Devonian Shale Gas Potential of the Southern Tier of New York
Faraj, Basim and James Duggan
Talisman Energy Inc, Calgary, AB
Deep structures in New York and Pennsylvania are drilled for
Trenton-Black River (Ordovician) dolomite reservoirs where they
often encounter "nuisance" gas in the Devonian shale succession,
requiring careful planning and selection of casing schemes. Often a
topic as a resource-type play, the shale gas potential of the the
Hamilton Group and selected units of the Upper Devonian shales are
under investigation. Mineralogical, geochemical and shale desorption
data were collected from cores, cuttings and outcrop samples, in order
to carefully characterize and delineate the reservoir and source rock
potential of the shale package.
The thickness of the overall package in the Southern Tier of New York where the Upper Devonian crops out varies from a few hundred feet to 5000 feet. A detailed sequence stratigraphy is made difficult by a lack of extensive marker beds in the Upper Devonian succession. However, the well control and occurrence of favorable markers (Onondaga Fm. and Tully Fm.) make the Geneseo Fm. and Marcellus Fm. suitable candidates for horizontal drilling.
The lateral extent of the shales of the Appalachia Basin from New York to Kentucky suggests a vast, underexplored shale gas resource in the Southern Tier of New York and much of Pennsylvania where a thermogenic origin of dry gas is predicted. Gas in place (GIP) is large and range between 20 and 100 bcf/section. The Marcellus, Geneseo, and Rhinestreet contain up to 25% TOC with favorable mineralogies and pressures to consider a variety of stimulation techniques. High rate/volume, low sand completions technologies applied in shale basins elsewhere may yield results that are improved over conventional methods.
AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah