Burial-Thermal Histories and Timing of Petroleum Generation in the Barents Sea: Results from a 2D Petroleum-System Mode

A regional 2D model from interpreted seismic data was developed to evaluate the timing and extent of petroleum generation across the Norwegian and Russian Barents Sea. Triassic shales with Type II/III kerogen and Upper Jurassic Type II kerogen-rich shales were defined as the principal source rocks in the model. Generation of oil and gas was simulated using isothermal and non-isothermal kinetic parameters. A complex heat flow model was defined and tested over ranges of 50 to 100 mW/m2 in the Norwegian Barents and 50-75 mW/m2 in the Russian Barents. Model results indicate that petroleum generation was controlled by a combination of burial depth and paleoheat flow, and was not affected by Ice Age erosion. Presently, Upper Jurassic and Upper Triassic shales along most of the modeled section are thermally immature and have not generated oil or gas. Lower to Middle Triassic source rocks, however, have undergone extensive generation, indicating that they are the source of the majority of the oil and gas trapped in Upper Triassic and younger reservoir rocks. The model indicates the potential for additional petroleum generation updip from Triassic shales associated with marine flooding surfaces at sequence boundaries.