Surface, Geochemical Studies in the Norwegian Barents Sea: Comparison with Drilling Results

BJOROY, MALVIN, AND RITA LOBERG, Geolab Nor A/S, Trondheim, Norway

During the last four years a number of surface geochemical studies have been undertaken over virgin areas in the Barents Sea. All of these areas have subsequently been up for bidding and a number of wells have been drilled.

Sampling for surface geochemistry has been undertaken using a gravity-corer, where samples were taken 2 m below the seafloor. The sampling grids were either regular or grids selected based on known geological features in the areas, or a combination of the two.

The samples were subsequently analyzed for interstitial gas, adsorbed gas, grain size distribution, organic and inorganic carbon content, fluorescence of the hexane extract, and heavy hydrocarbons in the hexane extract.

The different areas analyzed gave different conclusions ranging from barren, i.e., no indication of petrogenic hydrocarbons in the surface; anomalies of petrogenic hydrocarbons, i.e., indicating gas, condensate, or oil being generated to extremely strong anomalies of oil that were interpreted as indicating leaky or nonexistent caprock such that most of the generated hydrocarbons are being leaked to the surface.

In the meantime a number of wells have been drilled over the surveyed areas, where the results vary from dry, oil/gas shows and residual oil. Detailed results from the surveys will be discussed and compared with the drilling results from the different areas.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)