The Dutch State Supervision of Mines (SSM): Gas production needs to be reduced significantly for the safety of the people in Groningen
The Dutch State Supervision of Mines advises the Minister of Economic Affairs and Climate to reduce gas production significantly for the safety of the inhabitants of Groningen. "A major intervention is necessary in order to probably meet the safety standard and to reduce the risk of damage. Despite our inability to predict accurately which earthquakes will occur at which level of production, we advise the Minister to reduce the gas production as soon as possible to a maximum production level of 12 billion cubic meters per annum. The uncertainties in this assessment are large. We therefore choose to be on the conservative side. After all, it concerns the safety of the inhabitants of Groningen" says Inspector General of Mines, Theodor Kockelkoren.
Immediately and completely close the Loppersum clusters (Ten Post, Overschild, De Paauwen, 't Zandt and Leermens).
The Loppersum clusters should be closed immediately and completely. This prevents the clusters of being deployed at high capacity during a significantly cold period. Running the Loppersum clusters at full capacity could significantly increase the probability of more and possibly heavier earthquakes. There is a possibility that the opening and shut in of these clusters initiated the Zeerijp earthquake on the 8th January 2018. Ceasing production is also expected to have a positive effect on the seismicity in the short term (3-6 months).
Limit the total production offtake from the Groningen gas field as soon as possible to a maximum of 12 billion cubic meters per year
The best assessment SSM can currently make is that, at a production level of 12 billion Nm3 per year, the calculated risks in the period 2018 to 2022 will -with reasonable certainty- meet the personal safety norm. SSM understands that this number suggests that it is possible to accurately determine at which production level the safety norm is met. However, this is not the case.
SSM has applied a uncertainty margin when advising the recommended production level to deal with the major uncertainties. As a result of the applied margin, the safety norm is expected to be met with an estimated probability of 90%. With these production measures SSM expects to return to ‘code green’. This means that the likelihood of earthquakes (and also the heavier ones) is expected to decrease strongly, with damage being prevented and limited as much as reasonably possible.
Immediately limit the fluctuations in production from the Bierum cluster to a maximum of +/- 20%
The Bierum cluster is situated nearby the Loppersum clusters. This cluster can continue to produce, however fluctuations must be limited immediately to +/- 20% due to the fact that these have an effect in the Loppersum area and might initiate earthquakes.
Limit the regional fluctuations in the production of the other clusters as soon as possible to the current level of +/- 50%.
If the proposed measures are implemented, the limitation of fluctuations for production for the entire Groningen gasfield can be abandoned.
The perception of safety is taken into account
The earthquake at Zeerijp on January 8 has had a major impact on Groningen. SSM appreciates that there are consequences of gas extraction beyond safety risks and damage to buildings. She also recognizes that the earthquakes cause feelings of insecurity and anxiety, and depreciation of real estate. As a result, the consequences of gas extraction continue to impact the feelings of safety and thereby the well-being and in part even the health of people. SSM has taken notice of the Council of State considerations of the nature and extent of these social consequences as an independent substantial factor of consideration.
Theodor Kockelkoren: "The perception of safety of the Groningers also played an important role in our advice. I notice that the feelings of insecurity and the social consequences of gas extraction are increasing. In addition, with continued pressure drop as a result of production, seismicity will increase again raising the risk posed by earthquakes. I therefore expect that the gas production will need to be reduced further in the future, if necessary to zero.”
Assessment by the Minister of Economic Affairs and Climate
The immediate cause for this advice is the earthquake at Zeerijp on January 8, 2018 with a magnitude of 3.4 on the Richter scale. As a result, the highest level of the ‘measurement and control protocol’ was reached: the so-called intervention level (code red). SSM proposes the current measures to return to the cautiousness level (code green) thereby expectedly also meeting the personal safety norm. The reduction of gas production may have consequences for the security of supply of gas to companies and households. It is not the role of SSM as the supervisor of the safe extraction of gas, to take these factors into account. Gasunie Transport Services (GTS) advises the Minister on security of supply. The Minister will make an assessment of the safety risk and the gas production level necessary for security of supply. The minister ultimately determines which measures must be taken by the NAM.