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Steinthorsdottir, Katrin

University of British Columbia

This study assesses the feasibility of an in-situ carbon mineralization project, using Carbfix technology, into serpentinized ultramafic rocks in British Columbia (B.C.), Canada. Specifically, we looked at 1) site selection, 2) early engagement, and 3) characterization for injectivity and reactivity potential. Geological and logistical factors for a pilot project were assessed through nine different multi-criteria overlay analyses. From 746 mapped ultramafic bodies in B.C., we determined 84 viable bodies in 21 groups, and of those, three showed the most potential and were prioritized for further work. These sites are the Shulaps complex, the Coquihalla serpentine belt, and the Tulameen intrusion, in southwest B.C. Shulaps and Coquihalla are mantle massifs with variably serpentinized harzburgite and Tulameen is an Alaskan-type intrusion with a serpentinized dunite core. Before fieldwork, early engagement was conducted with 21 First Nations or alliances that have traditional lands encompassing the three sites. The total timelines, depth of engagement and topics of conversation varied between groups. Discussions were positive and included information about the project and its implications and we started building relationships. Consent for geological fieldwork was forthcoming and the field excursions were completed successfully. Outcrop characteristics of the variably serpentinized ultramafic rocks were used to infer shallow subsurface injectivity in the absence of drillholes. Surface samples were collected and assessed for reactivity by whole-rock composition, mineralogy and dissolution rates from experiments. An assessment of reactivity was benchmarked against Stapafell basaltic glass, which has been extensively characterized by other researchers. The pervasively serpentinized harzburgite at Shulaps and Coquihalla is more fractured and structurally complex and has higher injectivity potential than the partially serpentinized harzburgite and serpentinized dunite. Additionally, serpentinized harzburgite and dunite are more reactive than the glass, with brucite-bearing serpentinized dunite having the relatively highest dissolution rates. To get to a pilot-scale injection at one of these sites, the next steps will be more engagement and drilling of the first well to do subsurface geological and hydrogeological work.

Text

2025-04-23

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/90723

Geological Sciences

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/