Controlling factors and accumulation model of hydrocarbon accumulation in western Taibei Sag, Turpan-Hami Basin

In order to further clarify the role of different geological conditions in hydrocarbon accumulation process, the main controlling factors of hydrocarbon accumulation in western Taibei Sag, Turpan-Hami Basin were researched based on the angle of diverse geological conditions and their relationship in space-time. The results show that the distance and layer of hydrocarbon migrated upward are controlled by regional caprocks and faults. The direction, pathway and distance of the migrated oil-gas are controlled by palaeostructure and the relationship between unconformity, transport faults and reservoir. Vertical and lateral distributions of oil and gas are controlled by the factors of base level, sedimentary microfacies and recent tectonic. Based on the analysis of factors mentioned above coupled with structural history, oil sources conditions, sedimentary microfacies, four kinds of hydrocarbon accumulation models are summarized, i.e. inside source-lower source upper reservoir model and self-generating and self-preserving model, near source-short distance vertical and lateral migration-faults or local structures screened model, far source-long distance lateral migration-up, and down of unconformity model and secondary migration and accumulation model.