Abstract: Structural Evolution and Petroleum Potential of the Norwegian Barents Sea

Kare T. Nilsen

The tectonic history of the Norwegian Barents Sea has provided potential hydrocarbon traps in clastic reservoirs associated with rotated fault blocks, compressional anticlines and salt domes. Significant stratigraphic potential also resides in Paleozoic carbonates. Drilling in the Hammerfest basin has yielded large gas discoveries in rotated fault blocks, but other trapping concepts remain relatively untested. The undrilled area north of 74° 30^primeN, currently being mapped by the Norwegian Petroleum Directorate using exclusive seismic and geological data from shallow boreholes, represents a significant area for future exploration. Prospectivity is critically dependent on the sealing of traps following Neogene uplift of large areas of the Barents platform.

The area is dominated by structural trends inherited from the Caledonian and older orogens. Carboniferous rifting established a system of half grabens and intervening highs followed by late Permian faulting in the west which initiated regional subsidence continuing into the early Jurassic. Fault reactivation in early Triassic times triggered salt diapirism and provided structural control for the formation of Triassic shelf margins. During the late Jurassic-early Cretaceous western basins underwent tectonic subsidence. while the northeastern platform area was subject to gentle compression.

In the late Cretaceous salt was reactivated in the Nordkapp basin and compressional structures developed west of the Loppa High. Further subsidence of the western basins was promoted by late Mesozoic and early Tertiary transtensional movements along the North Atlantic rift system. Subsequent regional compression in these basins, and basin inversion east of the Loppa High, are of post-Eocene age.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France