One of the reports adds that the Marcellus reserves that lie below parts of Pennsylvania, West Virginia, Ohio and New York are far larger than recent government estimates, while another said the powerful combination of resource, cost and location is altering natural gas prices and market trends across the nation.

The Marcellus could contain “almost half of the current proven natural gas reserves in the U.S,” a report from Standard & Poor’s issued this week said.

The Marcellus is a gas-rich formation thousands of feet below much of the four states, but current production is centered in Pennsylvania and West Virginia.

Earlier this year, the federal Energy Information Administration sharply lowered its estimates of Marcellus reserves, from 410 trillion cubic feet down to 141 trillion cubic feet. That adjustment was widely reported, including by The Associated Press. [Hmmmm.]

But that lowered estimate doesn’t correspond with actual well production, said Nikhanj. He said their analysis shows that the Marcellus contains about 330 trillion cubic feet of gas, more than double the size of the next largest field in the nation, the Eagle Ford in south Texas.

Some financial firms and critics of gas drilling had suggested that the EIA estimates supported theories that Marcellus production might decline more rapidly than expected, and thus be far less profitable for energy companies. But Nikhanj said a review of actual Marcellus well data shows that on average they’re producing more gas than expected, not less.

But the gas may not be as easy and cheap to extract from shale formations deep underground as the companies are saying, according to hundreds of industry e-mails and internal documents and an analysis of data from thousands of wells.

In the e-mails, energy executives, industry lawyers, state geologists and market analysts voice skepticism about lofty forecasts and question whether companies are intentionally, and even illegally, overstating the productivity of their wells and the size of their reserves. Many of these e-mails also suggest a view that is in stark contrast to more bullish public comments made by the industry, in much the same way that insiders have raised doubts about previous financial bubbles. [Wow.]

“Money is pouring in” from investors even though shale gas is “inherently unprofitable,” an analyst from PNC Wealth Management, an investment company, wrote to a contractor in a February e-mail. “Reminds you of dot-coms.”

Even critics of gas drilling should accept that it isn’t going away, said the head of one leading Pennsylvania environmental group.

“We should realize by now this is not going to be a short play. It’s going to be here, probably for generations, because it’s so productive,” said George Jugovic Jr., president of PennFuture.

That’s a mixed blessing for environmental groups, Jugovic said.

“It lengthens the horizon. It means that we have time to get it right because they’re not going to be in here and out,” Jugovic said of drilling companies, yet “at same time that it raises the imperative of getting our regulations in order.”

Ironically, the vast production coming out of Marcellus wells in Pennsylvania and West Virginia may have given some breathing room to New York, where residents, government officials and gas drillers are engaged in an extended debate over whether to allow the new gas production method known as hydraulic fracturing, or fracking.

Fracking is under moratorium in New York until the debate is resolved.