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The South Viking Graben (SVG), in the northern part of the North Sea, is a well-studied Middle to Upper Jurassic rift basin containing a major hydrocarbon province that extends across the border between the U.K. and Norway. Thermal doming during the Toarcian–Aalenian, centered on the area south of the southern end of the SVG, resulted in the deposition of thick Middle Jurassic sequences along a north-trending basin that is now the SVG (Underhill and Partington, 1993; and see Hoth et al., 2018). Subsequent deflation of the dome was followed by significant rifting in the SVG, which began in the Callovian. However, the most active phases of rifting occurred during the Oxfordian to early Volgian (early Tithonian), when very thick synrift sequences were deposited in the graben. The graben is bounded on the west by the Fladen Ground Spur (FGS) and on the east by the Utsira High (Figure 1). A large proportion of the hydrocarbon reserves is found in synrift to early postrift, deep-marine clastic sediments of the Brae Formation; these accumulations are informally termed the Brae Play. The Brae Formation interfingers with, and is overlain by, the Kimmeridge Clay Formation (KCF; termed Draupne Formation in Norway). The KCF-Draupne Formation is the major source rock and is the most significant seal for trapped Brae Play hydrocarbons. Several previous publications have shown the outlines and general internal structure of this buried half-graben (e.g., Harris and Fowler, 1987; Johnson et al., 1993; Sneider et al., 1995; Thomas and Coward, 1996; Fraser et al., 2003; Zanella and Coward, 2003) and numerous papers have dealt with various other aspects of the graben (see Connell, 2018, for a full reference list). However, more accurate depictions of the structure, particularly the western fault-bounded margin and the internal structure of the graben fill, are now possible due to the complete coverage of the area by high-quality 3-D seismic data. A 3-D image of the south and central parts of the Viking Graben and its flanks, at Base Cretaceous level, is shown in Figure 2. In addition, extensive released well-data sets are available in this mature hydrocarbon province that allow comprehensive analysis of the stratigraphy and a clearer understanding of the extent of submarine fans containing hydrocarbon reservoirs.

The South Viking Graben (SVG), in the northern part of the North Sea, is a well-studied Middle to Upper Jurassic rift basin containing a major hydrocarbon province that extends across the border between the U.K. and Norway. Thermal doming during the Toarcian–Aalenian, centered on the area south of the southern end of the SVG, resulted in the deposition of thick Middle Jurassic sequences along a north-trending basin that is now the SVG (Underhill and Partington, 1993; and see Hoth et al., 2018). Subsequent deflation of the dome was followed by significant rifting in the SVG, which began in the Callovian. However, the most active phases of rifting occurred during the Oxfordian to early Volgian (early Tithonian), when very thick synrift sequences were deposited in the graben. The graben is bounded on the west by the Fladen Ground Spur (FGS) and on the east by the Utsira High (Figure 1). A large proportion of the hydrocarbon reserves is found in synrift to early postrift, deep-marine clastic sediments of the Brae Formation; these accumulations are informally termed the Brae Play. The Brae Formation interfingers with, and is overlain by, the Kimmeridge Clay Formation (KCF; termed Draupne Formation in Norway). The KCF-Draupne Formation is the major source rock and is the most significant seal for trapped Brae Play hydrocarbons. Several previous publications have shown the outlines and general internal structure of this buried half-graben (e.g., Harris and Fowler, 1987; Johnson et al., 1993; Sneider et al., 1995; Thomas and Coward, 1996; Fraser et al., 2003; Zanella and Coward, 2003) and numerous papers have dealt with various other aspects of the graben (see Connell, 2018, for a full reference list). However, more accurate depictions of the structure, particularly the western fault-bounded margin and the internal structure of the graben fill, are now possible due to the complete coverage of the area by high-quality 3-D seismic data. A 3-D image of the south and central parts of the Viking Graben and its flanks, at Base Cretaceous level, is shown in Figure 2. In addition, extensive released well-data sets are available in this mature hydrocarbon province that allow comprehensive analysis of the stratigraphy and a clearer understanding of the extent of submarine fans containing hydrocarbon reservoirs.

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[[file:M115CH02FG03.jpg|300px|thumb|{{figure number|3}}Main structural elements of the South Viking Graben and its flanks. The extent of the thick Middle-Upper [[Jurassic]] [[graben]] fill is defined by the limits of the [[KCF-Draupne Formation]]. Unshaded areas on the Fladen Ground Spur and Utsira High have pre-Upper Jurassic rocks beneath [[Cenozoic]] or [[Cretaceous]] strata (with very thin, <approximately 2 m [6.6 ft], KCF-Draupne Formation in a few wells). The locations of Upper Jurassic [[oil]] and [[gas]] [[condensate]] fields within the graben are shown with solid fill. Fields with Cenozoic [[reservoir]]s are shown with black outlines; [[field]]s and discoveries with Middle Jurassic and older reservoirs are shown with orange outlines. Most faults shown are derived from mapping by some of the authors of the [http://archives.datapages.com/data/specpubs/memoir115/data/9_aapg-sp2050009.htm full paper] associated with this Wiki article, but a few in the southeast portion of the map are from Zanella et al. (2003<ref name=Zanellaetal2003>Zanella, E., M. P. Coward, and A. McGrandle, 2003, Crustal structure, in D. Evans, C. Graham, A. Armour, and P. Bathurst, eds., The millennium atlas: Petroleum geology of the central and northern North Sea: Geological Society (London), p. 35–43.</ref>). Bi = Birch; Br = Braemar; CB = Central Brae; D = Devenick; EB = East Brae; G = Gudrun; JS = John Sverdrup; K = Kingfisher; L = Larch; M = Miller; NB = North Brae; SB = South Brae; S = Sycamore; Th = Thelma; Ti = Tiffany; To = Toni.]]

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[[file:M115CH02FG04.jpg|300px|thumb|{{figure number|4}}West-east [[seismic]] section across the South Viking Graben, through Sycamore field. Location shown on [[:file:M115CH02FG01.jpg|Figure 1]], [[:file:M115CH02FG02.jpg|Figure 2]], and [[:file:M115CH02FG03.jpg|Figure 3]]. Courtesy of PGS.]]

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