AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
(1) University of Texas at Austin, Austin, TX.
The Heidrun field, Norwegian Sea, is one of the first giant oil fields found on the Haltenbanken, mid-Norwegian Continental Shelf. Modern 3D seismic and well data over the field were used to define the key structures and stratigraphic intervals and surfaces. The basic framework history is typical of most North Sea plays, and includes Triassic rift sequences masked by reactivation of bounding faults during the Jurassic rift phase, followed by deposition of marine black shales and subsequent carbonaceous shales, overlain by Paleocene-Eocene boundary tuffs due to Norway-Greenland rift generated volcanism and finally an Eocene to present passive margin marine sequence composed of glacial deposits. Traditional reservoirs within the field are in Jurrasic-age inter-rift sediments. However, Cretaceous-age turbidites are currently being explored in the Norwegian and North Sea as possible targets, with some success. These turbidites are traditionally found in rifted deeps along the Norwegian continental shelf and are believed to be sourced from localized erosion of Jurassic-age rifted highs. Data within our study area reveal the existence of a Cretaceous-age wedge of possible deep water facies accommodated within the downthrown hanging wall of several smaller half-grabens formed on a regional platform. Image extractions suggest the presence of several lobate bodies, some of which parallel the adjacent structural highs prior to cascading over the slope. Attribute analysis show several discontinuous high amplitudes. Several wells penetrate the updip, tilted half graben hanging walls which are believed to be sourcing these turbidites. These half graben fills represent a new play in this area that flanks the Central Graben.