The crude's heavy and sour. Diluting agents required to refine it are not getting through due to sanctions.
Their communist friends and fellow dictators not helping them out? Or are you buying into Maduro's claim that all of the Venezuela's problems are caused by the US?
No, that's a horrible dictatorship operating over decades for you folks. Venezuela is no more indicative of socialism then Somalia is indicative of limited government, free markets, and freedom from gun control. The whole "we'll all be up like Venezuela..." trope is utterly moronic, you're better than that!