The Tui oilfield, off the Taranaki coast, is almost a third bigger than thought – news that pushed up partner New Zealand Oil and Gas’ share price 11 cents to $1.12.
The oil reserves for the field are now put at 41.7 million barrels, up from the previous estimate of 32 million barrels. Getting about half of the extra reserves will involve drilling one more well, which is expected to cost tens of millions of dollars.
A large part of the reserves will come out of the field in the next two years, but smaller amounts over at least the next decade.
New Zealand Oil & Gas has 12.5 per cent of the field.
Its share of reserves has moved up to 5.2 million barrels, potentially worth about $600 million over the life of the field if oil prices remain at such high levels.
The increase puts NZOG in an even better position to carry out plans to expand, through a “growth strategy”.