BRUIJN, B., Nederlandse Aardolie Maatschappij, Assen, Netherlands

ABSTRACT: De Wijk Gas Field: Reservoir Mapping with Amplitude Anomalies

De Wijk field, discovered in 1949, is located in the northeastern part of Netherlands. The main gas accumulation is contained in Cretaceous and Triassic sandstone reservoirs trapped in a broad salt-induced structure of around 80 sq km areal extent. The field contains gas in the Tertiary, Chalk, Zechstein 2 Carbonate, and Carboniferous reservoirs as well.

De Wijk field is unique in the Netherlands as most gas-producing reservoirs in the Cretaceous/Triassic are of no commercial interest. Post-depositional leaching has positively affected the reservoir properties of the Triassic formations subcropping below the Cretaceous unconformity.

Optimum interpretation of 3-D seismic data acquired in 1989 resulted in spectacular displays highlighting the uniqueness of the field. Most gas-bearing reservoirs are expressed on seismic by amplitude anomalies. Various attribute-measurement techniques show the effects of gas fill, leaching, and sand distribution in the various reservoirs.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.