Virtually all of the Venezuelan oil is being refined in Texas. Since most of the world refineries work with sweet light crude, Chavez will have a very tough time selling his heavy sour crude to ANYONE other than us. It's a simple matter of economics, as most countries would instead prefer to pay more for sweet light than retool their refineries to accomodate Chavez. He can run around with his mouth wide open, shout imprecations and threaten Uncle Sam, but guess what, if we stop refining his oil, his gravy train is over.
But doesn't the deal with China mean that not only are China building refineries for Venezuelan oil in China , they are also building them in Venezuela . Doesn't part of the deal with Brazil mean that Brazil is building refineries for Venezuelan oil , same with India and every other country he has been doing oil deals with over the past few years .
He may be an idiot , but he isn't completely stupid , he plans ahead .

Who is going to transport it in the first place, the panama channel isn't ready for the biggies would hardly be worthwile for China or India or whatever, they can get it elsewhere with these cool things called pipes.
Ah of course , that would be the deal with China building new Pacific ports and oil terminals in South America with pipelines from Venezuela .