Natural Gas Plays of the Knox Group in the Appalachian Basin: A Significant Element of the U.S. Department of Energy Atlas of Major Appalachian Gas Plays

Abstract

Oil and gas have been produced from the Knox Group in the Appalachian basin since the early 1990s. However, only since the 1960s have significant volumes of hydrocarbons been produced. Porosity development along the Knox unconformity is the dominant geologic control for hydrocarbon migration and entrapment. Other important controls include stratigraphy, diagenesis, paleokarst, structure, and fractures. Cumulative production is ultimately, controlled by the reservoir conditions characteristic to each play. The two most significant Knox plays in terms of total cumulative gas production are (1) the Lower Ordovician-Upper Cambrian eroded shelf sandstones known as the Rose Run sandstone in Kentucky, Ohio, and Pennsylvania, and the Theresa sandstone in New York, and (2) the Lower Ordovician-Upper Cambrian paleokarstic carbonates known as the Beekmantown dolomite in Kentucky, Ohio, and Tennessee, and the Copper Ridge (Trempealeau) dolomite in Ohio. Minor volumes of gas have been produced from fracture and paleokarstic carbonate plays in the Know dolomite of Kentucky, Tennessee, and Virginia, and from localized sandstones of the Copper Ridge (Trempealeau) in Ohio. Some individual wells in Ohio have produced more than 1 billion ft[sup 3] of gas from the Beekmantown, Rose Run, or Copper Ridge (Trempealeau). Cumulative gas production from all the Knox playsmore » in the Appalachian basin has been in excess of 60 billion ft[sup 3] of gas. The Knox Group plays are currently the most active exploration targets in the basin.« less