The Kraka Field, discovered in 1966, was the first oil discovery in the North Sea. The field, a large elongated chalk structure, is located in the southern part of the Central Trough in the Danish sector of the North Sea.
The Kraka field is characterized by a low permeability matrix with some enhancement of permeability due to natural fracturing. The fluid distribution in the reservoir is complex. Throughout the hydrocarbon bearing zone, matrix water saturations are in excess of 50 %. Fluid contacts are tilted, the matrix oil water contact due to tectonics and the fracture free water level due to a regional hydrodynamic gradient. Variations in pressures and fluid properties further add to the complexity of the field.
This paper describes an integrated study of the Kraka field. The integration of a geological fracture study with a reservoir simulation study has resulted in an improved reservoir characterization.
The development history of the field demonstrates how new technology can promote the development of a marginal field.