The following documents and links provide access to information on induced seismicity resulting from mining operations. Reports and cover letters provided as part of the production plan procedure for the Groningen field can be found here. This does not include information on natural causes of seismicity occurring in the Netherlands.
Liability for damage is regulated in legislation and regulations and specifically in production and monitoring plans. The supervisory authority uses a risk analysis guideline on induced seismicity resulting from gas production as its assessment framework. The following links also provide information on induced events resulting from gas injection (nitrogen or methane) into the subsurface.
Risk analysis guideline on induced earthquakes resulting from gas production
In response to the Dutch Safety Board (Onderzoeksraad voor Veiligheid = OVV) report: ‘Earthquake risks in Groningen, the cabinet has stipulated that “safety risks should be explicitly analysed in mining companies’ production plans”. The cabinet thus wishes to ensure that safety is fully taken into account in the decision-making process. As a safety risks analysis entails more than just seismic hazards – which has been the focus until now – the Minister of Economic Affairs has asked the State Supervision of Mines (Staatstoezicht op de Mijnen = SodM) to develop a temporary guideline for analysing risks as a result of earthquakes induced by gas production (in Dutch) ahead of a definitive guideline on seismic hazards that is to be developed by operators and research institutes.
The temporary guideline is based on the results of existing studies. Wherever possible, the measures used in the guideline are based on quantifiable parameters found in existing analyses and sources of information. The guideline may be updated or superseded in future in response to new viewpoints and studies.
The guideline covers the risk analysis of seismic hazards (=risk x effect), as required in hydrocarbon production plans (Mining Decree, Article 24.1p). It does not cover the broad risk assessment outlined in the proposed amendment to the Mining Act (increased importance and implementation of safety measures). Nor does it include the interpretation of risks (i.e. what the measures in this guideline mean in terms of, for instance, the possible extent and expected nature of the damage caused by ground movement; Mining Decree, Article 24.1q). The operator has to address this aspect separately in the production plan. With regard to measures to prevent or reduce ground movement (Mining Decree, Article 24.1r) or damage caused by ground movement ((Mining Decree 24.1s), the guideline only indicates the basic conditions for monitoring and risk management.
The temporary guideline is documented in detail in a TNO report on the seismic risks of producing onshore gas fields in the Netherlands: Seismicity onshore gas fields in the Netherlands (in Dutch)
Documents on induced seismicity caused by gas production
TNO has carried out a number of studies, in cooperation with the Royal Netherlands Meteorological Institute KNMI, to delineate the seismic hazards of earthquakes resulting from gas production:
- Seismic hazard of induced earthquakes - Integration of partial studies (TNO/KNMI report, TNO 2012 R11139, 24 December 2012) (in Dutch).
- Seismic hazard of induced earthquakes – Phase 1 report (TNO report, NITG 03-185-C, November 2003) (in Dutch).
- Seismic hazard of induced earthquakes – Phase 2 report (TNO report, NITG 03-186-C, January 2004) (in Dutch).
- Deterministic hazard analysis for induced seismicity in the Netherlands (TNO report 2012 R10198, 25 June 2012).
- Maximum damage caused by induced earthquakes: inventory of studies with applications to the Bergermeer gas storage facility (TNO-KNMI report, 3 May 2011).
- Calibration study on earthquake damage (TNO report, TNO-034-DTM-2009-04435, 11 November 2009).
The Netherlands Journal of Geosciences (Volume 96 - Special Issue 5 - December 2017) published a special issue about seismicity caused by gas production of the Groningen field. All articles are Open Access and are free to download. The articles include various subjects related to seismicity caused by gas production of the Groningen field: from static analyses to geomodelling to hazard and risk analyses.
Documents on seismicity resulting from injection
At the request of NAM, TNO has carried out a literature study focusing on the occurrence of seismicity as a result of injection into the subsurface, the underlying physical mechanisms and their relevance to nitrogen injection. As no case of seismicity resulting from nitrogen injection into depleted fields is known, other similar subsurface injection activities have been studied.
- Literature review on Injection-Related Induced Seismicity and its relevance to Nitrogen Injection (TNO report 2014 R11761, 18 December 2014).
- Synthesis of the main findings from the three main parts of the study (TNO report 2015 R11648, 21 December 2015).
- Description and analysis of field cases of injection in The Netherlands (TNO report 2015 R10906, 5 November 2015).
- Geomechanical modelling of the effects of (nitrogen) injection on fault stability in a reservoir, representative for a typical Rotliegend reservoir in the northern part of The Netherlands (TNO report 2015 R11259, 11 November 2015).
Documents on seismicity resulting from gas storage
These documents relate to the Bergermeer gas storage facility.
- Plan Taqa to prevent or limit ground movement on the basis of measurements obtained by the (micro)seismic monitoring system at the Bergermeer gas storage facility, 31 March 2011 (in Dutch).
- Maximum damage caused by induced earthquakes: inventory of studies with applications to the Bergermeer gas storage facility (TNO-KNMI, May 2011) (in Dutch).