Carbon Dioxide Migration Along Faults at the Illinois Basin—Decatur Project Revealed Using Time Shift Analysis of Seismic Monitoring Data

Abstract Large scale geological storage of CO2 is being deployed worldwide to reduce greenhouse gas emissions to the atmosphere. Previous modeling studies have investigated the potential for CO2 migration along faults. We observe such migration at a commercial‐scale, demonstration CO2 storage project, including subsequent emergence of the CO2 into overlying permeable layers. Previous attempts at interpreting the time‐lapse seismic data using amplitude attributes were hindered by noise from the limited survey repeatability combined with a weak signal due to the stiffness of the rock. Here we apply an alternative interpretation of the seismic data using time shift attributes, resulting in clear plume anomalies. In addition to migrating up the fault, we observe the plume diverted by the start of injection at a neighboring project. This work provides field observations of theorized plume behaviors and demonstrates an alternative approach to overcome challenges in interpreting seismic monitoring data for geological CO2 storage.