ABSTRACT: Central Graben (Norway)--Hydrocarbon Distribution Related to Source Rock Maturation and Pressure Regimes

Andre Chiarelli, Francois Issard

This study of the Central graben was limited to the north by 57°25^primeN, to the west by 4°30^prime, and to the east and south by the borders of the United Kingdom and Denmark, respectively. Several fields have been discovered within the Upper Cretaceous, Paleocene, and Jurassic strata, for which the source rocks are Jurassic age.

The amount and types of hydrocarbons generated from the source rocks have been estimated by accounting for their thickness, their initial potential, and their degree of maturation. The possibilities for hydrocarbon migration have been interpreted through an integration of the structural history and the hydrodynamic framework within the Central graben region. The hydrodynamic framework, which appears to be a very important parameter in the study area, has been reconstructed from pressure measurements in the reservoirs, compaction profiles, and numerical modeling. It appears that vertical migration from the Jurassic source rocks toward the Upper Cretaceous and Paleocene reservoirs was mainly dependent on tectonics, salt diapirism, and geopressuring.

In the Central graben region the understanding of areal distribution and nature of hydrocarbons formed has been greatly improved by the integration of geochemistry and hydrodynamics. This conclusion could be extended to many other sedimentary basins in the world.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990