Using Stable Isotopes to Detect Potential Inter-Formation Mixing of Fluids and Gases Following the Hydraulic Fracturing of Marcellus Shale Wells at NETLs Greene County Test Site in Southwestern Pennsylvania
Sharma, Shikha; Sack, Andrea; Bowman, Lindsey; Schroder, Karl; Hammack, Richard W.
Stable isotope signatures of produced gas and waters are being monitored at a location in Greene County, Pennsylvania that contains eight Marcellus Shale gas wells (six horizontal and two vertical wells) and seven vertical Upper Devonian gas wells. Natural gas and produced water samples were collected from two vertical Marcellus Shale wells and seven Upper Devonian wells before and after the hydraulic fracturing of the nearby horizontal Marcellus Shale wells. Analyses of samples collected prior to hydraulic fracturing demonstrate that the gas composition, carbon and hydrogen isotope signatures of methane and ethane, oxygen and hydrogen isotope signatures of water, and carbon isotope signatures of dissolved inorganic carbon in the water and gas produced from Upper Devonian sands are different from that produced from the Marcellus Shale. Hence, we propose that spatiotemporal stable isotope monitoring of different water and gas sources before, during, and after hydraulic fracturing can provide insight into possible gas and fluid migrations. The analyses of produced gas and water samples collected post-hydraulic fracturing is currently underway and will be discussed.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013