Continuous monitoring of field conditions over 7 years of intermittent cold CO2 injection at the Aquistore storage site has provided substantial learnings related to the subsurface storage reservoir responses under dynamic injection conditions. suggests a general increase in well injectivity performance with time. The Aquistore CO2 Storage Project is an integral component of SaskPower’s Boundary Dam CO2 Capture Project and is located in southeastern Saskatchewan, Canada. The Boundary Dam Project is one of the world’s first commercial post-combustion carbon capture, utilization, and storage projects where CO2 is captured at SaskPower’s Boundary Dam coal-fired power plant and is primarily used for CO2-EOR operations in the Weyburn Field. Operational synergies between the capture facility (supply) and CO2-EOR (demand) also require excess CO2 to be transported via pipeline to the Aquistore site where it is injected into a hyper-saline fluid filled sandstone formation at approximately 3300 m depth. The injection interval consists of the Deadwood and Winnipeg Formations, which lie unconformably on Precambrian basement rocks, and is overlain by the Icebox Member of the Winnipeg Formation and the Prairie Evaporite. The reservoir temperature is 116 °C, and average reservoir pressure is 35 MPa. Preliminary laboratory measurements on core plugs gave average values of porosity and permeability, 6% and 5 mD respectively. This presentation will highlight observations of hydromechanical (pore pressure) and thermomechanical (pore temperature) processes are involved in the CO2 injection. The presentation will also review data collected from DTS/DAS systems and downhole tubing and casing conveyed pressure sensors over this 7-year period and highlight several learnings observed in the data. An update on issues related to salt precipitation that was initially observed during a downhole camera deployment in May 2017 will be discussed in relation to a follow-up downhole camera run in August 2020.
Professor Rick Chalaturnyk