Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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11.11.2024 - 01:26
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NANSEN FM

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  • General information

    General information
    Attribute Value
    Lithostrat. unit
    The lithostratigraphic unit's official name.
    NANSEN FM
    NPDID lithostrat. unit
    Norwegian Offshore Directorate's unique id for lithostratigraphic units.
    108
    Level
    Indicates the lithostratigraphic unit's level. Legal values: GROUP, FORMATION, MEMBER.
    FORMATION
    Lithostrat. unit, parent
    The parent lithostratigraphic unit's official name. See also level. Will be empty if Level = GROUP.
  • Level below

    Level below
    Lithostrat. unit
  • Description

    Nansen Formation

    Name
    After the Norwegian polar scientist, explorer and statesman, Fridtjof Nansen.
    Well type section
    UK well 211/24-1 (Conoco/Gulf/NCB) (Fig 1.17-18) . 1.17) from 3112 m to 3159 m below KB.
    Well reference section
    Norwegian well 33/12-2 (Mobil) (Fig 1.17-18) .
    Thickness
    46 m in the type well and 19 m in the reference well.
    Lithology
    In the type well the formation consists of medium- to coarse-grained, fairly well-sorted, homogeneous, white sandstones with a calcite-cement and a subordinate kaolinite matrix. Occasional horizons with granules or pebbles are present. Carbonaceous material and mica are rare but glauconite is quite common. Thin shale beds containing marine fossils are present, most commonly in its upper part.
    At the top of the formation, from 3112 m to 3135 m in the type well is a more prominent calcareous horizon defined informally as the calcareous sandstone bed. This may grade locally into a sandy limestone, for example in the Brent Field.
    The Nansen Formation thins towards the east and passes laterally into calcareous siltstones and shales in the Norwegian sector
    (Fig 1.17-18) . Although these siltstones and shales are lateral equivalents of the Nansen Formation they are placed in the overlaying Dunlin Group on lithological grounds.
    Boundaries
    The originally Nansen Member of the Statfjord Formation was elevated to formation level by Lervik, 2006. The lower boundary is marked by the change from the non-calcareous sandstones of the Eiriksson Formation to the cleaner, generally calcareous sandstones of the Nansen Formation. The upper boundary is marked by the change from calcareous sandstone to the argillaceous sediments of the Dunlin Group . Both boundaries are well marked on gamma ray and sonic logs particularly in the UK sector where the formation is best developed. The calcareous sandstone bed at the top of the formation is normally reflected by a distinctive sonic log response (Fig 1.17-18) . However, as this passes laterally into calcareous siltstones and shales the sonic log still responds to the calcareous nature of the sediments.
    Distribution
    The formation is widespread in the northern North Sea. Deegan and Scull (1977) describes the formation as well developed in the Brent Field area. The lower part of the formation overlaps westwards to the Cormorant Field area where it is probably the only representative of the Statfjord Group . The calcareous sandstone bed at the top does not extend as far west as the lower part of the formation.
    Age
    Probably Hettangian to Early Sinemurian.
    Depositional environment
    Subaerial depositional conditions are suggested for parts of the fine-grained units by the presence of calcrete, coals and root-traces. In contrast, delicate lenticular and flaser lamination, wave-ripple laminae and abundant bioturbation suggest that the other parts of the fine-grained units were deposited in standing water (Røe and Steel, 1985). Based on the stacking pattern of facies associations and the presence of marine fossils, the upper part of the sequence is interpreted to have been deposited in a marine environment.
    Although the Nansen Formation in the Gullfaks and Statfjord area has been described as marine (Deegan and Scull, 1977; Røe and Steel, 1985), Nystuen and Fält (1995) interpret this formation as being a massive, rapidly deposited and dewatered fluvial sandstone with evidence of glauconite only near its top at Statfjord. Evidence for marine incursions at the
    Snorre Field is equivocal, for they may be stratigraphically higher than the Nansen Formaion. Equally the sandstones interpreted as shallow marine in origin may be interpreted as the deposits of a fluvial environment, such as a laterally extensive braided stream or a sheetflood.
    Compiled from
    • Deegan, C. E. and Scull, B. J. (compilers) 1977: A standard lithostratigraphic nomenclature for the Central and Northern North Sea. UK Institute of Geological Sciences, Report 77/25. The Norwegian Petroleum Directorate, NPD-Bulletin No. 1, 36 pp.
    • Goldsmith, P. J., Hudson, G. and Van Veen, P. Triassic. 105 – 127 in: Evans, D., Graham, C., Armour, A. and Bathurst, P. (editors and coordinators) 2003: The Millennium Atlas: petroleum geology of the central and northern North Sea. The Geological Society of London, 389 pp.
    • Lervik, K.-S. 2006: Triassic lithostratigraphy of the Northern North Sea Basin. Norwegian Journal of Geology, Vol. 86, pp. 93-116.
  • Wellbores penetrating

    Wellbores penetrating
    Wellbore name
    Wellbore completion date
    Top depth [m]
    Bottom depth [m]
    22.04.2019
    2927
    2972
    09.01.2020
    2976
    2995
    19.03.2020
    2211
    2286
    30.12.2019
    2245
    2263
    18.01.2015
    2241
    2249
    10.02.2023
    3944
    3978
    05.10.1992
    4288
    4294
    16.02.1981
    3228
    3298
    22.09.1979
    2712
    2786
    16.12.1982
    3046
    3226
    12.05.1990
    3044
    3224
    08.02.1984
    2784
    2799
    05.09.1984
    3241
    3272
    21.01.1985
    2960
    2967
    21.06.1986
    3255
    3275
    25.05.1994
    3254
    3274
    01.07.1990
    3163
    3179
    29.03.2012
    2483
    2590
    01.03.1996
    4691
    4729
    30.03.1985
    4173
    4209
    23.12.1988
    3535
    3565
    06.11.1989
    2757
    2775
    08.08.1994
    3457
    3476
    26.02.2016
    3645
    3717
    28.06.2021
    3008
    3043
    24.07.2012
    4267
    4285
    23.08.1974
    2700
    2719
    26.04.2002
    3647
    3731
    08.05.1981
    3840
    3865
    11.06.1985
    4063
    4107
    19.05.2015
    4640
    4658
    05.11.2012
    4055
    4095
    24.09.2014
    4360
    4407
    30.05.1985
    2510
    2527
    29.10.1986
    2531
    2562
    08.09.1978
    2268
    2329
    08.12.1978
    3325
    3379
    07.06.1979
    2495
    2561
    10.10.1987
    2492
    2558
    15.10.1979
    2340
    2435
    02.01.1980
    2562
    2649
    23.03.1980
    2053
    2140
    14.07.1983
    2050
    2137
    03.07.1980
    2375
    2421
    05.03.1981
    1890
    1935
    22.10.1984
    3906
    3914
    13.07.1987
    3353
    3386
    10.08.1987
    3353
    3386
    11.04.2001
    3878
    3946
    08.07.2001
    3720
    3776
    14.11.2002
    2964
    3020
    18.04.2014
    4467
    4512
  • Wellbores with cores

    Wellbores with cores
    Wellbore name
    Wellbore completion date
    Core length [m]
    09.01.2020
    20
    30.12.2019
    10
    16.02.1981
    3
    22.09.1979
    10
    08.02.1984
    14
    05.09.1984
    18
    08.08.1994
    17
    26.02.2016
    55
    23.08.1974
    10
    30.05.1985
    9
    29.10.1986
    29
    08.12.1978
    39
    15.10.1979
    6
    03.07.1980
    4
    05.03.1981
    27
    13.07.1987
    25
    18.04.2014
    38