TOC is much higher in Marcellus than in Utica (up to 12%). TOC values are highest in central part of state and decrease to the east.
There are at least two potential gas shale plays in New York in the Devonian Marcellus and the Ordovician Utica. A program was initiated to try to characterize both organic rich shales geochemically in New York. To date we have samples from 15 outcrops, 70 wells with well cuttings, and five cores from over 15 counties for the geochemical database. New isopach and structure contour maps have been constructed along with TOC, transformation ratio, and hydrogen index maps. These maps will help define fairways to explore.
Preliminary results show that the Utica has TOC values between 1.5 to 3 percent. The Devonian Marcellus Shale has TOC values between 0.3 and 11 percent. The Marcellus may be more favorable to newer completion techniques because of the high-silica Stony Hollow member that overlies the more organic rich Union Springs member. The Utica might have zones of higher porosity at a reasonable depth to create pore pressure in the quartz rich units of the Indian Castle and Dolgeville.