You’ve heard of the Marcellus Shale. You’ve also heard of the Utica Shale. Now get ready to hear about another geologic formation that may “rock” the energy world: the Upper Devonian, a group of shale and sandstone layers that sit above the Marcellus and the Utica. Range Resources said on Tuesday there’s a lot of natural gas trapped in the Upper Devonian layers—so much so that in Pennsylvania, the Upper Devonian may contain as much gas as the Marcellus.
The Upper Devonian geologic horizon, located a couple of hundred feet above the prolific Marcellus Shale natural gas field in Pennsylvania, could contain as much gas per section as the Marcellus layer itself, a top manager at Range Resources said.
Upper Devonian, found at shallower depths than the Marcellus Shale that sits around 6,500 feet deep in southwest Pennsylvania, may hold "probably an equal amount of gas per section…as there is in the Marcellus," Ray Walker, a senior vice president of Range, said late Tuesday at the Independent Petroleum Association of America’s Oil and Gas Investment Seminar in San Francisco. His comments were webcast.
The Upper Devonian horizon "lays right on top of" the Marcellus, Walker said. "The Marcellus in that part of the state is wet, and where it’s wet, [the Upper Devonian layer] will also be wet," he said, referring to the BTU content of the gas. In that area of Pennsylvania, gas often holds abundant with gas liquids.
Walker said Range has drilled a couple of test wells in the Upper Devonian so far and will likely drill the next one late in 2012 because of scheduling. One of the company’s initial wells appears to hold estimated reserves of 4.7 Bcfe of gas, which is "pretty good for the first well out of the box," he said.
"We’ll drill in the thickest, richest part of the Devonian to determine just how much liquids we’ll be dealing with" and how much more gas processing capacity may be needed, he added.*
*Platts (Sep 28, 2011) – Upper Devonian may hold as much gas as Marcellus Shale: Range executive