SFU Earth Sciences professor assessing carbon storage potential beneath Metro Vancouver

An SFU professor is looking at the viability of storing large volumes of carbon dioxide in a soda pop-like solution thousands of metres below the streets of Metro Vancouver to help B.C. meet its net-zero emission goals.

Business and industry are among the highest emitters of greenhouse gas (GHG) emissions in Metro Vancouver, contributing half of the 15 million tonnes of total regional emissions, with industrial facilities accounting for approximately 2.5 million tonnes (17 per cent).
 
While multiple approaches are being implemented to reduce industrial emissions, these are unlikely to achieve carbon neutrality in the industrial sector within the next 30 years. 
 
Could carbon capture and storage (CCS) help B.C. meet its net-zero goals? Yes, however for now CCS is not possible in the Lower Mainland due to regulatory restrictions on storage-reservoirs.  It is being pursued in Northeast B.C. and could be an option for the future for the Lower Mainland.    

SFU Earth Sciences professor Shahin Dashtgard has received $399,070 from the Natural Sciences and Engineering Research Council of Canada (NSERC), $500,000 from the B.C. Ministry of Energy, Mines and Low Carbon Innovation, and support from Metro Vancouver to assess carbon dioxide storage potential in the Lower Mainland of B.C.
 
“Our goal is to identify areas within the subsurface with the highest potential for long-term storage of large volumes of CO2,” Dashtgard says. “We’re considering a novel approach – a made-in-B.C. solution.”

Unlike in Alberta and northeast B.C., where fine-grained, impermeable rock formations make it possible to trap compressed CO2 deep underground, Metro Vancouver sits on a basin of mostly porous, sedimentary rock, which requires a different approach.  
 
“We're looking at dissolving CO2 in water like a soft-drink,” Dashtgard explains, “and then storing that CO2-rich brine solution between a thousand and two thousand metres deep underground.” 
 
The water found at this depth has a concentration of over 12,000 parts per million dissolved salts, making it unsuitable for drinking or agricultural use. The high pressure deep underground will keep the CO2 dissolved in this brine solution, which is denser than the brine in the rock, causing it to sink. 
 
As part of this project, Dashtgard’s team is assessing the potential impact of seismic activity on storage sites. He explains that while most earthquakes in the region happen below Vancouver Island or are too deep in the Earth’s crust to directly affect stored carbon, any potential storage sites would need to be located away from major fault lines.

To map these fault lines and narrow down sites to study in detail, Dashtgard’s team is using geophysical, geological, and reservoir engineering data from previous geological exploration around Metro Vancouver. This data includes geophysical well logs, cores, drilling reports and previous geotechnical reports that are publicly available or have been acquired as a part of this project, as well as other data donated by Suncor Energy. 
 
“This is the first time a lot of this data has been available to the academic world,” Dashtgard says. “We'll be creating the first subsurface geohazard maps where we can map the distribution of faults underground, and this will add a level of detail that doesn't exist in the public sphere.”
 
Once the initial mapping is completed, Dashtgard’s team will create a detailed geological model of one or two sites with the highest potential for long-term CO2 storage. This model will be used by project co-investigator and professor of Chemical and Petroleum Engineering Hassan Hassanzadeh and his team at University of Calgary to simulate the short- and long-term behaviour of stored CO2 and assess the risks and storage capacity of carbon storage at those sites.
 
Dashtgard is hopeful that this modelling will have other benefits. The data on temperature, pressure, and fluid flow capacity will help researchers understand the potential for harnessing geothermal energy in the region, and the workflow they develop will help others conduct similar assessments of carbon storage potential in tectonically active regions.
 
“Our mandate is to share our data so people can see the information used to build our model,” Dashtgard says. “We will give the academic community and companies a sense of how you would carry out a CO2 sequestration evaluation in a tectonically active region. We’re adding a massive amount of information about what the subsurface below the Lower Mainland looks like, and the process to make a project like this work.”