Characterizing Acoustic-Based Reservoir Injectivity Monitoring with Perforation Laboratory Testing

This paper investigates the application of a laboratory experiment to acoustically characterize and monitor carbon dioxide (CO2) injection at the scale of the perforation interval. We perform a perforating laboratory experiment to replicate the flow of supercritical fluid through a perforated casing into a permeable rock formation at reservoir conditions, mimicking carbon dioxide (CO2) injection typical of carbon capture and storage (CCS) operations. We capture acoustic signals during controlled flow experiments at various injection pressures with a hydrophone. Analysis of the spectral content revealed distinct characteristics in the specific acoustic bands, indicating the potential for passive acoustic monitoring to quantify injection processes. In practice, that permanent monitoring would be achieved via distributed acoustic sensing (DAS). We acknowledge the need for further research and development to subsequently derive an equivalent DAS response for quantifying CO2 injection rates at the individual perforation level to improve understanding of CO2 injectivity.