Mineralogical, geochemical and petrographical characterisation of Nordland Shale cores from well 15/9-A-11, Sleipner field, northern North Sea

Kemp, S.J. ORCID: https://orcid.org/0000-0002-4604-0927; Pearce, J.M.; Steadman, E.J.. 2002 Mineralogical, geochemical and petrographical characterisation of Nordland Shale cores from well 15/9-A-11, Sleipner field, northern North Sea. Nottingham, UK, British Geological Survey, 40pp. (CR/02/313N) (Unpublished)

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Abstract/Summary

This report summarises the results of mineralogical, geochemical and petrographical characterisation of three mudstone core samples (Nordland Shale) taken from well 15/9-A-11, northern North Sea. A range of analyses including X-ray diffraction, X-ray fluorescence, inductively coupled plasma-mass spectroscopy, scanning electron microscopy, particle-size analysis, cation exchange capacity and total organic carbon analyses were employed in order to fully characterise the samples. The results of such analyses were then used to predict the seal capacity of the Nordland Shale for injected CO2 in the underlying Utsira Sand reservoir. The fine-grained clay or silty clay samples show broadly similar characteristics to previously studied material and are composed of undifferentiated mica, quartz, kaolinite, K-feldspar, calcite, smectite, albite, chlorite, pyrite and halite. The cores have a weak, sedimentary lamination and lack primary and secondary porosity. The samples have similar geochemistries which closely match that of the North American Shale Composite (NASC). Geochemical variations can generally be explained in terms of the detected mineralogy with the exception of Fe2O3t which may suggest the undetected presence of poorly crystalline Fe-oxyhydroxides. Although small quantities of smectite in the Nordland Shale may invalidate its predictions, XRD-determined quartz contents suggest displacement pore throat diameters of 2.2 to 21.1 nm using the Krushin (1997) methodology. As found by previous workers, considering that the Utsira Sand has a maximum thickness of c.300 m in the Sleipner area, capillary leakage through the Nordland Shale would appear unlikely.

Item Type:	Publication - Report
Programmes:	BGS Programmes > Other
Funders/Sponsors:	British Geological Survey
Additional Information. Not used in RCUK Gateway to Research.:	This item has been internally reviewed, but not externally peer-reviewed. Report made open in 2008.
Date made live:	25 Nov 2024 10:51 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/538431

Item Type:

Publication - Report

Programmes:

BGS Programmes > Other

Funders/Sponsors:

British Geological Survey

Additional Information. Not used in RCUK Gateway to Research.:

This item has been internally reviewed, but not externally peer-reviewed. Report made open in 2008.

Date made live:

25 Nov 2024 10:51 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/538431