Tracing the Migration of Natural Gas in the Marcellus Shale using the Noble Gas Geochemistry of Silicate Mineral Phases

Recent improvements in horizontal drilling and hydraulic fracturing technologies have opened numerous unconventional reservoirs such as black shales for hydrocarbon exploration and production globally. Still, the success rate of individual wells remains highly variable and poorly understood. By better understanding the fundamental properties of fluid flow in low permeability rocks such as the porosity, permeability, thermal maturity, and geological fluid flow, one might improve the extraction of hydrocarbons from unconventional reservoirs. Here, we examined the noble gas and trace element geochemistry of black shale silicate mineral samples collected along the lateral of a production well from the Marcellus Formation located in the northern Appalachian Basin in the northeastern US. We used the element data to compared the anticipated versus measured 4He/21Ne ratio throughout the vertical and lateral section of the production well in order to determine how porosity and permeability vary along the well, and determine areas of gas accumulation. The preliminary data suggests that the majority of radiogenic noble gases are retained in samples from the Marcellus Formation indicating that hydrocarbons crustal fluid migration is minimal within this formation. By comparison, samples from overlying Upper Devonian sequences have experienced loss of more than 90% and 50% of the radiogenic 4He and 21Ne*, respectively. These results suggest that extensive fluid migration has occurred in the top 0.5km of the crust in comparison to the Marcellus. The preferential loss of 4He with respect to 21Ne* suggests that fluid migration occurs in lower temperature regimes, possibly following neotectonic fracturing.Chevron USA, Inc., Kinder Morgan, Inc., and the NSF EAR EAGER Award 1249255, Shell Exploration and ProductionA three-year embargo was granted for this item.Academic Major: Earth Science

Challenges of Cardiopulmonary Bypass—A Review of the Veterinary Literature

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96252/1/vsu1008.pd