If you're still one of those who feels that the oil companies need to maintain their high profit margins due to "exploration" and other "research and development" programs, you need to rethink that line of reasoning.
Yes, if one does their research they will learn that Global Discovery peaked in 1962. In 2003 and 2004, not a single field over 6 million barrels was found, to put that in perspective, the world uses 85 million barrels a day.
The companies are no longer doing exploration, because everything has been found and tapped. You can check their expenditures yourself if you don't believe me.
Do you know how companies are appearing to "get" more oil? Mergers. They then claim the reserves of that company as their own.
Here's a nice little graphic to maul around: