New Zealand's estimated gas reserves have been restated early following the Government's decision last month to quit offering any new offshore exploration permits.
Exploration permitting onshore was also limited to Taranaki only.
All existing onshore and offshore exploration permits will be honoured, such as those held in the Canterbury Basin and Great South Basin.
Industry sources have said two oil rigs for exploration are due in the country during the next 12 months, but that had not been announced by any permit-holding companies.
At the time of the mid-March announcements, which took the oil and gas sector by surprise, there was an estimated 11 years of gas still available, which yesterday was pruned down to 10 and a-half years.
Because of recent public interest in the country's gas reserves, the Ministry of Business, Innovation & Employment's annual summary report was bought forward four months, and released yesterday.
MBIE's national petroleum manager Josh Adams said the report showed a 5% decline in ``proved plus probable'' gas reserves estimates during the past year.
He said the gas reserves, defined as quantities which are commercially recoverable, stood at 1985 Petajoules of energy as at January 1, which represented about 10 and a-half years of demand at 2017 demand levels.
The main driver of the decline was a 27.2% decrease in gas reserves at the offshore Pohokura field in Taranaki, while gas reserves at Mangahewa had increased by 44.5%.
The estimate of ``contingent resources'', those not ready for extraction, are within the fields Kapuni, Maui, Pohokura, Mangahewa, Turangi, Maari, Kupe, Kowhai, Ngatoro, Cheal-E, McKee, Moturoa, Puka, Wingrove and Karewa.
Collectively the 15 onshore and offshore fields have between them an estimated 94.7million barrels of crude oil, 61.5million barrels of condensate (light oil), 626,000 tonnes of LPG and 1899.9 Petajoules of gas.
