Abstract: Since 2003 breakthroughs have been made successively in the exploration of shallow light oil and shallow heavy oil in Shengli Prospect Area in Western Margin of Junggar Basin, and development of Chunguang Oilfield has been also fulfilled with high speed and high efficiency. With new theories of petroleum geology in the west of the Junggar Basin, researchers further studied the achievements of predecessors in oil and gas exploration in Chepaizi, and summarized regular cognition of oil and gas generation, migration, accumulation and reservoir formation in the area. Through plausible reasoning, the direction of exploration was made clear, and breakthroughs were made in the understanding that large-medium-sized oilfields were expected to form in high lifts in western margin of Junggar Basin. Through the study of oil and gas sources, oil source direction and strata in Chepaizi were made clear. Through the study of oil and gas transporting system, two major oil and gas transporting passages were proved. The study of sedimentary system provides theoretical basis for reservoir prediction and description in the area. Based on persistent oil and gas exploration in the area, techniques of three-dimensional seismic exploration, class highlights, synthetic seismograms, wavelet frequency extension processing, logging constrained inversion, and multiple seismic attribute analysis techniques were applied successfully. Finally 14 light oil reservoirs and high-yield reservoirs, six shallow gas reservoirs, and three shallow heavy oil reservoirs were discovered, with annual production capacity of crude oil reaching 475,000 tons

Key words: lithologic reservoir, Chunguang Oilfield, western margin of Junggar Basin, three-dimensional seismic exploration