Assessing Geologic Uncertainty of CO2 Sequestration Targets in the Jeanne d’Arc Basin

The Jeanne d’Arc Basin, within the Grand Banks of offshore Newfoundland and Labrador, Canada, holds prolific oil and gas fields and is currently being assessed for its CO₂ sequestration potential. Several factors, including the presence of existing infrastructure from conventional energy production, volume of available datasets, and favourable geologic conditions for storage, make the Jeanne d’Arc Basin and sequestration target areas in the basin attractive as CO₂ injection sites. We are assessing subsurface geologic conditions in areas of interest for CO₂ sequestration to determine the geologic risks and benefits of a variety of targets.

The target strata for CO₂ sequestration in this assessment are predominantly in post-rift sequences, sedimentary units that have not experienced complex extensional stress regimes and that mostly lack delineated vertical fluid flow pathways. However, a major consideration for targeting potential sequestration formations is understanding how sequestered fluids will behave and identifying possible migration pathways within and between the reservoir units. Understanding how the subsurface changes on a fine scale may become important for ongoing assessments, target ranking, and injection strategies. However, well data constraints are not distributed uniformly across the basin and seismic data are often too coarse to capture the fine details of the subsurface or are non-unique.

This presentation documents factors that we are considering for geologic assessment of the CO₂ storage potential in the Jeanne d’Arc Basin, such as changes in depositional regimes, fluid migration pathways (both vertical and horizontal), stress regimes and data quality/coverage. We also discuss the uncertainties and potential risk mitigation for storage targets.