New Zealand Oil and Gas says early results indicate that more can be extracted from the Kupe gas and oil field.
The energy explorer, which has a 15 percent interest in Kupe, said tests conducted on the offshore Taranaki field in the last couple of months showed the operator could get more out of existing fields, while previously untapped gas reserves may be accessible.
The listed company said further information to update reserves should be completed by the end of June.
Meanwhile the Kupe joint venture partners agreed to maintain increased gas production of up to 77 terajoules a day, with actual production averaging between 63 to 65 terajoules a day
New Zealand Oil and Gas has a 15 percent interest in Kupe. while the operator, Origin Energy has 50 percent, Genesis Energy 31 percent and Mitsui 4 percent.
Its shares rose 1.5 cents to 63 cents each.