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

PANEL REPORT: MULTIPHASE FLUID TRANSPORT IN GEOLOGIC MEDIAthe limitations of modern architectures. We anticipate that forward and inverse modelingalgorithms of the type we require here will need to drive development of new hardwarearchitectures that are better suited to the applications at hand.CONCLUSIONUnderstanding of multiphase flow of fluids in rocks builds on more than a century of developmentin oil and gas production, soil science, and geothermal energy production. Nevertheless,scientific challenges remain for applications such as geological storage of CO 2 . In particular, thelarge injection volumes, long transport distances and long time frames raise new issues withregard to the reliability and robustness of current understanding. Carbon dioxide is highly mobilein subsurface environments due both to its low viscosity and density—and will tend to migratealong high permeability pathways, moving upward until it encounters capillary barriers in finetextured rocks. Complex and path-dependent behavior results from the interplay of buoyancyforces, natural rock heterogeneity, and capillary forces. Small-scale processes along fluid-fluidand fluid-solid interfaces, and within the fluid phases, ultimately control many of the propertiesand behaviors that are observed at larger scales.Five critical fundamental scientific research needs have been identified.1. New approaches are needed to accurately predict migration of multiple fluid phases inenvironments that are highly heterogeneous, from the pore scale to the basin scale—overlarge spatial scales and long time frames.2. Methods to quantify and predict rates of geochemical reactions between multiphase, multicomponentfluids and minerals are needed to understand how quickly dissolution andmineralization will occur.3. Fundamental scientific understanding of basin-scale geomechanical processes is needed topredict shallow crustal deformation and basin-scale brine displacement caused by large andrapid anthropogenic perturbations such as injection or extraction of multiphase fluids in thesubsurface.4. A new multidisciplinary approach is needed to assess the multiphase flow properties ofmembrane seals, faults and fractures to determine whether or not a geological reservoir hasan adequate seal.5. Dynamic field-scale imaging is needed to test and validate multiphase flow models.A fundamental research program in these areas will significantly improve our ability tounderstand and predict multiphase flow in complex subsurface environments—and provide astrong scientific foundation for assessing the full potential of geological storage of CO 2 in deepgeological formations.22 Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems