Oil accumulation temperature and depth
Some criteria of temperature and depth determination of "the general zone of oil accumulation" are considered. Basic provisions of classical organic theory are analyzed. It is stated that sharp increase of bitumoids content in rocks is no more perceived as reliable sign of oil accumulation. Borders of oil accumulation are more exactly fixed on the basis of kinetic modeling of kerogen transformation by Arrenius equation, as it is accepted in modern basin modeling. Corresponding calculations for various regimes of rocks plunging are performed. Oil is shown not to generate up to the depth of 2.0…2.5 km. In mid-latitudes regions "the general zone of oil accumulation" begins at the depth of 2.5…4.0 km, maximum intensity of oil accumulation is found at the depth of 3.5…5.5 km and "the general zone of oil accumulation" ends at the depths from 4.0 till 7.0 km. Sharp increase of dispersed-scattered bitumoids ("micro-oil" by N. Vassoevich), visible from the depth of 1.2…1.5 km, is explained by condensation of liquid components from rising hydrocarbon flow.