But that is how many scales of production lower than current production? Keep in mind that all the cheap, easy, light, sweet crude that is just a couple feet b

But that is how many scales of production lower than current production? Keep in mind that all the cheap, easy, light, sweet crude that is just a couple feet below the ground is LONG gone. So every oil development is a ... BIG ... industrial project. Tar sands, fracking, shale oil, deep sea drilling, mega mega mega tankers. First of all, that implies a larger amount of upfront investment. No deep sea oil until you build the huge drilling platform. But if the return on investment drops sufficiently (or risk profile, etc), then the projects don't start. So the supply starts to tail off. So refineries don't need to be as big. But... they are ALREADY that big, so the maintenance is a semi-fixed cost. So the costs go up. The financing get riskier. Can you see the spiral I refer to? The oil industry has developed with a certain degree of demand and demand growth to continue its expansion, as extraction has become more difficult. Now, I think based on my VERY limited research that the shale oil in the dakotas has a certain floor, and production will continue for decades. But other parts of the world may not have such guarantees, especially if the old US Navy decides to stop securing everyone's oil (insert the cheeto talking about everyone freeloading off the USA).