ABSTRACT: Integrated Exploration Search for Additional Upper Jurassic Prospectivity in the North Viking Graben, Norwegian North Sea

BARNES, KEVIN R., Mobil Exploration Norway, Stavanger, Norway, JOHN N. SNEDDEN, Mobil Research Laboratory, Dallas, TX, and DAVID MCADOW, Mobil Exploration Norway, Stavanger, Norway

An extensive integrated exploration effort has established additional prospectivity on the flanks of known oil accumulations including the giant Mobil-interest Statfjord field.

Petrographic provenance studies suggest that, during the Late Jurassic/Early Cretaceous lowstand, many eroded fault blocks shed large volumes of sand into surrounding conceptual play areas or "halos." Sedimentation was intimately controlled by local faulting. Detailed sedimentological study of cores from Statfjord Nord field indicate that Late Jurassic sandstones were deposited predominantly by dipslope sedimentation in shoreface and slope environments of a large braid delta.

These sandstones can have excellent reservoir properties, and record flow rates of 12,500 BOPD have been achieved. In addition, biostratigraphical analysis has aided the development of a syndepositional tectonic and structural model. Detailed 3-D seismic interpretation has allowed the refinement of several stratigraphic traps, one of which is to be drilled in early 1992. Seismic inversion, using Jason Geosystems software, suggests the presence of late Jurassic sandstones within the prospect anomaly.

These prospects are typical of a new phase of exploration in the Norwegian North Sea devoted to finding "second order" targets around existing "first order" oil fields.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)