I'm quite certain if America cared about Venezuelan oil, then the Neocons & Demhawks would have found a reason to invade already. Shit, there was more direct evidence that Chavez put MANPADS and bomb-making materials into the hands of the FARC terrorists in Colombia (a US ally) than any evidence that Saddam provided material support to Al-Queda.
America cares about Venezuela only in the head canon of Maduro, who simultaneously thinks the US is trying to kill him at every turn, but also thinks the US is somehow is too scared to just fucking Soleimani him and be done with it.