Cottageville (Mount Alto) Gas Field, Jackson County, West Virginia: A Case Study of Devonian Shale Gas Production

摘要

Exploration and development of upper Devonian organic shales in the Cottageville gas field of western West Virginia began in the late 1920s. Continued development has led to the drilling of over 110 shale wells with accumulative production of more than 10 billion cubic feet of natural gas. Data indicate primary production from zones of organic shales in the lower part of the Huron Member of the Ohio Shale. Because of the extremely low porosity (3 to 4%) and permeability (less than 0.1 millidarcy) of these shales, gas production is considered to be through natural fracture systems. These fracture systems have been delineated through the study of oriented cores and the mapping of surface joints. Historically, production of gas has been through natural completion or by stimulation with gelled nitroglycerine. Varied success of this stimulation technique has recently led to more advanced types of stimulation (hydraulic and foam fracturing). Total production, natural gas-flow trends, final gas-flow trends, and structural breaks and trends have led to the delineation of the fractured-shale reservoir. (ERA citation 06:034307)