EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assessing the potential for permanent carbon storage in volcano-sedimentary sequences offshore mid-Norway: initial results from IODP Expedition 396

John Millett1,2, Sverre Planke1,3, Christian Berndt4, Carlos Alvarez Zarikian5, Peter Betlem6, Marija Rosenqvist3, Ben Manton1, David Jolley2, Simona Pierdominici7, Stefan Buenz8, Reidun Myklebust9, and the Expedition 396 Scientists*
John Millett et al.
  • 1VBER AS, Norway (
  • 2Department of Geology and Geophysics, University of Aberdeen, UK
  • 3University of Oslo, Norway
  • 4GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
  • 5International Ocean Discovery Program, Texas, USA
  • 6UNIS, Svalbard
  • 7Helmholtz Center Potsdam, GFZ, Germany
  • 8UiT The Arctic University of Norway, Tromsø, Norway
  • 9TGS, Askekroken 11, Norway
  • *A full list of authors appears at the end of the abstract

International Ocean Discovery Program (IODP) Expedition 396 drilled 21 holes at 10 sites spanning the mid-Norwegian volcanic rifted margin in 2021. Six sites recovered volcanic sequences with one objective of the cruise being to appraise the potential for permanent carbon storage within the offshore volcanic sequences.

This study presents a core-log-seismic and reservoir appraisal of the Kolga High Site U1566 which penetrated a c. 120 m Seaward Dipping Reflector (SDR) sequence beneath a thin Quaternary sediment cover below c. 2100 m water depth. Coring with high average recovery > 65 % through the volcanic sequence revealed a variably altered basaltic lava flow dominated sequence with inter-layered volcaniclastic and siliciclastic sediments, the latter containing granitic clasts eroded from the nearby high. The base of the volcanic sequence was recovered in the cores and marks a sharp transition from sub-aerial lava flows into deeply altered granite.

Shipboard petrophysical and wireline data for Site U1566 are analysed to characterize the SDR sequence and integrated with available seismic data. Whole-Round Multisensor Logger data were collected on cores for natural gamma radiation, bulk density, magnetic susceptibility, and P-wave velocity at 2.5 cm spacing. 588 P-wave caliper measurements along with 2219 point magnetic susceptibility measurements were made on the working-half sections. In addition, a total of 102 discrete samples were taken for moisture and density (MAD) analysis including 2 cm cubes and 34 additional minicore samples which were also tested for ambient permeabilities. Wireline data including gamma, density, P- and S-wave velocity, resistivity, magnetic susceptibility and image log data (micro-resistivity and acoustic) were collected over the main volcano-sedimentary sequence enabling a comprehensive appraisal of the penetrated volcanic sequence.

The volcanic sequence is characterized by vertically stacked compound to simple lava flows showing asymmetrical log profiles with individual flow lobes rarely exceeding c. 3 m in thickness. Primary vesicular porosity exceeds 40 % in fresh unaltered flow margins and decreases to < 10 % in flow interiors and where alteration and secondary mineralization are pervasive. Matrix permeability ranges from microdarcies within flow interiors up to several 10’s of millidarcies within flow margins and up to 100’s of millidarcies within sediment interbeds highlighting significant vertical heterogeneity linked to facies development through the studied sequence. The presence of alteration and fracturing within the studied sequence significantly alter reservoir properties and form key elements, along with facies scaling, that must be incorporated into reservoir appraisal. This pilot study reveals clear reservoir potential within both lava flows and inter-bedded sediments offshore mid-Norway. 

Expedition 396 Scientists:

Amar Agarwal, Graham D.M. Andrews, Peter Betlem, Joyeeta Bhattacharya, Henk Brinkhuis, Sayantani Chatterjee, Marialena Christopoulou, Vincent J. Clementi, Eric C. Ferré, Irina Y. Filina, Joost Frieling, Pengyuan Guo, Dustin T. Harper, Morgan T. Jones, Sarah Lambart, Jack Longman, Geoffroy Mohn, Reina Nakaoka, Reed P. Scherer, Christian Tegner, Natalia Varela, Mengyuan Wang, Weimu Xu, Stacy L. Yager

How to cite: Millett, J., Planke, S., Berndt, C., Alvarez Zarikian, C., Betlem, P., Rosenqvist, M., Manton, B., Jolley, D., Pierdominici, S., Buenz, S., and Myklebust, R. and the Expedition 396 Scientists: Assessing the potential for permanent carbon storage in volcano-sedimentary sequences offshore mid-Norway: initial results from IODP Expedition 396, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16180,, 2023.