US unconventional gas resources underestimated, study finds

The United States has 2,247 tcf of natural gas reserves, enough to last 118 years at 2007 demand levels, a new study has said.

Nick Snow
Washington Editor

WASHINGTON, DC, July 30 -- The United States has 2,247 tcf of natural gas reserves, enough to last 118 years at 2007 demand levels, a new study has said.

The study, released by American Clean Skies Foundation (ACSF) and Navigant Consulting Inc., explains why existing forecasts have underestimated unconventional natural gas potential from tight sands, coalbed methane, and gas shale formations.

"New technologies have allowed the rapid emergences of gas shales as a major energy source representing a truly transformative event for us energy supplies," said Aubrey McClendon, ACSF chairman and chairman and chief executive officer of Chesapeake Energy Corp.

"The assessments and estimates on natural gas supply are very impressive and have, frankly, caught industry forecasters off guard, said Richard G. Smead, one of the study's coauthors and overall project manager for Navigant.

The growth in proved US reserves has come almost exclusively from natural gas sources that have been termed "unconventional" but today are a large part of the future supplies. For example, proved CBM reserves are nearly 20 tcf today, up from 11.5 tcf in 1998, and less than 4 tcf a decade earlier. Proved shale reserves have grown to 15 tcf today from 3.5 tcf in 1998. And tight gas proved reserves today total 80 tcf up from roughly 36.6 tcf in 1998.

Two US house members who have cosponsored a bill to increase natural gas vehicle use said the study shows that a dramatic change is under way. "We're going to have a paradigm shift in the automobile business. You don't often get a hat trick in politics," said Rep. Rahm Emanuel (D-Ill.), chairman of the House Democratic Caucus. "Natural gas vehicles solve three problems: the environment, the economy, and energy security," he said.

"This legislation is personal to me," said Rep. Dan Boren (D-Okla.). "The Woodford shale play is in my district, which is one of the poorest in the country. The natural gas industry is spending money there, leasing property and hiring people. It's helping our economy. This changes the US energy debate," he said.

Smead said Navigant spoke to 114 producers covering 90% of North America's total gas supplies. Sixty-six of these provided substantial and meaningful information about the resource base and ultimate production levels.

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