2025 Gas Reserves

The 2025 annual gas reserves data published today.

A quick update because its hot off the press today and it’s the most urgent energy issue we have at the moment.

Each year MBIE (Ministry of Business Innovation & Employment) publish the updated petroleum reserves data.

This year’s data reinforces what we already know. Gas reserves are declining fast.

The media are reporting on the 2P numbers which is why the numbers in this article are different. I’m more interested in the 1P numbers. To explain why I first need to explain what these numbers mean.

The amount of gas remaining in a particular field is known as “reserves” and are rereferred to as “proven, probable, possible” or in short “P”.

• 1P reserves = proven reserves (both proven developed reserves + proved undeveloped reserves).

• 2P reserves = 1P (proven reserves) + probable reserves, hence "proved AND probable."

• 3P reserves = the sum of 2P (proven reserves + probable reserves) + possible reserves, all 3Ps "proven AND probable AND possible."

The reason I use the 1P is because the 2P and 3P are increasingly unknown and would need investment to recover (drilling typically).

Going from 1P to 3P is like going from kind of knowing, to really hoping.

So, what are the latest numbers.

The 1st of Jan 2025 1P reserves total (arithmetic) is 599.27 PJ.

The 1st of Jan 2024 1P reserves total (arithmetic) were 806.56 PJ.

Last year the total production was 119PJ meaning that 88.29 of the 1P reserves were written off (overestimated the previous year). Which shows the unpredictable nature of even the most reliable 1P profile.

Also, very importantly the deliverability has dropped from 17.6 TJ/hour to 13.7 TJ/hour.

So, we essentially have less gas in the bank, and we can’t with draw it as fast. All of which will make gas constraints and associated industrial curtailment even more acute.

Much more to come.

MBIE have published the last ten years of reserves data with this year’s data which is really helpful. Nice work MBIE.

Over the next week or so I’ll break down this data so we can look at a few things like which fields in the 1P are producing and by subtracting the inactive fields we will get a more accurate picture of what reserves we actually have. I’ll also look at the 1P vs 2P of the active fields and see what the potential short-term upside might be and assess the viability of getting these 2P reserves.

I’m also working on a piece with an energy strategy for New Zealand as a follow up to Rudderless.

So much to cover, so little time.

Thanks to everyone reading and following this Substack, it’s great. I appreciate all your comments, especially the critical ones. If you’re enjoying these updates hit the like button and share far and wide, it seems to tickle the Substack algorithm and helps to get the word out there.

Larry