Distribution of Gas, Organic Carbon, and Vitrinite Reflectance in the Eastern Devonian Gas Shales and Their Relationship to the Geologic Framework

摘要

Gas volume data from outgassing tests were available from twenty one sites in the Appalachian Basin and seven sites in the Illinois Basin. Most of these sites also had data available on organic carbon and vitrinite reflectance. Gas volume distribution varies with each stratigraphic unit tested in the Appalachian Basin. Thermal maturity increased from northwest to southeast in the Appalachian Basin. Gas volume, organic carbon, and thermal maturity increased from northwest to southeast in the Illinois Basin. High gas volumes were present in the Appalachian Basin in the Cleveland, Upper Huron, and Lower Huron Members of the Ohio Shale, the Rhinestreet Member of the West Falls formation, and the Middlesex Member of the Sonyea formation. In the Illinois Basin, The Grassy Creek and Sweetland Creek Shales of the New Albany showed relatively high gas volumes at some locations. Prior production areas of the Appalachian Basin are characterized by a thick sequence of radioactive shale, high measured gas volume, optimum stress ratio, and optimum thermal maturity. These same characteristics are present in an extensive area of Ohio, Pennsylvania, and New York and present areas of optimum exploration potential. The Devonian shale gas resource of the Illinois Basin is most probably the area of southeastern Illinois and adjacent areas of Indiana and Kentucky. (ERA citation 08:029060)