High-quality 3D seismic data are used to analyze the history of fault growth and hydrocarbon leakage in the Snøhvit Field, southwestern Barents Sea. The aim of this work is to evaluate the role of tectonic fracturing as a mechanism driving fluid-flow in the study area. To achieve this aim, an integrated approach including seismic interpretation, multiple seismic attribute analysis, fault modeling and displacement analysis was used.The six major faults in the study area are dip-slip normal faults which are characterized by complex lateral and vertical segmentation. The three main episodes of fault reactivation interpreted were in late Jurassic (Kimmeridgian), early Cretaceous and Paleocene times. Fault reactivation in the study area is mainly through dip-linkage. Throw-distance plots of the representative faults also revealed along-strike linkage and multi-skewed C-type profiles. The throw profiles show that faults in the study area evolved through polycyclic activity involving both blind propagation, syn-sedimentary activity and that they have their maximum displacement at the reservoir zone. The expansion and growth indices provide evidence for coeval fault activity with sedimentation and interaction of the faults with a free surface during their evolution.

Canyons and other sediment conduits are important components of the deep-water environment and are the main pathways for sediment transport from the shelf to the basin floor. Using 3-D and 2-D seismic reflection data, seismic facies and statistical morphometric analyses, this study showed the architectural evolution of five canyons, two slide scars and four gullies on the southern part of the Loppa High, Barents Sea. Morphometric parameters such as thalweg depth (lowest point on a conduit's base), wall depth (middle point), height, width and base width, sinuosity, thalweg gradient, aspect ratio (width/height) and cross-sectional area of the conduits were measured at intervals of 250-m perpendicular to the conduits' pathways. Our results show that the canyons and slide scars in the study area widen down slope, whereas the gullies are narrow and short with uniform widths. The sediment conduits in the study area evolved in three stages. The first stage is correlated with a time when erosion and bypass were dominant in the conduits, and sediment transferred to the basin in the south. The second stage occurred when basin subsidence was prevalent, and a widespread fine-grained sequence was deposited as a drape blanketing the canyons and other conduits. A final stage occurred when uplift and glacial erosion configured the entire southern Loppa High into an area of denudation. Our work demonstrates that the morphometric parameters of the canyons, slide scars and gullies generally have increasing linear trends with down-slope distance, irrespective of their geometries. The morphometric analysis of the sediment conduits in the study area has wider applications for understanding depositional processes, reservoir distribution and petroleum prospectivity in frontier basins.

a b s t r a c tThis study investigates the evolution of supra-salt faults in the Eastern Hammerfest Basin using high equality seismic reflection data. Traditional techniques of displacement analysis, including the variation of fault displacement (throw) against distance (x), depth (z), expansion and growth indices were adopted. Fault reactivation was assessed using bivariate plots of a) cumulative throw vs. age and b) throw (t) vs. depth of nine (9) representative faults.The interpreted faults are supra-salt crestal and synclinal faults striking NE, E and SE. These faults have complicated t-x and t-z plots and are characterized by considerable stratigraphic thickening in their downthrown section. Faults in the study area have developed over the salt structure since latest Paleozoic times; some of them were reactivated by Early to Middle Triassic through dip linkage of initially isolated fault sets. Along strike, the fault exhibit complex segmentation through coalescence of several subunits linked by local throw/displacement minima. Expansion and growth indices show that the faults of the study area developed during the deposition of Paleozoic to Early Cretaceous sediments by polycyclic growth involving both blind and syn-sedimentary activity.An important piece of information from this study is that fault propagation is controlled by lithological heterogeneity and that both lateral and vertical segmentation of faults are important for hydrocarbon migration within the Triassic to Late Cretaceous interval.

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Mass-wasting on the NE Atlantic margin is generally attributed to Cenozoic glaciations. Using high-quality 2D seismic datasets and two exploration wells, this study investigates the types and driving mechanisms of mass-wasting in the Sørvestsnaget Basin, Southwestern Barents Sea. The methods include seismic interpretation of shelf margin clinoforms, mass-transport deposits (MTDs), submarine channels and v-shaped canyons. The shelf-edge trajectory provided information about sea-level conditions, paleo-sediment routes, and dispersal patterns during the evolution of the basin. In terms of the internal geometry of reflectors, the major depositional units in this work are five sedimentary packages (P1 to P5) characterised by distinct southwest dipping shelf margin clinoforms. The seven MTDs here discussed have Late Miocene to Pleistocene ages. Miocene and Early Pliocene MTDs in the basin demonstrate a tendency for initial translation through canyons and channels. The youngest MTDs are composed of glaciogenic sediments remobilized by ice streams during large-scale Neogene and Quaternary glaciations. This work shows that mass-wasting has been a recurrent and inherent process in the Sørvestsnaget Basin from the Miocene until recent times. The main triggering 1 mechanisms for slope failure in the basin are increased pore pressure from sea-level fall and high sedimentation rate. Mass-wasting in the study area occurred through progressive, retrogressive and coherent downslope failures.