Rate-and-state simulations of fluid-injection laboratory experiments

Maryam Alghannam, Nadia Lapusta, Ares J. Rosakis, Stacy Larochelle, Vito Rubino, Krittanon Sirorattanakul, & Attilio lattanzi

Published September 8, 2024, SCEC Contribution #14021, 2024 SCEC Annual Meeting Poster #160

Understanding the influence of fluid pressure on friction and fault stability is essential in efforts to mitigate the seismic risk associated with subsurface operations. Recent frictional sliding experiments on PMMA surfaces by Gori et al. (2021) show that, in cases of rapid increase in pore pressure, unstable, fast slip is promoted nearly instantaneously and for rupture lengths considerably smaller than the critical sizes predicted by quasistatic theoretical estimates. In cases of gradual pore pressure increase, dynamic slip is triggered from larger scales and at higher levels of injection fluid pore pressure.

Here, we perform elastodynamic numerical simulations motivated by the laboratory experiments using rate-and-state friction coupled with effective stress that resolve both slow and fast slip. Our simulations reveal the significant effect of fault initial conditions on the outcomes of the fluid injection experiments, highlighting the need to control and record experiment preparation times, even if they differ only by minutes or tens of minutes. Our simulations also indicate that friction properties may depend on fluid presence and its properties (e.g., wet vs dry) and fluid pressurization may induce additional frictional weakening effects that are rate-dependent. These effects need to be systematically studied and quantified through additional experimental studies.

Citation
Alghannam, M., Lapusta, N., Rosakis, A. J., Larochelle, S., Rubino, V., Sirorattanakul, K., & lattanzi, A. (2024, 09). Rate-and-state simulations of fluid-injection laboratory experiments. Poster Presentation at 2024 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)