Yeah of course.
Typical CSG drainage area depends on permeability but is usually 0.5 to 2 km2.
The ellipses in that preso range from 0.02 to 0.09 km2 (calculated by knowing K2 and K3 are 200m from K1). STX have said they are targeting 3 to 5 PJ per well, which given the gas seems to be about 30% CO2 (from Davenport and Chiffre WCRs), means they need 4 to 7 bcf of raw gas per well.
If we assume the whole 60m of Patchawarra is produced and contains about 8 m3/t of gas (which is the gas content I've backed out of STX's presentations before and also fits the isotherms that I later got from the Chiffre WCR) that is a gas in place of ~24 bcf per km2. This is VERY high and this is the effect of your four stories of coal!
Recovery factor we don't know, but if the play works should be somewhere in the range of 50-70%, so let's say 60%. So that's recoverable gas of ~14 bcf per km2.
So if STX wants 4 to 7 bcf and can get 14 bcf/km2 then they need a drainage area of 0.3 to 0.5 km2.
That's 3 to 5 times larger than the current K3 drainage area.
Question is whether those drainage areas are still growing. The presentation has two points, "drainage areas are expanding" and "dewatering task is finite" which seem a bit contradictory to me. If the drainage area is still expanding, you wouldn't know the dewatering task is finite, because a larger drainage area means your connected water volume is growing, which means it's not finite.
As for why K4's drainage is so small despite being a monster frac, there are two possibilities. Either the frac screened out and didn't work properly as somebody posted here at the time (who appeared to know what he was talking about) or it may just be that K4 has only just come online so that drainage area is still growing. Or maybe a bit of both.
If these fracs can't access a large enough drainage area for economic EURs, all is not lost, it just means the development wells will need to be modified. Either bigger or better fracs or, my personal favourite, horizontal wells.
But hopefully those drainage areas are still growing and the current generation of wells can deliver the goods.
(20min delay)