Giant Gas Chimneys and Gas Hydrate Occurrence in the Southwestern Barents Sea

Abstract

Dedicated : 'Fluids and Fluid Flow' 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 amount of net erosion in the area showed no direct relation to the distribution of fluid flow features. This suggests fluid flow in the region is caused mainly by repeated glacial cycles and differential geographic uplift, which caused tilting and spilling of various structural traps in the area, although erosion might have had an added effect.