Study estimates Utica shale holds gigantic amount of recoverable gas
The amount of natural gas trapped in the Utica shale might rival what drillers hope to extract from its more famous neighbor the Marcellus, a group of geologists said Tuesday.
“It's comparable to the highest number I've seen for the Marcellus,” said Doug Patchen, head of the Appalachian Oil and Natural Gas Research Consortium at West Virginia University and lead editor of a geologic report on the Utica.
The Utica Shale Play Book, the result of a two-year study by federal, state and university researchers, estimates the shale rock formation below the Marcellus holds 782 trillion cubic feet of recoverable gas. Estimates for the Marcellus range from 500 to 800 trillion.
Gas companies last year pulled 4 trillion cubic feet from Pennsylvania shale wells.
“It's going to take many years to drill it up. It will take decades,” Patchen said of the implications of the report. “It's not a flash-in-the-pan thing.”
Estimates of recoverable gas in shale layers fluctuate. In 2012, the U.S. Geological Survey estimated the Utica had 38 trillion cubic feet.
Exploration of the reserves help improve estimates. The study led by Patchen used core samples of rock from drilling operations and production data from companies.
Drillers have been tapping the Utica — which is below the Marcellus — in Ohio since 2012 and have moved east to the northern panhandle of West Virginia and western Greene and Washington counties. A few Utica test wells in northeastern Pennsylvania showed big results, though Patchen said the rock there is riskier.
“The billion-dollar question is how far east will it prove to be profitable and productive,” said Gregory Wrightstone, owner of Ohio Township-based Wrightstone Energy Consulting.
The consortium's study, which was presented to scientists and industry leaders at a conference in Cecil, found gas concentrated in a strip of rock that is sometimes thin, which will challenge drillers in aiming their wells thousands of feet below ground, Patchen said.
“They might need to change that landing zone, or the volume of stimulation they use,” Patchen said, referring to the amount of water used during fracking.
During a gas conference last month, several executives said they hope to reach the Marcellus, Utica and other layers with multiple wells from single pads.
“There are very few fields of that size, but here's at least two right under our feet,” Wrightstone said.
David Conti is a staff writer for Trib Total Media. He can be reached at 412-388-5802 or email@example.com.