Early Tertiary evolution and sequence stratigraphy of the Faeroe-Shetland Basin: implications for hydrocarbon prospectivity

C. C. Ebdon; P. J. Granger; H. D. Johnson; A. M. Evans

doi:10.1144/GSL.SP.1995.090.01.03

Abstract

Eight seismically resolvable packages have been identified in the Early Tertiary succession of the Faeroe-Shetland Basin. These packages are calibrated with the microfaunal and microfloral biostratigraphy, thus allowing correlation between wells and comparison with other basins. Mapping of the facies distribution within each package has allowed a detailed understanding of the evolution of the southwestern part of the basin, including the Quad 204 acreage. The development of the area can be related to the plate tectonic evolution of the North Atlantic and has highlighted implications for hydrocarbon exploration. In the earliest part of the Palaeocene (Sequences T10–T32) the position of the shelf/slope break was controlled by the underlying end Cretaceous fault induced topography. The depositional character of the submarine fans which accumulated in the basin is aggradational, collecting in basin floor deeps and progressively onlapping basin floor highs. Reservoir quality is initially controlled by depositional facies but is, essentially, excellent. Basinal muds, particularly regionally extensive maximum flooding surfaces, are believed to provide effective seals. Sequences T36–T40 are progradational in character, the position of the shelf/slope break advancing significantly beyond the positions of underlying Cretaceous fault scarps. This change in depositional character is related to thermal doming and rifting in the North Atlantic. The results of this uplift in the Faeroe-Shetland Basin also instigated a change in sediment provenance, volcanism and the deposition of extensive base-of-slope fan systems. Reservoir effectiveness remains excellent in these fan systems and potential seals are provided by downlapping, progradational shelf/slope systems. Sequences T45 and T50 represent flooding of the Palaeocene shelf systems as the thermal dome collapsed and rifting progressed. The overall control on Early Tertiary reservoir effectiveness in the Faeroe-Shetland Basin is depth of burial. In this part of the basin the Early Tertiary reservoir sands are generally buried at depths less than 2.5 km below sea-bed and reservoir quality remains excellent (porosity > 25% and permeability > 100 Md). The challenge to the oil industry is to understand the charge of this attractive hydrocarbon play.

References

1. Anderton R.
(1993) Petroleum Geology of Northwest Europe: Proceedings of the 4th Conference Sedimentation and basin evolution in the Palaeogene of the northern North Sea and Faeroe-Shetland Basins, ed Parker J. R. (Geological Society, London), p 31.
1. Blow W. H.
(1979) The Cainozoic Globigerinida (Elsevier, Amsterdam).
1. Bott M. H. P.
(1984) in Petroleum Geology of the North European Margin, Deep structure and origin of the Faeroe-Shetland Channel, ed Spencer A. M., et al. (Graham & Trotman, London), pp 341–347.
1. Duindam P.,
2. van Hoorn B.
(1987) in Petroleum Geology of Northwest Europe, Structural evolution of the west Shetland continental margin, eds Brooks J., Glennie K. W. (Graham & Trotman, London), pp 765–773.
1. Galloway W. E.
(1989) Genetic stratigraphic sequences in basin analysis I: Architecture and genesis of flooding surface bounded depositional units. American Association of Petroleum Geologists Bulletin 73:125–142.
OpenUrl Abstract
1. Heilmann-Clausen C.
(1985) Dinoflagellate stratigraphy of the uppermost Danian to Ypresian in the Viborg 1 borehole, central Jylland, Denmark. Undersogelse Danmarks Geologiske Series A 7. 69.
1. Hitchen K.,
2. Ritchie J. D.
(1987) in Petroleum Geology of NW Europe, Geological review of the West Shetland area, eds Brooks J., Glennie K. W. (Graham & Trotman, London), 2, pp 737–749.
OpenUrl
1. Jacque M.,
2. Thouvenin J.
(1975) in Petroleum and the Continental Shelf of North-west Europe, Lower Tertiary tuffs and volcanic activity in the North Sea, ed Woodland A. W. (Elsevier, Barking), pp 455–465.
1. Joppen M.,
2. White R. S.
(1990) The structure and subsidence of Rockall trough from two-ship seismic experiments. Journal of Geophysical Research 95:19821–19837.
OpenUrl CrossRef
1. Knott S. D.,
2. Burchell M. T.,
3. Jolley E. J.,
4. Fraser A. J.
(1993) Petroleum Geology of Northwest Europe: Proceedings of the 4th Conference Mesozoic to Cenozoic plate reconstructions of the North Atlantic and hydrocarbon plays of the Atlantic margins, ed Parker J. R. (Geological Society, London), pp 953–974.
1. Mitchell S. M.,
2. Beamish G. W. J.,
3. Wood M. V.,
4. Malacek S. J.,
5. Armentrout J. A.,
6. Damuth J. E.,
7. Olsen H. C.
(1993) Petroleum Geology of Northwest Europe: Proceedings of the 4th Conference Palaeogene sequence stratigraphic framework of the Faeroe Basin, ed Parker J. R. (Geological Society, London), pp 1011–1023.
1. Mudge D. C.,
2. Copestake P.
(1992a) A revised Lower Palaeogene lithostratigraphy for the Outer Moray Firth, North Sea. Marine and Petroleum Geology 9:53–69.
OpenUrl CrossRef Web of Science
1. Mudge D. C.,
2. Copestake P.
(1992b) Lower Palaeogene stratigraphy of the northern North Sea. Marine and Petroleum Geology 9:287–301.
OpenUrl CrossRef Web of Science
1. Mudge D. C.,
2. Rashid B.
(1987) in Petroleum Geology of Northwest Europe, The Geology of the Faeroe Basin area, eds Brooks J., Glennie K. W. (Graham & Trotman, London), pp 751–763.
1. Ridd M. F.
(1983) in Structure and Development of the Greenland-Scotland Ridge, Aspects of the Tertiary geology of the Faeroe-Shetland Channel, eds Bott M. H. P., Saxov S., Talwani M., Thiede J. (Plenum Press, New York), pp 133–158.
1. Rochow K. A.
(1981) in Petroleum Geology of the Continental Shelf of Northwest Europe, Seismic stratigraphy of the North Sea ‘Palaeocene’ deposits, eds Illing L. V., Hobson G. D. (Heyden, London), pp 255–266.
1. Vail P. R.,
2. Wornardt W. W.
(1990) Gulf Coast Section SEPM Foundation Eleventh Annual Research Conference, Program and Abstracts in Sequence Stratigraphy as an Exploration Tool: concepts and practices in the Gulf Coast, Well-log seismic sequence stratigraphy: an integrated tool for the ’90’s, eds Armentrout J. M., Perkins B. F. pp 379–388.
1. Vail P. R.
(1977) in Seismic Stratigraphy — applications to hydrocarbon exploration, Seismic stratigraphy and global changes in sea level, American Association of Petroleum Geologists Memoir, ed Payton C. E. 26, pp 49–212.
OpenUrl