West Greenland versus Vøring Basin: comparison of two deepwater frontier exploration plays

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Two new frontier exploration areas were opened during 1996 in deepwater areas of the Northern Atlantic, the Fylla area (Davis Strait, offshore West Greenland) and the Vøring Basin (Norwegian Sea). Both are part of the North Atlantic rift system but have different rift histories. The Labrador Sea–Davis Strait probably did not begin to rift until Early Cretaceous times: Cretaceous sediments most likely rest on Ordovician carbonates or Precambrian basement. The Norwegian Sea area has experienced episodic rifting since Palaeozoic time and much of the area has Jurassic source and reservoir rocks. Jurassic rocks remain unproven in the Vøring Basin, because Cretaceous deposits are very thick in most of that area. Both rifts culminated with volcanism and seafloor spreading beginning in the Paleocene. Although the two areas have different rift histories, they share many common geological characteristics which influence their petroleum prospectivity. Exploration plays in both areas rely primarily on unproven Cretaceous source rocks. Jurassic rocks are probably absent across the Davis Strait area and, if present, are overmature across much of the Vøring Basin. Both basins have seismic evidence that hydrocarbons may be present, however. The Fylla area has seismic flat spots on at least four separate fault blocks. Direct hydrocarbon indicators (DHI) in the Vøring Basin include the well-known seismic flat spots and amplitude anomalies on several fault blocks of the western Nyk High. The chance for oil is high-risk in both areas, because the organic quality of the possible source rocks is unknown. Oil seeps (Davis Strait) and traces of oil shows (Vøring Basin) suggest that oil may be present. Immaturity is a concern for potential source rocks in the Fylla area, but overmaturity into the gas window is a risk for much of the Vøring Basin. Reservoir rocks are also anticipated to be of Cretaceous age. Cretaceous sandstones are common in Canadian wells in the Labrador Sea and in outcrops in West Greenland, where they are mostly continental to deltaic. Cretaceous sandstones have not yet been found in offshore West Greenland wells, but equivalent sandstones may be more distal and turbiditic in the offshore Fylla area. Cretaceous sandstones had been found in a scattering of wells in the Norwegian Sea and their presence in much of the central Vøring Basin was suggested by a prominent high-amplitude seismic package. The 6707/10-1 well found excellent reservoir-quality Upper Cretaceous turbidite sands on the Nyk High in the Vøring Basin. Paleocene sediments appear to be mostly shale-prone in both areas, although coarse Paleocene sandstones crop out in West Greenland. Both exploration areas offer huge structures which could hold world-class hydrocarbon deposits, yet carry high exploration risk for oil. No wells had been drilled in the Fylla licence as of 1998, but a late 1997 well discovered gas on one of the Vøring Basin fault blocks. These two exploration areas still offer exciting potential for significant future discoveries. In addition, data are sparse in these frontier basins, thus workers of each area may benefit by learning about the other basin.