Daniel Faulkner, University of Liverpool

Estimating the size and frequency of earthquakes during subsurface fluid injection is currently not possible. Understanding the fundamental controls on earthquake-size distributions is the first step to making these predictions. This study shows that the laboratory measured frictional stability parameter (a-b) relates closely to fault-related induced earthquake-size distributions (b-values) in a shale gas play. Fluid injection promoted seismicity along faults that cut lithologically distinct horizons, each with characteristic frictional stability parameters and earthquake-size distributions, are compared. Results indicate material properties play a key role in earthquake-size distributions. As such, it may be possible to constrain the expected seismicity from laboratory measurements prior to any fluid injection into the subsurface.