CATO 2 | CO2 Capture, Transport and Storage in The Netherlands

SP3 Underground Storage, Monitoring and Verification

Main objective

The objective of SP3 is to demonstrate technical feasibility and monitoring of underground CO2 storage in depleted gas fields, aquifers, coal seams and porous rock. The most important activities are associated with injection and storage capacity, gas-fluid-rock interaction, well-, reservoir- and overburden integrity and issues dealing with monitoring, health safety and environment, i.e.:

To evaluate the potential and performance of geological systems for storage of CO2 in the Netherlands, focusing specifically on the potential pilot field operations presently planned in, among others, depleted gas fields (Rotterdam Area, NE-Netherlands, Limburg Area and on/off-shore W-Netherlands).
To implement monitoring and verification techniques for the implementation of large scale underground CO2 storage. According to the current (draft) EU-directive on CCS, CO2 storage will be admitted to the ETS only in the case that monitoring and verification can be carried out satisfactorily.
Verification will essentially take place by comparing monitoring data with simulated predictions. Large deviations from the predicted behaviour must lead to mitigating measures. In case of leakage, quantification of the fluxes is important not only for HSE reasons, but also for economical reasons. Emitted CO2 must be deducted from the carbon credits provided under the ETS-scheme.

SP3 will address storage capacity, injectivity, CO2 migration, and the effects of gas-fluid-rock interaction and storage system integrity on both short and long time scales. These subjects will be investigated at scales of the well bore system, the reservoir-seal system and the regional geo/hydrological system.

In addition, existing baseline and monitoring data for the selected sites need to be planned, acquired and interpreted. Thresholds for CO2 detection need to be determined based on modelling and laboratory measurements. Closer to the surface, this implies that baseline time-series of natural CO2 emissions need to be determined using groundwater sampling and/or sniffer techniques.

The link of SP3 with initiatives like Lofar-Geo is very strong. The Lofar-Geo project is essentially focused on the installation of a semi-permanent buried monitoring network over a CO2 storage site. Exploitation and interpretation of the data in terms of CO2 migration will be carried out essentially in CATO-2.