Apparently, there is vanadium in petroleum wastes, as well as iron wastes and other industrial wastes. Vanadium occurs naturally in the petroleum and their on ore. I don't know the answer to your question, but I'll make a guess. Vanadium is one of the essential elements in our bodies. Do you know what oil comes from? I think it comes from all the dead dinosaurs and plants and other animals. That's my theory - vanadium is in oil because it was in the plants and animals that decomposed into oil millions of years ago.