摘要
Based on Vail classic sequence stratigraphy theory, according to the core, well logging and seismic data, the sequence stratigraphic framework of Cretaceous in western slope of Beisantai Uplift, Junggar Basin was established by the well-seismic correlation comprehensive analysis method; high-frequency sequences for the main system tracts with hydrocarbon were divided; the structural characteristics and hydrocarbon accumulation models of parasequences with hydrocarbon were comprehensively studied, and the accumulation characters were summarized; the direction for exploration of subtle reservoirs of Cretaceous was shown. The results showed that Cretaceous in western slope of Beisantai Uplift could be divided into four third-order sequences and six system tracts; hydrocarbon showing mainly distributed in low system tract and transgressive system tract of SQ2, which could be divided into four parasequence sets and fourteen parasequences, and three of the parasequences were high-frequency sequence stratigraphic units of Cretaceous with hydrocarbon through hydrocarbon homing; three stratigraphic units with hydrocarbon at the bottom of Cretaceous were overlap and pinchout, and the structural configuration could be divided into Shanan, Xiquan and Bei38 nasal processes; there were Xiquan and Bei38 nasal process accumulation models in the typical oil points, the former was controlled by lithologic pinchout in the slope, and the latter was controlled by complex structural and stratigraphic lapouts; Cretaceous accumulation was controlled by nasal structure, partial fracture, stratigraphic overlap pinchout line and lithologic break zone. In general, the next exploration target of Cretaceous in westen slope of Beisantai Uplift, Junggar Basin should be mainly stratigraphic trap near the stratigraphic overlap pinchout lines of Xiquan and Bei38 nassal processes.