Estimating the crust permeability from fluid-injection-induced seismic emission at the KTB site |
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Authors: | Sergei A Shapiro Ernst Huenges Günter Borm |
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Institution: | Wave Inversion Technology Group, Geophysical Institute, Karlsruhe University, Hertzstr. 16, 76187, Karlsruhe, Germany. E-mail: sergei@gpiwap2.physik.uni-karlsruhe.de;ENSG, INPL, Nancy, France;GeoForschungsZentrum, 14473 Potsdam, Germany |
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Abstract: | During the hydraulic-fracturing experiment in the German Continental Deep Drilling Borehole (KTB) in December 1994, microseismic activity was induced. Here we develop a technique for estimating permeability using the spatio-temporal distribution of the fluid-injection-induced seismic emission. The values we have obtained for the KTB experiment (0.25times10-16 to 1.0times10-16 1.0times10-16 m2) are in a very good agreement with the previous hydraulic-type permeability estimates from KTB deep-observatory studies. In addition, our estimates of the hydraulic diffusivity support the previously calculated value for the upper crust, which is of the order of 1 m2 s-1. However, this estimate now relates to the depth range 7.5-9 km. |
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Keywords: | crust fault zones fluid dynamics permeability poroelasticity seismicity |
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