The US government wouldn't be happy about that. One of the things that supports the US Dollars position in the world is it's near ubiquitous use in the oil trade. It would be beyond huge for Bitcoin though.
Bitcoin is also priced in USD. So pricing oil in bitcoin is not that much different than pricing oil in USD.
That really isn't correct because The Dollar has had a proven track record for a while before the debasement of the currency it was found to be the best option for transactions around the world.