This is a Ph.D. dissertation. Many gas fields are currently being produced in the northern Netherlands. Induced seismicity related to gas production has become a growing problem in the Netherlands in the past two decades. To date, a few hundred induced seismic events occurred. Induced seismicity is generally assumed to be the result of induced reactivation of discontinuities in the subsurface. Field data of the Groningen and Annerveen gas fields as well as other Rotliegend gas fields in the Netherlands are analyzed. A large amount of seismic cross sections through seismic events is studied. It is very likely that the seismic events are the result of reactivation of existing discontinuities (like faults) in or near the reservoirs. The objective of the research presented in this dissertation is to obtain a better understanding of the mechanisms of gas production induced reactivation of faults by means of 3D geomechanical modeling of gas reservoirs. It is a step towards future assessment of expected seismic energy release when (further) developing gas fields in the Netherlands. Contents include: (1) Introduction, (2) Theoretical concepts of stress, infinitesimal strain, linear elasticity and poroelasticity, (3) Generally concepts of fault reactivation and rock failure in producing hydrocarbon reservoirs, (4) Fault slip, asperities and seismicity, (5) Theoretical background of geomechanical modeling by means of finite element calculations, (6) Literature study on hydrocarbon reservoir induced seismicity, (7) Geological setting and characteristics of the Groningen and Annerveen gas fields in the northern Netherlands, (8) Model set-up, (9) Quantification of calculation results, (10) Stress development in generic basic reservoir models without fault, (11) Stress development and fault slip in generic basic disk-shaped reservoir models with fault, (12) Discussion, conclusions and recommendations.F.M.M. Mulders is the author of 'Modelling of Stress Development and Fault Slip in and around a Producing Gas Reservoir', published 2003 under ISBN 9789040724541 and ISBN 9040724547.