The Use of Modern Analogues in Shared Earth Modelling - Case Study of the Cook Formation, Oseberg Field, Offshore Norway

Shared earth modeling aims to use subsurface data sets with a wide range of scales for the modelling and visualization of reservoir bodies in the subsurface. In the present paper the shared earth modeling of potential reservoir bodies in a complex sedimentary environment (estuarine Cook Formation, offshore Norway) is extended with the aim to identify subtle stratigraphic shapes in real migrated seismic data. First, core, wireline log and seismic data were integrated to interpret the estuarine depositional environment and general spatial distribution of the reservoir bodies therein. Next, quantitative size and shape data were extracted from sediment bodies in modern reservoir analogues in the Gironde and Western Scheldt Estuaries. These data were then compared with the shapes and spatial extent of inclined reflectors in seismic cross sections and plan views. This approach yielded the detailed interpretation of reservoir bodies in the Cook Formation as sand bars and adjacent channels in an estuarine environment. Sizes, shapes and orientation of the reservoir bodies very well compare with the modern analogues. The extension of the shared earth modeling with quantitative data from modern analogues resulted in an improved visualization of the reservoir architecture.