Abstract:

There aren’t any other exploration breakthroughs after the discovery of the Chunguang Oilfield in well  Pai 2 area, Junggar Basin. Some problems need be solved, such as that thin sandbodies is difficult to be depicted and that the main factors and models of reservoirs are not clear, and so on. In this study, through the comprehensive study of high resolution sequence stratigraphy, seismic sedimentary and petroleum geology, the sedimentary microfacies of the study area are indentified as subaqueous distributary channels, interdistributary channels of fan delta, bar and beach of shallow lacustrine. The main factors which control the reservoirs in Lower Cretaceous are the favorable sandbody, translocating system and preservation condition. Due to the different preservation conditions, the oil quality is different in different places and different intervals, so there are three reservoir models in the lower, middle and upper of the slope zone. The favorable zones and intervals is SQq _1 to SQq_2 in the lower of the slope zone.

Key words: sedimentary system, beach and bar, petroleum reservoir, Lower Cretaceous, Chepaizi area, Junggar Basin