f Constraints on Magnitude of Cenozoic Uplift and Petroleum Systems Modelling for the Russian Barents Sea

The Cenozoic regional uplift remains very poor investigated for the Russian part of the Barents Sea. Several methods were used to estimate magnitude of the uplift and erosion for the Eastern Barents Sea. First method was related with using of generalized porosity-depth trends. Geophysical well logging data from the Russian Barens Sea (about thirty deep offshore wells) were compiled and processed. The joint interpretation of sonic, gamma-ray, resistivity, spontaneous potential logs were used to calculate porosity and shale fraction for siliciclastic rocks. Comparison of smoothed exponential porosity-depth curves from different wells reveals the rate of compaction for the different kinds of sediments (sands, silts and shales) and different level of erosion. Similar results were obtained with Magara’s approach for sonic logs of shales. We used vitrinite reflectance data for the independent evaluation of the uplift and for calibration. Combining the data on wells we have determinated uplifts ranging from 300 m in the south (Pechora Sea) to 700 m in the central part of the South-Barents deep and to 2 km in the Franz-Joseph Land. The magnitude of erosion increase eastward as well. Seismic profiles and structural maps were used to trace and interpolate the estimates of uplift between wells.