Monitoring Integrated Digital Support Tool – for CO2 and hypersaline brine monitoring applied to UK waters (MIDST-UK) (Flexible Funding 2023)

Dr Marius Dewar, Plymouth Marine Laboratory, was awarded funding in the UKCCSRC’s Flexible Funding 2023 call to look at “Monitoring Integrated Digital Support Tool – for CO2 and hypersaline brine monitoring applied to UK waters (MIDST-UK)”.

The ACTOM Decision Support Tool (DST) was designed to aid users in defining a marine monitoring plan over a range of field cases with diverse subsurface geology and environmental marine characteristics. In the Monitoring Integrated Digital Support Tool – for CO2 and hypersaline brine monitoring applied to UK waters (MIDST-UK) project, this DST has been extended to also include monitoring for brine releases (high salinity, high temperature and varied contaminants) based on our recent collaboration with BP to manage reservoir pressure. Case studies are then developed within the UK CCS clusters (East Coast Cluster, HyNet Cluster and the Scottish Cluster, plotted on Figure 1), with extensive data collection and analysis for each site.

Figure 1. Locations of the three chosen CCS projects in the UK

The DST provides a marine monitoring strategy as a technical summary and report based on the site-specific data and user-defined input values. The first and second rows of Figure 2. illustrate the impact potential based on user-specified thresholds under CO₂ leakage scenarios of 10 and 55 t/a, respectively. In a low-leak scenario, the maximum change in pH suggests a negligible impact on marine biota. In a higher leak scenario, the largest reductions in pH are above the minimum extent of impact zone, but it should be noted these values are highly localised.

Figure 2. Outputs from DST. Rows 1-2: impact potential for leakage rates of 10 and 55 t/a, respectively. Rows 3-4: optimal placement of stationary sensors and area of detectable anomalies under the two leakage scenarios

Analysis of the Hypersaline brine production provides vital data on where to place sensors to ensure the impact region remains contained, with the output within the same order of magnitude as the previous study, giving confidence in the ability to perform hypersaline plume analysis using the DST.

The quality of the results from the DST depends on the input data, and most likely operators and regulators would have far greater datasets than the publicly available ones here. Therefore, the results presented should be interpreted with extreme caution with this limitation in mind, and are shown to demonstrate the DST at these locations rather than to provide definitive answers.

The Monitoring Integrated Digital Support Tool – for CO2 and hypersaline brine monitoring applied to UK waters (MIDST-UK) project is led by Plymouth Marine Laboratory, and funded through the UK Carbon Capture and Storage Research Centre (UKCCSRC) Flexible Funding 2023 call, The UKCCSRC is supported by the EPSRC as part of the UKRI Energy Programme (EP/W002841/1). Marius would like to thank Bingjie Jia for her dedication during her Master’s project at Exeter University, assisting in collecting data, analysis and running case studies allowing a full and in-depth analysis during this ambitious study.

Read more on Marius’s Flexible Funding 2023 project page.