It's not so much oil running out.
It is the easy oil running out, i.e. oil which has a high energy return on energy input. As humans we like to pick the low hanging fruit first. Coal mining is a good example, we go for the stuff on the surface, then open cast, then dig shafts.
Ghawar field in Saudi is an excellent example, it is 150 or so metres down on dry land. You can shift big machines on dry land.
Deep water horizon gulf of Mexico is an excellent example too the oil was in deep water, which presents logistical challenges and deeper down meaning more work is required to get it to the surface.
The Russian find is 300 or so metres down and thus it is easy oil.