Publications
From Nanofluidics to Basin‐Scale Flow in Shale: Tracer Investigations
Understanding fluid flow and transport in shale is of great importance to the development of unconventional hydrocarbon reservoirs and nuclear waste repositories. Tracer techniques have proven to be a useful tool for gaining such understanding. Shale is characterized by the presence of nanometer‐sized pores and the resulting extremely low permeability. Chemical species confined in nanopores could behave drastically differently from those in a bulk system and the interaction of these species with pore surfaces is much enhanced due to a high surface/fluid volume ratio, both of which could potentially affect tracer migration and chromatographic differentiation in shale. Nanoconfinement manifests the discrete nature of fluid molecules in transport, therefore enhancing mass‐dependent isotope fractionations. All these effects combined lead to a distinct set of tracer signatures that may not be observed in a conventional hydrocarbon reservoir or highly permeable groundwater aquifer system. These signatures can be used to delineate flow regimes, trace fluid sources, and quantify the rate and extent of a physical/chemical process. Such signatures can be used for the evaluation of cap rock structural integrity, the postclosure monitoring of a geologic repository, or the detection of a possible contamination in a water aquifer by a shale oil/gas extraction.