New Zealand's remaining gas reserves are in gradual decline. The current position reflects the absence of new field discoveries, declining annual production, and a number of significant fields nearing the end of economical production.
April update: This new data page provides information on Gas Reserves.
Gas Reserves
Although there are currently 22 active petroleum mining fields, six main fields account for approximately 97% of gas production. Of the six fields, three are nearing the end of economic viability, and only the Turangi and Kowhai field is showing reserve figures that are not currently in decline.
Each gas field is different, with different variables impacting on the success of whether reserves will be developed.
Gas field owners make an assessment of the Proved reserves (1P) and Proved + Probable reserves (2P) at their fields (see definitions below). It is important to understand that the 2P reserve figures also include the 1P reserves in a given year.
An estimation of 1P and 2P reserves in New Zealand's six major gas fields is presented in the graphs below.
The Society of Petroleum Engineers defines proved reserves as "those quantities of petroleum anticipated to be commercially recoverable by application of development projects to known accumulations from a given date forward under defined conditions”.
Proved Reserves (1P) are reserves that have an at least 90% chance to be produced over the lifetime of a field. Proved + Probable Reserves (2P) are reserves that have a 50% chance or better to be produced over the lifetime of a field.
More information on reserve definitions published by BP in 2021 can be found here.
MBIE note that the reserve figures are volumes reported by each plant operator in the Annual Summary Reports.