Ann: Drilling Program Revised to Focus on Near-Term Production, page-13

Is that PV4 or PV5? Both were air drilled by Richter Rig 9 in the 80s. Regardless, neither of them went deep, only around 2500m and finished in the Pacoota. The Pacoota was gas charged in both locations, they just didn't encounter fractures which is why they didn't flow much (1.5 Mmscfd in PV4 and nothing in PV5). They were both located off the crest of the structure which is probably why they didn't find fractures.

Air drilling isn't really a good technique for tight reservoirs. It was popular in the 80s and 90s because they basically had nothing else but there are very limited situations where drilling with air instead of mud actually turns a sub-commercial well into a commercial well. Those situations are usually when there are water-sensitive clays which is not likely to be an issue in rocks this deep, or this old.

Air drilling here now would have nothing to do with avoiding formation damage, it would be purely to get through the depleted zone and it doesn't have to be air, it can be any underbalanced method.

There are actually quite a lot of gas hits in the deeper Amadeus Basin wells drilled from the 60s to 80s, so the gas is there. They just couldn't find good reservoir because of the depth and lack of fracturing. So I think it's actually fairly likely there is gas deep down at PV. What I'm not confident in is that a) the fractures are as pervasive and open down that deep as they are at Pacoota level and b) that there is any matrix permeability at all to provide tight gas support like there is at Pacoota level.

But that's what exploration drilling is about. You don't avoid drilling just because the chance of success is low. If the prospect EMV is positive and higher than other opportunities then you drill the well.