3D modelling for time-lapse cross-well CSEM monitoring of CO2 injection into brine filled reservoirs.

Borehole EM Monitoring at Aquistore: Final Report to the Carbon Capture Project (CCP)

“…We see increased relative strength of the anomalous vertical electric field away from the source dipole where source fields are weaker, with maximum relative anomalies of 0.014, 0.027, 0.04 and 0.12 for 1, 2.5, 5, and 10 kt CO 2 , respectively. These anomalous fields are much smaller than the previously mentioned results of Swanepoel et al (2012), presumably due to the destructive interference of image dipole fields in the resistive basement immediately below the CO 2 mass (as discussed above).…”

“…Thus, single-well, cross-well, or wellbore-to-surface measurements can be more sensitive to the injection or withdrawal of gas at large depths. For example, Swanepoel et al (2012) show 2% to 100% anomalies in synthetic single-well electric field data 300 m from 0.1 to 10 kt (kilotonnes) CO 2 injected in a resistive layer in a homogeneous background.…”