Search for seismic velocity changes associated with CO2 injections at the carbon capture and storage site in Decatur, Illinois

Taka'aki Taira, J. Ole Kaven, Justin L. Rubinstein, & Elizabeth S. Cochran

Submitted August 14, 2019, SCEC Contribution #9660, 2019 SCEC Annual Meeting Poster #044

We explore the temporal variations in seismic velocity at the Decatur carbon capture and storage (CCS) site by using seismic interferometry with ambient noise. A dense local seismic network has been installed and operated by U.S. Geological Survey since 2013, and the network consists of 14 stations with broadband sensors and borehole geophones. A single-station cross-correlation method [Hobiger et al., 2014, Geophys. J. Int.] was applied to continuous seismic recordings collected from 2014 through 2018 from the USGS network. Our preliminary results identified that the majority of stations exhibit a gradual reduction of seismic velocity (about 0.05%) since the middle-late 2017. This observed velocity reductions is most clear in a frequency range of 2.0-8.0 Hz, which suggests that the velocity change likely occurred in the top few kilometers of the crust, and this reduction might have been related to the on-going CO2 injection at the CSS#2 well that started in April 2017. However, other environmental effects (e.g., precipitation) can also modulate subsurface velocity. We systematically characterize velocity changes with other geophysical data to explore the underlying mechanism of the observed velocity reduction.

Citation
Taira, T., Kaven, J., Rubinstein, J. L., & Cochran, E. S. (2019, 08). Search for seismic velocity changes associated with CO2 injections at the carbon capture and storage site in Decatur, Illinois. Poster Presentation at 2019 SCEC Annual Meeting.


Related Projects & Working Groups
Seismology