For what it's worth, I'm hearing repeated rumours from multiple sources that Santos is really going to do a deal with GOG/EPE over Smegsy.
CO2 is probably around 15-20% in Smegsy, so it's probably safe discount the flow rate by 20% ("shrinkage").
I'd be expecting a price closer to $2.50 than $3 for gas.
Ian Whitchurch