US sanctions usually work by denying violators access to US dollar flow, US customers, or just punitive taxes on US operations.
So even if they can’t go and grab the oil, they could force the issue: you buy this pretend-not-Russian oil, very well, next time someone pay you in dollars, we take a 75% cut.
But in the current climate, they would like to agree that ahead of time with Europeans who are right now dependant on Russia hydrocarbons for dear life.
Sounds like an easy way for Europeans to get rid of the dollar as a world currency - they would just doing business with third parties in Euros then. Which would have catastrophic consequences on the US economy.
So even if they can’t go and grab the oil, they could force the issue: you buy this pretend-not-Russian oil, very well, next time someone pay you in dollars, we take a 75% cut.
But in the current climate, they would like to agree that ahead of time with Europeans who are right now dependant on Russia hydrocarbons for dear life.