Injection-induced seismicity along multiple faults: magnitude and rate in a 3-D poroelasticity system
Abstract
Understanding of the potential to injection-induced seismicity along the faults requires the response of fault zone system to changes in pore pressure and stresses over time. In this study, three-dimensional (3-D) model system consisting of the upper caprock, reservoir, and basement is intersected by vertical strike-slip faults. We examine the full poroelastic behavior of the formation and perform the mechanical analysis along the fault zone using the Coulomb stress change. Using the spatio-temporal distributions of stresses and pore pressure, the magnitude, rate, and location of potential earthquakes are predicted. Direct diffusion of pore pressure destabilizes conductive faults, potentially inducing most frequent seismicity with large magnitudes. Less permeable faults can be destabilized by poroelastic stressing or delayed pore-pressure diffusion. A two-dimensional (2-D) horizontal model, representing the interface between the reservoir and the basement, limits diffusion of pore pressure and deformation of the formation in the vertical direction that may over- or under-estimate the potential of earthquakes along the fault. Our simulation results suggest that the 3-D modeling of faulting system including poroelastic coupling is required to properly predict the seismic hazard along the faults by considering the hydraulic and mechanical interaction between faults and bounding formations.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This study describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the study do not necessarily represent the views of the U.S. Department of Energy or the United States Government.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.S22A..07C
- Keywords:
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- 7209 Earthquake dynamics;
- SEISMOLOGYDE: 7223 Earthquake interaction;
- forecasting;
- and prediction;
- SEISMOLOGYDE: 7230 Seismicity and tectonics;
- SEISMOLOGYDE: 8168 Stresses: general;
- TECTONOPHYSICS