If in fact they can keep capex to US$2.0B (based on the Feb 2022...

If in fact they can keep capex to US$2.0B (based on the Feb 2022 STO estimate) that would be very impressive. Given the way capex blowouts have occurred across the globe in the last couple of years, I imagine this is assuming the revised approach, i.e. repurposing an existing FPSO and drilling fewer wells to start, relying on cashflow to do the others. If you assume say a 15% capex blowout (just to be safe) it'd look something like this, all at 0.65 ROE:

Project capex: US$2.3B
CVN share: US$230M
less CPC carry: US$90M
Balance US$140M
less CVN cash 31/12: US$114.4M
Debt required: US$25.6M

Obviously they can't erode their cash down to zero and there's corporate costs, time value of money etc that has to be factored in, but that's my rough guide.