Storing Swiss CO2 in Icelandic Basalt: the DemoUpStorage Geophysical Monitoring Project

Summary Here, we describe the testing of geophysical techniques to monitor and evaluate a pilot site for in-situ CO2 mineral storage in Helguvik, Iceland. In addition to hydraulic spinner tests and borehole logging data, the stratigraphic sequence of the reservoir was characterized using drill cutting samples. The porosity network and flow characteristics of drill cores were examined in laboratory both before and after they were exposed to saline water that was enriched with CO2. Both before and during injection operations, cross-hole seismic measurements were carried out. At the same time, all of the wells underwent single-hole electrical resistivity measurements. A seismic array of 3D nodal geophones and a backbone seismic network positioned around the injection site were used to monitor the background seismicity and any seismicity that might have been caused by the injection activities. The datasets depict a coherent and detailed image of the targeted reservoir.