To date the oil-in-place volume is estimated at 23 billion barrels, page-76

It may be that timing had something to do with the reason that GBP managed to get comprehensive 3D and also their early wells,
GBP got onto the slope in 2011 when Alaska was heavily supporting exploration activity and they managed ~4 plus years of heavily supported activity even if ultimately it killed the company when Alaska placed a moratorium on purchase of tax credits.
But in recognising that 88E could / should have commissioned 3D in 2015 instead of what seems like very limited 2D and majored on Icewine if the 3D supported instead of adopting the strategy that we ultimately did.