Getting back to an earlier post, most of the world's proven oil reserves are owned by national governments. More precisely, corrupt governments that are democratic in name only. Do you think that these governments maintain their reserves better than a private company would?
The best analogy I can think of is this: Imagine if the US government was responsible for growing our food crops. Do you think the government would be efficient? Do you think they'd provide accurate reports on how many acres were planted, how many acres are fallow, and how much potential cropland lies unused "in reserves"?
You can see how messed up our farm system is, and that's with a fairly open process (notwithstanding meddling from Congress.) Imagine if the President was unelected, and he hand-picked some uneducated cronies to make decisions on how to best grow our nation's food? This is how the petrothugs run the national oil companies.
What's going to happen next is oil will take another violent dive. The markets are held up by speculation only. This time prices won't rebound. The petrothugs will then call for/beg western companies to revive their fields. Oil will stay down for a very long time.