An analysis of the formation and distribution of oil pools within the Varandey-Adz'va Zone in the northeast of the Timan-Pechora Basin has revealed differing patterns of oil migration and accumulation in various parts of the area. Oil fields in the north and centre of the Sorokina Swell and in the Gamburtseva Swell are reservoired over a wide stratigraphic ranger: from the Triassic through the Lower Devonian. This suggests the possibility of uninterrupted upward transit of fluids from lower stratigraphic levels (Ordovician-Lower Devonian). The oils found in the Upper Devonian at the Saremboy-Lekkeyaga Swell and in the south of the Sorokina Swell are syngenetic, mixed with oils brought by inflow from underlying strata. Oils in the other complexes are epigenetic. Triassic through Lower Permian strata have not yet entered the main oil window and cannot be the sources of commercial hydrocarbons.
- GeoRef, Copyright 2008, American Geological Institute.