Daniel studies CO2 sequestration in the Baltic


To reduce our CO2 emissions, we can implement more effective energy use and replace fossil fuels with renewable energy sources. But we can also stop the CO2 from entering the atmosphere in the first place. 

Daniel Sopher has just defended his PhD thesis, in which he explored the potential sites for CO2 sequestration in the sedimentary succession in the Baltic sea. 

- To store CO2 in the ground, we need three things, Daniel says. First of all, there needs to be a reservoir rock - a porous sedimentary succession such as sandstone, that can take up CO2 like a sponge. Furthermore, the reservoir needs to be situated fairly deep, at more than 800 meters depth, to be precise. And finally we need a gas trap, such as a non-permeable rock or sediment that stops the CO2 from leaking out once it is inserted into the reservoir. In other words, these requirements are very similar to the geological environments that can host rock oil and gas. 

Schematic illustration of carbon sequestration (Sopher 2016)

In the 70's, the Swedish oil company Opab were desperately trying to find petroleum in the Baltic, to emulate the success of the oil boom in neighbouring Norway. We all know how that went - not very well! But the data generated by the oil exploration is valuable still today. 

- All of the thousands of seismic profiles commissioned by Opab have so far been virtually inaccessible, but I have now digitised and reworked them so that they are useble again, Daniel says. I find it a bit ironic that we are using 40 year old data from failed oil exploration to find solutions to the current climate crisis! 

Map over the Baltic sea including all the seismic profiles commissioned by Opab in the 1970's, recently used in Daniels dissertation. (Sopher 2016)

Based on the old measurements from the 70's, reworked with modern methodology and algorithms, Daniel has been able to construct a first regional sedimentary succession down to the crystalline basement. After that, he has devoted endless hours to identify potential future CO2 reservoirs, and he has also attempted to quantify the total volumes that could be sequestered into the basement. 

- Sweden alone produces something in the order of 64 megatonnes of CO2 every year. My conservative estimates predict that we can store at least ten times that amount in the Baltic reservoirs identified in this study, Daniel explains. There is still a lot of science waiting to be done before we are ready to start sequestering, but I believe this is an important step towards that goal!

A simplified illustration of the different kinds of CO2 reservoirs that has been identified in the Baltic (Sopher 2016)

​Daniels research is a part of a large project at the Geophysics programme at the Department of Earth Sciences that has been funded by the Swedish Research Council.  Read more about the ongoing research on CO2 sequestration here!

/Börje Dahrén

News archive 2016

Last modified: 2023-04-24