DAS VSP Monitoring of CO2 Plume in Carbonate Saline Aquifer Onshore Abu Dhabi

Summary CO2 sequestration well was drilled in a carbonate saline aquifer in onshore Abu Dhabi. The MMV plan included DAS VSP monitoring program which consists of Zero-Offset VSPs every month, and repeat Walkaway and 3D VSPs after one month then after every four months of CO2 injection. Zero-Offset VSP corridor stacks showed a clear time delay (i.e. velocity decrease) below the top of the perforations as injected CO2 volumes increase every month. 3D VSP processing time-lapse analysis detected similar time delay in the injection zone as observed by Zero-Offset VSPs, showing spatial CO2 plume extension.