Our Center addresses the following scientific gaps, but does not address induced seismicity specifically. While induced seismicity is a practical topic of great importance, it is being addressed effectively elsewhere (e.g., Yoon et al 2017; Snee and Zoback 2018).
Our main science questions are as follows:
- How are shale compositional and structural heterogeneities, interfaces, and disorder characterized and how do these attributes control the behavior, performance, and transport within this natural energy system?
- How are characterization data from multiple sources integrated and extended to solve the scientific puzzle of multiscale, multiphysics porous media?
- How do complex fluids wet the heterogeneous surfaces of natural porous media, i.e., shale?
- How does sorption of gas and liquid species interplay with transport to determine permeability and how does sorption affect with mechanical properties?
- How do the many interfacial processes in heterogeneous solid-liquid and solid-gas phase systems control dissolution, adsorption, deposition, and failure?
- How do we achieve mechanistic control of interfaces and transport in complex and extreme environments?
- How are experimental and simulation data transformed into information?
- How is a predictive understanding of subsurface system behavior developed that embraces multi-scale complexity, dynamics, and reactivity across approximately ten orders of magnitude?
- How are robust predictive models developed for highly complex, multiphase, heterogeneous, and reactive natural systems?
- How are numerical algorithms advanced to reach across traditional mathematical boundaries to provide computer models of sophisticated, coupled, multiscale phenomena and experiments to process and understand data?
- How are theory, computation, and experiment combined to probe the structure, chemistry, mechanics, and response of complex natural systems?
Importantly, addressing these scientific gaps has impacts in other areas of energy. For example, basic scientific knowledge of shales is essential to understanding isolation of chemical and nuclear wastes in the earth’s crust. Shale reaction fronts are also not unlike those observed in engineered materials, such as porous battery electrodes and concrete, although the chemical complexity and heterogeneity in shales is much greater. Additionally, the Center is focused on geoscience, but the understanding of the interplay of sorption and transport is important to improved understanding of multicomponent gas and liquid separations.
In view of the economic, strategic, and environmental importance of shale resources, the mission of this EFRC is to provide the fundamental knowledge needed to achieve mechanistic control over the various nonequilibrium physical and geochemical processes that occur in extreme geological environments such as shale, mudstones, and other tight rocks with nanoscale pores. Our vision is to enable science-based management of the US shale resource to provide foundational understanding for building subsurface hydrogen and carbon dioxide storage infrastructure as well as for reduced environmental impacts of natural gas production in the short term.
Our mission is achieved by accomplishing the following fundamental science goals that integrate experimental, theoretical, and computational modeling aspects.
- Develop and exploit advanced multiscale imaging capabilities to characterize and analyze the fabric of disordered nanoporous shale media at nm to cm scales before, during, and after interaction with fracture fluids.
- Elucidate the coupled phase behavior, geomechanical, and transport mechanisms of single and multiphase flow through nanoporous media across cascading length and time scales to understand and model the controls on flow and transport of water, hydrocarbons, CO2 and N2.
- Delineate aqueous fluid interactions at shale mineral interfaces and the influence of water composition on matrix, microfracture, and fracture fluid transfer and transport.
- Characterize the mechanisms of viscoplasticity and ductility of shale when exposed to alternate hydraulic fracturing fluids such as CO2, N2, and aqueous foams of CO2 and N2.
- Enable translation of physical and chemical mechanisms to assess their influence at macroscopic length and time scales using advanced algorithms and modeling that take advantage of emerging high-performance computing with heterogeneous processors and complex memory hierarchies.
Meeting these basic-science goals means that our Center will deliver (i) a set of experimental tools to acquire essential data; (ii) greatly improve understanding and the mechanisms related to the interplay of mineralogy, pore networks, sorption, and reactivity that govern transport at and across scales; (iii) a set of algorithms and modeling tools for scale translation.
The US Department of Energy's office of Basic Energy Science sponsors a number of EFRCs (Energy Frontier Research Centers), which are broken into teams. MUSE is part of the Orange team, which also includes several sister EFRCs, including: