How Much Currently Recoverable Oil in the Bakken -- North Dakota, USA

This links you to the relevant discussion over at the Bakken Shale Discussion Group. I have linked it at another posting, but don't want the link to get lost.
Some data points from the opening salvo:

• 6,000 drilling / spacing units within the "mature area" of the Bakken pool in North Dakota (I don't know if this includes the TF pinch out in the southwest, which will be important)
• Spacing units will be 640-, 1280-, and 2560-acre units; most will be 1280-acre spacing units
• So far, about 50% of these spacing units have at least one well; and, thus held by production
• The author thinks that all spacing units will be held by production by the end of 2012 (I could be wrong, but there seems to be a lot of state land yet to be leased; I'm probably wrong)
• In general, operators talk of estimated ultimate recovery (EUR) of 350,000 bbls; I think it's higher
• Author agrees that re-fracking, more stimulation is the wild card. I agree.

Now for the math:

• 6,000 wells x 350,000 bbls = 2.1 billion bbls; two wells (one Bakken; one TFS) is 4.2 billion bbls, which he says is close to the USGS 2008 estimate
• At seven bbls per spacing unit: 15 billion barrels (same ballpark as Harold Hamm's 20 billion estimate; author notes that Harold Hamm includes Montana's ND Bakken in his estimate
• How many wells are we talking about?
• If four wells on average/unit, then nearly 25,000 wells targeting the Bakken/TFS. It could be higher. Regardless, the author says there are currently about 3,500 Bakken/TFS wells drilled.

Long term production:

• 25,000 wells at 40 bbls/day = 1,000,000 bbls per day. And that's at 40 bbls/day.

And we've haven't even begun talking about the Lodgepole, the Tyler, the Spearfish, or the legacy formations.