If demand dropped, initially supply would drop offline as prices could no longer support the more difficult wells rather quickly. And as actual production falls, the amount charged that the market could bear (if the market was mostly the non-fuel, high-value uses) could be significantly higher than what we see today. A scary time to be an investor in an oil company, absolutely. But taken in the broad view, leaving oil for later will almost certainly enhance total future potential profits, if not the rate of profit per unit time.