Title of article :
Source Parameters of Injection-induced Microseismicity
Author/Authors :
S. Talebi ، نويسنده , , T. J. Boone ، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 1998
Abstract :
We analyze source parameters of microseismic events (MB 1) associated with high
flow-rate water injections in a shale formation at a depth of 220 m. Two types of events were observed:
several hundred impulsive events with clear P- and S-wave arrivals, and continuous emissions with
peaked spectra detected well into the experiment. For a representative collection of impulsive events, an
v 2 model provided satisfactory fits to displacement spectra corrected for attenuation, and average
quality factors of 34 and 15 were obtained for P and S waves. P-wave first motion analysis and ES :EP
ratios indicated the existence of a non-double-couple component in some events, particularly early in the
experiment. A clear difference was observed for estimates of stress release parameters as non-doublecouple
events had smaller stress drops and apparent stresses. The seismic efficiency of double-couple and
non-double-couple events was limited to 0.9% and 0.05% respectively, with average values being 0.25%
and 0.02%. A comparison of our results with those reported for a similar magnitude range in a
hard-rock formation indicates considerably smaller estimates of stress drop and apparent stress in our
case while seismic efficiencies are comparable.
Keywords :
microseismic events , Water injection , source parameters.
Journal title :
Pure and Applied Geophysics
Journal title :
Pure and Applied Geophysics