Netherlands Journal of Geosciences — Geologie en Mijnbouw |96 – 5 | s131–s148 | 2017 doi:10.1017/njg.2017.27 Fault reactivation mechanisms and dynamic rupture modelling of depletion-induced seismic events in a Rotliegend gas reservoir Loes Buijze1,3,∗, Peter A.J. van den Bogert2, Brecht B.T. Wassing1, Bogdan Orlic1 &Johanten Veen1 1 Applied Geosciences, TNO, Princetonlaan 6, 3584 CB Utrecht, the Netherlands 2 Shell Global Solutions BV, Kessler Park 1 (At-126L), 2288 GS Rijswijk (ZH), the Netherlands 3 HPT Laboratory, Faculty of Geosciences, Utrecht University. Budapestlaan 4, 3584 CB, Utrecht, the Netherlands ∗ Corresponding author. Email:
[email protected] Manuscript received: 6 February 2017, accepted: 11 September 2017 Abstract Understanding the mechanisms and key parameters controlling depletion-induced seismicity is key for seismic hazard analyses and the design of mitigation measures. In this paper a methodology is presented to model in 2D the static stress development on faults offsetting depleting reservoir compartments, reactivation of the fault, nucleation of seismic instability, and the subsequent fully dynamic rupture including seismic fault rupture and near-field wave propagation. Slip-dependent reduction of the fault’s strength (cohesion and friction) was used to model the development ofthe instability and seismic rupture. The inclusion of the dynamic calculation allows for a closer comparison to field observables such as borehole seismic data compared to traditional static geomechanical models. We applied this model procedure to a fault and stratigraphy typical for the Groningen field, and compared the results for an offset fault to a fault without offset. A non-zero offset on the fault strongly influenced the stress distribution along the fault due to stress concentrations in the near-fault area close to the top of the hanging wall and the base of the footwall.