Shale Gas Potential of the Southern Tier of New York
James Duggan1 (1) 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) ranges from 20 to 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.