Risks of loss of injectivity for a CO2 storage operation can impact both the effectiveness and economics of the operation and affect the public acceptance of the methodology. Loss of injectivity can be caused by salt precipitation, in the near-well area, when injecting dry CO2 into saline formation water.

The phenomena of capillary backflow can enhance the precipitation of salt. The applied project will investigate the phenomena of salt precipitation; understanding the phenomena at pore-scale level and upscaling the understanding to mitigate risk of salt precipitation at field-scale injection operations.

The project will study the effect, starting from the pore-scale level with micromodels and further to laboratory experiments with core-size samples and taking it to field-scale demonstration injection. The novelty is to include capillary backflow to understand and model the impact of salt precipitation in the pore space. Numerical modelling of the phenomena can guide mitigation measures for a field-scale injection operation.

The project will collaborate with Gas Storage Denmark, who are planning a CO2 injection demonstration operation at a natural gas storage facility at Stenlille. This provides a unique opportunity to combine laboratory and modelling studies with actual field-scale implementation. Mitigation measures for field-scale implementation of CO2 storage can lower the risk for added costs due to unwanted salt precipitation.

Results from the project can be implemented in future CO2 storage operations, saving costs in the use of CCS as a means for reducing climate impact from CO2 emissions.