The probability of not fracturing and remaining propped open as...

The probability of not fracturing and remaining propped open as predicted remains the greatest risk. The problem being the composition of the rock is variable, crack propagation is predictable when the rock properties are consistent, but the cracking will stop or alter when a composition change is encountered. We know the composition changes at IW1 from the variable permeability encountered in the core samples. Much of this is due to the presence of tempestite layers of variable thickness (Typically ranging from 1 to 30cm in other plays)
Imagine a multi layered cake with the icing being much softer and more permeable, how do you fracture reliably through the icing and stay on track when much of the fracking fluids and proppants will travel down the easier flowing icing layers.
88e have designed a fracture stimulation with this in mind, hence the single stage multi perforation cluster stimulation, which should induce crack propagation throughout the targeted zone simultaneously radiating out, above and below the multiple layers of icing. But it still has to happen as designed that is the main risk
It would be unrealistic to expect the perfect frack on a first attempt, its a learning process. But it only has to be good enough, so I am certainly optimistic given the expertise of the team.
On the upside these pesky tempetsites have exceptional permeability and potentially can feed into the fractured zone from further out leading to lower decline rates.