RESERVOIR CHARACTERIZATION OF THE DEVONIAN SHALE FORMATIONS IN THE APPALACHIAN BASIN AND THE IMPACT ON CURRENT GAS DEVELOPMENT

The historic unconventional gas and oil research in the Appalachian Basin funded by the USDOE has provided oriented drill core for all of the shale formations in the Middle to Upper Devonian Age sediments. Reservoir characterization wells were drilled during the Eastern Gas Shale Project to evaluate all of the shale formations including the Marcellus, Rhinestreet, Olentangy, Huron and Cleveland. The current research and analysis targets the Marcellus Shale in the deepest portion of the basin. There are wells in New York, Pennsylvania, Ohio and West Virginia that intercept the Marcellus at shallow (1000m) to deep (2500 m) depths. Data from several wells in Ohio, Pennsylvania and West Virginia are presented to show depositional stratigraphy, organic type, content and maturation, trace elements, and natural fracture distribution in the central to western areas of the basin. Maturation, organic type and content play the key roles in the type of fluids produced from the shale and control where the plays are now being developed in the basin.

The data is correlated to current well design and drilling activity to target the gas and condensate potential of the organic shale source and reservoir. Comparison of stress orientation and regional structure also provides for an understanding of the interaction between natural fractures, well orientations and stimulations currently being applied across the basin. The production from the shale formations is initiating further development with use of the gas and condensate as feedstock for chemical and plastics industries in the western part of the basin.

Reports, data, and fact sheets are available on the NETL website at: http://www.netl.doe.gov/technologies/oil-gas/index.html