This website uses cookies to improve your experience. If you continue without changing your settings, you consent to our use of cookies in accordance with our cookie policy. You can disable cookies at any time.


Scaling of seismicity induced after injection stop to better understand hydraulic fracturing processes



Fluid injections into unconventional reservoirs, performed for fluid-mobility enhancement, are accompanied by microseismic activity which frequently continues after the injection stop. Previous studies reveal that the triggering of seismic events can be described by non-linear diffusion of pore-fluid pressure where the diffusivity becomes pressure-dependent. The spatio-temporal distribution of postinjection-induced microseismicity has two important features: the triggering front, corresponding to early and distant events, and the back front, enveloping the growing aseismic zone around the well bore-hole. To describe the temporal behavior of postinjection-induced seismicity, we introduce a scaling law for the back front. We show that it is sensitive to the degree of non-linearity of the fluid-rock interaction and to the Euclidean dimension of the space of seismicity. To validate the theory, we numerically model non-linear pore-fluid pressure diffusion and generate catalogs of synthetic seismicity. We demonstrate that back fronts of synthetic seismicity and of observed fluid-induced seismicity can be well described by the proposed asymptotic scaling. Therefore, this theoretical understanding is of particular importance for future reservoir characterization and hazard assessment.

Presentation Date: Wednesday, October 19, 2016

Start Time: 11:35:00 AM

Location: 144/145

Presentation Type: ORAL