Though serious drilling only began five years ago, the sheer volume of Marcellus production suggests that in some ways there's no going back, even as New York debates whether to allow drilling in its portion of the shale, which also lies under large parts of Pennsylvania, West Virginia and Ohio.
The top spot for the Marcellus "doesn't surprise me," said Jay Apt, a professor of technology at Carnegie Mellon University. "But will it lead to industries that spring up to use that gas?" he asked, adding that much of the bounty could also end up being shipped to Canada, the Gulf Coast or overseas.
In 2008, Marcellus production barely registered on national energy reports. In July, the combined output from Pennsylvania and West Virginia wells was about 7.4 billion cubic feet per day, according to Kyle Martinez, an analyst at Bentek Energy. That's more than double the 3.6 billion cubic feet from last April, and represents over 25 percent of national shale gas production.
That's neck-and-neck with production from the Haynesville region in Arkansas and Texas, but new drilling permits there have declined sharply.
The Powell Shale Digest, an industry newsletter based in Fort Worth, Texas, concluded that a recent report from the U.S. Energy Information Agency means "it is reasonable to assume" that the Marcellus has or will soon pass Haynesville as the top producer.
The Marcellus Shale is a gas-rich formation of rock thousands of feet below ground. Advances in drilling technology made the shale accessible, which led to a boom in production, jobs and profits, and a drop in natural gas prices for consumers. But there are also concerns about pollution and impacts to roads and other public services.
Apt said having a natural resource bounty is one thing, and using it wisely is another. The current wholesale price of natural gas is about $3 here, but $12 or more in Europe and Japan.
"It's clear people will want to export" the Marcellus gas, Apt said, adding that such an outcome could lead to what economists call "the resource curse," which is when the general population hardly benefits, while a few get very rich.
But Apt said there are some hopeful signs, such as the Shell Oil Co. plan to build a petrochemical plant to turn Marcellus gas into other consumer and industrial products including plastics. It's widely believed that if Shell moves ahead with plans to build that $2 billion plant north of Pittsburgh, other small industries will follow.
For now, it looks like the Marcellus region will be in the top production spot for several years, analysts say. While drilling has slowed, there were still 288 new well permits issued in May, and over 1,200 for the first five months of the year, according to data from LCI Energy Insight, an El Paso firm that tracks national energy trends.
Martinez noted that several major Marcellus region pipeline expansions are scheduled for completion this fall, which should allow production to grow even more, and make it easier to ship gas to other parts of the northeast.
That could boost wholesale prices, he said, and keep energy companies focused on the region.
"Long-term, being able to move the gas out of the region will give some support to those prices," Martinez said.