Events

Speaker: Tiziana Vanorio, Assistant Professor of Geophysics, Stanford University

Title of Seminar: "From Ancient Rome to Shale Plays: Rock Physics Characterization of Ash Beds"

Abstract: Volcanic ash beds are found in many shale reservoirs, constituting both a blessing and a curse. They are the cause for the preservation of organic material but also a challenge for well completion and stimulation, inhibiting fracture height growth during hydraulic fracking. At other times, they are linked to increased production. Why do ash beds inhibit crack propagation? What causes such heterogeneity and how to differentiate them? Cemented ash beds would seem to have little to do with concrete. From an engineering perspective volcanic ash is a pozzolan (or pozzolanic ash): an amorphous, high-surface area ash being highly reactive in presence of lime-rich fluids — the basic recipe for Roman concrete. Through the examples of an ash bed serving as caprock of an Italian caldera and cores of Roman-era concrete for which the region is known, I will show how the reaction with lime-, sulfates-, and alkali-rich fluids provide a polymeric matrix with intertwined fibers, contributing to ductility of the material and strength.

Biography: Tiziana Vanorio is Assistant Professor in the Geophysics Department at Stanford University where she leads the Stanford Rock Physics Laboratory (SRPL). Together with her students, she uses laboratory and imaging techniques to study the physical and mechanical properties of rocks and their response to Earth’s conditions and processes. The work of her group focuses on understanding how rock-fluid interactions affect physical and mechanical properties of rocks and geomaterials. Specific applications of her research include the geophysical response of reservoirs and geological seals to fluid injection and/or diagenetic processes, the physical and mechanical properties of shales, carbonates, and ancient materials. Tiziana is a Marie Curie Fellow, the recipient of the 2018 Wegener Award by the European Association of Geoscientists and Engineers, 2015 NSF Career Award, and 2014 Innovative Teaching Award by the Society of Petroleum Engineering.