New Zealand's natural gas reserves as of Jan. 1 declined by 27%, compared with last year, according to data released by the Ministry of Business, Innovation and Employment on Thursday.

In 2024, natural gas proven plus probable reserves shrank from 1,300 petajoules to 948 petajoules. Annual gas production is now forecast to fall below 100 petajoules by 2026.

The reduction in natural gas reserves was largely driven by field operators reducing their estimates of gas readily extractable in the ground by 234 petajoules, Karlene Tipler, the ministry's head of data service delivery, said. The remaining reduction of 119 petajoules reflects the portion of gas reserves that were used during the year.

The contingent natural gas reserves, gas that exists in the ground, but cannot be extracted due to current economic or technical conditions, increased by 184 petajoules or 10% year-over-year.

A significant contributor to the figure was the Pohokura field, which included a large volume of previously unreported contingent gas.

The Turangi field's reserves were revised upward by 22 petajoules.

Natural gas delivered from gas fields also reduced 22% in 2024, compared to 2023, primarily driven by the Pohokura, Maui, Mangahewa, and Kupe fields.