2D parallel simulation of seismic wave propagation in poroelastic media to monitor a CO2 geological sequestration process

Abstract

Geological sequestration of carbon dioxide CO2 involves storing CO2 beneath geological formations to reduce atmospheric emissions. Typically, CO2 is pressurized into a liquid state and injected into porous rock formations. Monitoring this process relies on seismic data. For the effective monitoring of seismic wave propagation in extensive formations, a highly efficient and robust algorithm is essential. We developed an efficient approach to alleviate the computational workload associated with simulating CO2 sequestration using the staggered grid finite difference method. The method developed was applied to a moderately complex medium which represents pre- and post-CO2 injection of Utsira Formation, North Sea. The model was developed for two scenarios, representing the stages before and after the injection of CO2 into the Formation. The effect of CO2 was observed and picked efficiently in the reservoir by the algorithm developed for the scenarios before and after the injection of CO2. We could see the brightening of reflections with an increased CO2 saturation in the post-CO2 injection cases. The method developed greatly reduces the computational requirement of the simulation which makes it more efficient for large scale applications.