|16.05.2017, 09:30 - 10:30|
|Geb. 6.42, Raum 001|
I characterize pressurized fluid injection into permeable rock with a thermodynamic perspective, which requires to characterize the system under study appropriately in terms of its energy forms and energy flows, the evolution of its entropy, and in terms of reversible and irreversible processes. One rather trivial implication is that the power injected into the rock is unrelated to the intensity of seismicity as the latter one takes its energy from the internal energy of the pre-stressed and pre-heated rock. This circumstance includes an upper limit to seismic activity. I introduce a new approach for modelling induced seismicity by the injection of fluid in a homogeneous, porous medium with faults with variable proximity to rupture conditions by modifying the rate- and state-dependent frictional fault theory (RST) of Dieterich (1994). An immediate advantage of this method is the direct dependency of induced seismicity on the existing tectonic seismicity. A disadvantage is its higher computational complexity as compared to the Critical Pressure Theory (CPT) developed by Shapiro (2015) where the local seismicity is proportional to the pressure rate and limited by the Kaiser Effect. I show that both methods are closely related.
Prof. Friedemann Wenzel
Geophysikalisches Institut (GPI)
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