MSc Thesis Utrecht University Supervisors: Prof.dr. C.J. Spiers, Dr. S.J.T. Hangx Utrecht, May 2016 Field Data Correlation of Reservoir Compaction and Seismic Potential of Dutch Onshore Gas Fields Fekkes, F.1 1Faculty of Geosciences, Utrecht University,
[email protected] Abstract The discovery of the Groningen gas field in 1959 led to a significant increase of the Dutch natural gas industry. Yet, deformation and stress changes in and around a reservoir during production may generate problems, such as surface subsidence due to compaction and seismicity due to fault induction on pre-existing faults. Induced seismic events are monitored since 1986 and at present times 1103 induced seismic events are registered, mainly located in the northern Netherlands. The magnitudes of these seismic events are reaching 3.6 on the Richter scale. This study correlates production and reservoir characteristics of 68 onshore gas fields in the northern Netherlands to the amount of surface subsidence and induced seismicity, thereby assessing vertical strain, total seismic moment and maximum seismic magnitude. Reservoir compaction and induced seismicity are both complex problems influenced by reservoir parameters that may also impact each other. As a consequence of the complexity of the problem and a limited data set, one univocal answer is not obtained and no single reservoir parameter can be assigned to solely contribute to reservoir compaction and seismic potential. Yet, several field parameters are interpreted to correlate well and confirm literature-based hypotheses. By examining individual reservoir parameters on their seismic potential, a general outline of a field that would be prone to seismicity is provided.