Basin Analysis of North Sea Viking Graben: New Techniques in an Old Basin

J. E. Iliffe, S. Cao, I. Lerche

Rapid sedimentation rates from the Upper Cretaceous to Tertiary in the North Sea require that burial history modeling account for overpressuring.

Use of a quantitative fluid flow/compaction model, along with the inversion of thermal indicators to obtain independent estimates of paleoheat flux, can greatly enhance our knowledge of a basin's evolution and hydrocarbon potential.

First we assess the modeling sensitivity to the quality of data and variation of other input parameters. Then application to 16 wells with vitrinite data in the Viking graben north of 59° latitude and to pseudo-wells derived from deep seismic profiling of BIRPA greatly enhances the study of regional variations. A Tissot generation model is run on all the wells for each potential source rock. The resulting amounts of oil and gas generated are contoured to produce a regional oil and gas provenance map for each source rock. The model results are compared and tested against the known producing fields.

Finally, by restoration of the two-dimensional seismic reflection profiles, the temporal variations of basement subsidence and paleoheat flow are related to the tectonic zoning of the region and to the extensional history.

The combined structural, thermal, and depositional information available due to technological progress in both modeling and deep seismic profiling allows a better understanding of previously proposed models of extension.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.