Taranaki's Kupe offshore gasfield is probably a lot bigger than originally thought, its operators say.
Origin Energy has announced that Kupe's proved and probable reserves estimate has been upped to 83.8 million barrels of oil.
That's more than 25 per cent more than the original estimate of the recoverable quantities of gas, LPG and condensate in the South Taranaki field when it first began producing 2 1/2 years ago.
The reserves increase - the second since production started - also means it is almost certain Kupe will continue to produce for longer than the originally forecast 15 to 20 years.
"What this revision means is that we've basically added 2 1/2 years to the life of the field," Origin Energy's New Zealand general manager Chris Bush said in New Plymouth yesterday.
"Everything that Kupe has produced since the wells were opened, we've just replaced."
Kupe has produced 46.6 petajoules of sales gas, 190 kilotonnes of LPG, and 4.7 million barrels of condensate. This meets 15 per cent of New Zealand's total annual gas demand, and more than 50 per cent of LPG demand.
The new reserves estimate means the field's remaining 2P (proved and probable) reserves are 276.4 PJ of gas, 1178 kilotonnes of LPG, and 13.6 million barrels of condensate - the equivalent of a total of 70 million barrels of oil.
Mr Bush said the Kupe field's owners were delighted with the reserves increase, because they had been achieved without any further production wells being drilled.
The field's three existing wells were performing strongly, which gave staff time to make the right decisions on what needs to be done in the future to at least maintain production.
"Our current thinking is that while we will need to drill some more wells some time in the future, it won't be necessary in the immediate time frame," said Mr Bush.
Kupe is 50 per cent owned by Origin, with the other shareholders being Genesis Energy (31 per cent), New Zealand Oil and Gas (15 per cent) and Mitsui E&P Australia Pty Ltd (4 per cent).
NZOG chief executive Andrew Knight said market opportunities were already being looked at for the extra output.
"Such a substantial increase in NZOG's Kupe reserves is a very pleasing result," Mr Knight said.
"We are evaluating market opportunities for accelerating production of the additional gas."
The Kupe gas and oilfield lies 30 kilometres off the South Taranaki coast and has been producing natural gas, LPG and light oil since the wells were opened in early December 2009.
- © Fairfax NZ News
Should the NPDC councillors get iPads?Related story: Tech-wary councillors hedge their bets