Modeling the HC Potential Formation in the Southern Part of the Lena-Tunguska Oil and Gas Province

The primary objective of geological exploration in the south of Eastern Siberia is improvement the reliability of resource potential assessment in the southern part of the Lena-Tunguska petroleum province and justification of the oil-and-gas accumulation zones inside. Formation of the current hydrocarbon saturation of the section occurs mainly due to the Riphean source strata with subsidiary role of the Vendian and the Cambrian. The three main stages of hydrocarbon emigration and migration are identified in the southern part of the Lena-Tunguska oil-and-gas province: the Vendian-Early Palaeozoic, the Middle Palaeozoic and the Late Palaeozoic-Mesozoic. Hydrocarbons generated before the formation of the Vendian-Cambrian regional seals were most likely scattered in sedimentary deposits and had no impact on the modern oil-and-gas potential. Main regional oil-and-gas prospects are related to the three oil-and-gas bearing complexes - the Riphean, the Vendian and the Vendian-Lower Cambrian. The hydrocarbon accumulation formation in the latter two is caused predominantly by vertical migration from the Riphean generating centers. The major HC field formation mechanism was the secondary migration of gaseous hydrocarbons and the rearrangement of pre-existing oil fields into the oil-and-gas, and the oil-gas-condensate deposits