%A Yao Jingli, Zhao Yande, Deng Xiuqin, Guo Zhengquan, Luo Anxiang, Chu Meijuan %T Controlling Factors of Tight Oil Reservior in Triassic Yanchang Formation in Ordos Basin %0 Journal Article %D 2015 %J Journal of Jilin University(Earth Science Edition) %R 10.13278/j.cnki.jjuese.201504102 %P 983-992 %V 45 %N 4 %U {http://xuebao.jlu.edu.cn/dxb/CN/abstract/article_10340.shtml} %8 %X

Ordos basin is a typical area of distribution of low permeability and ultra-low permeability oil reservoirs. Triassic Yanchang Formation is rich in low permeability oil reservoirs. They are characterized by many sets of thin sand layers containing oil with large reserve, low reserve abundance, and low single well production. Based on exploration and development practices, greater than 0.3×10-3μm2 permeability reservoirs have been well exploited in Changqing oilfield, while (0.1-0.3)× 10-3μm2 tight sandstone reservoir is currently the focus for exploration and development. The controlling factors of tight oil reservoirs in Triassic Yanchang Formation were investigated. The tight oil in Yanchang Formation is featured as large-sized sand body complex, tight reservoir, complicated pore throat structure, high content of rigid components, abundant fracture and saturation, low fluid pressure, et al. The forming of the large-scaled superimposed tight oil reservoir is controlled by the combination of the interbed lithology of wide-ranging source rock and reservoirs with strong hydrocarbon generation and expulsion during the geological history.