SEGJ Technical Conference

CO2 reservoir monitoring by VSP with a permanent seismic source (ACROSS) and Optical-fiber DAS

Abstract Monitoring data was acquired using ACROSS and DAS at the Aquistore CCS site in Dec. 2016 and Mar. 2018. This method can achieve high position repeatability as the source and the receiver positions are fixed. The offset VSP data was processed with 4D regularization methods and calculated repeatability index for evaluating the 4D response. Data acquisition was successful, resulting in highly-repeatability. A difference section between baseline data and repeat data was produced using a systematic processing procedure. The 4D repeatability index within the reservoir section was also calculated. As the repeatability near the reservoir depth was unstable, further data processing is important for detecting 4D responses.