Lomvi Formation
(NPD Bulletin no. 3)
Hegre Group
Name
From the bird (English: guillemot) of the same name.
Well type section
Norwegian well 33/12-5
(Mobil) from 3747 m to 3867 m, coord N 61°ll'05.53", E01°51'53.34", (Fig. 2).
Well reference section
Norwegian well 33/5-1
(Norsk Hydro) from 3220 m to 3298 m, coord N 61°44'46.10", E 01 °34'47.40" (Fig. 3).
Thickness
120 m in the type well, 78 m in the reference well.
Lithology
The Lomvi Formation consists of fine to coarse-grained kaolinitic
sandstone with subordinate and thin red marls and claystones. The sandstones,
which are light brown, grey or white, are generally more coarse-grained in
the reference well than in the type well.
Boundaries
The lower boundary represents the transition from interbedded sandstones
and marls to the coarse-grained sandstones of the Lomvi Formation. The
upper boundary, in the Statfjord Field area, is chosen at the base of
the first thick argillaceous unit belonging to the Lunde
Formation. Gamma ray log patterns are more regular in the Lomvi Formation
than in the overlying and underlying formations.
Distribution
The Lomvi Formation is present in all deep wells between the Brent Field
and the southern edge of the More Basin.
Age
Triassic; no more precise dating available.
Depositional environment
The Lomvi Formation most probably consists of fluvial deposits.
