Marcellus natural gas production soared from May 2011 to May 2012. In fact, it doubled, rising from 3.37 to 6.85 billion cubic feet per day. Bloomberg News reports that the foregoing and other facts will be reported to Congress on August 1 by the US Department of Energy. http://fuelfix.com/blog/2012/07/24/u-s-says-shale-gas-output-rose-24-in-may-from-year-earlier/.
As of May, the Marcellus provides more than 10% of America's gas; has 40% higher production than the Barnett Shale; and produces a tiny bit less than the Haynesville Shale's 6.92 bcf/d.
Indeed the Marcellus accounts for about 25% of all the shale gas produced in the US, and shale gas provides about 37% of all of America's gas.
From all angles, the Marcellus is a big, huge deal. It is the motherload of US gas production and reserves.
The extraordinary Marcellus production jump from May to May took place, despite the gas drilling slowdown during most of that time. Why? More and more gas wells drilled are being hooked to gas pipelines and sending gas to market. And while new gas well drilling has slowed, it has not stopped.
One big advantage of the massive Marcellus production is that now natural gas in Pennsylvania costs less than it does in Louisiana at the Henry Hub. See johnhanger.blogspot.com/2012/07/stunning-fact-pennsylvania-gas-price.html.