"Assessment of storage capacity and monitoring the storage locations are the most important issues associated with CO2 storage," says senior geologist Svein Staal Eggen in Gassnova.
"In the broadest sense, petroleum technology is used in the work with CO2 storage. One of the challenges involves finding out how much you can inject over time. Another is quantitative monitoring of what the storage locations contain, and discovering leaks," he says.
The capture aspect has received most attention in CCS research so far, both in CLIMIT and CO2 research in general. The industry has gotten involved with this activity because it sees a future market connected to CO2 capture. The efforts on CO2 storage have not been as significant, but this year, CLIMIT has budgeted nearly NOK 54 million for R&D projects associated with storage.
Special adviser Aage Stangeland in the Energy Department in the Research Council of Norway says that this is approximately half of CLIMIT's R&D budget for 2011.
"The industry has not had any economic drivers for R&D on storage yet. The challenge is achieving results through the storage research that the industry can use," he says.
Stangeland points out two important research areas within storage where there are significant knowledge gaps. One involves understanding the pressure build-up in storage areas. The other area, which receives significantly more attention, is storage of CO2 in combination with enhanced oil recovery (EOR).
"The research associated with enhanced oil recovery was tabled for awhile, but is now being discussed again. A problem being solved is preventing CO2 from coming up with the oil. We want project applications within this field in connection with new announcements from CLIMIT," Stangeland says.
Significant Norwegian potential
A subsurface deposit area for CO2 must consist of two different types of rock: A porous rock for storage and a dense cap rock to prevent leaks. Norway has areas on the continental shelf matching this geology.
"Norway has a large theoretical storage potential on the Norwegian shelf. While plans for CO2 storage in Germany are being met with opposition, because it involves storing CO2 in the subsurface on land, we do not have similar opposition against storage on our continental shelf. If Norway facilitates the infrastructure, storage could provide a foundation for new industrial activities," says Aage Stangeland.
He believes the possibilities in the future will facilitate a wide spectrum of deliveries to such a storage industry, from development solutions to sub-deliveries of metering instruments, sensors and simulation programmes, to mention just a few.
Learning from nature
But can CO2 be stored in a safe and stable manner for a thousand years? Svein Eggen in Gassnova has worked extensively on this question.
"We know that nature has done this "by itself". We know of natural occurrences of CO2 and natural gas that have collected for millions of years. Furthermore, there are a large number of natural gas storage facilities in the world, so this is not completely new. However, we do not have much experience in studying man-made CO2 storage. Sleipner has been studied for ten years, and indicates that it is possible.
Access to suitable storage locations has not been a problem so far, Eggen continues:
"However, we need to start projects to find out how storage should be implemented. In the same way as when the oil development started, we don't have an overview of all the issues before we start and gather practical experience. The challenges must be solved through projects," he says.
To acquire practical experience with injection of CO2 in the subsurface, CLIMIT has provided support to establish field laboratories on Svalbard and in Hurum. At Longyearbyen CO2 Lab, four wells have been drilled to examine a possible reservoir 670–970 metres below the subsurface. Water is pumped down to simulate CO2, and injection of CO2 is planned. Longyearbyen has coal mines and Norway's sole coal power plant.
At Svelvikryggen in Hurum municipality, a field laboratory for CO2 has been established in a 300-metre thick moraine where sandpits have been run. This is not a sealed reservoir, but the objective is to gather knowledge about how we can monitor the movement of CO2 in geological formations. It is important to be able to discover possible leaks of CO2 as early as possible.
Some examples of CO2 storage research in CLIMIT
Two major projects are nearing completion:
- MatMoRa (Mathematical Modelling and Risk Analysis) uses mathematical modelling of CO2 storage. The goal is to develop analytical and numerical tools for geological storage of CO2.
- SSC Ramore (Subsurface Storage of CO2 – Risk Assessment, MOnitoring and REmediation) addresses geochemical aspects of storing CO2 in the subsurface.
Two new projects in CLIMIT:
- Efficient CO2 Absorption in Water-Saturated Porous Media through Hydraulic Fracturing will generate knowledge about hydraulic fractioning as a tool to increase CO2 absorption in porous rocks saturated with water
- Permanent CO2 Storage by In Situ Injection in Ultramafic Rocks will develop quantitative models for transport, reaction and deformation processes with injection of CO2 in rocks rich in silicate. This will provide knowledge about storage through mineralising of CO2
CLIMIT has several expertise projects where industry companies are partners.