Abstract: A large amount of bitumen and heavy oil with high density are found in the Triassic and Jurassic reservoirs in Santai-North Santai area in eastern Junggar basin. They filled into the reservoir pores, occupied the megapores, reduced the porous connection rate, caused the post-generating crude oil to enter the pores with difficulty, hence it is difficult to form larger-scale and higher-yielding oil reservoir. The reservoir property contrast between before and after the organic solvent extraction indicates that the porosity of 9 samples adds to 21.5%, averaging about 13.4%; the permeability of 7 samples adds to 121.50×10^-3μm², averaging about 31.99×10^-3μm². It is pointed out that it should keep away from the reservoir with high amount of bitumen as far as possible to find high-yielding oil reservoirs in the future, in addition to considering structural factors, integrated with sedimentary facies and reservoir research results.

Key words: Junggar basin, eastern Junggar basin, Santai-North Santai area, Reservoir, bitumen, petrophysical property