Carbon Capture and Storage (CCS) projects play a role in reducing CO2 emissions, and when I started my Master’s program at Fluxlab, I began working on the Aquistore project in Estevan, Saskatchewan. The Aquistore project is a comprehensive, full-scale CCS geological field laboratory, capturing and injecting CO2 from the Boundary Dam Power Plant into 3400 m deep saltwater-infused sandstone. The project is storing up to 2100 tonnes of captured CO2 each day and has already injected 107,000 cumulative tonnes. Since CO2 is continuously injected it is important to monitor the injection well and its surroundings which helps demonstrate storage containment to both regulators and the general public and increases acceptance of the technology which paves the way for future large-scale implementation.
There are several parallel monitoring programs used for monitoring storage containment, traditionally known as Measurement, Monitoring, and Verification (MMV) techniques. MMV programs at Aquistore include surface-based programs (surface soil gas monitoring, groundwater monitoring, tiltmeters, GPS, and InSAR reflectors) and downhole programs (surface and passive seismic monitoring, and reservoir fluid sampling). Fluxlab operates in the surface soil gas monitoring sector, where we use gas concentrations and isotopes of CO2 as tracers to monitor storage containment. The Aquistore surface soil gas MMV program comprises regular sampling at 49 sites distributed across ∼49 km2 centered on the injection well. The sampling site distribution is based on the potential maximum extent of CO2 plume. A continuous monitoring station near the injection site at Aquistore has been installed, because risk-based analysis shows that well failures would be the most probable cause for containment loss.
The MMV program at Aquistore started in 2012 and is divided into two basic stages, pre- and post-injection monitoring. Soil gas samples were collected in three visits pre-injection: November 2012, September 2013 and November 2014. This pre-injection monitoring establishes regional baseline levels for all the tracers, allowing us to look for deviation in subsequent post-injection visits. Post-injection monitoring has been done bi-annually since July 2015 to monitor containment. In 2017, my involvement with the project began and I have conducted two separate field studies with Katlyn, Alex, and Susan. Field work requires perseverance in the face of Saskatchewan’s harsh environment! The summer field work is accompanied by hundreds of ticks. We have to tape our clothing shut at our wrists, waist and ankles to prevent ticks from crawling inside and burrowing into our skin. We also had to contend with barb wire and electric fences that were intended for grazing farm animals. Our record was facing eight barbwire fences while trying to reach a single sampling well, and after jumping over or crawling underneath these sharp barbwires we felt very successful to reach a sampling well with none of our clothes torn. Fall field work was cold and accompanied by wind so strong wind we had to put rocks in the car to weigh it down, so it wouldn’t be moved by the wind.
Despite our unique field environment challenges, we were able to conduct our research successfully. Data collected from the field work shows there are no indications of leakage, and since the CO2 injection began, we have observed no changes in the surface soil gas environment in the surface soil gas MMV program, which is a positive indicator of potential future success of CCS applications elsewhere and the global mitigation of GHGs.
Thank you to Dave for allowing me the opportunity to undertake work with the Aquistore project and thank you to my FluxLab team members who helped me gather data.