凹陷向斜区岩性类油藏油富集主控因素及成藏模式--以松辽盆地升西-徐家围子向斜葡萄花油层为例

凹陷向斜区岩性类油藏是油气勘探的新领域，以松辽盆地升西-徐家围子向斜葡萄花油层为解剖对象，在向斜区构造单元细分基础上，对不同构造部位油藏类型和油水分布规律进行剖析:向斜外缘缓坡区主要发育油水界面相对统一的构造-岩性油藏；向斜过渡陡坡区主要发育上油下水或油水互层的断层-岩性油藏；向斜中心深洼区主要发育油水到置的岩性油藏；油平面上受断层密集带背形构造控制呈“条带状”分布，垂向上受沉积演化序列和微相物性差异影响“择层”分布。进而对向斜区油成藏主控因素与成藏模式进行了研究，得出向斜区成藏的4个主控因素:①有效烃源岩匹配古构造决定南北构造单元油富集差异；②油源断层组成油优势输导通道；③微相物性差异造成高孔渗分流河道砂体为油聚集优质储层；④断层密集带背形构造构成油富集主要部位。最终建立了向斜区4种成藏模式:①向斜中心深洼区断层密集带背形构造控藏模式；②向斜中心深洼区断层密集带间油选择性充注分流河道控藏模式；③向斜过渡陡坡区反向断层遮挡控藏模式；④向斜外缘缓坡区正向构造圈闭控藏模式。

Oil Enrichment Main Controlling Factors and Accumulation Model of Lithologic Reservoir in Depression Syncline Area: A case of the Putaohua reservoir in Songliao Basin Shengxi-Xujiaweizi syncline

The lithological class reservoir of depression syncline area is a new field of oil and gas exploration. This paper took Song-Liao Basin Shengxi-Xujiaweizi syncline Putaohua reservoir as the research object, and in the base of tectonic units segmentation in syncline area, analyzed the reservoir type and oil-water distribution law of different tectonic parts: Syncline outer edge ramp area mainly develops oil-water interface relatively unified structure-lithological reservoir; Syncline transition steep slope zone develops oil upside of the water or oil-water interblended fault-lithological reservoir; Syncline center deep depression area develops oil-water interblended lithological reservoir; Oil is controlled by the antiformal structure of fault dense zone which present “banded” distributions on plane, it is controlled by the sedimentary evolution sequence and propertied differences in the vertical direction and distributions with “select layer”. Then, it is concluded four main factors of the syncline area accumulation by studied syncline area accumulation mainly factor and model:① the effective hydrocarbon source rocks matching palaeostructure control oil distribution on plane;② oil source faults compose of advantage translocation channels;③ physical property differences cause the high pore and permeability of distributary channel sand bodies becomes oil accumulation premium reservoirs;④ fault dense zone antiformal structure becomes the main part of oil enrichment. Finally, syncline area has established four kinds of accumulation models: ① the control reservoir model of syncline center deep depression area fault dense zone antiformal structure; ② the control reservoir model of syncline center deep depression area dense zone distributary channel oil selective filling; ③ the control reservoir model of syncline transition steep slope zone reverse fault barrier; ④ the control reservoir model of syncline outer ramp area positive structure trap.