Industry report says U.S. natural gas supply abundant

By Jasmin Melvin

WASHINGTON (Reuters) - The United States has over 100 years worth of natural gas supplies, and forecasters have consistently low-balled the amount of the clean-burning fuel trapped in unconventional places like shale rock, an industry group said on Wednesday.

Total U.S. recoverable supplies amount to 2,247 trillion cubic feet, or 118 years worth of supply at current production levels, according to a report funded by the American Clean Skies Foundation and completed by Navigant Consulting Inc.

The foundation is chaired by Aubrey McClendon, the outspoken chief executive of Chesapeake Energy Corp, the third-largest U.S. natural gas producer.

"The size of these shale gas deposits is so enormous that they can no longer be overlooked," said McClendon, whose company is making big bets in shale gas plays like the Barnett Shale in Texas and the Haynesville Shale in Louisiana.

More conservative estimates peg U.S recoverable natural gas supplies at 1,680 trillion cubic feet, or 88 years of supply.

But such estimates ignore the potential of unconventional gas production from shale, tight sands and coal-bed methane, said Rick Smead, co-author of the report and project manager for Navigant.

Forecasts from the U.S. Energy Information Administration "have been significantly outstripped by actual behaviour," Smead said.

Shale formations, sedimentary rock found across the United States that makes natural gas, were once untouchable.