Distribution of Sub-surface Fluid Flow Systems in the SW Barents Sea

Abstract

The southwestern Barents Sea is a large hydrocarbon-prone basin of the Norwegian Arctic region. A significant portion of hydrocarbon gases has leaked/migrated into the shallow subsurface and is now trapped in gas hydrate and shallow gas reservoirs. The leakage of these fluids through marine sediments,due to glacio-tectonics and denudation, may have controlled the evolution of various sedimentary basins of this region. We analyzed 2D seismic data from the southwestern Barents Sea to identify different fluid-flow features and study their relationship with the geological setting. Gas chimneys were the most abundant feature observed. Among the various observed fluid-flow features were giant gas chimneys covering large areas,associated shallow gas accumulations and fluid leakage along faults. Fluid-flow features were located above deep-seated faults in the area suggesting a relation with tectonic processes and glacial cycles.The proximity of large gas chimneys with major petroleum discoveries suggest a close link between the fluid flow and petroleum systems. The amount of net erosion in the area showed no direct relation to the distribution of fluid-flow features. The strong correlation between major faults and fluid-flow features suggests that extensional tectonics, glaciations and uplift could have played major roles in the timing and activity of fluid leakage.