Petroleum Budget of Arctic Basins: Generated Petroleum from Proven Source Rocks vs. Discovered Resources

Balazs Badics

The successful assessment of the oil and gas resources of the Arctic basins requires an integrated approach to petroleum systems analysis. We have used petroleum systems analysis in regional 3D basin models for the Arctic basins to estimate the total generated petroleum volumes per basin. The extent, organic richness and maturity evolution of proven source rocks have been investigated to estimate the generated total petroleum volume per basin area. The dataset was from published sources and included the observed thickness, organic matter content and type and maturity evolution of the known source rocks. The basins and source rocks investigated were: East Greenland (U. Permian Ravnefjeld, U. Jurassic Hareelv); Norwegian Margin, Barents Platform and East Barents Basin (U. Permian Ørret, Triassic Klappmyss, Kobbe and Snadd, U. Jurassic Hekkingen and L. Cretaceous Knurr and Kolje); Timan-Pechora (Ordovician to U. Devonian Domanik facies); West Siberia (M. Jurassic Togur/Tyumen and U. Jurassic Bazhenov ); Arctic Alaska (Triassic Shublik, Early Jurassic Lower Kingak, Cretaceous Pebble Shale, GRZ and Hue Shale); Amerasia Basin (U. Jurassic Husky, Cretaceous Boundary Creek and Smoking Hills, Palaeogene Aklak-Taglu); Sverdrup Basin (Permian Van Hauen, Middle Triassic Schei Point). Generated petroleum volumes were calculated with a probabilistic method, using the mapped source rock properties in ArcGIS and PetroMod. Measured mature source rock area (km2), net source rock thickness (m), rock density (kg/m3), immature TOC (wt.%) and HI (mgHC/gTOC) and transformation ratio (as maps) were the input per USGS province per source rock interval. As the public data coverage varies from very good (North Slope Alaska) to very poor (East Barents Sea), a confidence value (from 5 to 1) was applied to each calculated volume. The generated petroleum volume from each source rock was then summed up in each province, giving the total generated volume per USGS province. This was compared with the discovered resources and the estimated yet-to-find petroleum volumes of the USGS Circum-Arctic Resource Appraisal. By plotting the generated petroleum volume against the discovered volume, it was possible to identify the basins which have generated the largest volumes of petroleum (West Siberia, Arctic Alaska) and to identify basins which have generated large volumes but so far have small discovered resources (Barents Platform, East Barents Basin and Amerasia Basin).

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