Repurposing Trenton-Black River Gas Fields as Low-Temperature Geothermal Reservoirs in New York State

Abstract

Geothermal resources have the potential to meet a significant portion of the low-temperature (30–100°C) thermal energy needs in the United States, in applications such as space heating, warming greenhouses, desalinization, food drying, and refrigeration. Harnessing heat from sedimentary basins may be one option for fulfilling those low enthalpy needs. For a region with a known thermal resource, a major contributor to investment risk is locating a reservoir capable of heat extraction. An approach to reduce that risk is to target specific structural and/or stratigraphic settings that have been proven as commercial oil and gas reservoirs. This study focused on the Appalachian basin of New York, for which there are abundant geophysical and borehole data. Known oil and gas fields in New York were evaluated for potential repurposing as geothermal reservoirs using a Monte Carlo Simulation of an innovative productivity index equation tailored to low-temperature geothermal systems, measured in liters per megapascal (L/MPa). Reservoir parameters included in the productivity index were formation depth, thickness, pressure, area, porosity, permeability, fluid viscosity, and distance between wells. Results were incorporated into a geographical information system to determine the extent to which the best performing reservoirs coincide with the highest thermal gradient in the region. The Trenton-Black River hydrothermal dolomite gas fields of New York showed the most promising opportunity for conversion to low-temperature geothermal reservoirs. First, the calculated productivity index for these fields is the highest in the state, ranging from 19–33 L/MPa. Second, the reservoirs are located at 2500–3200 meters depth, coinciding with New York's highest thermal gradient, resulting in temperatures at depth ranging from 65 to 85°C. The fields are conveniently located near the Elmira-Corning townships, where heat can be provided for a variety of end-uses. This study confirms the potential to produce geothermal heat in southern New York, specifically using the Trenton-Black River gas fields, and suggests that a similar analysis could be done for Trenton-Black River trends in Indiana, Ohio, Michigan, and West Virginia.

AAPG Datapages/Search and Discovery Article #90218 © 2015 Eastern Section Meeting, Indianapolis, Indiana, September 20-22, 2015