Mechanical and Civil Engineering Seminar
Mechanical and Civil Engineering Seminar Series
Title: Scaling of Triggered Seismicity and Permeability Evolution in the Subsurface – A Key Need in the Energy Transition
Abstract: Contemporary methods of energy conversion that reduce carbon intensity and address the energy transition draw heavily on fluids in the subsurface. This includes sequestering CO2, fuel switching to lower-carbon sources, such as from abundant gas shales, recovering deep geothermal energy via EGS, and diurnal and inter-seasonal storage of H2 and energized fluids (CAES). In all of these endeavors, either maintaining the low permeability and integrity of caprocks or in controlling the growth of permeability in initially very-low-permeability shales or geothermal reservoirs represent key desires. Injected volumes are necessarily enormous, anticipated overpressures large and the potential for hazardous triggered seismicity significant. We explore conditions controlling the linked evolution of seismicity and permeability in particular with respect to the (i) scaling of seismicity, (ii) controls on permeability evolution and the (iii) potential to recover permeability evolution from physics-based models of microearthquakes linked to permeability evolution.
Bio: Derek Elsworth is a Professor in the Departments of Energy and Mineral Engineering and of Geosciences and the Center for Geomechanics, Geofluids, and Geohazards. His interests are in the areas of computational mechanics, rock mechanics, and in the mechanical and transport characteristics of fractured rocks, with application to geothermal energy, the deep geological sequestration of radioactive wastes and of CO2, unconventional hydrocarbons including coal-gas, tight-gas-shales and hydrates, and instability and eruption dynamics of volcanoes.
NOTE: At this time, in-person Mechanical and Civil Engineering Lectures are open to all Caltech students/staff/faculty/visitors with a valid Caltech ID. Outside community members are welcome to join our online webinar.
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https://caltech.zoom.us/j/81858490601?pwd=d0c0OGxMK0t6bDd0NEZPcWVtSG5Qdz09
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