关键词: 二连盆地, 阿南洼槽, 岩性油藏, 致密油藏, 地质特征, 成藏模式, 勘探潜力

Abstract: Anan subsag has been explored for more than 30 years. Structural reservoir here has high exploration degree, but lithologic reservoir has low exploration degree. Comprehensive geologic study is made on the structural feature, oil source conditions, sequence stratigraphy, reservoir attributes, source-reservoir-caprock conf iguration, and reservoir-forming mode, etc., with an aim to make breakthrough in exploration of lithologic reservoirs in the subsag. Research results show that structure evolution in the subsag generates different types of geologic structure, high-quality source rocks developed in the lower submember of the fi rst member of Tenggeer Formation and the fourth member of Aershan Formation, sequence stratigraphy distribution rules are different in the third and fourth members of Aershan Formation, the middle and lower submember of the f irst member of Tenggeer Formation, conventional strata developed in the third and fourth members of Aershan Formation and unconventional strata developed in the lower submember of the fi rst member of Tenggeer Formation, different types of lithologic-stratigraphic reservoir-forming modes are formed in different structural units. Analysis shows that the fourth member of Aershan Formation and the lower submember of the f irst member of Tenggeer Formation are lithologic reservoir and tight oil potential exploration strata in Anan subsag; limbs in large-scale structures such as Anan anticline, Jihe nosal structure, Hanan substrata elevating anticline are favorable for lithologic reservoir exploration, and the lower submember of the fi rst member of Tenggeer Formation is favorable for tight oil reservoir exploration.