An automated system for continuous monitoring of CO2 geosequestration using multi-well offset VSP with permanent seismic sources and receivers: Stage 3 of the CO2CRC Otway Project

A permanent automated continuous seismic CO2 geosequestration monitoring system for was installed at CO2CRC Otway Project site (Victoria, Australia) in early 2020. The is composed of five deviated ?1600 m deep wells equipped with distributed acoustic sensing (DAS) acting as receivers and nine orbital vibrators (SOV) sources. DAS recording performed continuously by three iDASv3 units. Each SOV operates 2.5 h a time, hence all SOVs operating sequentially (during daytime only) produce single vintage every two days. consists 45 offset VSP transects covering predicted plume migration paths over ?0.7 km2 area. An data processing implemented on-site reduces size from ?1.3 TB/day to ?500 MB/day the results transmitted office daily. repeatability analysis based on pre-injection (acquired May October 2020 before injection start December 2020) shows that variability performance main source non-repeatability while borehole measurements are stable. waveform could reach NRMS value 20 100 % within few However, deconvolution seismograms direct wave 10–15 NRMS.