Mining Publication: Geology and Methane Content of the Upper Freeport Coalbed in Fayette County, Pa.

As part of the Bureau of Mines methane control program, the Upper Freeport coalbed was studied in Fayette County, Pennsylvania, where this coalbed lies about 650 feet below the Pittsburgh coalbed and contains the largest remaining reserves of any coalbed in the county. Coal and overburden isopachs, structure and joint pattern maps, and a fence diagram were prepared using data from gas and oil exploration logs and coal outcrops. These maps will aid in determining the need and/or feasibility of degasifying the Upper Freeport coalbed in the study area. Much of the coalbed in this area is under 600 to 1,400 feet of overburden. By correlation with data from the Pittsburgh coalbed, the gas content at depths of this order is estimated to be between 140 and 300 cu ft/ton of coal, for a total of 190 to 400 billion cubic feet of methane in this coalbed in Fayette County.