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.
Range, a virtually unknown Fort Worth, Texas, operator when its Marcellus results began to reach the industry's radar screen around 2004, now is producing north of 200,000 Mcfe/d from the Marcellus, mostly from southwest Pennsylvania, although it also has acreage in northeast Pennsylvania. The company is on target to exit this year with 400,000 Mcfe/d of Marcellus production and hopes to end 2012 at 600,000 Mcfe/d, said Walker.
In addition, southwest Pennsylvania also contains the much-touted Utica Shale zone. Unlike its Ohio counterpart, the Utica horizon tends to be gassy in Pennsylvania, said Walker. Range has drilled and completed the Utica's first horizontal test in the Appalachian Basin with an initial gas production rate of 4,400 Mcf/d, comparing favorably with Marcellus-zone wells.
Range has said a "significant" portion of its acreage is prospective for the Utica Shale. In southwest Pennsylvania, the Utica sits below the Marcellus -- as much as 2,000 feet below it in certain places, said Walker.
"It looks very productive -- 120-140 Bcf per square mile," he said. "If you start adding the three plays together in southwest Pennsylvania, you could have as much as 300 Bcf per square mile in that area, which is pretty substantial reserves."
