In the South Building of Cardiff University on 10th September 2014 at 17:00, I attended the informative talk of Sarah Hannis titled “Near surface gas monitoring at the CO2 Field Lab, Norway”.
Sarah is a member of British Geological Survey (BGS), which is the UK’s leading centre in earth science information and expertise. She received her MSc (First-class honours) degree in Geological Sciences from Imperial College, London. She has the experience of working as Senior Field Engineer for Reservoir Evaluation Wireline, Schlumberger. Her studies are focusing on monitoring geological CO2 storage, petrophysics, static geological models, and UK and world mineral resources.
Sarah explained the process of CO2 injection in 20m depth at the CO2 Field Lab site in Svelvik, Norway, and monitoring the leakage. Her team injected 1.8 tonnes CO2 in 124 hours. The investigations showed that the areas of surface seepage of CO2 spread more with injection rate. They monitored the field using different methods such as continuous and periodic surveys. Continuous method includes several soil gas locations, CO2 flux chambers, an eddy covariance, and a weather station. The periodic surveys have been done in mobile and static way to obtain soil gas concentration and surface gas flux. It was interesting that the mobile surveys detected different place of leakage from the prediction of modelling. Because of this unpredictability and limited size of seeps, mobile monitoring is preferable in wide areas.
After Sarah, at 17:50 Professor Stuart Haszeldine had a short talk. Stuart Haszeldine is the first professor of CCS in the world and the current director of SCCS at the University of Edinburgh. He has over 35 years research experience in movement and geochemistry of fluids in porous and fractured sedimentary rocks, storage of carbon dioxide in hydrocarbon fields, aquifers and coal, and geological sequestration, establishing a new industry in Carbon Capture and Storage, in the UK, EU and worldwide, radioactive waste disposal, Low, Intermediate and High level, spent fuel, energy sources and policy in the UK and EU, and modelling of sedimentary basins.
He talked about the difficulty of selecting and using geological basins for CO2 storage, seeking test sites in various countries, and the high cost of monitoring injection sites.
These two speeches helped me get more familiar with the monitoring part of CCS: how this process is undertaken in practice and what are the hurdles in finding leakage sources.