Let me explain "Petrodollar" to you.
The term "Petrodollar" has nothing to do with USD. The term simply means the revenue a country makes by selling oil.
People confuse it with how oil is priced (not sold).
Crude oil is priced in USD, regardless of the currency it is traded in. This gives the USD value. Basically, the USD is partially backed by a commodity which is unique among all currencies and effectively makes the USD the world's reserve currency.
So whenever someone gets excited about some country selling oil for Rupees or Rubles, it doesn't mean shit because the buyer still has to pay the equivalent of the price in USD.
Also, in the past, high oil prices would be bad for the US because they'd have to pay more for importing oil and that would increase the trade deficit.
These days, the US imports very little oil due to massive domestic production, so changes in the oil price have little impact on the economy.
The meme that the US would go to war over access to global oil has run its course because the US isn't dependent on oil exports anymore.
Yeah, well. That's why I wrote that this meme is outdated.