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Clay mineral distribution in the Devonian-Carboniferous sandstones of the Clair Field, west of Shetland, and its significance for reservoir quality

Published online by Cambridge University Press:  09 July 2018

M. D. Pay ,
T. R. Astin  and
A. Parker
M. D. Pay*
Affiliation:
Postgraduate Research Institute for Sedimentology, University of Reading, PO Box 227, Whiteknights, Reading RG6 6AB, UK
T. R. Astin
Affiliation:
Postgraduate Research Institute for Sedimentology, University of Reading, PO Box 227, Whiteknights, Reading RG6 6AB, UK
A. Parker
Affiliation:
Postgraduate Research Institute for Sedimentology, University of Reading, PO Box 227, Whiteknights, Reading RG6 6AB, UK
*
*E-mail: mark.pay@london.entoil.com
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Abstract

The Devonian-Carboniferous reservoir of the Clair Field contains a complex and variably abundant clay mineral assemblage. An abrupt vertical change in clay mineralogy has been observed in both wells studied (UKCS 206/8-7 and 206/8-8) from being rich in Mg-chlorite, chlorite- smectite (including dioctahedral corrensite), illite, illite-smectite and Fe-chlorite, to being smectite- rich. This change broadly coincides with the unconformable boundary between the Lower Clair Group and Upper Clair Group of the reservoir which possibly defines the Devonian-Carboniferous boundary. The clay minerals present reflect interaction between: (1) tectonic stability and climate that controlled the detrital composition of the sediment; (2) the pore-waters that developed; and (3) the result of diagenetic modification.

Matrix porosity and permeability is severely restricted where the pore-lining clays are abundant (>15%) and where the clays bridge or fill pores. The type of clay mineral species appears to have a minor influence on reservoir quality, although they may be extremely important during production. The best reservoir quality occurs in mature aeolian sediments with a thin illite and illite-smectite clay coating.

Keywords

clay mineralsClair FieldShetlandreservoir quality
Type
Research Article
Information
Clay Minerals , Volume 35 , Issue 1 , March 2000 , pp. 151 - 162
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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Footnotes

†

Present address: Enterprise Oil plc, Grand Buildings, Trafalgar Square, London WC2N 5EJ, UK

References

Allen, P.A. & Mange-Rajetzky, M.A. (1992) Devonian- Carboniferous sedimentary evolution of the Clair area, offshore north-western UK; impact of changing provenance. Marine Petrol. Geol. 9, 9–29.CrossRefGoogle Scholar
Bodine, M.W. & Madsen, B.M. (1987) Mixed-layer chlorite/smectites from a Pennsylvanian evaporite cycle, Grand County, Utah. Proc. Int. Clay Conf. Denver, 85-93.Google Scholar
Brigatti, M.F. & Poppi, L. (1984) Crystal chemistry of corrensite: a review. Clays Clay Miner. 32, 32–391.CrossRefGoogle Scholar
Chamley, H., Debrabant, P. & Flicoteaux, R. (1988) Comparative evolution of Senegal and eastern central Atlantic Basins from mineralogical and geochemical investigations. Sedimentology, 35, 35–85.CrossRefGoogle Scholar
Chang, H.K., MacKenzie, F.T. & Schoonmaker, J. (1986) Comparisons between the diagenesis of dioctahedral and trioctahedral smectite, Brazilian offshore basins. Clays Clay Miner. 34, 34–407.CrossRefGoogle Scholar
Helmold, K.P. & van de Kamp, P.C. (1984) Diagenetic mineralogy and controls on albitization and laumontite formation in Paleogene arkoses, Santa Ynez Mountains, California. Pp. 239-276 in: Clastic Diagenesis (McDonald, D.A. & Surdam, R.C., editors). Am. Assoc. Petrol. Geol. Memoir, 37.Google Scholar
Hillier, S.J. (1989) Clay mineral diagenesis and organic maturity indicators in Devonian lacustrine mudrocks from the Orcadian Basin, Scotland. PhD thesis, Univ. Southampton, UK.Google Scholar
Hillier, S.J. (1993) Origin, diagenesis and mineralogy of chlorite minerals in Devonian lacustrine mudrocks, Orcadian Basin, Scotland. Clays Clay Miner. 41, 41–240.CrossRefGoogle Scholar
Hillier, S.J. (1994) Pore-lining chlorites in siliciclastic reservoir sandstones: electron microprobe, SEM and XRD data, and implications for their origin. Clay Miner. 29, 29–665.CrossRefGoogle Scholar
Hillier, S.J., Fallick, A.E. & Matter, A. (1996) Origin of pore-lining chlorite in the aeolian Rotliegend of northern Germany. Clay Miner. 31, 31–153.Google Scholar
McKie, T. & Garden, I.R. (1996) Hierarchical stratigraphic cycles in the non-marine Clair Group (Devonian) UKCS. Pp. 139-157 in: High Resolution Sequence Stratigraphy; Innovations and Applications (Howell, J.A. & Aitken, J.F., editors). Geological Society, London, Spec. Publ. 104.Google Scholar
Moore, D.M. & Reynolds, R.C. (1989) X-ray Diffraction and the Identification and Analysis of Clay Minerals. Oxford University Press, UK.Google Scholar
Morrison, S.J. & Parry, W.T. (1986) Dioctahedral corrensite from Permian red beds, Lisbon Valley, Utah. Clays Clay Miner. 34, 34–613.CrossRefGoogle Scholar
Owen, M.A. (1994) The controls on reservoir properties of Devonian sandstones in the Orcadian Basin, North East Scotland. PhD thesis, Univ. Reading, UK.Google Scholar
Pettijohn, F.J., Potter, P.E. & Siever, R. (1973) Sand and Sandstone. Springer-Verlag, Berlin.CrossRefGoogle Scholar
Reynolds, R.C. Jr. (1980) Interstratified clay minerals. Pp. 249-303 in: Crystal Structures of Clay Minerals and their X-ray Identification (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Rogers, D.A. & Astin, T.R. (1991) Ephemeral lakes, mud pellet dunes and wind-blown sand and silt; reinterpretations of Devonian lacustrine cycles in North Scotland. Pp. 199-221 in: Lacustrine Fades Analysis (Anadon, P., Cabrera, L. & Kelts, K., editors). International Association of Sedimentologists, Spec. Publ. 13.Google Scholar
Wilson, M.D. (1992) Inherited grain-rimming clays in sandstones from eolian and shelf environments: Their origin and control on reservoir properties. Pp. 209-225 in: Origin, Diagenesis and Petrophysics of Clay Minerals in Sandstones (Houseknecht, D.W. & Pittman, E.D., editors). SEPM Spec. Publ. 47.Google Scholar