Why weren’t these figures included in the reserves data reported...

Why weren’t these figures included in the reserves data reported on Page 16 of the 2015 Annual Report, which suggested there was no 2C reserves at all?

I can't say for sure, but that would be something to ask the company. I don't think it's any indication that they have revoked the 2C resource. More likely either an oversight or some internal company decision not to publish them (due to something such as an ongoing review with NSAI).

Based on the comments in the 21 July 2015 announcement, is it correct to assume with the NEGI FID now done, the PV/Dingo 2C figures should now be added onto the 2P figures

Probably, but not necessarily. It depends on what criteria NSAI have given CTP for satisfying the "market" condition. It also depends what gas price assumptions NSAI incorporate into their NEGI calculations, which is likely to get updated as new info becomes available. If the entire 2C figure satisfies the commerciality criteria (ie is economic at, say, $5/GJ) then the entire lot should become 2P.

If some of the 2C figure is in tighter reservoirs that NSAI considers requires further proof of deliverability, that portion of 2C may stay 2C until NSAI is satisfied. Each PJ of 2C needs to pass both the commerciality cutoff and the market availability criterion before it becomes 2P.

CTP seemed to imply in that July 2015 announcement that NSAI consider that all the 2C in PV and Dingo passes the commerciality cutoff, but I wouldn't bank it until NSAI formally sign off on it as 2P.

Alternatively, it may be that NEGI FID is not enough for NSAI to consider NEGI "certain." They may have another trigger for the declaration of certain and signing off on the market criterion.

Comments in the subject announcement suggest this will be done in Stage 3 of the reserves certification, but what is stopping it being reported now?

Stage 3 involves this deliverability testing I mentioned above. It is expensive and technically more risky. A fair chunk of the Mereenie 2C seems to fall into this category but whether any of PV and Dingo's 2C does, I don't know.

If we don't see the PV and Dingo 2C getting upgraded, it's probably one of the two issues I mentioned above. Either FID doesn't count as "certain" or NSAI has decided it wants more proof of deliverability in PV and Dingo as well as at Mereenie.

Page 8 of the 27 Oct 2015 Investor Presentation notes ~125PJ of 2P available from Storage (PV & Mereenie) via the GAP; this does not appear to be mentioned in the recent 3-stage programme. What is required to firm this up?
I am pretty sure it's already accounted for in the Mereenie 2P figures. Note that Mereenie is listed as 123 PJ 2P on that slide (and in the annual report), and this is a net to CTP figure ie the gross JV 2P total for Mereenie is 246 PJ. If you add the blue bars in Mereenie and Storage you get approx. 110 + 135 = 245 PJ.

So what that tells you is that of Mereenie's gross 2P, ~110PJ is in new reservoirs and ~135PJ is gas they have previously reinjected into producing oil reservoirs. This storage is probably entirely in Mereenie where they have used gas injection to enhance oil recovery for many years.

The reference to "Mereenie and Palm Valley" as storage probably just represents the fact that PV is an ideal reservoir for storing gas in the future. I don't think significant volumes have actually been stored there, but as a very high deliverability, depleted, fractured reservoir, it is a great storage target.

Also the “Cumulative Reserves Growth Plan” contained on Slide 11 of the same presentation suggests a potential cumulative reserves figure of almost 600PJ (assumed by 2018) without any further exploration; is this still valid?

Just looking at those numbers on slide 11, every bar seems to represent a number greater than the 2P target figure. For instance, Mereenie is ~290PJ even though the 2P target on Slide 8 is only 210PJ net. So while I don't know for sure, I suspect all these figures represent 3P or upside figures.

So I would take those numbers with a grain of salt. That's our upside case. The current 2P numbers are our low side case and the target 2P numbers are our best estimate. I don't think it's likely we will see 600 PJ net to CTP from just the appraisal program.