Former Groningen supervisor insists on an exit plan: earthquakes are now also being measured outside the gas field

Jan de Jong is worried. While hardly any gas is being extracted in Groningen, the unrest in the soil has not diminished. On the contrary. Things happen there, says the former Inspector General of the State Supervision of Mines, “that nobody expected. The cabinet has no strategy for that” and the oil companies “make sure they get away” now that gas extraction in Groningen has stopped.

The former supervisor should know. Ten years ago, Jan de Jong was the first to warn of more and more severe earthquakes as a result of gas extraction, but the oil companies Shell, ExxonMobil and their joint venture NAM, senior officials and the government ignored his advice and extracted a maximum of Groningen gas for another two years. Now he warns about the way in which State Secretary Hans Vijlbrief (Mining, D66) wants to close the gas field in Groningen. That will happen this summer or next year, he will make a decision about this this month.

Also read this reconstruction of how oil companies and the cabinet reacted to the severe quake near Huizinge

The 71-year-old De Jong lacks “an exit strategy” for the gas field, he says in the run-up to the parliamentary debate with State Secretary Vijlbrief and Prime Minister Rutte (VVD) this Tuesday about Groningen gas extraction. “You can reinforce and reinforce what you want to reduce safety risks, but as long as you don’t systematically investigate the movement in the subsurface and try to reduce seismicity, mopping with the tap will remain open.”

Will the soil not settle if gas extraction stops?

“No. The soil keeps shaking, houses keep shaking. Inhabitants of the gas field in Groningen must expect hundreds of earthquakes in addition to the 1,622 that the KNMI had registered until last February. Poll chairman Tom van der Lee warned of this when presenting the survey report. But the report, for which I fully appreciate, does not elaborate on it, it has not been discussed in the House of Representatives, and the cabinet is silent about it.”

What exactly are you concerned about?

“While we are extracting less and less gas, the ground in Groningen has not started to shake less. The density of earthquakes is increasing, especially around Loppersum, Uithuizen and Wirdum. An earthquake heavier than the blow in 2012 near Huizinge – the strongest to date – cannot be ruled out. We also see soil subsidence in places where this was never the case. Contrary to expectations, two earthquakes were measured in a number of places outside the gas field in the city of Groningen. Still light, thankfully. But this will also occur in other places where the field moves.”

Also watch this animation about how a Groningen earthquake occurs

How do you explain that?

“This is due to pressure differences that have arisen since 2013. Then, against our advice – irresponsible and ruthless, I still think – the cabinet started to extract considerably more gas, especially in the south of the field. Natural gas flows from places with high pressure where gas extraction has been halted to southern places with low pressure where most of the gas has been removed. Also flowing now water from so-called aquifers – the parts of the reservoir that are filled with water – to the parts that still contain some gas, which leads to a drop in pressure in those aquifers, which in turn causes subsidence and soil subsidence. This causes stresses on fractures in the deep subsurface, which will lead to new quakes. This ‘pressure equalization’ will last for decades, especially if the water continues to flow from the aquifers.”

The density of earthquakes is increasing, and earthquakes are also measured outside the gas field

Jan de Jong (71) former Inspector General

What can be done about that now?

“First of all, you have to monitor and study seismicity, subsidence and reservoir pressure. The State Secretary has allowed gas producer NAM to do this because of its ‘duty of care’. But I would have that monitored by an independent body, with independent scientists, such as the expert panel Knowledge Program Effects Mining. We know how NAM’s duty of care ended after the earthquake at Huizinge. The safety of Groningen residents was ignored, the cabinet gave Shell, ExxonMobil and NAM all the space they needed to maximize gas extraction for the sake of profit.”

But Marjan van Loon of Shell Nederland announced that they are going to close the extraction locations, right?

“Shell wants to stop extraction, fill the wells with cement, demolish the sites and then get out of there as quickly as possible. That’s the worst thing you can do. These wells provide the opportunity to obtain crucial information about the subsoil. Every change there needs to be analyzed carefully. I welcome stopping gas extraction, but please stay away from the wells, don’t break anything. You have to monitor the subsoil, do a study and use the results to take measures to reduce seismicity.”

Can you limit the quakes?

“That needs to be studied. You could think of injecting nitrogen or CO₂ to adjust the underground pressure. This is now being investigated by TNO. You can also spray seawater into the surface to create counter pressure. And maybe you can take natural gas out of one place and pump it back into the field in another, so that the stress around the fractures decreases.”

The State Secretary does not want to experiment with this, he writes to the House of Representatives.

“That sounds very noble. He suggests that he does not want to plunge Groningers into uncertainty. But that uncertainty already exists. The majority of the homes have not yet been reinforced. Now the State Secretary has no plan. He has the wells collapsed, extraction sites dismantled and then waits thirty years for the seismicity to subside.”

The earthquakes in Groningen won’t let you go, will they?

“It is a great injustice that has been done to the people of Groningen. Willingly and knowingly, the cabinet pumped up more gas, ignored the duty of care and the House was informed carelessly and incorrectly. Over the years, this has become increasingly worse, just like with the Supplements scandal. People are seen by the government as objects, no longer as individuals with their own dignity. One resident after another is going to die and if we are not careful, the whole of society.”