Constraints on Upper Jurassic palaeogeography in the Ula Gyda trend

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · AAPG Bulletin

OSTI ID:127658

Mundal, I; Milton, N; Robinson, N ^[1]

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1. BP Norge, Stavanger (Norway)

BP Norway`s semi-regional 3D database in the Central Trough covers an area of nearly 3000 sq.km. around BP Norway`s two producing fields, Ula and Gyda, and includes strategic acreage within tie-back distance to the fields. Prospectivity in the Ula Gyda trend involves complex salt influenced structures and localized Upper Jurassic depositional systems. The objective of this paper is to demonstrate how the understanding of the semi-regional structures and salt tectonics helped constrain the interpretation of the Upper Jurassic palaeogeography. The control of basement structures (Permian) on cover structures (Upper Jurassic/Base Cretaceous) through Zechstein Salt was interpreted using the 3D semi-regional dataset. Analogue sandbox experiments from the Austin Geodynamics Laboratory provide support for the complex structures which were interpreted on the 3D seismic data. Sandbox models mimic the interpreted monoclinal drape of the Triassic and Jurassic section over the critical basin bounding fault in the Base Zechstein. Structural cells can be identified with the help of the salt isochore. The understanding of the relationship between structural development and salt distribution was a major control on the interpretation. This interpretation coupled with the Upper Jurassic reservoir distribution from well data provided the primary evidence for the gross depositional environment maps which were used in prospect evaluation in the area. 3D visualization and shaded relief displays of the interpreted horizons and isochores played a significant part in developing an understanding of the interplay between the deeper structures and the likely Upper Jurassic palaeogeography and depocentres.

• OSTI ID: 127658
• Report Number(s): CONF-950995--
• Journal Information: AAPG Bulletin, Journal Name: AAPG Bulletin Journal Issue: 8 Vol. 79; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
EXPLORATION
GEOLOGIC STRUCTURES
JURASSIC PERIOD
NORWAY
OFFSHORE SITES
PETROLEUM
SEISMIC SURVEYS