Basic Research Needs for Geosciences - Energetics Meetings and ...

EXECUTIVE SUMMARYpurpose of linking with macroscopic models, to follow interfacial reactions in real time, and tounderstand how minerals grow and dissolve and how the mechanisms couple dynamically tochanges at the interface.Nanoparticulate and colloid chemistry and physics. Colloidal particles play critical roles indispersion of contaminants from energy production, use, or waste isolation sites. New advancesare needed in characterization of colloids, sampling technologies, and conceptual models forreactivity, fate, and transport of colloidal particles in aqueous environments. Specific advanceswill be needed in experimental techniques to characterize colloids at the atomic level and tobuild quantitative models of their properties and reactivity.Dynamic imaging of flow and transport. Improved imaging in the subsurface is needed to allowin situ multiscale measurement of state variables as well as flow, transport, fluid age, andreaction rates. Specific research needs include development of smart tracers, identification ofenvironmental tracers that would allow age dating fluids in the 50–3000 year range, methods formeasuring state variables such as pressure and temperature continuously in space and time, andbetter models for the interactions of physical fields, elastic waves, or electromagneticperturbations with fluid-filled porous media.Transport properties and in situ characterization of fluid trapping, isolation, andimmobilization. Mechanisms of immobilization of injected CO 2 include buoyancy trapping offluids by geologic seals, capillary trapping of fluid phases as isolated bubbles within rock pores,and sorption of CO 2 or radionuclides on solid surfaces. Specific advances will be needed in ourability to understand and represent the interplay of interfacial tension, surface properties,buoyancy, the state of stress, and rock heterogeneity in the subsurface.Fluid-induced rock deformation. CO 2 injection affects the thermal, mechanical, hydrological,and chemical state of large volumes of the subsurface. Accurate forecasting of the effectsrequires improved understanding of the coupled stress-strain and flow response to injectioninducedpressure and hydrologic perturbations in multiphase-fluid saturated systems. Sucheffects manifest themselves as changes in rock properties at the centimeter scale, mechanicaldeformation at meter-to-kilometer scales, and modified regional fluid flow at scales up to100 km. Predicting the hydromechanical properties of rocks over this scale range requiresimproved models for the coupling of chemical, mechanical, and hydrological effects. Suchmodels could revolutionize our ability to understand shallow crustal deformation related to manyother natural processes and engineering applications.Biogeochemistry in extreme subsurface environments. Microorganisms strongly influence themineralogy and chemistry of geologic systems. CO 2 and nuclear material isolation will perturbthe environments for these microorganisms significantly. Major advances are needed to describehow populations of microbes will respond to the extreme environments of temperature, pH,radiation, and chemistry that will be created, so that a much clearer picture of biogenic products,potential for corrosion, and transport or immobilization of contaminants can be assembled.Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systemsxi