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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Petroleum
Systems of Southern Norway
1 Department of Geosciences, University of Oslo,
P.O. Box 1047 Blindern, N-0316 Oslo, Norway, fax: +4722854215, [email protected]
2 RWE Dea Norge AS, Oslo, Norway
Traces of petroleum
generated from Lower Palaeozoic marine type II source rocks are known from numerous locations
onshore Norway and Sweden. Oil stains occur in fractured granitic basement rocks and Ordovician carbonate mounds in
Sweden, and pyro-bitumen and oil are found in Palaeozoic rocks in the Oslo Graben, Norway. Oil residue found in Permian
sediments in a Norwegian North Sea well, together with migrated oil and gas in a Permian volcanic intrusion cutting through
the offshore Palaeozoic Skagerrak Graben, may originate from offshore Palaeozoic source rocks.
This organic geochemical study examines Palaeozoic sediments and petroleum
from outcrops and wells both on - and
offshore Scandinavia, in order to better understand and evaluate the potential Palaeozoic
petroleum
system
(s) of this
region. Source rocks are found among Cambrian/Ordovician marine shales, Carboniferous coals and Permian marine
shales. We also suggest, from studying well samples from Norwegian and Danish offshore wells, that good reservoir and
cap rocks are present in the Permian section offshore southern Norway.
In our proposed model of a Palaeozoic petroleum
system
offshore southern Norway, the critical moment is related to the
timing of
petroleum
expulsion and migration, i.e. if structures and/or cap rocks were formed in time to trap
petroleum
expelled from Palaeozoic source rocks. Peak oil generation from Lower Palaeozoic source rocks was probably during the
Carboniferous, while Upper Palaeozoic source rocks matured rapidly during the Lower Triassic. The results from this survey
may be beneficial for
petroleum
exploration for deep prospects offshore southern Norway.
Petroleum
Geologists. All Rights Reserved.