Why is there so much wastewater from oil extraction?
NAM stores most of the water that comes up during oil extraction as steam in the ground to extract the oil. Without that water, the oil will not rise to the top.
The NAM stopped oil extraction in Schoonebeek in 1996. From 1943 onwards, oil was extracted with nozzles: about 250 million barrels. Because it became increasingly difficult to extract the tough, thick, viscous oil from the ground, extraction was finally stopped in 1996. All pump jacks, pipelines and drilling locations were cleared.
In 2004, NAM again looked at resuming oil extraction with modern pumps and water. By heating water to steam at 300 degrees and injecting it into the oil field, the viscous oil becomes less viscous. This makes it easier to extract the oil with modern pumps. The 8,000 cubic meters of ultra-clean water required per day is made in a special pure water factory.
When the water with the oil comes back to the surface, it is now very salty. That salt comes from the deep soil. And the water contains chemical and hazardous substances. These are partly substances that are in that deep subsurface and also come to the surface. Substances that you don’t want above ground either. In part, these are chemical mining additives that NAM adds during oil extraction to ensure that extraction points, pipelines and installations are affected as little as possible.
Once back above ground, water and oil are separated. Since the restart of oil extraction in 2011, the polluted water has been pumped into empty gas fields in Twente. Ultimately, there was a lot of resistance to this in Twente, which led NAM to choose to put the water in empty gas fields as close as possible to oil extraction. The picture showed empty gas fields in Oosterhesselen, Dalen and Schoonebeek, among others. Of these, only Schoonebeek remained.
Right through that process is the reconsideration that NAM is required to make every six years by the Ministry of Economic Affairs and Climate Policy whether injecting untreated wastewater into empty gas fields is still the best solution. According to NAM, this is still the case.