“The answer is a definite yes”, says Ole Gunnar Tveiten, geologist at AGR, regarding the possibility for Norway to maintain oil production in the years to come and at the same time reducing emissions of CO2.
CO2 displaces the oil
“CO2 for increased oil recovery – CO2-EOR (Enhanced Oil Recovery) – is a method that can help us make better use of our producing fields, while at the same time removing CO2 from the atmosphere”, explains Tveiten.
CO2-EOR is well known, both in Norway and in a number of oil-producing countries such as the USA, Canada and China. The Norwegian Petroleum Directorate, Sintef and other Norwegian professional groups have been conducting research on CO2-EOR for a number of years.
In short, the method involves injecting CO2 into a producing oil field in order to increase the recovery rate. According to Tveiten, CO2 is very suitable as a medium for this.
“When CO2 gas is injected beyond at least 800 m depth, it is compressed into a liquid as a result of pressure. This liquid has similar flow properties to oil, and thus displaces the oil from the pores better than water does”, Tveiten explains.
Climate-friendly tail production
A report prepared by NTNU, based on 30 years of experience from dozens of other oil fields in the world, shows that the recovery rate can be increased by 7-15 percent relative to the oil originally in place.
From a climate perspective, oil production is assessed based on kg CO2 per barrel of oil produced, which also triggers a CO2 tax. In certain mature fields on the NCS, emissions per barrel are increasing strongly as a result of high water cuts of up to 98%. The Johan Sverdrup field, however, pulls down the average for the NCS significantly.
“Increasing the oil output during the final years of production can therefore help reduce greenhouse gas emissions per barrel of oil produced. Injection of CO2 that is permanently stored can be added to that”, Tveiten argues.
The geologist also refers to a study carried out by Sintef in 2017 where the researchers identified 23 mature oil fields in the North Sea where CO2-EOR could be suitable, including Ekofisk, Brage, Oseberg Sør, Troll, Gullfaks, Snorre and Statfjord.
In the study, it was simulated that if up to 70 million tonnes of CO2 per year were injected into the 23 fields over 40 years, it would have led to the extraction of 1.8 to 2 .2 billion extra barrels of oil. This corresponds to the entire Snorre field. As a comparison, Norway’s total emissions are approximately 50 million tonnes of CO2 per year.
We have not had CO2 available for injection, as they have had in the USA and Canada.
CO2-EOR can be profitable
Today, existing projects and ongoing developments are far from good enough to achieve climate goals. Longship – the most advanced CCS project in Norway – has cost NOK 27.6 billion, of which NOK 17.9 billion has been financed by the Norwegian state and taxpayers. However, the capacity is a fraction of the 300-600 million tonnes of CO2 per year that the EU has set as a target to store by 2050.
“We would benefit from seeing concrete plans for large CO2 storage sites, but that can be expensive. The degree of state funding in other countries is, to put it mildly, uncertain”, Tveiten adds.
The geologist does not envisage that CCS as a climate measure will succeed unless the projects are profitable. In this context, CO2-EOR scores well.
“EOR extends the life of fields, which means reusing existing infrastructure and providing funds to finance new CO2 storage projects. It will also reduce the environmental and climate footprint”, claims Tveiten.
We ask why CO2-EOR has not been adopted in Norway.
“We have not had CO2 available for injection, as they have had in the USA and Canada. The research that has been performed in Norway on CO2-EOR has been done under the assumption that the greenhouse gas will at some point become available in the North Sea”, Tveiten says.
At this point in time though, it is unlikely that a CO2-EOR project on the NCS could be realised through importing the gas. The explanation for this lies in the fact that in 2020 the EU launched a classification system (taxonomy) for sustainable activity.
“The European Commission’s taxonomy for the phasing out of fossil energy lays down very strong guidelines for, among other things, the financing of projects. An EOR project cannot qualify for support from the EU, and will also have problems obtaining other funding from institutions and investors because it is not properly labelled as green”, Tveiten adds.
The result is that oil companies in Norway, and in other oil-producing countries in Europe, will be reluctant to make such investments. Without external funding, they will carry all the risks themselves.
Research on CO2-EOR: Positive for the climate
Tveiten believes that CO2-EOR can and should be accepted by the EU in light of the energy crisis and the important role Norway has gained as the largest and most stable supplier of gas to the continent.
Furthermore, the EU has very high ambitions for CCS – several hundred million tonnes of CO2 are to be stored annually by 2050 – but very little has so far been realised.
“It has been documented in several reports that CO2-EOR stores more of the greenhouse gas than is emitted through burning the extra oil we collect. The accounts are climate-positive and profitable”, Tveiten argues.
One of these reports is the Sintef study from 2017 mentioned earlier in the article, which focused on the EOR potential for Norwegian oil fields. The diagram shown here clearly depicts that CO2-EOR on the 23 Norwegian oil fields will store more CO2 than what is released into the atmosphere by burning the extra volumes of oil.
It’s urgent
“If logic and common sense prevail, we should be able to expect good news from Brussels.” Tveiten is cautiously optimistic, but stresses that it is urgent. “Time is running away from us.”
“The method is time critical. On the NCS, we have many fields that are nearing the end of their lives, they are nearing shutdown, and when that first happens, the infrastructure is dismantled. In addition, it often takes two to three years to carry out the necessary CO2-EOR studies for a given field, so if this is something we want to realise on the NCS on a larger scale, we must get started.”
Tveiten believes that CO2 for increased oil extraction is feasible in Norway even without “the green stamp”, as long as the will is there. “However, at the Ministry of Petroleum and Energy, the Norwegian Petroleum Directorate and the largest players on the Norwegian continental shelf, it seems that the taxonomy dominates the decisions.”
CO2-EOR is a self-financing climate measure and should be able to fall under the EU’s taxonomy as sustainable.
Not fully dependent
Tveiten further points out that we are also not fully and completely dependent on deliveries of CO2 from Europe to make this happen.
“A Norwegian offshore gas power plant, powered by Norwegian gas, and which captures and stores the CO2 emissions through CO2-EOR would be one way to do it.”
But also in Norway, a gas power plant with capture and storage of CO2 will be subject to the EU Commission’s taxonomy system, which makes financing more demanding.
The geologist is an advocate for CO2-EOR as one solution that can secure Norwegian supplies of low-emission oil in the coming years, which also means getting a step closer to zero-emission targets. “The method should be part of the energy transition”, he says.
“CO2 for increased oil extraction is certainly something that should be able to happen. It is a self-financing climate measure and should be able to fall under the EU’s taxonomy as sustainable. I hope that politicians and governing authorities make arrangements for CO2-EOR to be realised on the Norwegian continental shelf”, concludes Ole Gunnar Tveiten.
