Seismic reservoir monitoring over the Oseberg field

The Oseberg field is located in the Norwegian North Sea in blocks 30/6 and 30/9, approximately 140 km northwest of Bergen (Fig. 1). The field was discovered in 1979, and came onstream in December 1988. The Oseberg field comprises three major eastward tilted fault blocks called Alpha, Gamma and Alpha North (Fig. 2). The reservoir rocks are found within the Brent group, where the Oseberg formation is the main reservoir (Fig. 3). The total Brent group thickness is 40-200 m. Seal is provided by the Heather formation and the Cretaceous limestones and shales.