Seismic Imaging Capability for Locating CO2 Leakage: A Synthetic Study

Abstract:

The 3D Kimberlina 2 model is built for modeling hypothetical, commercial-scale geologic carbon storage and CO₂ leakage through a real fault at the Kimberlina site in the southern San Joaquin Basin, CA. The model is used for studies in the U.S. National Risk Assessment Program, a collaborative research program among the U.S. Department of Energy’s national laboratories. We use the 2D Kimberlina elastic models with various stages of CO₂ leakage to study the capability of seismic imaging for locating CO₂ leakage plumes. We use the models to generate synthetic surface elastic-wave reflection data, and perform least-squares elastic reverse-time migration to invert for images of P- and S-wave velocities and density. We use the time-lapse differences of the images obtained from noise-free and noisy data to locate plumes of leaked CO₂ in the shallow, middle, and deep formations. Our results show that least-squares elastic reverse-time migration can locate the very early stages of CO₂ leakage with noise-free data, and that the capability decreases with increasing noise levels.