The greatest impediment to oil discovery and recovery is government. Great swaths of onshore and offshore oil resources have been placed off-limits by our government. We don't even really know what we have — and what we know is there, we can't get at.
This just shows it is possible to get all the details right and still draw an absurd conclusion.
National oil companies may be inefficient piƱatas but there is no way this is going to change. The potent mix of nationalism, populism and patronage is a near unbreakable iron triangle. Mexico should be the test case. They seem willing to turn into net importers of petroleum products rather than go to market mechanisms with foreign investment.
The green phobias of the US urban electorate may similarly be irrational but they are a political fact of life. If a Republican President with Republican majorities in both the House and Senate couldn't open up the North Slope, what other set of political facts will do the trick? If California going de facto bankrupt couldn't get production restarted in the Santa Barbara Channel, what will?
So while there theoretically may be more oil, the issue of whether there will be effective supply in 10-20 years is quite real.