Induced seismicity: monitoring, control and hazard mitigation

Developing and validating methods for generating input for risk management and control systems

State of the art

Induced seismicity risk in connection with subsurface fluid injection and production has recently become an increasingly important concern. For instance, observations of induced seismicity related to conventional gas production, gas storage, shale gas production, waste water injection, and geothermal activities have demonstrated that there is a need to improve our ability to reduce the uncertainty in seismic hazard assessment and investigate mitigation options. For onshore CO2 storage in populated areas, induced seismicity is a major public concern and therefore a critical project and safety risk. Until now, CO2 storage operations have resulted in very few recordings of induced earthquakes (IEAGHG report 2013/09, 2013). However, detailed monitoring studies of induced seismicity are scarce and cannot be generalized into a standard practice approach. In induced seismicity risk management so-called traffic-light systems are common in geothermal and O&G. However, these approaches, that prescribe measures to be taken if the seismicity observed exceeds a threshold, are highly qualitative and have not been tested widely under a wide variety of conditions. At present, the protocol that has been developed in the context of geothermal energy production in the EU FP7 Geiser project is the most advanced and detailed and no such protocol exists for CO2 storage.

Progress beyond the state of the art

The objective is to develop and validate methods for generating input for risk management and control systems. This includes improvements on the physical modelling of seismic wave propagation to optimize monitoring systems and development of innovative approaches that combine physical modelling and statistical data to update the seismicity risk model as more observations and operational data become available.