THE DEVELOPMENT OF GAS ISOTOPE TRACERS FOR HYDROCARBON EXPLORATION IN UNCONVENTIONAL SHALES (Invited Presentation)

As petroleum exploration has expanded to more sedimentary basins and to greater depths in the crust, numerous questions about the genetic source, thermal maturity, residence time, and the role of microbial activity have emerged. These questions are of exceptional importance in unconventional shale systems. Over the last decade, gas geochemical databases, specifically for compound-specific hydrocarbons and noble gases, have become available in a diverse set of geographic areas, from a variety of source rock types, and from varied lithologies (e.g., organic-rich mudstones and micrites). Here, I will present an update on the state-of-the-science applications of noble gas isotopes to interrogate unconventional hydrocarbons systems based on these recently matured datasets. I will focus on how noble gases can be integrated with other more traditional hydrocarbon tracers to examine the genetic source, thermal maturity, residence time of natural gas, and its mechanism and extent of fluid migration. Specifically, I will explore how noble gases tracers can be used to reinterpret traditional hydrocarbon data within the context of unconventional systems and provide important insights on hydrocarbon recovery.