Suspect this "Russian Scientist" resides on Planet Narnia.
Everything in our Universe, such as Earth, is material and as such, finite!!!
Most likely, but let's look at how to get to a supply you will never fully deplete. At $100/bbl, more will become available until that is depleted. At $200/bbl, other marginal reserves become economical to produce...At $500/bbl, even a 10 BOPD well is a nice bit of change. At $1K/bbl, even sketchier formations become major producers, and so on. Theoretically, there will always be
some oil left, because no one will pay what it takes to get it out.