From “best information meeting so far” to “what a theater”. Floating in between was the opinion of the Schoonebekers at the well-attended information meeting about wastewater injection from oil extraction. RTV Drenthe summarizes the state of affairs.
Whether the wastewater injection will actually continue; No one doubts that anymore, although the Ministry of Economic Affairs and Climate (EZK) has not yet issued a permit. The State Supervision of Mines (SodM) has already given its approval to how the Dutch Petroleum Company (NAM) wants to pump the wastewater into the almost empty gas field under Schoonebeek.
The clearest explanation of how the wastewater injection will take place and the risks came from the NAM and the SodM. Project leader Jacob Spiegelaar of the NAM explained to questions from the audience that the wastewater injection in Schoonebeek will be done differently and more safely than in Twente. “First of all, plastic pipes are used through which the water flows. Iron pipes such as in Twente can be affected by corrosion, but this does not happen with plastic.”
Two existing Schoonebeker gas extraction locations will be made suitable for water injection. In one place, water from gas extraction has also been pumped back into the almost empty gas field in the past. But both locations will have four newly drilled water injection wells.
Spiegelaar then showed that the first 100 meters of the well will consist of four metal pipes with cement layers in between and finally the plastic inner pipe. That is in the groundwater area. Up to a depth of 600 meters the casing is triple. Then you have passed the biosphere (at 500 meters) and you are already in the bedrock. At 3000 meters, the water is pumped into the limestone layer from which the natural gas has disappeared. “By working with a plastic inner tube for the entire distance, we can also use fewer substances against corrosion and mining aids,” Spiegelaar explains.
“But with a plastic tube, it is much less easy to monitor whether everything is still OK deep down there?” asked a woman in the room. “That’s right, because the inspection equipment is attached to a steel cable and that can damage the plastic pipe. But with steel pipes we measure the wall thickness of the pipe and whether it has not decreased due to corrosion. This is not necessary with plastic,” Spiegelaar explains.
Britt van Vleuten from SSM explained in detail why SSM has come to the conclusion that injecting the wastewater is still the best method. “Completely purifying it, removing all the substances and leaving a mountain of salt, produces many above-ground negative environmental effects. Partially purifying the water flow and continually reusing it for oil extraction also produces too many environmental effects. But NAM must continue to look at other processing methods in the future.”
Van Vleuten of SSM was clear: “The risk in mining is never zero. That is impossible. NAM must do everything to keep the risk as small as possible.”
The SodM investigates at the front whether what the NAM wants is responsible and safe. “We will provide advice on this to the Ministry of Economic Affairs and Climate Policy, which will grant the permit. We will come and inspect the water injection announced and unannounced to ensure that everything is happening properly and as agreed. We keep an eye on the composition of the water, we monitor the pipes and the injection wells, We keep an eye on the almost empty gas field where the water enters and we come if there are any complaints or nuisance.”
But the underground risks in Schoonebeek are naturally different from those in Twente, according to the SodM. Van Vleuten’s explanation: the gas field under Schoonebeek behaves differently from the large Groningen field. Simply because the fractions are smaller. If there is a lot of tension on the large faults in the Gronigerveld and “the two faults slip past each other” then you have an earthquake. A ground shaking or earthquake below Schoonebeek is also possible, but they are probably smaller and less intense than in Groningen.
“Why then has NAM stipulated in the agreements at the relief table that oil extraction and wastewater injection will only stop above an earthquake of 3.0 on the Richter scale. At 2.3 or 2.9 you can continue quietly,” asked one man in the room the NAM.
Project leader Spiegelaar then said that even in the event of an earthquake of less than 3.0 with a major impact on the environment, the soil behaves differently and it will be examined whether continuing to extract is still wise. And at 3.0 or more, NAM immediately stops production permanently. “We don’t have to do that, but we promise to.”
Maarten Pluymaeckers from TNO Geological Survey came up with a lesson about land subsidence. This occurs in the shallow subsurface through subsidence and peat oxidation and in the deep subsurface through gas and oil extraction. The groundwater that is kept low or adjusted in agricultural areas also plays a role. If your house is partly on sand, and that of the neighbors is on peat, then that also matters whether or not you are affected by subsidence. “But it is very clear, in areas where there is gas or oil extraction, the ground sinks slowly and evenly. By injecting water into the gas field, the ground also rises again.”
“Can you completely eliminate the subsidence under Schoonebeek through water injection?” the audience asked. Pluymaeckers: “In theory yes, but the question is whether you should want it.” This is partly due to the pressure in the gas field.
“What do you do with the outcome of the survey that Dorpsbelangen Schoonebeek has conducted?”, said village interests chairman Jos van Hees. The survey showed that 57 percent of residents do not want wastewater injection, while 26 percent do. There was a moment of silence, after which the (repeated) dry announcement came from Nicole Hardon of EZK that the State Secretary said he would take the results of the survey into account in his decision on wastewater injection. But how this will be taken into account and how heavily remains unclear.
The same question was later asked again from the audience to councilor Jan Bos (Wakker Emmen), who was confronted with the fact that the municipalities are the representatives of the residents. Bos: “We represent the interests of our residents and also draw attention to their voices. We will certainly draw the EZK’s attention to the survey.” But even before the results of the survey were known, the mayor and aldermen of the same municipalities sent a letter to EZK stating that they ‘understand’ and think it is ‘logical’ that NAM wants to put the wastewater in the gas field.
Much to the frustration of the NAM, nothing could yet be said about the contribution that the Schoonebeek region will receive from the proceeds of oil extraction. NAM has already put a (still unknown) offer on the table and is eager to announce it. But The Hague is not that far yet, so the hiccup must be with EZK or State Secretary Hans Vijlbrief. The government receives the most money from oil extraction and cannot lag behind or be inferior to the NAM.
Vijlbrief was supposed to send a letter to the House of Representatives last November about the contribution for the region. It was the missed opportunity of the evening in Schoonebeek, because everyone wanted to know. The oil extraction proponents of Naoberschap Oliedorp are confident that they will soon be able to raise a glass to the money that will become available for the region.
The long meeting in Schoonebeek was somewhat ‘hijacked’ by two residents of New Amsterdam who suffered a lot of damage and consequences from the subsidence in that area. Perhaps logical, because those residents have tried to get compensation through the Mining Damage Commission, but because it has not been conclusively established that their damage due to the subsidence on site is solely due to oil or gas extraction, the door keeps slamming shut.
You can’t blame those people for trying it through a different door. They seized the opportunity in Schoonebeek to have a direct confrontation with the NAM and the government. As a result, the Schoonebekers’ questions were somewhat obscured.
Stop Afvalwater Schoonebeek (SAS) believes that after the meeting there are “still many questions and few answers.” Noaberschap Oliedorp was satisfied and treated to oliebollen after the meeting in the beautifully renovated church.