Current topics explained by RUG experts


The Dutch government has decided to put an end to all gas extraction activities in the Groninger fields. At the same time, the NAM (the Dutch Natural Gas Company), has been given permission to start ‘fracking’ in the small gas field near Pieterzijl, in order to get as much gas from the location as possible. Is this a good thing?
By Jurgen Tiekstra

Rien Herber

Professor of geo-energy

‘The fact that this is happening is not such a big deal. Over the past few decades, more than two hundred gas wells have been fracked. The technique of fracking is used whenever a gas reservoir has trouble flowing through rock.

In most cases, gas is found in sandstone. If the pores in the sandstone are connected properly, the gas can easily flow into the well. But if the rock pores are too small, it can’t. Fracking causes hairline fractures in the rock to help the gas flow. These days it’s called ‘hydraulic stimulation’, because the term ‘fracking’ has taken on a life of its own because of shale gas.

Shale gas is normal gas, but it’s found in claystone. Claystone has barely any pores and isn’t permeable, which means the gas won’t flow into the borehole. Fracking is the only way to get the shale gas out. Because of all the commotion around this, partially caused by the Gasland documentary, the Netherlands decided that we wouldn’t be doing that. But that’s also because the potential for shale gas is quite small here. But we’ve been fracking in sandstone for a long time. The State Supervision of Mines has protocols in place to ensure that the process is a safe one.

Fracking can also be used for geothermic wells, because those reservoirs also have trouble flowing sometimes. But in geothermic wells, they use water. They drill two holes, approximately a mile apart. They inject cold water into one well and pump up warm water from the other. These wells can be as deep as 2,500 to 3,000 metres. No one in the Netherlands ever protested against this, because geothermal energy has a good reputation, while gas doesn’t. It’s really just a matter of emotions.’

Ruven Fleming

University lecturer at the Groningen Centre of Energy Law

‘Legally and technically speaking there is a difference between conventional fracking, which is what the NAM wants to do in Pieterzijl, and unconventional fracking.

Conventional fracking is done in various type of rock, including sandstone. This technique has been used in the Netherlands since the fifties, just as has in Germany and basically all of Europe. But unconventional fracking in shale (claystone) is new.

Many European countries, the Netherlands included, have laws that prohibit shale gas extraction. But there are two types of prohibitions. The first one is what I call the political moratorium, where a government says that they will ban shale gas extraction until more research has been done. Or they name a final date for the gas extraction. In the Netherlands, that final date is in 2023. Governments can input this moratorium and lift it whenever they want. Then there’s the legal moratorium, or a ban, such as in France or Bulgaria: parliament has published a law that prohibits shale fracking.

Based on the Mining Act of 2003, the exploitation and manufacture of oil and gas requires a licence, in addition to an extraction plan and a measuring plan. The manufacturing plan outlines which techniques will be used, such as fracking. The measuring plan contains the measurements of the earth’s movements, among other things.

Based on the manufacturing plan, I don’t see how ordinary citizens hope to stop the fracking near Pieterzijl, unless they go to court. One example is if a farmer has a source of drinking water near the gas field. But people have to be able to prove that they are personally affected. That’s the crucial point.’

Kees Hummelen

Professor of chemistry and solar panel researcher

‘If you ask me as a Groningen citizen how I feel about the government extracting gas from other areas in Groningen in an attempt to get everything they can from us: I am entirely against it. It’s very clear that we should dial back the gas extraction and focus on the energy transition.

The State Supervision of Mines has banned us from extracting high-grade water from the Zernike area because it might cause issues with gas bubbles. In light of that decision, why would they take a similar risk with a gas field in northern Groningen?

I have been saying for years that it’s time to make the change from gas to sustainable energy sources in the province of Groningen. I’d prefer it if the inhabitants themselves became the energy manufacturers. Many people are opposed to wind energy, but solar is very versatile. We could construct many hectares of solar panels in Groningen with no issues. We have plans in place.

I’m not saying that electricity can easily replace gas. We would also need heat pumps and thermal energy storage installations. I’m old enough to remember when we first started using gas. My mother used to cook with electricity. When I was a teenager, the landscape turned increasingly orange in the night because of the way the natural gas fields were illuminated. Now they’ll go dark again. I may make the transition sound easy, but it’s a process that will take approximately twenty to thirty years.

I’m a typical scientific optimist: I’m perennially convinced that technological development will propel mankind forward. And that progress is happening so fast; just look at what they’re doing using silicon and solar panels. It’s a beautiful revolution.’