The US is not a petrostate. Petrostates are defined not just by the large amounts of oil and gas they extract but the relative absence of other economic activity and the dependence of the state on that money.

42% of Saudi GDP is petroleum. 35% of Kazakh GDP is petroleum. 8% of US GDP is petroleum.

It's quite mind blowing !

Quite frankly, I always knew oil / gas was big in US, when I realized it's THE largest petrostate, it felt weird.