Rediscovering Natural Gas

NPR's Morning Edition on the glut of shale gas hitting the market.

"I used to say the nation is awash in natural gas," Hefner says. "Now I say we're drowning in it."

One area getting new attention is the Marcellus basin, a 400-million-year-old shale formation stretching from New York to West Virginia. That basin alone is believed to hold as much as 500 trillion cubic feet of natural gas, the equivalent of about 80 billion barrels of oil. (There are also large shale gas basins in Texas, Wyoming, Arkansas and Michigan.) It is not clear how much of the shale gas is recoverable, but the new production techniques have boosted all previous estimates.

Shale formations are deep underground — 6,000 feet or more — and the rock is relatively impermeable. Deep drilling is expensive, and in the past the amount of gas that could be reached was not considered sufficient to justify the cost.