Thanks, yeah I remember the three well options but it just seems...

Thanks, yeah I remember the three well options but it just seems to me the language used in this announcement suggests the original wellbore option is being ruled out - maybe I'm reading too much into it. It's no big deal, happy to wait and see what Santos decides. The original wellbore is preferable financially but there may be issues around kick tolerance at such huge pressures which may require a new well with casing set deeper.

Thanks for clarification on the carry option. 55-45 is a bit high for CTP so I hope this option is taken up. Conversely 55% is a bit low for STO when they could have 70% of any successful potentially TCF-scale development for what is chump change for them, so it makes sense. But when dealing with majors (and competing priorities within them, including management KPIs) you don't always get the sensible choice.

I don't know much about Zevon other than what's been in CTP's recent announcements but I can add a few comments. At 1600km2 it's beyond massive and into the realm of "gargantuan." On top of that it's just the biggest of around a dozen other potential sub-salt leads CTP has identified so if Dukas and Zevon were to come off you're talking an entirely new major petroleum province. Sub-salt is a special type of play as shown in Dukas, because salt seals are the best in the business and can hold basically any amount of pressure without breaching. This compares with traditional shale seals which can hold up to a certain reservoir pressure before the capillary entry pressure of the shale pore throats is exceeded and then the seal can't hold any more hydrocarbons. Salt seals are also able to trap helium which is rare, helium molecules are so small and light that shale seals often can't trap them effectively.

The risk of these sub-salt targets is actually finding an effective reservoir below them. This is a problem everywhere in the Amadeus and once you start getting this deep, porosity gets even harder to find. On top of that, the 2D seismic over Zevon is so sparse (see slide 12 of the 7 Aug 2020 ann) that it's too premature to really know what sort of structure might be here, which is why they are shooting 500km of extra seismic. It's currently at a stage geologists would refer to as a weak lead, would expect a fairly major revision to the size and shape of the Zevon structure by the time that seismic is shot and interpreted. Hopefully that's enough to upgrade it from a weak lead to a drillable prospect, although to be honest 500km doesn't get you a lot of coverage of a 1600km2 target.

The only well in the area to near the target depth is Mt Winter 1 which was drilled in 1981 and stopped in the salt member - possibly luckily as if they'd gone further they may have hit the same overpressure as at Dukas and may not have been equipped to handle it - from the WCR I see they were drilled with air for most of the well. So the presence of the seal is confirmed but what's underneath is anyone's guess.

So the next update for Zevon should be about the seismic program. The quarterly sounded pretty non-committal on this point but hopefully they will be able to shoot it this year.