FKPE Recommendations on Seismic Monitoring of Induced Seismicity

Transcription

1 FKPE Recommendations on Seismic Monitoring of Induced Seismicity Milestone Group "Seismic Monitoring" of the FKPE e.v. Working Group on Induced Seismicity GEOPHYSICAL INSTITUTE, FACULTY OF PHYSICS National Research Center of the Helmholtz Association Background 2009: no clear positioning on induced seismicity by German geophysicists FKPE: Forschungskollegium Physik des Erdkörpers e.v. AG Induzierte Seismizität des FKPE e.v. open group MS-1: Seismic monitoring MS-2: Discrimination between induced and natural earthquakes MS-3: Expert opinions (guidelines) position papers, recommendations, workshops etc. 2

2 FKPE Recommendations on Seismic Monitoring of Induced Seismicity Stefan Baisch Q-con GmbH, Bad Bergzabern Ralf Fritschen DMT GmbH, Essen Jörn Groos KIT, Geophysical Institute Toni Kraft Swiss Seismological Service at ETH-Zurich Thomas Plenefisch Fed. Inst. for Geosciences and Natural Resources, Hannover Katrin Plenkers Swiss Seismological Service at ETH-Zurich Joachim Ritter KIT, Geophysical Institute Joachim Wassermann Dept. Earth Sciences, LMU Munich 3 Recommendations for Seismic Monitoring Goals minimum requirements for monitoring induced seismicity at geotechnical installations [reservoirs (e.g. gas, oil, geothermal), dams, underground waste deposits, ] reliable recording and detection of potentially felt events hypocentre localisation goals recommendations for industry, authorities Not Applicable unfelt microseismicity reservoir monitoring 4

3 Recommendations for Seismic Monitoring Contents 1) measurement precision 2) network operation 3) data integration 4) transparency A1) note on site selection A2) monitoring scenarios 5 1) Measurement Precision ground velocity as proxy seismometer output, DIN 4150 potentially felt events (DIN ) factor 10 as safety (shear wave) factor 5 for the compressional wave SNR 3 for onset time reading maximum noise level mm/s 30 µm/s 6 µm/s 2 µm/s ±2 µm/s 6 µm/s amplitude with SNR of 3 localisation of M L ~1 6

4 1) Measurement Precision Signal/Noise Δ ~ 39 km surface Δ ~ 90 km mine M L = 2.4 M L = 2.2 Groos & Ritter, ) Measurement Precision Signal/Noise - Example 2 µm J. Groos, KIT-GPI one week (working days, weekend) of noise measurements recommended continuous noise amplitudes (I95), transient signals, 8

5 1) Measurement Precision 3 components timing as close as some milliseconds GPS frequency bandwidth 5-40 Hz f s 100 Hz (borehole recording: 80 Hz f s 200 Hz) 9 2) Network Operation objective detection only: 1 recording station localisation: minimum 5 recording stations 98.5% data availability (24 / 7) [max. 5 days per year failure] real time operation [if necessary: triggered modes] standard data formats & exchange protocolls SEED GSE2 SeedLink, ArcLink 10

6 2) Network Operation localisation precision (2σ) Example: Landau events 15. Aug. & 14. Sept ±500 m horizontal ±2000 m vertical if necessary numerical simulation depth / km FKPE J. Ritter, KIT-GPI 11 3) Data Integration combined database monitoring of microseismicity (emissions) standardised immission monitoring (DIN4150, DIN 45669) measurements of state earthquake services seismological research projects, university networks, etc. comprehensive analysis 12

7 4) Transparency open data policy central databases Transparency assists verification proactive public relation strategy confidence 13 Publication official German version: Mitteilungen der Deutschen Geophysikalischen Gesellschaft 3/2012, dgg-online.de Mitteilungen ( Arbeitsgruppe) English: abstract AGIS Workshop Acceptance mining authorities GtV Richtlinie 14

8 Ackowledgements J. Groos and J. Ritter are supported by Verbundprojekt MAGS - Konzepte zur Begrenzung der mikroseismischen Aktivität bei der energetischen Nutzung geothermischer Systeme im tiefen Untergrund (Förderkennzeichen A) wird finanziert durch das Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit. 15