Detailed observation of any leakage pathways is essential for sound and safe CO2 storage. Fibre optic distributed sensors provide a cost-effective solution for fault characterisation and caprock integrity monitoring.
Monitoring the temperature in wells offers a traditional method of continuously monitoring the injection of CO2 to facilitate the early detection of leaks or gas migration. As a result, many CO2 projects routinely instrument wells with permanent real-time DTS monitoring systems.
The use of iDAS™ and Carina® Sensing System can complement this measurement by adding acoustic detection for gas migration and leaks. Leakage pathways can be highlighted by time-lapse seismic surveys or the occurance of microseismic events.
The iDAS performance allows seismic data to be acquired with dense spatial sampling and high temporal resolution for better characterisation of faults and borehole leakage.
Retrofitting an iDAS to an existing monitoring system is relatively easy for Silixa due to the unique ability of the iDAS to operate on both single-mode and multi-mode fibres. iDAS does this without the need to introduce additional apparatus and without any appreciable difference in data quality. This enables the operator to utilise legacy fibres originally intended for DTS systems.