Emphasis of High Order Stratigraphic Sequences Enabled by the Relative Geological Time Modelling Method: Application to Fractured Thin Reservoirs in a Pre-Salt Gas Field, Offshore Netherlands

Summary The author describes the method and results of a global and automated approach for seismic interpretation (Pauget et al, 2009), applied to a pre-salt gas field of the Dutch Cleaver Bank High platform, offshore Netherlands. A sequence stratigraphic framework called ‘Relative Geological Time (RGT) model’ is built from the seismic data to emphasize structural and stratigraphic features. Basin and reservoir characterizations are thus enabled by RGT-derived advanced attributes, rock physics modelling, Wheeler diagrams and sub-sample stratal slicing. Several fault networks related to different tectonic phases are emphasized, key stratigraphic surfaces are delineated, and major facies trends of the pre-salt reservoir level are discriminated. Those outputs are finally used to assess the impact of fault networks and subsequent subsidence on the eustasy-controlled thin beds succession. The author ultimately demonstrates the potential of the global RGT modelling method to revise hydrocarbon fields and identify pre-salt siliciclastic carbon storage sites.