Sub salt Helium and Hydrogen, page-19

Looks like they are using a very unrealistic assumption around economic limit there. Look at the chart forecast on that link, it's basically dead by 2030 and everything after that is just a dribble. Even if the field did stay operational until then, the tiny volume of gas isn't going to turn any sort of profit that shareholders will be benefit from. And I'd say they are massively underestimating the economic limit, it will shut in a much higher rate than they are forecasting there.

But this also doesn't include reserves extensions, in reality it should keep going past 2030 as long as they can find another PV13 or PV12. Which I think they can do - they've got a 2 from 2 success with the horizontals so far and they have both been barnstormers. But eventually they'll run out of compartments to tap and that'll be the end.