Tampen Spur

Figure 5.5 Hydrocarbon traps in the Tampen Spur Block 34/7, North Sea (from Nybakken, 1991. Reprinted by permission of the European Association of Exploration Geophysicists).

Fig. 1. Data localities for the present study (KvalvSgen, Spitsbergen Tilje Formation, Haltenbanken Brent Group, Tampen Spur Brora, Scotland Gulf of Corinth, Greece).

Fig. 3. Interpreted seismic profile (NW-SE) across parts of the Tampen Spur. Note the changes in fault throw when moving upsection. Largest throw is experienced within the deeper parts of the section. The Base Cretaceous Unconformity is only minor affected by faults.

Fig. 4. (a) Synsedimentary fault (sand dike) within the Etive Formation, Tampen Spur, (b) Early faults in the Etive Formation characterized by enrichment of phyllosilicates. Some of the faults are embedded by early carbonate cement (see text for further details). 

The textures for the faults from Tampen Spur which are not interpreted as synsedimentary, suggest that most sediments were poorly lithified at the time... 

The faulted, non-carbonate cemented sandstones which were sampled from Haltenbanken and Tampen Spur, show clear evidence of diagenetic modifications after the deformation had occurred. Feldspar dissolution, illite precipitation and stylolitization are examples of such diagenetic processes. The pre- and post-faulting diagenetic reactions have been demonstrated to be a useful tool for the purpose of dating fault movements relative to basin subsidence (Sverdrup and Bjprlykke, 1992 Saigal et al., 1995). 

The observations from Haltenbanken, Tampen Spur and Gulf of Corinth further demonstrate that carbonate cemented faults and fractures are limited to carbonate cemented sequences, suggesting that most of the carbonate is derived from the surrounding rock, probably transported by diffusion. The absence of... 

In loose sandstones containing small amounts of clay minerals, relative movement will cause grain reorganization and pore collapse. If accompanied by fluid escape, fault parallel dikes develop. The positions of these types of structures from Kvalvagen, Tampen Spur and Gulf of Corinth are indicated as Kl, T1 and G1 in Fig. 11. Soft sediments cannot remain open for long periods due to their low shear strength, and cement seals are therefore not expected for such structures. 

Subsequent to the faulting, the sediments from Kvalvaegen, Haltenbanken and Tampen Spur got buried to approximately 3500 m, 3000 m and 2500 m, respectively. The positions are indicated as K6, H6 and T6 in Fig. 11. The presence of micro-stylolites was observed for the Kvalvagen and Haltenbanken faults only, which is explained by the fact that these sediments are buried at or below the onset of extensive pressure solution of quartz at ca. 3 km depth (Fig. 11). 

In Mesozoic sandstones on Tampen Spur and Haltenbanken, normal faults are usually characterized by grain reorientation and enrichment of clay minerals which suggest that ductile deformation dominates. Abundant quartz cement is only observed along these faults associated with stylolites. Open fractures were not present in the sandstones from Tampen Spur and Haltenbanken. Fractures in these sediments therefore normally represent permeability barriers for fluid flow. 

Moretti, I. and Deacon, K. 1995. Subsidence, maturation and migration history of the Tampen Spur area. Mar. Pet. Geol., 12 345-375. 

Nybakken, S. 1991. Sealing fault traps - an exploration concept in a mature petroleum province Tampen Spur, northern North Sea. First Break, 9 209-222. 

Horstad, 1., Larter, S.R. and Mills, N. 1995. Migration of hydrocarbons in the Tampen Spur area, Norwegian North Sea a reservoir geochemical evaluation. Geol. Soc. Spec. Publ., 86 159-183. 

Fig. 1. The North Sea area and the location of the Snorre Field on the Tampen Spur structural high in the northernmost North Sea. Major structural elements are of late Jurassic-Early Cretaceous age.

The Snorre Field is located in the northern North Sea area within the Tampen Spur, a structural high... 

The alluvial reservoir rocks in the Tampen Spur area were deposited within a Permian-early Trias-sic rift basin that comprised most of the North Sea area (e.g. Ziegler, 1988 Glennie, 1990, 1995). 

Fig. 3. General stratigraphy of the Tampen Spur area, revised from Campbell Ormaasen (1987) with lithostratigraphical nomenclature from Vollset Dore (1984) and Isaksen Tonstad (1989) and time scale from Gradstein et al. (1995).

During deposition of the Lunde Formation, the palaeodrainage direction in the Tampen Spur area... 

Fig. 4. Stratigraphic column of Triassic-Lower Jurassic on the Tampen Spur showing general lithostratigraphy of the Lunde Formation (modified from Nystuen Fait, 1995). Time scale is according to Gradstein el al. (1995).

Nystuen, J.P. Falt, L.-M. (1995) Upper Triassic-Lower Jurassic reservoir rocks in the Tampen Spur area, Norwegian North Sea. In Petroleum Exploration in Norway, Vol. 4 (Ed. Hanslien, S. et al). Norwegian Petroleum Society. Elsevier, Amsterdam, 41 pp. 

Fig. 1. Regional framework in this study. BCU map of the Tampen Spur area, with geochemical classification of petroleum populations (Horstad et al. 1995).

Horstad, L, Larter, S. R. Mills, N. 1995. Migration of Hydrocarbons in the Tampen Spur Area, Norwegian North Sea A Reservoir Geochemical Evaluation. Geological Society, London, Special Publications, 86, 159-183. 

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