二连盆地阿南洼槽岩性油藏及致密油勘探潜力

二连盆地阿南凹陷已有30多年的勘探历史，构造勘探程度高，岩性油藏勘探程度低。通过对阿南洼槽构造特征、油源条件、层序地层、沉积储层特征、生储盖组合配置关系、成藏模式等综合地质研究，目的是寻求阿南洼槽岩性油藏勘探的突破。研究结果表明：阿南洼槽构造演化形成多种类型地质结构；优质烃源岩发育于腾一下亚段和阿四段；阿三段、阿四段及腾一中、下亚段层序地层的分布具有不同的规律；发育阿三段、阿四段常规储层和腾一下亚段非常规储层；不同构造单元形成不同类型岩性地层油藏成藏模式。分析认为，阿四段和腾一下亚段是阿南洼槽岩性油藏和致密油潜力勘探层系；阿南背斜、吉和鼻状构造、哈南基底升降背斜等大型构造翼部是岩性油藏勘探有利区；洼槽区腾一下亚段是致密油藏勘探有利方向。

Lithologic Reservoir and Tight Oil Exploration Potential in Anan Subsag,Erlian Basin

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 configuration, 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 first 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 first 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 first 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 first member of Tenggeer Formation are lithologic reservoir and fight 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 first member of Tenggeer Formation is favorable for tight oil reservoir exploration.