Fig. 1: Production rates and observed seismicity in the Groningen gas field.
From: Production-induced seismicity indicates a low risk of strong earthquakes in the Groningen gas field
a Annual production rates and annual pressure decrease averaged over all wells, b Moment magnitude calculated from Eq. (1) using the known local reservoir thickness and assuming a stress drop of 10 MPa. c Annual number of earthquakes above MC=1.2 and maximum observed magnitude for each year, d Spatial distribution of observed earthquakes and maximum observed magnitudes within the Groningen field. Observed maximum magnitudes increase from SE to NW which is in good agreement with the theoretical estimates of reservoir-limited rupture sizes (1b).
