I shouldn't laugh :)

1. There are refineries to refine heavy sour crude in US, in Texas and California, all the capacity is taken by San Joaquin Valley Heavy crude, and Bakken Sour Crude.

2. You can't build additional refinery capacity overnight, last big refinery constructed in the US was 1990s. No one wants to build refinery. It's impossible to get permits, and it's billions of dollars in upfront cost even if you get a permit by some miracle.

3. You don't build refinery capacity for sour crude when you have plenty of regular crude that you can refine for cheap.

4. You don't build additional refinery capacity at $60 oil.

5. There is no market for Venezuelan crude anywhere in the world

PS: the crude Venezuela currently ships is better, lighter crude. Closer to light crude that we have here. They have some of that regular stuff, about 800K-900K b/d of production. This they sell some to US about 30K b/d and rest internationally.