קולוקוויום בחוג לגאופיזיקה: Bridging the extremes in physical scales of fluid-fault interactions in physics-based simulations
Elias Heimsson, ETH
The interactions of fluids and faults occur widely in tectonic and seismogenic processes. A problem of particular importance today is developing a mechanical description and characterization of the fault response due to fluid injection. Such descriptions would give an improved understanding of injection-induced seismicity and potentially lead to hazard mitigation in, for example, enhanced geothermal systems, carbon sequestration, and wastewater disposal.
In this talk, I will discuss some of the less recognized problems associated with developing a mechanical model of fluid injection into a rate-and-state frictional fault. In particular, I address the problem of accounting for the extreme length scale differences of the frictional shear zone and that of the slip patch. Further, I discuss how pore fluid processes occurring at these scales are intricately coupled. I offer a solution by developing a novel spectral boundary integral method, which reduces the dimension of the problem and offers efficient simulations. The simulations incorporate full coupling for fault, fluids, and bulk through injection, inelastic dilatancy, poroelastic bulk response, and pressure-dependent frictional strength.
Finally, I show application to field experiments of controlled fluid injection into a fault.
מארגני האירוע: ד"ר רועי ברקן וד"ר אסף ענבל