Graphic: monitoring concept of the DemoUpStorage project
Comprehensive geo-scientific monitoring and laboratory tests
Before the injection
In the framework of the DemoUpStorage pilot project, different scientific teams carry out extensive measurements before, during and after the injection. Already in summer 2022, the Swiss Seismological Service (SED) at ETH Zurich installed five seismic stations placed in a radius of 300 meters around the injection well in Iceland. The stations consist of broadband seismometers measuring the level of background seismicity. During the injection, these stations will monitor if the CO2 injection produces any induced seismicity. They can also be used to track changes in the subsurface that could potentially occur in connection with the injection of the CO2- seawater mixture and the subsequent changes in the physical properties of the rock.
After the drilling work was completed and prior to the injection, the SED conducted a first series of cross-hole seismic, fibre, ground penetrating radar (GPR), and resistivity measurements in the injection and geophysical monitoring borehole. Along with these measurements, a dense seismic array consisting of fourty nodes was temporarily set up across the injection site.
The data of the high-resolution monitoring campaign will provide a reference dataset and will allow the researchers to get a profound knowledge of the surrounding geological structures. This dataset is also crucial for developing a numerical model of the reservoir, which is the volume where the CO2- seawater mixture is distributed.
Parallel to the work in Iceland, a team of researchers from EPFL conducted laboratory tests with basaltic cores from Iceland. Rock cores were taken from locations close to the injection site and most likely represent the formations that can be found at the site in the relevant depth itself. The researchers exposed the cores to a CO2- seawater mixture for different lengths of time with a maximum time of exposure of 3.5 months. The lab results showed flow reduction, and thus carbon mineralization, already after two months in some of the tested cores. A more detailed description of the laboratory tests will soon be published in a dedicated blog text.