none 10.1190/1.1451573 Society of Exploration Geophysicists Society of Exploration Geophysicists 186 4732228 5981 2025121112385541200 10.1190 2025-12-11T17:39:05Z 2002-10-11T14:50:24Z 49 Geophysics 1942-2156 0016-8033 2002 01 01 2002 67 1 Pascal Audigane ∗ Center for Petroleum Studies, T. H. Huxley School, Imperial College, Prince Consort Road, London, SW7 2BP, England. E-mail: pascal.audigane@ic.ac.uk. Jean-Jacques Royer ‡ Centre de Recherches Pétrographiques et Géochimiques, 15 Rue Notre Dame des Pauvres, F-54501 Vandoeuvre-les-Nancy, France. E-mail: jean-jacques.royer@ensg.inpl-nancy.fr. Hideshi Kaieda ∗∗ The Central Research Institute of Electric Power Industry, Geology Department, Abiko Research Laboratory, 1646, Abiko, Abiko-city, Chiba, 270-1194, Japan. E-mail: kaieda@criepi.denken.or.jp. Abstract Hydraulic fracturing is a common procedure to increase the permeability of a reservoir. It consists in injecting high-pressure fluid into pilot boreholes. These hydraulic tests induce locally seismic emission (microseismicity) from which large-scale permeability estimates can be derived assuming a diffusion-like process of the pore pressure into the surrounding stimulated rocks. Such a procedure is applied on six data sets collected in the vicinity of two geothermal sites at Soultz (France) and Ogachi (Japan). The results show that the method is adequate to estimate large-scale permeability tensors at different depths in the reservoir. Such an approach provides permeability of the medium before fracturing compatible with in situ measurements. Using a line source formulation of the diffusion equation rather than a classical point source approach, improvements are proposed for accounting in situation where the injection is performed on a well section. This technique applied to successive fluid-injection tests indicates an increase in permeability by an order of magnitude. The underestimates observed in some cases are attributed to the difference of scale at which the permeability is estimated (some 1 km3 corresponding to the seismic active volume of rock compared to a few meters around the well for the pumping or pressure oscillation tests). One advantage of the proposed method is that it provides permeability tensor estimates at the reservoir scale. 2002 01 01 2002 01 01 2002 204 211 10.1190/1.1451573 https://pubs.geoscienceworld.org/geophysics/article/67/1/204/107134/Permeability-characterization-of-the-Soultz-and https://pubs.geoscienceworld.org/seg/geophysics/article-pdf/67/1/204/3182752/gsgpy_67_1_204.pdf https://pubs.geoscienceworld.org/seg/geophysics/article-pdf/67/1/204/3182752/gsgpy_67_1_204.pdf http://geophysics.geoscienceworld.org/cgi/doi/10.1190/1.1451573 Caractérisation microsismique des massifs rocheux fracturés. Modélisation thermo-hydraulique. Application au concept géothermique de Soultz Audigane 2000 J. Appl. Phys. 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