Temporal Stability of the Transient Electromagnetic Response with Respect to the Development of Monitoring Techniques

• Applicant: Professor Dr. Klaus Spitzer
• Subject Area: Geophysics
• Term: from 2018 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400686672

In this project, we develop a surface-to-borehole-based transient electromagnetic monitoring technique for the sequestration of CO2 within the subsurface. The challenging aspects are the repeatability of the measurements over time and understanding the processes leading to changes in the conductivity of the reservoir by CO2. To guarantee the repeatability it is crucial to prove the temporal stability of the measuring system. We therefore investigate influences on the temporal behavior of the measuring system arising from assembling and disassembling the measurement setup at a known field site with a fixed survey layout. The repeated measurements will also help to understand seasonal effects on the recorded data. Our virtual electromagnetic experiments have shown that, due to the injection of 600 t of CO2, changes > 5% can be expected at the CO2 field research station in Brooks, Alberta (Canada). A repeat survey on site is intended to prove that the transient electromagnetic method is principally suitable to detect the sequestration process. Finally, we investigate the possibilities of spatially reconstructing the CO2 injection using our three-dimensional inversion software.

• DFG Programme: Research Grants