With few exceptions, oil is priced in dollars, even when it is produced in countries with diverse economies and major currencies, rather than petrostates with little going on except oil production.
In the latter case, oil that was priced in the local currency would leave it subject to unpredictable swings in response to global oil prices and the output of the country in question.
As it is, a great deal of oil is produced in countries with little to underpin their economies besides oil, so pricing the black stuff in an international currency makes sense, especially when that currency is that of the primary buyer of the oil concerned. It makes things simple for the buyer and lets the seller take its revenue in a major currency.
The situation of primary buyer of the world's oil is the situation the US has found itself in for quite a few decades now, and in fact the US remains the single largest oil consuming nation. So the fact that oil is priced in dollars is unsurprising.
The result is that virtually every country in the world needs to hold dollars in order to buy oil on the world market. The same goes for large commercial oil buyers. This need for dollars has been a big factor in conferring the premium on the dollar that it has long enjoyed, but is now in the process of losing.
The eurozone economies considered as a whole come a close second to the US in oil consumption, but China probably could tear past both in the coming years.
With the dollar slipping downhill, there is a case for sales to be made in another currency, the most obvious candidate being the euro. Although the oil price moves with the dollar, there is now an unhelpful amount of uncertainty about the nominal price.
Indeed, oil's approach to within spitting distance of the psychologically huge $100 a barrel mark, although underwritten by extremely firm global demand, is as much about the falling dollar as it is about geopolitical uncertainty. Viewed in euros, the