From "Joint Operating Environment 2010" by the US Department of Defense (p.29)
To generate the energy required worldwide by the 2030s would require us to find an additional 1.4 MBD every year until then. During the next twenty-five years, coal, oil, and natural gas will remain indispensable to meet energy requirements. The discovery rate for new petroleum and gas fields over the past two decades (with the possible exception of Brazil) provides little reason for optimism that future efforts will find major new fields.
At present, investment in oil production is only beginning to pick up, with the result that production could reach a prolonged plateau. By 2030, the world will require production of 118 MBD, but energy producers may only be producing 100 MBD unless there are major changes in current investment and drilling capacity.
By 2012, surplus oil production capacity could entirely disappear, and as early as 2015, the shortfall in output could reach nearly 10 MBD."