Oil price will skyrocket when we go into ww3
Yeah, and after it is over, one barrel of oil will cost 50 kopecks
On a serious note though, if we really go into WWIII, I'm afraid the price of oil will soon be irrelevant since there will be neither buyers nor sellers. As I understand it, crude oil is not very useful for lighting as well as heating caves, so we will have to wait for a few millennia until another round of civilization gets well under way
Even the coming nuclear war will have it's winners and losers just like WW2 did... For example, by "erasing" North America rest of the planet will live on with less ecosystems but societies can still function.