Samples of Hot Dry Rock Soultz injection microearthquakes - mechanism using alternative source models

0386914 - GFÚ 2013 RIV NL eng C - Conference Paper (international conference)
Jechumtálová, Zuzana - Šílený, Jan
Samples of Hot Dry Rock Soultz injection microearthquakes - mechanism using alternative source models.
74th EAGE conference & exhibition incorporating SPE EUROPEC 2012. Houten: EAGE, 2012, D022/1-D022/5. ISBN 978-90-73834-27-9.
[EAGE Conference & exhibition incorporationg SPE EUROPEC 2010 /74./. Copenhagen (DK), 04.06.2012-07.06.2012]
R&D Projects: GA ČR GAP210/10/1728
Institutional support: RVO:67985530
Keywords : geothermal reservoir * induced microearthquakes * comparison of MT and STI models
Subject RIV: DC - Siesmology, Volcanology, Earth Structure

The geothermal reservoir at Soultz-sous-Forets is a valuable natural laboratory for understanding the mechanisms of the microearthquakes generated during stimulations and circulation tests. There is an ongoing effort towards the retrieval of the mechanisms though the indication of the type of fracturing of the rock massif still remains ambiguous. Recent studies indicate prevailingly shear slip but rarely there is also observed a non-shear pattern. Moment tensor - used today as a universal tool for description of the mechanism - captures general balanced dipole sources. However, for practice it may be too general as it may include also non-physical sources. Opening new fractures can be described in the first approximation by a tensile crack, optionally combined with a shear slip. We call this alternative model a shear-tensile/implosion source model. From the bulk of the seismicity recorded during stimulation in 2003, we concentrted on the first phase of the injection when only a single borehole in the site was stimulated.
Permanent Link: http://hdl.handle.net/11104/0216619