EIA raises estimate of proved gas reserves in Marcellus

A new estimate of the volume of recoverable natural gas in the Marcellus Shale puts the amount at 50 percent more than the previous estimate.

According to the U.S. Energy Information Administration's latest estimate, there is 64.9 trillion cubic feet of "proved reserves" locked up in the shale layer.

The estimate is part of its annual report on natural gas and crude oil proved reserves.

As the administration explains, proved reserves are "estimated volumes of hydrocarbon resources that analysis of geologic and engineering data demonstrates with reasonable certainty are recoverable under existing economic and operating conditions. Reserves estimates change from year to year as new discoveries are made, existing fields are more thoroughly appraised, existing reserves are produced, and prices and technologies change."

In the latest figures, based on 2103 data, an increase in natural gas prices over 2012 contributed to an overall increase in proved gas reserves. Overall gas reserves are now at a record 354 trillion cubic feet, according to the administration.

It said that Pennsylvania and West Virginia account for 70 percent of the increase in natural gas proved reserves.

The estimate was reported at about the same that the weekly science journal Nature questioned gas production projections. It cited the work of a University of Texas at Austin researchers who project that production will peak in 2020.

But Penn State geoscientist Terry Engelder said their work assumes current prices. He said that ignoring prices, there is likely 480 trillion cubic feet of gas that is technically recoverable in the Marcellus.

Sam Kusic covers energy for the Pittsburgh Business Times.