the field's position as easily the country's biggest producer.
The new figures were the result of hard work and the use of leading-edge technology by his more than 400 staff in Taranaki.
- Fairfax Media