--> Abstract: Subsurface Fluid Flow and Surface Anomalies at Veslemøy high, SW Barents Sea – What Do They Tell Us about Gas Hydrate Prospects in Barents Sea?, by Shyam Chand; #90177 (2013)

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Subsurface Fluid Flow and Surface Anomalies at Veslemøy high, SW Barents Sea – What Do They Tell Us about Gas Hydrate Prospects in Barents Sea?

Shyam Chand

The SW Barents Sea is versatile in its evolution from its old Caledonian compression related horst-graben structures which were modified during breakup with Greenland in the Cenozoic, and the effect of recent glaciations that have removed large thicknesses of sediments from the seabed. Loading and unloading by glaciers resulted in erosion and opening of pre-existing faults and creation of new ones facilitating fluid escape from the subsurface. Expressions of fluid escape, pockmarks, are widely distributed in the SW Barents Sea. Several gas flares, some of them 200 metre high, were reported to occur along a segment of the Ringvassøy Loppa Fault Complex (RLFC), indicating open fractures and still highly active fluid flow. The fluid expulsion probably started after the retreat of glaciers causing the release of methane from melting methane hydrates through slow fluid escape process which lasted until recent creating pockmarks. Fluids are also leaking from deeper source rocks through formation of pathways focussed by stratigraphic boundaries. Wherever open faults are available they escape to the water column and are observed as gas flares. We analysed selected gravity cores from Veslemøy High based on subsurface seismic gas anomalies and structural controls of fluid flow towards the subsurface. The subsurface fluid flow at Veslemøy High is observed to be controlled by the evolution history of the region. This includes 1) the morphology and orientation of regional faults, structural highs and basins formed during the Caledonian orogeny, 2) the presence of depositional environment dependent sediments such as siliceous ooze which changes in microstructure with temperature thereby controlling fluid flow and 3) the location of regional and local open faults formed by glacial loading and unloading activity. Analysis of hydrocarbons in subsurface sediments, micropaleontological studies for identifying and quantifying methane seep associated species and their juxtaposition to subsurface gas anomalies give a good understanding of the fluid flow system of this region. We combine these new results with those from earlier studies to give a comprehensive model for gas hydrate system and resource potential within SW Barents Sea.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013