Does the lifting of oil sanctions on Iran actually give them $14B dollars?

It's been stated by more than a few people: "The administration on Friday lifted sanctions on Iranian oil currently at sea. The lifting of sanctions will enable Iran to sell about 140 million barrels of oil, worth about $14 billion." It seems to me that if all that oil is already "at sea" then it must be going somewhere to be sold. Does our lifting of sanctions on it mean that the US will now be able to buy it and therefor the price Iran is paid for it will go up? Is the $14B the difference between the sanctioned and non-sanctioned price? Or is it a misleading number?