Their ships seem to have the range to reach a 1600-2000 mile out-and-back radius, but I wonder if they would do very well out into the Atlantic. The other factor, besides their range limit and single-digit numbers is wear and tear. The USN could, as you posted, track sanctioned tankers until they are out of Venezuela's range. But being able to escort one or two ships at a time means curtailing tanker sailings or many sanctioned tankers being unescorted. Like I posted, the Venezuelan Navy is a paper, possibly also sickly, kitten.