What is up with the leases?

Part of a staff report from reports from EIA and others mentioned. It occurs to me also, is there a difference between a ban and a moratorium?

In a Nutshell

_ On the Outer Continental Shelf, 82% of federal natural gas and 79% of
federal oil is located in areas that are currently open for leasing.
_ Onshore, 72% of oil and 84% of natural gas resources are either fully
accessible under standard lease stipulations designed to protect lands
and wildlife, or will be accessible pending the completion of land-use
planning or environmental reviews.
_ Between 1999 and 2007, drilling permits for oil and gas development on
public lands increased more than 361%.
_ Since 2004, the Bureau of Land Management has issued 28,776 permits
to drill on public land; in that same time, only 18,954 wells were actually
_ Oil and gas companies have stockpiled nearly 10,000 extra permits to
drill that they are not using to increase domestic production.
_ Onshore, of the 47.5 million acres of federal lands leased by oil and
gas companies, only about 13 million acres are actually producing oil
and gas.
_ Offshore, only 10.5 million of the 44 million leased acres are currently
producing oil or gas.
_ Combined, oil and gas companies hold leases to nearly 68 million acres
of federal land that are not producing oil and gas.
_ The 68 million acres of leased, inactive federal land could produce an
additional 4.8 million barrels of oil and 44.7 billion cubic feet of natural
gas each day.
_ That would nearly double total U.S. oil production, and increase natural
gas production by 75%.
_ 4.8 million barrels of oil equals more than six times the estimated peak
production from the Arctic National Wildlife Refuge.
_ Development of and production from the 68 million acres currently
under lease but not in production would cut US imports of oil by one third.

The magnitude of the numbers caught my eye. Does anyone have any knowledge of why the leases are not being developed? And do the numbers actually indicate what is implied, that these leases are not mainly useable so we need more? And where is the best drilling to be done, or is this a pissing contest? I have found no color coded maps that demonstrate this information.

Update: reader juan sends this link Crude oil and key characteristics and Parcel maps of oil and natural gas