Fault complex

The southwestern Barents Sea continental shelf is dominated by ENE-WSW to NE-SW, and NNE-SSW to NNW-SSE trends with local influence of WNW-ESE- to E-W-striking elements (Faleide et al., 1984, 1993 Gabrielsen et al., 1990). In the southern part of the Barents Sea, a regional ENE-WSW grain is defined by the major fault complexes bordering the Hammerfest and Nordkapp Basins. To the west and northwest, N-S trends prevail (Tromsp Basin, Knplegga Fault, Homsund Fault Complex). 

Fig. 3. Seismic anomalies (arrows) in the Bj0m0yrenna Fault Complex.

With the exception of well 7125/1-1, group GUI fractures are restricted to the master fault complexes which are known to be characterised by inversion. Well 7125/1-1 is situated in the foot-wall of the Nys-leppen Fault Complex, and it may be speculated as to whether the abundance of low-angle fractures in this well implies that inversion also took place at the northwestern margin of the Nordkapp Basin. 

More comprehensive fracture networks are encountered in connection with the major fault zones of the study area. The fracture intensity is highest within the master fault complexes, and particularly along those which were affected by inversion in Tertiary times. 

Gabrielsen, R.H., Grunnaleite, 1. and Ottesen, S. 1992. Reactivation of faults complexes in the Loppa High area, southwestern Barents Sea. In T.O. Vorren, E. Bergsager, 0.A. Dahl-Stamnes, E. Holter, B. Johansen, E. Lie and T.B. Lund (Editors), Arctic Geology and Petroleum Potential. NPF Special Publication 2. Elsevier, Amsterdam, pp, 631-641. 

Gabrielsen, R.H., Grunnaleite, I. and Rasmussen, E. 1997a, Cretaceous and Tertiary inversion in the Bjpmdyrenna Fault Complex, south-western Barents Sea. Mar. Pet. Geol., 14 165-178,... 

Fault seal probabilities along the Revfallet Fault Complex are generally high to moderate with nearly... 

Another useful tool for determining fault seal characteristics is the shale smear map. Although the fault seal probability calculation, derived from an empirical database which contains faults which were affected by shale smear, already incorporates a shale smear factor (see also Lindsay et al., 1993), the purpose of producing shale smear maps is to define the shale smear envelope for individual shale beds across fault surfaces. They can also be used as an independent check on the fault seal probability calculations. Only one shale smear map was produced in the study, for the Revfallet Fault Complex, where the greatest thickness of syn- to post-rift shale occurs. 

Fig. 9. Fault plane diagram Revfallet Fault Complex.

Fig. 10. Displacement contour plot Revfallet Fault Complex.

Fig. 11. Shale map of Revfallet Fault Complex, Shows footwall shale units superimposed on to the fault plane.

Johansen, M. 1997. Well 12 9l9- in the Ringvassoy— Loppa High Fault Complex, Hydrocarbon History, Filling and Dismigration. Master s dissertation. University of Oslo, Oslo. 

Since the 1980s, the fractal theory (Mandelbrot 1983) has been fairly applied in avariety of research areas including geology and geophysics. Some Chinese scholars explored the relationship between the fractal characteristics of coal mine area faults and gas outburst (He et al. 2002). They quantified the fault complexity using the fractal dimension as the... 

Complex Faulting Complex faulting involves the interaction of two or more faults. The example of two intersecting faults is illustrated in Figure 8. 

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