1887

Abstract

Summary

The Agardhfjellet Formation (Fm) in Svalbard, a middle Jurassic to lowermost Cretaceous mudstone-dominated unit, is investigated for its geomechanical properties critical for CO storage seal integrity. This study focuses on how mineralogy and depositional environment influence the formation’s geomechanical behavior, using borehole data from fully cored drill cores in central Spitsbergen. The Agardhfjellet Fm, partially equivalent to the Fuglen and Hekkingen formations in the Barents Sea, is analyzed for its lithology, grain size, and redox conditions through XRF-derived trace element ratios (Zr/Rb, U/Th, V/(V+Ni)). These indicate an oxic to anoxic depositional environment, with the coarser-grained Oppdalssåta Member contrasting the finer-grained Slottsmøya and Lardyfjellet Members. Geomechanical properties, assessed via log-derived Young’s modulus (E) and Poisson’s ratio (ν), reveal that the Oppdalssåta Member is more brittle, while Slottsmøya and Lardyfjellet Members are more ductile, indicating a correlating between Zr/Rb ratio and elastic response. Further, higher gamma ray values suggest more ductile behavior, however no clear trends between organic content (resistivity) and elastic properties are observed. Initial interpretation of these findings suggest that grain size and mineralogy significantly influence failure mode and fracture potential, with Zr/Rb ratios potentially serving as a useful proxy for assessing seal integrity in a CO storage context.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.202532026
2025-09-14
2026-02-15
Loading full text...

Full text loading...

References

  1. BetlemP., RodésN., BirchallT., DahlinA., Smyrak-SikoraA., SengerK. (2023). Svalbox digital model database: a geoscientific window into the high Arctic. Geosphere, 19: 1640–1666.
    [Google Scholar]
  2. Bohloli, B., Skurtveit, E., Grande, L., Titlestad, G.O., Børresen, M., Johnsen, Ø., and Braathen, A. (2014). Evaluation of reservoir and cap-rock integrity for the Longyearbyen CO2 storage pilot based on laboratory experiments and injection tests.
    [Google Scholar]
  3. Braathen, A., Elvebakk, H., Hansen, F., Hanssen, T. H., Jochmann, M., Johansen, T. A., Johnsen, H., Larsen, L., Lie, T., Mertes, J., Mørk, A., Mørk, M. B., Nemec, W., Olaussen, S., Oye, V., Rød, K., Titlestad, G. O., Tveranger, J., & Vagle, K. (2012). The Longyearbyen CO2 Lab of Svalbard, Norway—Initial assessment of the geological conditions for CO2 sequestration. NORWEGIAN JOURNAL OF GEOLOGY.
    [Google Scholar]
  4. Birchall, T., Senger, K., Hornum, M.T., Olaussen, S., and Braathen, A. (2020). Underpressure in the northern Barents shelf: causes and implications for hydrocarbon exploration. AAPG Bulletin.
    [Google Scholar]
  5. Dallmann, W.K. (ed.). (2015). Geoscience Atlas of Svalbard. Norsk Polarinstitutt Rapportserie, 148.
    [Google Scholar]
  6. Dypvik, H., & Harris, N. B. (2001). Geochemical facies analysis of fine-grained siliciclastics using Th/U, Zr/Rb and (Zr+Rb)/Sr ratios. Chemical Geology, 181(1), 131–146.
    [Google Scholar]
  7. Hatch, J. R., & Leventhal, J. S. (1992). Relationship between inferred redox potential of the depositional environment and geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the Dennis Limestone, Wabaunsee County, Kansas, U.S.A.Chemical Geology, 99(1).
    [Google Scholar]
  8. Johnson, J., Polteau, S., & Yarushina, V. (2024). Geochemical analysis and their geomechanical inferences for primary seals of CCS license zones, Norwegian Continental Shelf. 2024(1), 1–5.
    [Google Scholar]
  9. Koevoets, M. J., Hammer, Ø., & Little, C. T. S. (2019). Palaeoecology and palaeoenvironments of the Middle Jurassic to lowermost Cretaceous Agardhfjellet Formation (Bathonian–Ryazanian), Spitsbergen, Svalbard. Norwegian Journal of Geology.
    [Google Scholar]
  10. Park, J., Stein, H. J., Hannah, J. L., Georgiev, S. V., Hammer, Ø., & Olaussen, S. (2024). Re-Os geochronology of the Middle to Upper Jurassic marine black shales in the Agardhfjellet Formation, Central Spitsbergen, Svalbard:A cornerstone for global faunal correlation and Os isotopic change. Palaeogeography, Palaeoclimatology, Palaeoecology, 633, 111878.
    [Google Scholar]
  11. Thompson, N., Griffiths, L., Bjørnarå, T. I., Smith, H., & Andrews, J. S. (2024). Experimental and Numerical Validation of Cooling-Induced Stress Change Within a Caprock Shale – Seal Integrity Insights from the Northern Lights CCS Project. D032S038R002.
    [Google Scholar]
  12. Koevoets, M. J., Hammer, Ø., & Little, C. T. S. (2019). Palaeoecology and palaeoenvironments of the Middle Jurassic to lowermost Cretaceous Agardhfjellet Formation (Bathonian–Ryazanian), Spitsbergen, Svalbard. Norwegian Journal of Geology.
    [Google Scholar]
  13. Ogata, K., Senger, K., Braathen, A., Tveranger, J., & Olaussen, S. (2014). Fracture systems and mesoscale structural patterns in the siliciclastic Mesozoic reservoir-caprock succession of the Longyearbyen CO2 Lab project: Implications for g eological CO2 sequestration in Central Spitsbergen, Svalbard.
    [Google Scholar]
  14. Olaussen, S., Senger, K., Braathen, A., Grundvåg, S.A. & Mørk, A. (2019): You learn as long as you drill; research synthesis from the Longyearbyen CO2 Laboratory, Svalbard, Norway. Norwegian Journal of Geology99, 157–187.
    [Google Scholar]
  15. PerezAltamar, R. & Marfurt, K. J. (2015). Identification of brittle/ductile areas in unconventional reservoirs using seismic and microseismic data: Application to the Barnett Shale.
    [Google Scholar]
  16. Senger, K., Betlem, P., Braathen, A., Olaussen, S., & Sand, G. (2024). Longyearbyen CO2 lab project—From a vision of a CO2-neutral Svalbard to a geoscience data eldorado. Arctic Science.
    [Google Scholar]
/content/papers/10.3997/2214-4609.202532026
Loading
/content/papers/10.3997/2214-4609.202532026
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error