Aquistore Project Measurement, Monitoring, and Verification: From Concept to CO2 Injection

Abstract

Abstract As an independent research and monitoring project, Aquistore intends to demonstrate that storing liquid carbon dioxide (CO 2 ) deep underground (in a brine and sandstone water formation), is a safe, workable solution to reduce greenhouse gases (GHGs). Managed by the Petroleum Technology Research Centre, Aquistore is built upon the learnings of the IEAGHG Weyburn-Midale CO 2 Monitoring and Storage Project, where over 22MT of CO 2 have been stored in an oil field during EOR operations. As a global leader, PTRC has over a decade of experience in CO 2 storage and monitoring work. Aquistore is Canada's first dedicated CO 2 storage project, and is an integral component of SaskPower's Boundary Dam Integrated Carbon Capture and Storage (CCS) Demonstration project - the world's first fully integrated CCS demonstration project from a coal-fired power plant. As an unique CCS project, Aquistore is providing buffer storage to this commercial CO 2 capture plant and active oilfield EOR operations. In collaboration with SaskPower, Aquistore will be the first integrated project globally to demonstrate deep saline CO 2 capture, transport, and storage on a commercial scale from a coal fired power plant. CO 2 will be captured at unit 3 of the Boundary Dam power- station (BD3), transported via underground pipeline to the Aquistore site, and injected to a depth of 3.4 km. The Winnipeg and Deadwood formations, which constitute the deepest units within the Williston Basin and were chosen as the target zone for CO 2 injection. These geological formations have much greater capacity for storing CO 2 than any oil reservoir in western Canada. The suitability of the storage complex was investigated through 3D characterization using high-resolution 3D seismic images and data from the injection and observation wells. These data show that: there are no significant faults in the immediate area of the storage site; the regional sealing formation is continuous in the area; and lastly, that the reservoir is not adversely affected by knolls on the surface of the underlying Precambrian basement. In the Aquistore project PTRC has brought together internationally recognized expertise and diverse interests. Research in monitoring methods is central to the Aquistore Project. A permanent areal seismic monitoring array has been deployed which comprises 650 geophones installed at 20 m depth on a 2.5x2.5 km regular grid. The objective of this array is to test “sparse array” seismic imaging and to provide continuous passive monitoring. This array is being utilized in conjunction and comparison with time-lapse 3D seismic imaging, continuous microseismic monitoring, vertical seismic profiling, cross-well seismic tomography, and broadband seismographs. Injection-related surface deformation monitoring is provided by InSAR analysis in conjunction with a network of tiltmeters and GPS stations. Electromagnetic surveys and gravimeters are also being used. In an effort to minimize surface impact these monitoring technologies - where possible - have been collocated and solar-powered. Surface electromagnetic methods and time-lapse gravity monitoring will be tested in conjunction with deployment of a fibre-optic distributed acoustic sensing (DAS) line. A fibre-optic distributed temperature sensing (DTS) line is also installed. A unique fluid recovery system (FRS) as well as casing conveyed pressure and temperature gauges will contribute to the project's down-hole monitoring techniques. Aquistore's MMV program will test and develop effective methods for monitoring CO 2 storage sites and ensure conformance of the storage process through continuous monitoring. This program is seeking to minimize the risk associated with any potential leakage of CO 2 from the storage reservoir through early detection. Aquistore's MMV program has included an added focus on integrated monitoring methods such as the inclusion of non-seismic methods and constraints from reservoir flow simulations. Aquistore will provide an efficient, cost effective, and field-tested basis for designing effective MMV programs for other similar projects worldwide.