Thack,
Can you shed any light on this?
I don’t know what to add to it.
You have to understand, early estimates before much of a formation are drilled and flow tested, are very much on the educated guess side.
In spite of all the advances of seismic measurements, you really don’t know what is there until you get some holes spread around connected with pipe and let it flow for a while.
But the technology changes in the last couple decades have made great changes in what is economical to produce. I think there is so much gas from shale in the US that their will be a continued reduction in drill gas and more focus on the higher dollar oil from shale fields.
From that same referenced report:
http://www.eia.gov/forecasts/aeo/er/pdf/0383er(2012).pdf
Much of the growth in natural gas production is a result of the application of recent technological advances and continued drilling in shale plays with high concentrations of natural gas liquids and crude oil, which have a higher value in energy equivalent terms than dry natural gas. Shale gas production increases from 5.0 trillion cubic feet in 2010 (23 percent of total U.S. dry gas production) to 13.6 trillion cubic feet in 2035 (49 percent of total U.S. dry gas production)
The United States is projected to become a net exporter of liquefied natural gas (LNG) in 2016, a net pipeline exporter in 2025, and an overall net exporter of natural gas in 2021. The outlook reflects increased use of LNG in markets outside of North America, strong domestic natural gas production, reduced pipeline imports and increased pipeline exports, and relatively low natural gas prices in the United States compared to other global markets.
One last thing to add:
This report gives a decent introduction to early estimating practices and how they develop.
http://www.eia.gov/analysis/studies/usshalegas/