ANDREW FM

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• General information

  General information

  Attribute	Value
  Lithostrat. unit The lithostratigraphic unit's official name.	ANDREW FM
  NPDID lithostrat. unit Norwegian Offshore Directorate's unique id for lithostratigraphic units.	5
  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.	ROGALAND GP

• Level below

  Level below

  Lithostrat. unit

• Description

  Andrew Formation
  
  Name

  Named by Deegan & Scull (1977) after the Andrew Field in UK blocks 18/27 and 16/28.

  Well type section

  UK well 14/25-1 from 2199 m to 1897 m, coordinates N58°01'11.40", E 00°00'56.40". No cores.

  Well reference section

  UK well 21/10-1 from 2464 to 2370 m, coordinates N 57°43'50.37", E 00°58'29.19" (Fig 5.44) . No cores.

  Thickness

  The Andrew Formation is 302 m thick in the type well and 94 m in the reference well, which represents the general thinning southwards from the East Shetland Platform. Close to the Fladen Ground Spur, the formation reaches thicknesses of approximately 1200 m.

  Lithology

  The Andrew Formation consists of sandstones with claystone interbeds. The sandstones are generally very fine to medium grained and are composed of subangular to subrounded, clear to orange-stained quartz and feldspar grains. The sandstones are poorly sorted and often have a calcareous cement. Thin stringers of limestone occur.

  Basal stratotype

  The Andrew Formation overlies the shales, marls and limestone interbeds of the Våle Formation , reflected by a higher gamma-ray level in the Andrew Formation. It may also rest on the Maureen Formation , and in that case the boundary is still seen as an increase in gamma-ray readings upwards into the less calcareous Andrew Formation (Fig 5.44) .

  Characteristics of the upper boundary

  The Lista Formation usually overlies the Andrew Formation, and the boundary is characterized by higher gamma-ray readings and lower velocity upwards into the Lista Formation . Where the Forties Formation directly overlies the Andrew Formation, the boundary may be difficult to define, but the Forties Formation generally has a lower velocity than the Andrew Formation (Fig 5.44) . This boundary is very difficult to determine in the Norwegian sector.

  Distribution

  The Andrew Formation was deposited as an elongated lobe trending southeastwards from the western part of the Fladen Ground Spur into the Central Trough. The formation is not well developed in the Norwegian sector, even though the distal parts of the lobe may be expected to occur. Its approximate distribution is shown in (Fig 5.47) .

  Age

  Paleocene.

  Depositional environment

  The Andrew Formation was deposited as submarine fans.

  Source

  • Isaksen, D. and Tonstad, K. (eds.) 1989: A revised Cretaceous and Tertiary lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No. 5, 59 pp.

• Wellbores penetrating

  Wellbores penetrating

  Wellbore name	Wellbore completion date	Top depth [m]	Bottom depth [m]
  1/3-11	30.08.2008	3366	3482
  1/3-13	07.07.2021	3072	3094
  1/6-4	09.04.1976	3197	3253
  1/9-1	17.02.1977	2947	2952
  1/9-1 R	17.05.1987	2944	2949
  1/9-2	12.08.1977	3030	3033
  1/9-7	02.08.2003	2989	2992
  2/1-7	06.03.1985	3066	3102
  2/1-17 S	08.11.2019	3040	3070
  7/7-1	20.02.1990	2780	2808
  7/7-3	04.07.1993	2796	2808

• Wellbores with cores

  Wellbores with cores

  Wellbore name	Wellbore completion date	Core length [m]
  1/3-11	30.08.2008	29
  7/7-1	20.02.1990	17