Oil might last a lot longer than you think at first. Even at the proven oil reserves of 2016 the oil would last for 47 years (https://www.worldometers.info/oil/). Additionally, new reserves could be found. Another potentially very large source of oil is coal. You can make oil from coal via the Fischer-Tropsch technology. As there already are considerably more proven coal reserves than oil reserves, this would probably push out the point of "no oil left" a lot further.