trapping of the same oil type into both fields. The
varying oil/water contact between 1922 and 1935 m
MSL and deeper residual oil in the Johan Sverdrup
discovery demonstrates the effect of glacial down
warping and rebounds during the Pleistocene.
Both the Edvard Grieg and Johan Sverdrup
discoveries contain reservoirs that are new on the
NCS. In both discoveries Volgian reservoirs are the
main reservoirs that are overlying older reservoirs by a
major regional unconformity. The unconformity was
created by large-scale tectonic epeirogene basin inversion. Renewed weathering and erosion sourced the
various Volgian sandstone reservoirs in the two
discoveries. The Volgian inversion on the Haugaland
High is superimposed on the thermal-driven early
Middle Jurassic inversion that stripped off the Lower
Jurassic and older sequences down to basement over
large parts of the high. There are also marked tectonic
events in the Callovian and Kimmeridgian that have
influenced the presence of reservoir sequences.
The main Volgian reservoirs in the Edvard Grieg
discovery are proximal continental deposits and consist of high quality eolian sand, good quality braided
river and alluvial fan sands. There are also proximal
coarse sandy conglomerates of Triassic age, weathered basement gravel and Valanginian shell fragment
sand. All the reservoir types have been production
tested.
The main reservoir in the Johan Sverdrup Field is
the shallow marine Volgian sand with extreme
A
A
A'
A'
Basement
Hypothesis: Saturated system with 40-50 m oil leg.
1000
16/1-14
NW
SE
16/1-8
16/2-5
16/2-6
0 10 km
J72 basinal muds W
J72 basinal muds
Draupne Sandstone J71 E. Utsira
J72 Deep marine muds
J72 Draupne Spiculite
Basement subcrop
Zechstein Faults
1940-50 m MSL
1900 m MSL
Oil
J72 basinal muds
Partner
Lundin Norway Licenses
Operator
2000
3000
Ragnarock Discovery
Edvard Grieg
Johan Sverdrup Discovery
Apollo Discovery
Utsira High
Paleozoic
Paleocene
Jurassic/Triassic
Chalk
Rødby/Sola
Fig. 26.11 The basic assumption was sufficient. The drilling demonstrated under-saturated and saturated oil in new reservoir types
on the NCS. The oil fill of the reservoirs is late and is still ongoing
648
H. Chr Rønnevik
varying oil/water contact between 1922 and 1935 m
MSL and deeper residual oil in the Johan Sverdrup
discovery demonstrates the effect of glacial down
warping and rebounds during the Pleistocene.
Both the Edvard Grieg and Johan Sverdrup
discoveries contain reservoirs that are new on the
NCS. In both discoveries Volgian reservoirs are the
main reservoirs that are overlying older reservoirs by a
major regional unconformity. The unconformity was
created by large-scale tectonic epeirogene basin inversion. Renewed weathering and erosion sourced the
various Volgian sandstone reservoirs in the two
discoveries. The Volgian inversion on the Haugaland
High is superimposed on the thermal-driven early
Middle Jurassic inversion that stripped off the Lower
Jurassic and older sequences down to basement over
large parts of the high. There are also marked tectonic
events in the Callovian and Kimmeridgian that have
influenced the presence of reservoir sequences.
The main Volgian reservoirs in the Edvard Grieg
discovery are proximal continental deposits and consist of high quality eolian sand, good quality braided
river and alluvial fan sands. There are also proximal
coarse sandy conglomerates of Triassic age, weathered basement gravel and Valanginian shell fragment
sand. All the reservoir types have been production
tested.
The main reservoir in the Johan Sverdrup Field is
the shallow marine Volgian sand with extreme
A
A
A'
A'
Basement
Hypothesis: Saturated system with 40-50 m oil leg.
1000
16/1-14
NW
SE
16/1-8
16/2-5
16/2-6
0 10 km
J72 basinal muds W
J72 basinal muds
Draupne Sandstone J71 E. Utsira
J72 Deep marine muds
J72 Draupne Spiculite
Basement subcrop
Zechstein Faults
1940-50 m MSL
1900 m MSL
Oil
J72 basinal muds
Partner
Lundin Norway Licenses
Operator
2000
3000
Ragnarock Discovery
Edvard Grieg
Johan Sverdrup Discovery
Apollo Discovery
Utsira High
Paleozoic
Paleocene
Jurassic/Triassic
Chalk
Rødby/Sola
Fig. 26.11 The basic assumption was sufficient. The drilling demonstrated under-saturated and saturated oil in new reservoir types
on the NCS. The oil fill of the reservoirs is late and is still ongoing
648
H. Chr Rønnevik