The objective of this project is to investigate the gas recovery and fracking fluid migration in shale formations. Natural gas trapped in shale formations is an abundant energy resource. Enabled by production technologies such as hydraulic fracturing, the recent shale gas boom has transformed the natural gas market in the U.S. Nevertheless, shale gas production faces many challenges: profitable production is often hindered by the rapid decline of the gas recovery rate and the difficulties in managing the hydraulic fracturing fluids ("fracking fluids") in shale formations. In this project, these challenges are addressed by developing a fundamental understanding of the transport of gas and fracking fluids in shale formations at the nanopore scale. The insights gained here will help improve the production of shale gas and management of fracking fluids, thereby benefiting both the shale gas industry and the society. Graduate and undergraduate students will be trained in interdisciplinary research covering fluid dynamics, interfacial chemistry, and computational engineering. Newsletters summarizing recent pore-scale research in the shale gas field will be compiled and sent to simulation practitioners in the industry. A YouTube channel will be created and maintained to help increase the awareness of the role of chemistry in fluid dynamics by the public.
Shale gas recovery is ultimately controlled by gas and fracking fluid transport at the nanopore level and reliable simulation of shale gas recovery at field-scale must be built upon sound understanding of transport at the nanopore scale. In this project, the recovery of single- and multi-component gas from nanopores and the imbibition of fracking fluids into nanopores will be studied using molecular and continuum simulations. The study of gas recovery at the pore level will elucidate the synergistic effects of confinement and gas-wall interactions on the gas recovery. The study of fracking fluid transport at the pore scale will clarify how fracking fluid imbibition and gas transport are affected by the solution chemistry of fracking fluids as well as the size, surface chemistry, and partial saturation of nanopores. These studies will help further advance the modeling and simulation of gas recovery and fracking fluid migration in shale formations. In particular, the gas recovery study will provide theoretical basis and guidelines for selecting and parameterizing semi-phenomenological pore-scale gas recovery models; the multiphase transport study will break new ground for research on the simulation of multiphase transport in shale formations to move beyond the prevailing framework, which is based mostly on the classical capillary flows.
