http://shalebubble.org/drill-baby-drill/
This is a fascinating report. The abstract is below along with a paragraph from the Executive Summary about Shale gas. It comes from the website http://fracdallas.org/ which has so much info (like all the local citizen bans on fracking, the thousands of pipeline accidents, etc) that I don't know where to start.
Abstract
It's now assumed that recent advances in fossil fuel production - particularly for shale gas and shale oil - herald a new age of energy abundance, even "energy independence," for the United States. Nevertheless, the most thorough public analysis to date of the production history and the economic, environmental, and geological constraints of these resources in North America shows that they will inevitably fall short of such expectations, for two main reasons: First, shale gas and shale oil wells have proven to deplete quickly, the best fields have already been tapped, and no major new field discoveries are expected; thus with average per-well productivity declining and ever-more wells (and fields) required simply to maintain production, an "exploration treadmill" limits the long-term potential of shale resources. Second, although tar sands, deepwater oil, oil shales, coalbed methane, and other non-conventional fossil fuel resources exist in vast deposits, their exploitation continues to require such enormous expenditures of resources and logistical effort that rapid scaling up of production to market-transforming levels is all but impossible; the big "tanks" of these resources are inherently constrained by small "taps."
Shale gas
Shale gas production has grown explosively to account for nearly 40 percent of U.S. natural gas
production; nevertheless production has been on a plateau since December 2011 -80 percent of shale
gas production comes from five plays, several of which are in decline. The very high decline rates of shale
gas wells require continuous inputs of capital-estimated at $42 billion per year to drill more than 7,000
wells-in order to maintain production. In comparison, the value of shale gas produced in 2012 was just
$32.5 billion.
The best shale plays, like the Haynesville (which is already in decline) are relatively rare, and the number
of wells and capital input required to maintain production will increase going forward as the best areas
within these plays are depleted. High collateral environmental impacts have been followed by pushback
from citizens, resulting in moratoriums in New York State and Maryland and protests in other states.
Shale gas production growth has been offset by declines in conventional gas production, resulting in only
modest gas production growth overall. Moreover, the basic economic viability of many shale gas plays is
questionable in the current gas price environment.