Its not the amount of petroleum underground that's important. The deciding factor in any drilling decision is the estimate of the permiability of the rock that the petroleum is encased.

For example, there's more petroleum in North Dakota and Montana than in all the Middle East. The problem: the Bakken Formation shale has a 5% permiabilty, that means the petroleum flows like molasses. Contrast this with the Ghawar in Arabia that has a 95% permiability.

The oil is down there, but good luck trying to get it out. The very fact that someone is actually drilling down 3000 meters into the Bakken Shale tells us about desperation on the part of domestic drillers.

There are about 50 wells in the Bakken, costing 5 million apiece to complete. The average cost of predicted production is estimated at $60  a barrel, not exactly a bargain when the Ghawar produces at a cost of $4.

Sixty Dollars a barrel now seems to be the target production cost for any reserves left on the North American continent, including ANWAR,Canadian Tar Sands, or anything else approved for drilling in the U.S..

There are about 200 million acres that the continental U.S. that are preapproved for drilling right now, but no one seems to want to take the reins. ANWAR itself is just a guess as to exactly what the true figures might be if drilling there is approved. ANWARs' value seems to be as a political football more than an actual reserve.

A good way to lose your money in petroleum exploration is to invest without knowing all the facts. My guess is that high petroleum prices are here to stay.