I don't think anyone will respond to this substantially.
And I have a feeling OP won't help us either, judging from
his history, he usually does this, post one line and let others do the detective work.
Oil People, lol. If we exclude the race of "oil people",
there are hundreds of things relate to oil and people who are involved in these that will not help you in other branches, oil exploration, oil extraction, distribution, you need people that drill for oil, search for oil, oil traders, a business that own gas station, and on and on...
Or maybe he just wants to sell some barrels of oil as he did with
the copper