From the 2012 Dept of the Interior report on oil and gas drilling: "There are approximately 26 million leased acres offshore and over 20 million leased  acres onshore that are currently idle – that is, not undergoing exploration, development, or production."
Any idea why? Because it is too expensive to drill on them at the current price of oil.  This idea that opening even more acreage to drilling will sudenly cause a boom, and the US will get tons of jobs AND cheap gas are either uninformed or willfully blind.