The question on my mind is what else will this freed up oil will be used for? One area could be cheaper fuel for aviation? More plastics? This of course ignores the environmental cost of continuing to use oil.
If oil prices fall too low, Persian Gulf and Russian borders become unstable and from there its any ones guess, how things would take shape.
Energy is heavily interlinked with geo-politics and if Persian Gulf is out of the game even for few months - millions of people will starve to death. The only silver lining is that North America is self-sufficient in ONG for the coming years, and that is not the case for much or Europe, Asia and Africa.