Thanks for the link.
The catch is, even if that is accurate for their average cost of production (some of theirs is now offshore). It does not mean they can replace the amount of oil growth the US has had for the past 5~7 years at that price.
Commodities tend to level out at the price to produce the next unit.
I can sell a barrel of oil at $2 a barrel. But if I don’t have enough supply to meet the market demand, I won’t drive down the price with too small amount.
The Manifa project shows Saudi doesn’t have surplus cheap oil either.